As in the mythical story of Icarus, human beings in the modern world who fly too close to the sun have a price to pay, new research suggests.
Airline pilots and cabin crews have twice the incidence of melanoma as the general population, according to the largest meta-analysis to date on the subject.
The standardized incidence ratio of melanoma for any flight-based occupation was 2.21 (P < .001).
Furthermore, melanoma was more deadly in these professionals, who had a disease-related mortality rate 42% greater than that of more regularly earthbound beings.
Specifically, the standardized mortality ratio for any flight-based occupation was 1.42 (P = .02).
"Further research on the mechanisms [of harm] and optimal occupational protection is needed," conclude the researchers, led by Martina Sanlorenzo, MD, a research fellow in the Department of Dermatology at the University of California, San Francisco.
They suspect that the increase in melanoma risk seen in airline pilots and cabin crews comes from exposure to ultraviolet (UV) light, which becomes more intense the higher a plane flies. "At 9000 meters [30,000 feet], where most commercial aircraft fly, the UV level is approximately twice that of the ground," the researchers report.
Remarkably, UV light exposure is "not a well-recognized occupational risk factor" for flight crews, they note. In contrast, ionizing radiation is a well-known risk, and levels in airline crews are regularly monitored.
This study provides no details on the clinical aspects of the melanomas.
"It would be interesting to see the anatomic distribution of skin cancers in the crew, because only hands and face should be exposed to UV passing through the windows," said Steven Wang, MD, director of dermatologic surgery and dermatology at the Memorial Sloan Kettering Cancer Center in Basking Ridge, New Jersey, who was not involved in the study.
Frequent flier passengers are probably not at an increased risk, he said in an email to Medscape Medical News. But for the worried, pulling down the window shade and sitting in an aisle seat are protective strategies, added Dr. Wang, who is the author ofBeating Melanoma: A 5-Step Survival Guide.
The meta-analysis examined 19 studies (15 with data on pilots; 4 with data on cabin crews). Data from the studies, which involved more than 266,000 participants, were collected from 1943 to 2008 in more than 11 countries.
The researchers conducted separate analyses for pilots and for cabin crews (which include flight attendants).
They found that pilots were at greater risk for melanoma than the cabin crew.
In fact, pilots and crews would have more than double the annual number of new melanomas per year, which is 21.3 per 100,000 individuals in the general population.
Pilots as a group were also at greater risk for mortality, and had a higher mortality ratio than cabin crews (1.83 vs 0.90).
UVA Radiation and Glass Might Be the Problems
The researchers discuss the technicalities of the types of UV radiation and windshields.
They cite measurements of UV radiation that passes through the windshields of a variety of aircraft — large (e.g., Boeing737 and Airbus A320) and small (e.g., Cessna 182) — from a 2007 report by the US Federal Aviation Administration.
The transmission of UVB is less than 1% for both plastic and glass windshields.
However, UVA is a different story, especially in airplanes with glass windows. "While plastic materials blocked almost all UVA radiation, 54% of it came through glass," Dr. Sanlorenzo and colleagues report.
Welcome to my collection of health articles. Most of them contain little nuggets of health wisdom that we can easily apply to our daily lives. As you can gather, I've been consuming all sorts of supplements over the years, most of them from iherb. They deliver on time (DHL), and prices are good. If you're a first-time buyer, use my code 'pot089' to enjoy up to $10 off.
Showing posts with label cancer. Show all posts
Showing posts with label cancer. Show all posts
Thursday, 11 September 2014
Prediabetes Increases Cancer Risk
Prediabetes — even at lower levels of impaired fasting glucose (IFG) as defined by the American Diabetes Association (ADA) — is associated with a significant increase in cancer risk that is independent of the effects of obesity, according to the results of a large new meta-analysis.
Yuli Huang, MD, PhD, from First People's Hospital of Shunde, Foshan, China, and colleagues found that prediabetes was associated with a 15% increased risk for cancer overall, based on data derived from 16 prospective cohort studies, with differing risks depending on the type of cancer. The risk was particularly increased for liver cancer and stomach or colorectal cancer.
"Epidemiological studies have shown that diabetes increases the incidence of cancer and mortality from it, but we thought that maybe not only diabetes but prediabetes may be associated with an elevated cancer risk," Dr. Huang said.
"And considering the high prevalence of prediabetes as well as the robust and significant association between prediabetes and cancer we demonstrated in our study, a successful lifestyle intervention could have a major public-health impact on cancer prevention," he added.
"This information is important to health professionals and those engaged in the prevention of cancer," Dr. Huang and colleagues stress.
The study was published online September 8 in Diabetologia.
Screen for Prediabetes Using ADA Criteria for Cancer Prevention
A total of 891,426 participants from the 16 studies, 4 of which were from Asia, 11 from the United States and Europe, and 1 from Africa, were included in the meta-analysis. Prediabetes included individuals with impaired glucose tolerance (IGT), IFG, or a combination of the 2.
Over 10 years ago, the ADA lowered its definition of prediabetes to that of a fasting plasma glucose concentration ranging from 5.6 to 6.9 mmol/L, but other organizations have maintained their definition at a higher level, as a fasting plasma glucose concentration between 6.1 and 6.9 mmol/L.
The risks of site-specific cancer among individuals with prediabetes was highest for liver cancer (relative risk [RR], 2.01), followed by colorectal and stomach cancer (RR, 1.55 for both), endometrial cancer (RR, 1.60), and breast as well as pancreatic cancer (RR, 1.19 for both).
But prediabetes was not associated with cancer of the bronchus, lung, prostate, ovary, kidney, or bladder.
The risks were increased even when a lower fasting plasma glucose value of 5.6 to 6.9 mmol/L was used, as well as in participants with IGT — "an interesting finding," investigators note, "and one that reaffirms the importance of screening for prediabetes using the ADA criteria with a view to cancer prevention."
As the authors point out, obesity — in itself a key risk factor for diabetes — has also been linked to cancer.
To rule out obesity as a potential confounder, the authors did a sensitivity analysis that included only studies that adjusted for body mass index (BMI).
After controlling for BMI, "we found that...the presence of prediabetes remained associated with an increased risk of cancer by 22%," they state. "So we believe that the increased risk of cancer in individuals with prediabetes is independent of obesity."
"Our study indicates that, on the basis of a snapshot blood glucose measurement, prediabetes is associated with an increased risk of cancer," they state.
Need for Trials of Metformin to Prevent Cancer
Speculating on the reasons for the association between prediabetes and increased cancer risk, Dr. Huang and colleagues suggest that chronic hyperglycemia and resulting states, including chronic oxidative stress and the accumulation of advanced glycated end products, may serve as carcinogens.
Alternatively, increased insulin resistance characteristic of prediabetes increases insulin secretion, and increased insulin levels may promote the growth of cancer cells.
Certain genetic mutations may also predispose individuals with prediabetes to an elevated cancer risk, they suggest.
As the authors point out, it is noteworthy that metformin is associated with an approximately 30% reduction in the lifetime risk of cancer in diabetic patients.
"Considering the protective anticancer properties of metformin in patients with diabetes, as well as its ability to delay progress to diabetes in patients with prediabetes, we feel studies are urgently needed to explore the effects of metformin on cancer risk in people with prediabetes, and [if shown to be protective], metformin might be recommended in select high-risk individuals, especially those with IGT or a combination of IGT and IFG," they conclude.
