More Doubt on Link Between a Blood Chemical and Heart Disease

TUESDAY, Feb. 21 (HealthDay News) -- Having high levels of the amino acid homocysteine won't raise your risk of developing heart disease, a new analysis indicates.

The findings appear to close the door on the potential benefit of lowering homocysteine levels with folic acid supplements, according to report author Robert Clarke, of the University of Oxford in the United Kingdom, and his colleagues.

The researchers also said previous studies that suggested high levels of homocysteine might be a modifiable risk factor for heart disease were plagued by publication bias and methodological problems.

Clarke and his team analyzed data on nearly 50,000 heart disease patients and 68,000 healthy people, culled from 86 published studies and 19 unpublished studies. There was no increased risk of heart disease in people who had an MTHFR gene variant that is associated with 20 percent higher blood homocysteine levels.

The MTHFR gene plays a role in the production of methylene tetrahydrofolate reductase, which uses folate to break down and remove homocysteine.

The study appears in this week's issue of the journal PLoS Medicine.

"The discrepancy between the overall results in the unpublished and the published datasets is too extreme to be plausibly dismissed as a chance finding," the researchers wrote. "Some studies, particularly if small, might have been prioritized for publication by investigators, referees or editors according to the positivity of their results and some may have been liable to other methodological problems that bias the average of all results. To avoid such biases, we chiefly emphasize the new results from the previously unpublished datasets."

"The magnitude of the effect of publication bias is substantial and, in addition to distorting the association of MTHFR with [coronary heart disease] in published studies, publication bias may also help explain the discrepant findings recently reported for MTHFR and stroke," they concluded.

More information

The U.S. National Heart Lung and Blood Institute has more about coronary heart disease.

View the original article here

No Cancer Benefit From Vitamin B, Omega-3 Supplements in Heart Patients

MONDAY, Feb. 13 (HealthDay News) -- Patients with a history of heart disease will most likely not reduce their risk for developing cancer by taking vitamin B and/or omega-3 fatty acid supplements, a new French analysis suggests.

"In the population we studied, we found no beneficial effects of either B vitamins or omega-3 fatty acids taken over five years on cancer occurrence or cancer-related death," noted study author Valentina Andreeva, who is with the nutritional epidemiology research unit at the University of Paris XIII in Bobigny, France.

Andreeva and her colleagues report their findings in the Feb. 13 online edition of the Archives of Internal Medicine.

To explore the protective potential of B vitamins and fatty acid supplements, the authors did a secondary analysis of data that had been collected in a previous study involving almost 2,000 French men and 500 women.

All were between 45 and 80 years of age, and all had experienced cardiac trouble (heart attack, unstable angina or ischemic stroke) in the year leading up to the start of the study.

In turn, the participants were divided into one of four different groups that consumed a daily supplement regimen involving various types of vitamin B and omega-3 fatty acids at "relatively low supplementation doses."

By the end of the original five-year study, 7 percent of the participants had gone on to develop some form of cancer, and just over 2 percent ultimately died of cancer. The vast majority of cancer cases (including prostate, lung, bladder and colorectal cancer) and deaths occurred among men (81 percent and 83 percent, respectively).

The team unearthed no evidence that any form of vitamin B or omega-3 fatty acid supplement improved cancer outcomes in any way.

The investigators noted that there were some indications that cancer risk might have actually gone up, specifically among women taking vitamin B and/or omega-3 fatty acid supplementation. However, the authors stressed that this observation was based on too few cases to substantiate a firm conclusion, and called for further research involving a larger pool of participants.

"The results of our study suggest that individuals should exercise caution when deciding to take dietary supplements, especially over a long period of time and without a physician's advice," advised Andreeva. "Such supplements constitute active substances and might have adverse effects in some populations. To be on the safe side, individuals should strive to achieve dietary recommendations via healthy, balanced diets."

Joseph Su, the Washington, D.C.-based program director of the division of cancer control and population science within the U.S. National Cancer Institute's epidemiology and genomics research program, said that nothing about the findings struck him as surprising.

"So far, study findings have been very inconsistent," he noted. "But most supplement studies, if anything, have shown no beneficial effect whatsoever. Just like this one. So, I don't think there's anything that can really back up the idea that these supplements can prevent cancer."

However, Vicky Stevens, strategic director of laboratory services at the American Cancer Society in Atlanta, expressed some reservations about the French analysis.

"Compared with other trials, they used much lower levels of supplements," she noted. "From the B-vitamin point of view, dramatically lower. So, it could be argued that they just weren't using high enough levels of supplements to see any effects," Stevens suggested.

"And they used a natural form of folate [vitamin B supplement], whereas other trials use a synthetic form," Stevens added. "But the real problem in being able to evaluate the effects they do see is that they don't have enough people. And it's not really a long enough follow-up period to really see an effect of these supplements on cancer onset. Five years isn't really enough. It can take 10 or 20 years in most cases. So, what they may be seeing is an effect on preexisting abnormalities, but not the impact on cancer onset itself."