Yuli Huang, MD, PhD, from First People's Hospital of Shunde, Foshan, China, and colleagues found that prediabetes was associated with a 15% increased risk for cancer overall, based on data derived from 16 prospective cohort studies, with differing risks depending on the type of cancer. The risk was particularly increased for liver cancer and stomach or colorectal cancer.
"Epidemiological studies have shown that diabetes increases the incidence of cancer and mortality from it, but we thought that maybe not only diabetes but prediabetes may be associated with an elevated cancer risk," Dr. Huang said.
"And considering the high prevalence of prediabetes as well as the robust and significant association between prediabetes and cancer we demonstrated in our study, a successful lifestyle intervention could have a major public-health impact on cancer prevention," he added.
"This information is important to health professionals and those engaged in the prevention of cancer," Dr. Huang and colleagues stress.
The study was published online September 8 in Diabetologia.
Screen for Prediabetes Using ADA Criteria for Cancer Prevention
A total of 891,426 participants from the 16 studies, 4 of which were from Asia, 11 from the United States and Europe, and 1 from Africa, were included in the meta-analysis. Prediabetes included individuals with impaired glucose tolerance (IGT), IFG, or a combination of the 2.
Over 10 years ago, the ADA lowered its definition of prediabetes to that of a fasting plasma glucose concentration ranging from 5.6 to 6.9 mmol/L, but other organizations have maintained their definition at a higher level, as a fasting plasma glucose concentration between 6.1 and 6.9 mmol/L.
The risks of site-specific cancer among individuals with prediabetes was highest for liver cancer (relative risk [RR], 2.01), followed by colorectal and stomach cancer (RR, 1.55 for both), endometrial cancer (RR, 1.60), and breast as well as pancreatic cancer (RR, 1.19 for both).
But prediabetes was not associated with cancer of the bronchus, lung, prostate, ovary, kidney, or bladder.
The risks were increased even when a lower fasting plasma glucose value of 5.6 to 6.9 mmol/L was used, as well as in participants with IGT — "an interesting finding," investigators note, "and one that reaffirms the importance of screening for prediabetes using the ADA criteria with a view to cancer prevention."
As the authors point out, obesity — in itself a key risk factor for diabetes — has also been linked to cancer.
To rule out obesity as a potential confounder, the authors did a sensitivity analysis that included only studies that adjusted for body mass index (BMI).
After controlling for BMI, "we found that...the presence of prediabetes remained associated with an increased risk of cancer by 22%," they state. "So we believe that the increased risk of cancer in individuals with prediabetes is independent of obesity."
"Our study indicates that, on the basis of a snapshot blood glucose measurement, prediabetes is associated with an increased risk of cancer," they state.
Need for Trials of Metformin to Prevent Cancer
Speculating on the reasons for the association between prediabetes and increased cancer risk, Dr. Huang and colleagues suggest that chronic hyperglycemia and resulting states, including chronic oxidative stress and the accumulation of advanced glycated end products, may serve as carcinogens.
Alternatively, increased insulin resistance characteristic of prediabetes increases insulin secretion, and increased insulin levels may promote the growth of cancer cells.
Certain genetic mutations may also predispose individuals with prediabetes to an elevated cancer risk, they suggest.
As the authors point out, it is noteworthy that metformin is associated with an approximately 30% reduction in the lifetime risk of cancer in diabetic patients.
"Considering the protective anticancer properties of metformin in patients with diabetes, as well as its ability to delay progress to diabetes in patients with prediabetes, we feel studies are urgently needed to explore the effects of metformin on cancer risk in people with prediabetes, and [if shown to be protective], metformin might be recommended in select high-risk individuals, especially those with IGT or a combination of IGT and IFG," they conclude.
Thursday, 18 April 2013
High intake of processed meat linked to cancer deaths
Bacon, sausage, and ham are once again being singled out as key culprits driving the association between meat consumption and the world's most common diseases.
One of the largest studies to address this question, published online March 7 in BMC Medicine, found a moderate positive association between processed meat consumption and mortality. This was particularly true for cardiovascular diseases (CVDs), but was also true for cancer.
Over a mean of 12 years, high consumption of processed meat was associated with a near doubling of the risk for all-cause mortality in adults, compared with low consumption. The risk for cancer death was 43% higher and the risk for cardiovascular death was 70% higher in people eating more than 160 g/day of processed meats than in those eating 10.0 to 19.9 g/day.
"The clinical message [is] to limit consumption of processed meat — not every day and not in high amounts," said lead author Sabine Rohrmann, PhD, MPH, head of the Department of Epidemiology and Prevention at the University of Zurich in Switzerland, in an interview.
EPIC data
The new data come from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which involved 10 countries and almost half a million men and women.
A signal of increased mortality was seen in the highest consumers of red meat in general; however, the risk was much lower with red meat than with processed meats, and lost statistical significance after correction for measurement error, the researchers report. In fact, the high consumption of processed meat was associated with an 18% increased risk for all-cause mortality.
After multivariate adjustment, the consumption of more than 160 g/day of red meat was related to higher all-cause mortality than the consumption of 10.0 to 19.9 g/day (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01 to 1.28). The HR was higher for more than 160 g/day of processed meat (1.44; 95% CI, 1.24 to 1.66).
After correction for measurement error, all-cause mortality remained significantly higher only for the consumption of 50 g/day of processed meat (HR, 1.18; 95% CI, 1.11 to 1.25).
A very high consumption of red meat was nonsignificantly associated with increased cancer mortality, but not with deaths caused by CVD or respiratory diseases, diseases of the digestive tract, or any other disease.
As the researchers point out, processed meats tend to contain more saturated fat than unprocessed meat (where the fat is often trimmed off) and more cholesterol and additives (which are part of the smoking or curing process). Some of these are believed to be carcinogenic or precursors to carcinogenic processes.
When the researchers re-examined the association between processed meat intake and cancer risk using the lowest consumption category (0.0 to 9.9 g/d) as a reference, they observed a statistically significantly increased risk for cancer mortality in people who consumed 80.0 to 159.9 g/day (HR, 1.12; 95% CI, 1.01 to 1.24). There was also a nonsignificantly increased risk in the highest consumption category (HR, 1.19; 95% CI, 0.93 to 1.51).
"Another factor is the salt in processed meat products, which is linked to hypertension — a CVD risk factor," noted Dr. Rohrmann. Heme iron also links meat consumption to CVD risk, "but that's not limited to processed meat," she explained.
Dr. Rohrmann and colleagues point out that the high consumption of processed meat typically goes hand in hand with other unhealthy behaviors, including smoking, low levels of physical activity, and low consumption of fruit and vegetables.
"Overall, we estimate that 3% of premature deaths each year could be prevented if people ate less than 20 g of processed meat per day," she said in a press statement.
What about red meat?
Other studies have singled out processed meats as being particularly hazardous to health. Two large long-running American studies have documented the link between meat consumption and CVD and cancer deaths. However, the stronger association with processed meats that Dr. Rohrmann and colleagues found in their European cohort is somewhat at odds with the American data.
A number of studies have examined the link between meat consumption and cancer. For example, one large prospective trial linked the consumption of processed meat to an increased risk for bladder cancer. Another study found that the consumption of red and processed meats increases the risk for colorectal cancer.
"Although we did not find a statistically significant association between unprocessed red meat consumption and mortality in our studies, we would not say that there is definitely no association" between red meat consumption and CVD, Dr. Rohrmann explained.
"Our studies show it that it's okay to eat a moderate amount of meat (300 to 600 g per week), as recommended by many nutrition societies," she said. However, "a balanced vegetarian diet is okay as well," she added.
Significant association with processed meat
In their study, Dr. Rohrmann and colleagues examined the association between risk for early death and the consumption of red meat, processed meat, and poultry. The 448,568 study participants were 35 to 69 years of age, and had no prevalent cancer, stroke, or myocardial infarction, and had complete information on diet, smoking, physical activity, and body mass index.
A total of 26,344 study participants (11,563 men and 14,781 women) died during the median follow-up period of 12.7 years; 5556 died of CVD, 9861 of cancer, 1068 of respiratory diseases, 715 of digestive tract diseases, and 9144 of other causes.
The researchers note that, according to their estimates, "3.3% (95% CI, 1.5% to 5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g/day."
The consumption of poultry was not related to all-cause mortality.
One of the largest studies to address this question, published online March 7 in BMC Medicine, found a moderate positive association between processed meat consumption and mortality. This was particularly true for cardiovascular diseases (CVDs), but was also true for cancer.
Over a mean of 12 years, high consumption of processed meat was associated with a near doubling of the risk for all-cause mortality in adults, compared with low consumption. The risk for cancer death was 43% higher and the risk for cardiovascular death was 70% higher in people eating more than 160 g/day of processed meats than in those eating 10.0 to 19.9 g/day.
"The clinical message [is] to limit consumption of processed meat — not every day and not in high amounts," said lead author Sabine Rohrmann, PhD, MPH, head of the Department of Epidemiology and Prevention at the University of Zurich in Switzerland, in an interview.
EPIC data
The new data come from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which involved 10 countries and almost half a million men and women.
A signal of increased mortality was seen in the highest consumers of red meat in general; however, the risk was much lower with red meat than with processed meats, and lost statistical significance after correction for measurement error, the researchers report. In fact, the high consumption of processed meat was associated with an 18% increased risk for all-cause mortality.
After multivariate adjustment, the consumption of more than 160 g/day of red meat was related to higher all-cause mortality than the consumption of 10.0 to 19.9 g/day (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01 to 1.28). The HR was higher for more than 160 g/day of processed meat (1.44; 95% CI, 1.24 to 1.66).
After correction for measurement error, all-cause mortality remained significantly higher only for the consumption of 50 g/day of processed meat (HR, 1.18; 95% CI, 1.11 to 1.25).
A very high consumption of red meat was nonsignificantly associated with increased cancer mortality, but not with deaths caused by CVD or respiratory diseases, diseases of the digestive tract, or any other disease.
As the researchers point out, processed meats tend to contain more saturated fat than unprocessed meat (where the fat is often trimmed off) and more cholesterol and additives (which are part of the smoking or curing process). Some of these are believed to be carcinogenic or precursors to carcinogenic processes.
When the researchers re-examined the association between processed meat intake and cancer risk using the lowest consumption category (0.0 to 9.9 g/d) as a reference, they observed a statistically significantly increased risk for cancer mortality in people who consumed 80.0 to 159.9 g/day (HR, 1.12; 95% CI, 1.01 to 1.24). There was also a nonsignificantly increased risk in the highest consumption category (HR, 1.19; 95% CI, 0.93 to 1.51).
"Another factor is the salt in processed meat products, which is linked to hypertension — a CVD risk factor," noted Dr. Rohrmann. Heme iron also links meat consumption to CVD risk, "but that's not limited to processed meat," she explained.
Dr. Rohrmann and colleagues point out that the high consumption of processed meat typically goes hand in hand with other unhealthy behaviors, including smoking, low levels of physical activity, and low consumption of fruit and vegetables.
"Overall, we estimate that 3% of premature deaths each year could be prevented if people ate less than 20 g of processed meat per day," she said in a press statement.
What about red meat?
Other studies have singled out processed meats as being particularly hazardous to health. Two large long-running American studies have documented the link between meat consumption and CVD and cancer deaths. However, the stronger association with processed meats that Dr. Rohrmann and colleagues found in their European cohort is somewhat at odds with the American data.
A number of studies have examined the link between meat consumption and cancer. For example, one large prospective trial linked the consumption of processed meat to an increased risk for bladder cancer. Another study found that the consumption of red and processed meats increases the risk for colorectal cancer.
"Although we did not find a statistically significant association between unprocessed red meat consumption and mortality in our studies, we would not say that there is definitely no association" between red meat consumption and CVD, Dr. Rohrmann explained.
"Our studies show it that it's okay to eat a moderate amount of meat (300 to 600 g per week), as recommended by many nutrition societies," she said. However, "a balanced vegetarian diet is okay as well," she added.
Significant association with processed meat
In their study, Dr. Rohrmann and colleagues examined the association between risk for early death and the consumption of red meat, processed meat, and poultry. The 448,568 study participants were 35 to 69 years of age, and had no prevalent cancer, stroke, or myocardial infarction, and had complete information on diet, smoking, physical activity, and body mass index.
A total of 26,344 study participants (11,563 men and 14,781 women) died during the median follow-up period of 12.7 years; 5556 died of CVD, 9861 of cancer, 1068 of respiratory diseases, 715 of digestive tract diseases, and 9144 of other causes.
The researchers note that, according to their estimates, "3.3% (95% CI, 1.5% to 5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g/day."
The consumption of poultry was not related to all-cause mortality.
Source: http://www.medscape.com/viewarticle/780553?nlid=29163_1301&src=wnl_edit_dail
Wednesday, 13 June 2012
Dental plaque associated with 'premature' cancer death
Poor oral hygiene, reflected by dental plaque, was associated with increased cancer mortality in a Swedish study, published online today in BMJ Open.
After taking into account other risk factors, dental plaque was associated with a significant 79% increased risk for premature death from cancer.
The study was conducted by Birgitta Söder, PhD, and colleagues from the Department of Dental Medicine at the Karolinska Institute in Huddinge, Sweden, in collaboration with researchers from the University of Helsinki in Finland.
The researchers note that a high amount of dental plaque indicates poor oral hygiene and an increased risk for dental infections. In turn, these could trigger systemic reactions and lead to malignant transformations in a variety of tissues.
"The high bacterial load on tooth surfaces and in gingival pockets over a prolonged period of time may indeed play a role in carcinogenesis," they speculate.
However, the researchers emphasize that their findings do not prove that dental plaque causes or definitely contributes to cancer.
Assessment of Mouth Hygiene
The 1390 study participants were randomly selected in Stockholm; they were in their 30s and 40s when the study began, and had no signs of periodontitis. They completed a questionnaire about risk factors for cancer, including smoking, and they underwent a mouth hygiene check to assess levels of dental plaque, tartar, gum disease, and tooth loss.
The absolute risk for premature death was low; only 58 of the 1390 study participants were no longer alive when the study ended after 24 years. Of those who died, 35 died from cancer. Breast cancer was the most common type of cancer in women; the malignancies in men were varied.
When the researchers looked at the mouth hygiene results, they found that participants who had died had more dental plaque than the those who had survived. The dental plaque index, which indicates how much of the tooth is covered in plaque, was consistently higher in those who died from cancer than in the survivors (0.84 to 0.91 vs 0.66 to 0.67; P < .001).
In this study, the average age at death was 60 years for women and 61 years for men. According to demographic data for Sweden, the women should have lived another 13.0 years and the men another 8.5 years, so these deaths could be considered "premature," the authors note.
In addition to the presence of dental plaque, the other risk factors that significantly increased the risk for premature death were sex and age. Nearly two thirds of all those who died were men.