Duffy MacKay, a naturopathic doctor and vice president of scientific and regulatory affairs for the Council for Responsible Nutrition in Washington, D.C., agreed.

"When you look at an intervention like this, you're definitely not looking at the role of the supplements at preventing tumors, because the tumors likely started well before the trial," he noted. "So really what the trial is about is giving vitamin B and omega 3 and seeing if they altered the outcome, the progression, of these cancers," MacKay explained.

"And with that you have to realize that cancer is a very complex multi-factorial disease," MacKay stressed. "And two supplements would never be expected to be a successful treatment on their own. I would say, however, that proper nutrition is one of your best allies in terms of wellness, period. And while no one ever claimed these were cancer drugs, if you will, supplements make sense, cancer or no cancer."

More information

For more on vitamins and cancer, visit the American Cancer Society.

View the original article here

Y Chromosome Can Raise Heart Disease Risk by 50 Percent

Image courtesy of iStockphoto/luckyraccoon

Men tend to get coronary artery disease much earlier than do women. For some men, the reason for that might be in part because of their fathers and their father’s father according to a new study, published online Wednesday in The Lancet.

The study analyzed data from 3,233 unrelated white men enrolled in previous U.K. studies. From this information, the researchers took a close look at genetic markers on the Y chromosome, which is passed on from father to son. They found that 15 to 20 percent of the men fell into one of the 13 ancient ancestry branches known as haplogroup I.

Men in this haplogroup, who all showed a common variant on the Y chromosome, were 50 percent more likely to have coronary artery disease than those without it even when age, body mass, cholesterol, high blood pressure, smoking and other risk factors were taken into account. The genetic link is not entirely surprising, given that heart disease has been known to run in families, but the finding adds support to previously observed trends and insights into additional lines of research.

The finding follows well-described geographic distribution of coronary artery disease. Haplogroup I has been traced back to hunter-gatherers who arrived in Europe from the Middle East some 25,000 years ago and who today remain more prevalent in the northern areas of western Europe, where incidence of coronary artery disease is still higher than it is in the south where the haplogroup R1b1b2 is more common.

The genetic variant came with altered patterns of regulation in 19 key pathways all of which were linked to immune and inflammatory responses. These differences might play a role in atherosclerosis, or the hardening of the arteries, noted the researchers, who were led by Fadi Charchar, of Australia’s University of Ballarat. “Dysfunction of immune response is a well established contributor to atherosclerosis and coronary artery disease,” they wrote. Previous research had found other immuno differences in men from this haplotype, such as HIV-positive men in this group taking longer to show an immune response after getting antiretroviral therapy.

The findings do not suggest that heart disease risk for men is entirely or even mostly lodged on the Y chromosome. And the researchers noted that knowing which haplogroup a man is from is unlikely to yield predictions of his individual risk of coronary artery disease. But, as they pointed out, a better understanding of this widespread association “could have important public health implications,” especially in attempts to assess the prevalence of the disease within a population. And further study should help “to decipher complex interplay between human Y chromosome, immunity and cardiovascular disease,” the researchers wrote.

“These findings are exciting,” Virginia Miller of the Mayo Clinic wrote in an associated Lancet essay (Miller was not involved in the new research). The new work also suggests that there could be another side to the genetic equation that is protective, she added.

Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news.
© 2012 ScientificAmerican.com. All rights reserved.

View the original article here

Heart Disease May Be Risk Factor for Prostate Cancer

THURSDAY, Feb. 9 (HealthDay News) -- Heart disease may be a risk factor for prostate cancer, a new study suggests.

If this link is confirmed in future research, it means that lifestyle changes that reduce heart disease risk -- such as weight loss, exercise and a healthy diet -- may also protect men against prostate cancer, the Duke Cancer Institute researchers said.

"What's good for the heart may be good for the prostate," study author Dr. Jean-Alfred Thomas II, a postdoctoral fellow in the division of urology, said in a Duke Medicine news release.

He and his colleagues analyzed data from 6,390 men in a four-year clinical trial testing a drug's effectiveness in reducing prostate cancer risk. Of those men, 547 reported a history of coronary artery disease before the start of the trial.

The Duke researchers found that men with coronary artery disease had a 35 percent greater risk of developing prostate cancer over time and a 24 percent greater risk of being diagnosed with prostate cancer within the first two years of the study compared to men who did not have heart disease.

Four years into the clinical trial, men with coronary artery disease had a 74 percent higher risk of prostate cancer than those with no heart disease.

"We controlled for a number of risk factors, including hypertension, taking statins or aspirin," Thomas said. "We don't have a good grasp on what's causing the link, but we are observing this association."

The study appears online this month in the journal Cancer Epidemiology, Biomarkers & Prevention.

Coronary artery disease is the leading cause of death among adults in the United States, and prostate cancer is the second most deadly type of cancer for men in the United States, the release noted.

More information

The U.S. National Cancer Institute has more about prostate cancer risk.

View the original article here

Heart Disease Risk Gene May Pass From Dads to Sons

WEDNESDAY, Feb. 8 (HealthDay News) -- An increased risk for coronary artery disease can be passed genetically from father to son on the male Y chromosome, a new study says.