This same team of researchers showed an association between periodontal disease and breast cancer, with an odds ratio of 2.36 (Breast Cancer Res Treat. 2011;127:497-502), and previously reported that an association between periodontitis and missing teeth increased the risk for premature death from life-threatening disease, including cancer (J Periodontal Res. 2007;42:361-366).
A recent review article, which included these and other studies, asked whether oral and dental disease are linked to cancer (Oral Dis. 2011;17:779-784). Those authors conclude that "evidence in the literature remains inadequate to allow final conclusions to be drawn on whether infectious diseases of the mouth are a true risk factor for the development of malignancies. Some epidemiological data indicate an association but no causal relationship has been established."
Source: http://www.medscape.com/viewarticle/765436?sssdmh=dm1.793222&src=nldne
After taking into account other risk factors, dental plaque was associated with a significant 79% increased risk for premature death from cancer.
The study was conducted by Birgitta Söder, PhD, and colleagues from the Department of Dental Medicine at the Karolinska Institute in Huddinge, Sweden, in collaboration with researchers from the University of Helsinki in Finland.
The researchers note that a high amount of dental plaque indicates poor oral hygiene and an increased risk for dental infections. In turn, these could trigger systemic reactions and lead to malignant transformations in a variety of tissues.
"The high bacterial load on tooth surfaces and in gingival pockets over a prolonged period of time may indeed play a role in carcinogenesis," they speculate.
However, the researchers emphasize that their findings do not prove that dental plaque causes or definitely contributes to cancer.
Assessment of Mouth Hygiene
The 1390 study participants were randomly selected in Stockholm; they were in their 30s and 40s when the study began, and had no signs of periodontitis. They completed a questionnaire about risk factors for cancer, including smoking, and they underwent a mouth hygiene check to assess levels of dental plaque, tartar, gum disease, and tooth loss.
The absolute risk for premature death was low; only 58 of the 1390 study participants were no longer alive when the study ended after 24 years. Of those who died, 35 died from cancer. Breast cancer was the most common type of cancer in women; the malignancies in men were varied.
When the researchers looked at the mouth hygiene results, they found that participants who had died had more dental plaque than the those who had survived. The dental plaque index, which indicates how much of the tooth is covered in plaque, was consistently higher in those who died from cancer than in the survivors (0.84 to 0.91 vs 0.66 to 0.67; P < .001).
In this study, the average age at death was 60 years for women and 61 years for men. According to demographic data for Sweden, the women should have lived another 13.0 years and the men another 8.5 years, so these deaths could be considered "premature," the authors note.
In addition to the presence of dental plaque, the other risk factors that significantly increased the risk for premature death were sex and age. Nearly two thirds of all those who died were men.
This same team of researchers showed an association between periodontal disease and breast cancer, with an odds ratio of 2.36 (Breast Cancer Res Treat. 2011;127:497-502), and previously reported that an association between periodontitis and missing teeth increased the risk for premature death from life-threatening disease, including cancer (J Periodontal Res. 2007;42:361-366).
A recent review article, which included these and other studies, asked whether oral and dental disease are linked to cancer (Oral Dis. 2011;17:779-784). Those authors conclude that "evidence in the literature remains inadequate to allow final conclusions to be drawn on whether infectious diseases of the mouth are a true risk factor for the development of malignancies. Some epidemiological data indicate an association but no causal relationship has been established."
Source: http://www.medscape.com/viewarticle/765436?sssdmh=dm1.793222&src=nldne
Thursday, 22 March 2012
Aspirin reduces cancer mortality and risk for distant metastases
Evidence from 3 new studies demonstrates that aspirin can reduce the risk for cancer-related mortality and can reduce or prevent the risk for distant metastasis.
Peter M. Rothwell, MD, PhD, professor of clinical neurology at the University of Oxford, United Kingdom, was lead author on all 3 studies.
In the first study, published online March 21 in the Lancet, comparing daily aspirin with no aspirin to prevent vascular events, aspirin use reduced the risk for nonvascular death in all 51 trials examined (1021 vs 1173 deaths; odds ratio [OR], 0.88; P = .003). When data from 34 trials were examined (n = 69,224; 89% of total cohort), there were fewer deaths from cancer in the aspirin than in the control group (562 vs 664 deaths; OR, 0.85; P = .008).
Dr. Rothwell and colleagues note that even though the decreased risk for major vascular events in these trials was initially offset by a higher risk for major bleeding, both of these effects diminished over time, leaving only the reduced risk for cancer after 3 years.
"In view of the very low rates of vascular events in recent and ongoing trials of aspirin in primary prevention, prevention of cancer could become the main justification for aspirin use in this setting," they write.
Compelling but no recommendations yet
In an accompanying editorial, Andrew T. Chan, MD, MPH, and Nancy R, Cook, ScD, both from Harvard Medical School in Boston, Massachusetts, note that although these results are compelling, they do have limitations.
These analyses exclude the largest randomized trials in primary prevention, the editorialists point out. The Women's Health Study (WHS) of 39,876 women treated with alternate-day aspirin 100 mg over 10 years and the Physicians' Health Study (PHS) of 22,071 men treated with alternate-day aspirin 325 mg over 5 years were not included in the current study because of possible differences in the biologic effect between alternate-day and daily aspirin intake. However, in these 2 studies, aspirin was not associated with a lower risk for colorectal cancer or overall cancer incidence or mortality.
Another limitation, say the editorialists, is that the researchers only used 6 randomized trials to analyze low-dose aspirin in the primary prevention of cancer.
In these 6 trials (n = 35,535), aspirin was shown to lower the incidence of cancer after 3 years in women (132 vs 176; OR, 0.75; P = .01), in men (192 vs 245; OR, 0.77; P = .008), and in both (324 vs 421; OR, 0.76; P = .0003).
A third limitation is that because the included studies were designed to examine cardiovascular end points, there was no information about cancer screening or surveillance.
Finally, some of the analyses were limited by the quality of available data; some estimates pooled individual-level data with published results.
But "caveats notwithstanding, Rothwell and colleagues show quite convincingly that aspirin seems to reduce cancer incidence and death across different subgroups and cancer sites, with an apparent delayed effect," they write. For most individuals, "the risk–benefit calculus of aspirin seems to favor aspirin's long-term anticancer benefit. These findings are consistent with observational findings and our understanding of the stepwise progression of carcinogenesis."
These data might not be the final word on aspirin, as far as making a population-based recommendation, the editorialists caution, because the WHS and PHS remain "significant counterbalancing trials that have not shown a cancer benefit with alternate-day aspirin up to 10 to 12 years."
Another factor to be considered is the adverse events from daily aspirin. Even though there is a "convincing case" that the vascular and anticancer benefits of aspirin outweigh the harms of major extracranial bleeding, less serious adverse effects on quality of life, such as less severe bleeding, are not accounted for in these analyses, Drs. Chan and Cook write.
Nonetheless, until data from forthcoming trials and longer-term follow-up from the WHS and PHS become available, this "impressive collection of data moves us another step closer to broadening recommendations for aspirin use," they conclude.
Metastasis in randomized trials
In the second study, also published online March 21 in the Lancet, Dr. Rothwell and colleagues analyzed data from 5 large randomized trials of daily aspirin (75 mg or more daily) for the prevention of vascular events in the United Kingdom. The cohort consisted of 17,285 trial participants, 987 of whom had a new solid cancer diagnosed during a mean follow-up of 6.5 years.
Aspirin use reduced the risk for cancer with distant metastasis (hazard ratio [HR] for all cancers, 0.64; P = .001). The risk for cancer with distant metastasis was reduced by 36%, and the risk for adencarcioma was reduced by 46% (P = .0007). Among patients with adenocarcinoma who did not have metastasis at their initial diagnosis and who remained on trial treatment up to or after diagnosis, the use of aspirin reduced the risk for metastasis on subsequent follow-up by about 70%.
Aspirin lowered the cancer mortality rate among patients who developed adenocarcinoma, especially in those without metastasis at diagnosis (HR, 0.50; P = .0006). Aspirin also lowered the overall risk for fatal adenocarcinoma (HR, 0.65; P = .0002), but not the risk for other fatal cancers (HR, 1.06; P = .64). These effects were independent of confounders such as age and sex, but the absolute benefit was greatest in smokers, the authors note.
Observation vs randomized
The third study, published online March 21 in the Lancet Oncology, looked at the effect of aspirin on metastases, but with a different approach. The authors compared the effect of aspirin on the 20-year risk for cancer-specific mortality between observational studies and randomized trials.
They conducted this comparison because although randomized trials can clearly establish the risk for colorectal cancer, other solid tumors, and metastasis, such trials lack the statistical power to establish effects on less common cancers and on cancers in women.
Observational and case–control studies can provide these data if the results are shown to be reliable.
Overall, results from observational studies were similar to those from randomized trials, and showed that regular aspirin use lowered the long-term risk for several cancers and for distant metastasis.
In 6 eligible randomized trials, the aspirin group had a consistently lower 20-year risk for death from colorectal cancer than the control group (OR, 0.58; P = .0002). In the 26 case–control studies, any use of aspirin was associated with a lower risk for colorectal cancer (pooled OR, 0.67; P < .0001).
In 17 case–control studies, the regular use of aspirin was associated with a reduced risk for colorectal cancer (pooled OR, 0.62; P < .0001). In the randomized trials, there was good correlation between the effect of daily aspirin use and the 20-year risk for death from colorectal cancer (OR, 0.58; P = .0002).
The authors observed the same consistent reductions in risks for esophageal, gastric, biliary, and breast cancers, and estimates of the effect of aspirin on individual cancers in case–control studies were highly correlated with those seen in randomized trials (P = .0006). The largest effects were observed for gastrointestinal cancers.
In 5 studies, the regular use of aspirin was associated with a reduced proportion of cancers with distant metastasis (OR, 0.69; P < .0001); in 7 studies, it was not associated with a reduction in regional spread (OR, 0.98; P = .71). This was consistent with the findings from the randomized trials.
The authors note that "there is an urgent need for more data for effects on metastasis when aspirin is started after diagnosis of cancer."
More data are also needed for the effects of nonaspirin nonsteroidal anti-inflammatory drugs, they write, adding that "new case–control studies...have the potential to provide data quickly for each of these issues, with reasonable reliability and good statistical power."
Source: http://www.medscape.com/viewarticle/760565?sssdmh=dm1.769238&src=nldne
Peter M. Rothwell, MD, PhD, professor of clinical neurology at the University of Oxford, United Kingdom, was lead author on all 3 studies.
In the first study, published online March 21 in the Lancet, comparing daily aspirin with no aspirin to prevent vascular events, aspirin use reduced the risk for nonvascular death in all 51 trials examined (1021 vs 1173 deaths; odds ratio [OR], 0.88; P = .003). When data from 34 trials were examined (n = 69,224; 89% of total cohort), there were fewer deaths from cancer in the aspirin than in the control group (562 vs 664 deaths; OR, 0.85; P = .008).
Dr. Rothwell and colleagues note that even though the decreased risk for major vascular events in these trials was initially offset by a higher risk for major bleeding, both of these effects diminished over time, leaving only the reduced risk for cancer after 3 years.
"In view of the very low rates of vascular events in recent and ongoing trials of aspirin in primary prevention, prevention of cancer could become the main justification for aspirin use in this setting," they write.
Compelling but no recommendations yet
In an accompanying editorial, Andrew T. Chan, MD, MPH, and Nancy R, Cook, ScD, both from Harvard Medical School in Boston, Massachusetts, note that although these results are compelling, they do have limitations.
These analyses exclude the largest randomized trials in primary prevention, the editorialists point out. The Women's Health Study (WHS) of 39,876 women treated with alternate-day aspirin 100 mg over 10 years and the Physicians' Health Study (PHS) of 22,071 men treated with alternate-day aspirin 325 mg over 5 years were not included in the current study because of possible differences in the biologic effect between alternate-day and daily aspirin intake. However, in these 2 studies, aspirin was not associated with a lower risk for colorectal cancer or overall cancer incidence or mortality.
Another limitation, say the editorialists, is that the researchers only used 6 randomized trials to analyze low-dose aspirin in the primary prevention of cancer.
In these 6 trials (n = 35,535), aspirin was shown to lower the incidence of cancer after 3 years in women (132 vs 176; OR, 0.75; P = .01), in men (192 vs 245; OR, 0.77; P = .008), and in both (324 vs 421; OR, 0.76; P = .0003).
A third limitation is that because the included studies were designed to examine cardiovascular end points, there was no information about cancer screening or surveillance.
Finally, some of the analyses were limited by the quality of available data; some estimates pooled individual-level data with published results.
But "caveats notwithstanding, Rothwell and colleagues show quite convincingly that aspirin seems to reduce cancer incidence and death across different subgroups and cancer sites, with an apparent delayed effect," they write. For most individuals, "the risk–benefit calculus of aspirin seems to favor aspirin's long-term anticancer benefit. These findings are consistent with observational findings and our understanding of the stepwise progression of carcinogenesis."
These data might not be the final word on aspirin, as far as making a population-based recommendation, the editorialists caution, because the WHS and PHS remain "significant counterbalancing trials that have not shown a cancer benefit with alternate-day aspirin up to 10 to 12 years."
Another factor to be considered is the adverse events from daily aspirin. Even though there is a "convincing case" that the vascular and anticancer benefits of aspirin outweigh the harms of major extracranial bleeding, less serious adverse effects on quality of life, such as less severe bleeding, are not accounted for in these analyses, Drs. Chan and Cook write.
Nonetheless, until data from forthcoming trials and longer-term follow-up from the WHS and PHS become available, this "impressive collection of data moves us another step closer to broadening recommendations for aspirin use," they conclude.
Metastasis in randomized trials
In the second study, also published online March 21 in the Lancet, Dr. Rothwell and colleagues analyzed data from 5 large randomized trials of daily aspirin (75 mg or more daily) for the prevention of vascular events in the United Kingdom. The cohort consisted of 17,285 trial participants, 987 of whom had a new solid cancer diagnosed during a mean follow-up of 6.5 years.
Aspirin use reduced the risk for cancer with distant metastasis (hazard ratio [HR] for all cancers, 0.64; P = .001). The risk for cancer with distant metastasis was reduced by 36%, and the risk for adencarcioma was reduced by 46% (P = .0007). Among patients with adenocarcinoma who did not have metastasis at their initial diagnosis and who remained on trial treatment up to or after diagnosis, the use of aspirin reduced the risk for metastasis on subsequent follow-up by about 70%.
Aspirin lowered the cancer mortality rate among patients who developed adenocarcinoma, especially in those without metastasis at diagnosis (HR, 0.50; P = .0006). Aspirin also lowered the overall risk for fatal adenocarcinoma (HR, 0.65; P = .0002), but not the risk for other fatal cancers (HR, 1.06; P = .64). These effects were independent of confounders such as age and sex, but the absolute benefit was greatest in smokers, the authors note.
Observation vs randomized
The third study, published online March 21 in the Lancet Oncology, looked at the effect of aspirin on metastases, but with a different approach. The authors compared the effect of aspirin on the 20-year risk for cancer-specific mortality between observational studies and randomized trials.
They conducted this comparison because although randomized trials can clearly establish the risk for colorectal cancer, other solid tumors, and metastasis, such trials lack the statistical power to establish effects on less common cancers and on cancers in women.
Observational and case–control studies can provide these data if the results are shown to be reliable.
Overall, results from observational studies were similar to those from randomized trials, and showed that regular aspirin use lowered the long-term risk for several cancers and for distant metastasis.
In 6 eligible randomized trials, the aspirin group had a consistently lower 20-year risk for death from colorectal cancer than the control group (OR, 0.58; P = .0002). In the 26 case–control studies, any use of aspirin was associated with a lower risk for colorectal cancer (pooled OR, 0.67; P < .0001).
In 17 case–control studies, the regular use of aspirin was associated with a reduced risk for colorectal cancer (pooled OR, 0.62; P < .0001). In the randomized trials, there was good correlation between the effect of daily aspirin use and the 20-year risk for death from colorectal cancer (OR, 0.58; P = .0002).
The authors observed the same consistent reductions in risks for esophageal, gastric, biliary, and breast cancers, and estimates of the effect of aspirin on individual cancers in case–control studies were highly correlated with those seen in randomized trials (P = .0006). The largest effects were observed for gastrointestinal cancers.
In 5 studies, the regular use of aspirin was associated with a reduced proportion of cancers with distant metastasis (OR, 0.69; P < .0001); in 7 studies, it was not associated with a reduction in regional spread (OR, 0.98; P = .71). This was consistent with the findings from the randomized trials.
The authors note that "there is an urgent need for more data for effects on metastasis when aspirin is started after diagnosis of cancer."
More data are also needed for the effects of nonaspirin nonsteroidal anti-inflammatory drugs, they write, adding that "new case–control studies...have the potential to provide data quickly for each of these issues, with reasonable reliability and good statistical power."
Source: http://www.medscape.com/viewarticle/760565?sssdmh=dm1.769238&src=nldne
Friday, 3 February 2012
Broccoli health benefits require the whole food, not supplements
New research has found that if you want some of the many health benefits associated with eating broccoli or other cruciferous vegetables, you need to eat the real thing -- a key phytochemical in these vegetables is poorly absorbed and of far less value if taken as a supplement.
The study, published by scientists in the Linus Pauling Institute at Oregon State University, is one of the first of its type to determine whether some of the healthy compounds found in cruciferous vegetables can be just as easily obtained through supplements. The answer is no.
And not only do you need to eat the whole foods, you have to go easy on cooking them.
"The issue of whether important nutrients can be obtained through whole foods or with supplements is never simple," said Emily Ho, an OSU associate professor in the OSU School of Biological and Population Health Sciences, and principal investigator with the Linus Pauling Institute.
"Some vitamins and nutrients, like the folic acid often recommended for pregnant women, are actually better-absorbed as a supplement than through food," Ho said. "Adequate levels of nutrients like vitamin D are often difficult to obtain in most diets. But the particular compounds that we believe give broccoli and related vegetables their health value need to come from the complete food."
The reason, researchers concluded, is that a necessary enzyme called myrosinase is missing from most of the supplement forms of glucosinolates, a valuable phytochemical in cruciferous vegetables. Without this enzyme found in the whole food, the study found that the body actually absorbs five times less of one important compound and eight times less of another.
Intensive cooking does pretty much the same thing, Ho said. If broccoli is cooked until it's soft and mushy, its health value plummets. However, it can still be lightly cooked for two or three minutes, or steamed until it's still a little crunchy, and retain adequate levels of the necessary enzyme.
The new study was published in the Journal of Agricultural and Food Chemistry. It was supported by the National Institutes of Health.
Broccoli has been of particular interest to scientists because it contains the highest levels of certain glucosinolates, a class of phytochemicals that many believe may reduce the risk of prostate, breast, lung and colorectal cancer. When eaten as a raw or lightly-cooked food, enzymes in the broccoli help to break down the glucosinolates into two valuable compounds of intensive research interest -- sulforaphane and erucin.
Studies have indicated that sulforaphane, in particular, may help to detoxify carcinogens, and also activate tumor suppressor genes so they can perform their proper function.
Most supplements designed to provide these glucosinolates have the enzyme inactivated, so the sulforaphane is not released as efficiently. There are a few supplements available with active myrosinase, and whose function more closely resembles that of the whole food, but they are still being tested and not widely available, Ho said.
Small amounts of the myrosinase enzyme needed to break down glucosinolates are found in the human gut, but the new research showed they accomplish that task far less effectively than does whole food consumption.
Although broccoli has the highest levels of glucosinolates, they are also found in cauliflower, cabbage, kale and other cruciferous vegetables. The same cooking recommendations would apply to those foods to best retain their health benefits, Ho said.
Many people take a variety of vitamins, minerals and phytochemicals as supplements, and many of them are efficacious in that form, researchers say. Higher and optimal levels of popular supplements such as vitamins C, E, and fish oil, for instance, can be difficult to obtain through diet alone. Some researchers believe that millions of people around the world have deficient levels of vitamin D, because they don't get enough in their diet or through sun exposure.
But for now, if people want the real health benefits of broccoli, there's a simple guideline.
Eat your vegetables.
Source: http://www.sciencedaily.com /releases/2011/10/111011112501.htm
The study, published by scientists in the Linus Pauling Institute at Oregon State University, is one of the first of its type to determine whether some of the healthy compounds found in cruciferous vegetables can be just as easily obtained through supplements. The answer is no.
And not only do you need to eat the whole foods, you have to go easy on cooking them.
"The issue of whether important nutrients can be obtained through whole foods or with supplements is never simple," said Emily Ho, an OSU associate professor in the OSU School of Biological and Population Health Sciences, and principal investigator with the Linus Pauling Institute.
"Some vitamins and nutrients, like the folic acid often recommended for pregnant women, are actually better-absorbed as a supplement than through food," Ho said. "Adequate levels of nutrients like vitamin D are often difficult to obtain in most diets. But the particular compounds that we believe give broccoli and related vegetables their health value need to come from the complete food."
The reason, researchers concluded, is that a necessary enzyme called myrosinase is missing from most of the supplement forms of glucosinolates, a valuable phytochemical in cruciferous vegetables. Without this enzyme found in the whole food, the study found that the body actually absorbs five times less of one important compound and eight times less of another.
Intensive cooking does pretty much the same thing, Ho said. If broccoli is cooked until it's soft and mushy, its health value plummets. However, it can still be lightly cooked for two or three minutes, or steamed until it's still a little crunchy, and retain adequate levels of the necessary enzyme.
The new study was published in the Journal of Agricultural and Food Chemistry. It was supported by the National Institutes of Health.
Broccoli has been of particular interest to scientists because it contains the highest levels of certain glucosinolates, a class of phytochemicals that many believe may reduce the risk of prostate, breast, lung and colorectal cancer. When eaten as a raw or lightly-cooked food, enzymes in the broccoli help to break down the glucosinolates into two valuable compounds of intensive research interest -- sulforaphane and erucin.
Studies have indicated that sulforaphane, in particular, may help to detoxify carcinogens, and also activate tumor suppressor genes so they can perform their proper function.
Most supplements designed to provide these glucosinolates have the enzyme inactivated, so the sulforaphane is not released as efficiently. There are a few supplements available with active myrosinase, and whose function more closely resembles that of the whole food, but they are still being tested and not widely available, Ho said.
Small amounts of the myrosinase enzyme needed to break down glucosinolates are found in the human gut, but the new research showed they accomplish that task far less effectively than does whole food consumption.
Although broccoli has the highest levels of glucosinolates, they are also found in cauliflower, cabbage, kale and other cruciferous vegetables. The same cooking recommendations would apply to those foods to best retain their health benefits, Ho said.
Many people take a variety of vitamins, minerals and phytochemicals as supplements, and many of them are efficacious in that form, researchers say. Higher and optimal levels of popular supplements such as vitamins C, E, and fish oil, for instance, can be difficult to obtain through diet alone. Some researchers believe that millions of people around the world have deficient levels of vitamin D, because they don't get enough in their diet or through sun exposure.
But for now, if people want the real health benefits of broccoli, there's a simple guideline.
Eat your vegetables.
Source: http://www.sciencedaily.com /releases/2011/10/111011112501.htm
Thursday, 19 January 2012
The potential health benefits and drawbacks of coffee
Coffee may taste good and get you going in the morning, but what will it do for your health?
A growing body of research shows that coffee drinkers, compared to nondrinkers, are:
“There is certainly much more good news than bad news, in terms of coffee and health,” says Frank Hu, MD, MPH, PhD, nutrition and epidemiology professor at the Harvard School of Public Health.
But (you knew there would be a “but,” didn’t you?) coffee isn't proven to prevent those conditions.
Researchers don't ask people to drink or skip coffee for the sake of science. Instead, they ask them about their coffee habits. Those studies can't show cause and effect. It's possible that coffee drinkers have other advantages, such as better diets, more exercise, or protective genes.
So there isn't solid proof. But there are signs of potential health perks -- and a few cautions.
If you're like the average American, who downed 416 8-ounce cups of coffee in 2009 (by the World Resources Institute's estimates), you might want to know what all that java is doing for you, or to you.
Here is a condition-by-condition look at the research.
Type 2 diabetes
Hu calls the data on coffee and type 2 diabetes "pretty solid," based on more than 15 published studies.
"The vast majority of those studies have shown a benefit of coffee on the prevention of diabetes. And now there is also evidence that decaffeinated coffee may have the same benefit as regular coffee,” Hu tells WebMD.
In 2005, Hu's team reviewed nine studies on coffee and type 2 diabetes. Of more than 193,000 people, those who said they drank more than six or seven cups daily were 35% less likely to have type 2 diabetes than people who drank fewer than two cups daily. There was a smaller perk -- a 28% lower risk -- for people who drank 4-6 cups a day. The findings held regardless of sex, weight, or geographic location (U.S. or Europe).
More recently, Australian researchers looked at 18 studies of nearly 458,000 people. They found a 7% drop in the odds of having type 2 diabetes for every additional cup of coffee drunk daily. There were similar risk reductions for decaf coffee drinkers and tea drinkers. But the researchers cautioned that data from some of the smaller studies they reviewed may be less reliable. So it's possible that they overestimated the strength of the link between heavy coffee drinking and diabetes.
How might coffee keep diabetes at bay?
“It’s the whole package,” Hu says. He points to antioxidants -- nutrients that help prevent tissue damage caused by molecules called oxygen-free radicals. “We know that coffee has a very strong antioxidant capacity," Hu says.
Coffee also contains minerals such as magnesium and chromium, which help the body use the hormone insulin, which controls blood sugar (glucose). In type 2 diabetes, the body loses its ability to use insulin and regulate blood sugar effectively.
It's probably not the caffeine, though. Based on studies of decaf coffee, “I think we can safely say that the benefits are not likely to be due to caffeine," Hu says.
Hold the caffeine?
The fact that coffee contains good stuff does not necessarily mean that it’s good for us, says James D. Lane, PhD, professor of medical psychology and behavioral medicine at Duke University Medical Center in Durham, N.C.
“It has not really been shown that coffee drinking leads to an increase in antioxidants in the body,” Lane tells WebMD. “We know that there are antioxidants in large quantities in coffee itself, especially when it’s freshly brewed, but we don’t know whether those antioxidants appear in the bloodstream and in the body when the person drinks it. Those studies have not been done.”
Regular coffee, of course, also contains caffeine. Caffeine can raise blood pressure, as well as blood levels of the fight-or-flight chemical epinephrine (also called adrenaline), Lane says.
Heart disease and stroke
Coffee may counter several risk factors for heart attack and stroke.
First, there's the potential effect on type 2 diabetes risk. Type 2 diabetes makes heart disease and stroke more likely.
Besides that, coffee has been linked to lower risks for heart rhythm disturbances (another heart attack and stroke risk factor) in men and women, and lower risk for strokes in women.
In a study of about 130,000 Kaiser Permanente health plan members, people who reported drinking 1-3 cups of coffee per day were 20% less likely to be hospitalized for abnormal heart rhythms (arrhythmias) than nondrinkers, regardless of other risk factors.
And, for women, coffee may mean a lower risk of stroke.
In 2009, a study of 83,700 nurses enrolled in the long-term Nurses' Health Study showed a 20% lower risk of stroke in those who reported drinking two or more cups of coffee daily compared to women who drank less coffee or none at all. That pattern held regardless of whether the women had high blood pressure, high cholesterol levels, and type 2 diabetes.
Parkinson’s and Alzheimer's diseases
“For Parkinson’s disease, the data have always been very consistent: higher consumption of coffee is associated with decreased risk of Parkinson’s,” Hu tells WebMD. That seems to be due to caffeine, though exactly how that works isn't clear, Hu notes.
Coffee has also been linked to lower risk of dementia, including Alzheimer’s disease. A 2009 study from Finland and Sweden showed that, out of 1,400 people followed for about 20 years, those who reported drinking 3-5 cups of coffee daily were 65% less likely to develop dementia and Alzheimer’s disease, compared with nondrinkers or occasional coffee drinkers.
Cancer
The evidence of a cancer protection effect of coffee is weaker than that for type 2 diabetes. But “for liver cancer, I think that the data are very consistent,” Hu says.
“All of the studies have shown that high coffee consumption is associated with decreased risk of liver cirrhosis and liver cancer,” he says. That's a "very interesting finding," Hu says, but again, it's not clear how it might work.
Again, this research shows a possible association, but like most studies on coffee and health, does not show cause and effect.
Pregnancy
In August 2010, the American College of Obstetricians and Gynecologists (ACOG) stated that moderate caffeine drinking -- less than 200 mg per day, or about the amount in 12 ounces of coffee -- doesn't appear to have any major effects on causing miscarriage, premature delivery, or fetal growth.
But the effects of larger caffeine doses are unknown, and other research shows that pregnant women who drink many cups of coffee daily may be at greater risk for miscarriage than non-drinkers or moderate drinkers. Again, it's not clear whether the coffee was responsible for that.
Calories, heartburn, and urine
You won't break your calorie budget on coffee -- until you start adding the trimmings.
According to the web site myfoodapedia.gov -- part of the U.S. Department of Agriculture's Center for Nutrition Policy and Promotion -- a 6-ounce cup of black coffee contains just 7 calories. Add some half & half and you'll get 46 calories. If you favor a liquid nondairy creamer, that will set you back 48 calories. A teaspoon of sugar will add about 23 calories.
Drink a lot of coffee and you may head to the bathroom more often. Caffeine is a mild diuretic -- that is, it makes you urinate more than you would without it. Decaffeinated coffee has about the same effect on urine production as water.
Both regular and decaffeinated coffee contain acids that can make heartburn worse.
Related posts:
Coffee linked to lower endometrial cancer risk
Coffee could reduce skin cancer risk
Coffee keeps the blues away
Caffeinated coffee protects against Alzheimer's, diabetes, depression and prostate cancers
Coffee lowers liver fibrosis risk
Source: http://www.webmd.com/food-recipes/features/coffee-new-health-food
A growing body of research shows that coffee drinkers, compared to nondrinkers, are:
- Less likely to have type 2 diabetes, Parkinson's disease, and dementia
- Have fewer cases of certain cancers, heart rhythm problems, and strokes
“There is certainly much more good news than bad news, in terms of coffee and health,” says Frank Hu, MD, MPH, PhD, nutrition and epidemiology professor at the Harvard School of Public Health.
But (you knew there would be a “but,” didn’t you?) coffee isn't proven to prevent those conditions.
Researchers don't ask people to drink or skip coffee for the sake of science. Instead, they ask them about their coffee habits. Those studies can't show cause and effect. It's possible that coffee drinkers have other advantages, such as better diets, more exercise, or protective genes.
So there isn't solid proof. But there are signs of potential health perks -- and a few cautions.
If you're like the average American, who downed 416 8-ounce cups of coffee in 2009 (by the World Resources Institute's estimates), you might want to know what all that java is doing for you, or to you.
Here is a condition-by-condition look at the research.
Type 2 diabetes
Hu calls the data on coffee and type 2 diabetes "pretty solid," based on more than 15 published studies.
"The vast majority of those studies have shown a benefit of coffee on the prevention of diabetes. And now there is also evidence that decaffeinated coffee may have the same benefit as regular coffee,” Hu tells WebMD.
In 2005, Hu's team reviewed nine studies on coffee and type 2 diabetes. Of more than 193,000 people, those who said they drank more than six or seven cups daily were 35% less likely to have type 2 diabetes than people who drank fewer than two cups daily. There was a smaller perk -- a 28% lower risk -- for people who drank 4-6 cups a day. The findings held regardless of sex, weight, or geographic location (U.S. or Europe).
More recently, Australian researchers looked at 18 studies of nearly 458,000 people. They found a 7% drop in the odds of having type 2 diabetes for every additional cup of coffee drunk daily. There were similar risk reductions for decaf coffee drinkers and tea drinkers. But the researchers cautioned that data from some of the smaller studies they reviewed may be less reliable. So it's possible that they overestimated the strength of the link between heavy coffee drinking and diabetes.
How might coffee keep diabetes at bay?
“It’s the whole package,” Hu says. He points to antioxidants -- nutrients that help prevent tissue damage caused by molecules called oxygen-free radicals. “We know that coffee has a very strong antioxidant capacity," Hu says.
Coffee also contains minerals such as magnesium and chromium, which help the body use the hormone insulin, which controls blood sugar (glucose). In type 2 diabetes, the body loses its ability to use insulin and regulate blood sugar effectively.
It's probably not the caffeine, though. Based on studies of decaf coffee, “I think we can safely say that the benefits are not likely to be due to caffeine," Hu says.
Hold the caffeine?
The fact that coffee contains good stuff does not necessarily mean that it’s good for us, says James D. Lane, PhD, professor of medical psychology and behavioral medicine at Duke University Medical Center in Durham, N.C.
“It has not really been shown that coffee drinking leads to an increase in antioxidants in the body,” Lane tells WebMD. “We know that there are antioxidants in large quantities in coffee itself, especially when it’s freshly brewed, but we don’t know whether those antioxidants appear in the bloodstream and in the body when the person drinks it. Those studies have not been done.”
Regular coffee, of course, also contains caffeine. Caffeine can raise blood pressure, as well as blood levels of the fight-or-flight chemical epinephrine (also called adrenaline), Lane says.
Heart disease and stroke
Coffee may counter several risk factors for heart attack and stroke.
First, there's the potential effect on type 2 diabetes risk. Type 2 diabetes makes heart disease and stroke more likely.
Besides that, coffee has been linked to lower risks for heart rhythm disturbances (another heart attack and stroke risk factor) in men and women, and lower risk for strokes in women.
In a study of about 130,000 Kaiser Permanente health plan members, people who reported drinking 1-3 cups of coffee per day were 20% less likely to be hospitalized for abnormal heart rhythms (arrhythmias) than nondrinkers, regardless of other risk factors.
And, for women, coffee may mean a lower risk of stroke.
In 2009, a study of 83,700 nurses enrolled in the long-term Nurses' Health Study showed a 20% lower risk of stroke in those who reported drinking two or more cups of coffee daily compared to women who drank less coffee or none at all. That pattern held regardless of whether the women had high blood pressure, high cholesterol levels, and type 2 diabetes.
Parkinson’s and Alzheimer's diseases
“For Parkinson’s disease, the data have always been very consistent: higher consumption of coffee is associated with decreased risk of Parkinson’s,” Hu tells WebMD. That seems to be due to caffeine, though exactly how that works isn't clear, Hu notes.
Coffee has also been linked to lower risk of dementia, including Alzheimer’s disease. A 2009 study from Finland and Sweden showed that, out of 1,400 people followed for about 20 years, those who reported drinking 3-5 cups of coffee daily were 65% less likely to develop dementia and Alzheimer’s disease, compared with nondrinkers or occasional coffee drinkers.
Cancer
The evidence of a cancer protection effect of coffee is weaker than that for type 2 diabetes. But “for liver cancer, I think that the data are very consistent,” Hu says.
“All of the studies have shown that high coffee consumption is associated with decreased risk of liver cirrhosis and liver cancer,” he says. That's a "very interesting finding," Hu says, but again, it's not clear how it might work.
Again, this research shows a possible association, but like most studies on coffee and health, does not show cause and effect.
Pregnancy
In August 2010, the American College of Obstetricians and Gynecologists (ACOG) stated that moderate caffeine drinking -- less than 200 mg per day, or about the amount in 12 ounces of coffee -- doesn't appear to have any major effects on causing miscarriage, premature delivery, or fetal growth.
But the effects of larger caffeine doses are unknown, and other research shows that pregnant women who drink many cups of coffee daily may be at greater risk for miscarriage than non-drinkers or moderate drinkers. Again, it's not clear whether the coffee was responsible for that.
Calories, heartburn, and urine
You won't break your calorie budget on coffee -- until you start adding the trimmings.
According to the web site myfoodapedia.gov -- part of the U.S. Department of Agriculture's Center for Nutrition Policy and Promotion -- a 6-ounce cup of black coffee contains just 7 calories. Add some half & half and you'll get 46 calories. If you favor a liquid nondairy creamer, that will set you back 48 calories. A teaspoon of sugar will add about 23 calories.
Drink a lot of coffee and you may head to the bathroom more often. Caffeine is a mild diuretic -- that is, it makes you urinate more than you would without it. Decaffeinated coffee has about the same effect on urine production as water.
Both regular and decaffeinated coffee contain acids that can make heartburn worse.
Related posts:
Coffee linked to lower endometrial cancer risk
Coffee could reduce skin cancer risk
Coffee keeps the blues away
Caffeinated coffee protects against Alzheimer's, diabetes, depression and prostate cancers
Coffee lowers liver fibrosis risk
Source: http://www.webmd.com/food-recipes/features/coffee-new-health-food
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