The Y chromosome, a part of DNA present only in men, appears to play a role in the inheritance of coronary artery disease, according to researchers at the University of Leicester in England and their colleagues.

They analyzed DNA from more than 3,000 biologically unrelated men in the United Kingdom and found that 90 percent had variants of Y chromosomes belonging to one of two major groups -- haplogroup I and haplogroup R1b1b2.

Men with a Y chromosome from haplogroup I have a 50 percent higher risk of coronary artery disease than other men, and that risk is independent of risk factors such as smoking, high blood pressure and high cholesterol, the researchers found. Those men account for up to 20 percent of men in Britain, they said.

They attributed this increased risk to the effect of the haplogroup I Y chromosome on the immune system and inflammation.

"We are very excited about these findings as they put the Y chromosome on the map of genetic susceptibility to coronary artery disease. We wish to further analyze the human Y chromosome to find specific genes and variants that drive this association," principal investigator Dr. Maciej Tomaszewski, a clinical senior lecturer in the department of cardiovascular sciences, said in a university news release.

"The major novelty of these findings is that the human Y chromosome appears to play a role in the cardiovascular system beyond its traditionally perceived determination of male sex," Tomaszewski added.

The study appears online Feb. 8 in The Lancet.

Coronary artery disease is narrowing of the blood vessels that supply blood and oxygen to the heart. This can lead to angina symptoms and heart attacks. It develops in men about a decade earlier than in women.

More information

The American Academy of Family Physicians has more about coronary artery disease.

View the original article here

Heart Disease May Be Risk Factor for Prostate Cancer

THURSDAY, Feb. 9 (HealthDay News) -- Heart disease may be a risk factor for prostate cancer, a new study suggests.

If this link is confirmed in future research, it means that lifestyle changes that reduce heart disease risk -- such as weight loss, exercise and a healthy diet -- may also protect men against prostate cancer, the Duke Cancer Institute researchers said.

"What's good for the heart may be good for the prostate," study author Dr. Jean-Alfred Thomas II, a postdoctoral fellow in the division of urology, said in a Duke Medicine news release.

He and his colleagues analyzed data from 6,390 men in a four-year clinical trial testing a drug's effectiveness in reducing prostate cancer risk. Of those men, 547 reported a history of coronary artery disease before the start of the trial.

The Duke researchers found that men with coronary artery disease had a 35 percent greater risk of developing prostate cancer over time and a 24 percent greater risk of being diagnosed with prostate cancer within the first two years of the study compared to men who did not have heart disease.

Four years into the clinical trial, men with coronary artery disease had a 74 percent higher risk of prostate cancer than those with no heart disease.

"We controlled for a number of risk factors, including hypertension, taking statins or aspirin," Thomas said. "We don't have a good grasp on what's causing the link, but we are observing this association."

The study appears online this month in the journal Cancer Epidemiology, Biomarkers & Prevention.

Coronary artery disease is the leading cause of death among adults in the United States, and prostate cancer is the second most deadly type of cancer for men in the United States, the release noted.

More information

The U.S. National Cancer Institute has more about prostate cancer risk.

View the original article here

Y Chromosome Can Raise Heart Disease Risk by 50 Percent

y_chromosome_heart_disease Image courtesy of iStockphoto/luckyraccoon

Men tend to get coronary artery disease much earlier than do women. For some men, the reason for that might be in part because of their fathers and their father’s father according to a new study, published online Wednesday in The Lancet.

The study analyzed data from 3,233 unrelated white men enrolled in previous U.K. studies. From this information, the researchers took a close look at genetic markers on the Y chromosome, which is passed on from father to son. They found that 15 to 20 percent of the men fell into one of the 13 ancient ancestry branches known as haplogroup I.

Men in this haplogroup, who all showed a common variant on the Y chromosome, were 50 percent more likely to have coronary artery disease than those without it even when age, body mass, cholesterol, high blood pressure, smoking and other risk factors were taken into account. The genetic link is not entirely surprising, given that heart disease has been known to run in families, but the finding adds support to previously observed trends and insights into additional lines of research.

The finding follows well-described geographic distribution of coronary artery disease. Haplogroup I has been traced back to hunter-gatherers who arrived in Europe from the Middle East some 25,000 years ago and who today remain more prevalent in the northern areas of western Europe, where incidence of coronary artery disease is still higher than it is in the south where the haplogroup R1b1b2 is more common.

The genetic variant came with altered patterns of regulation in 19 key pathways all of which were linked to immune and inflammatory responses. These differences might play a role in atherosclerosis, or the hardening of the arteries, noted the researchers, who were led by Fadi Charchar, of Australia’s University of Ballarat. “Dysfunction of immune response is a well established contributor to atherosclerosis and coronary artery disease,” they wrote. Previous research had found other immuno differences in men from this haplotype, such as HIV-positive men in this group taking longer to show an immune response after getting antiretroviral therapy.

The findings do not suggest that heart disease risk for men is entirely or even mostly lodged on the Y chromosome. And the researchers noted that knowing which haplogroup a man is from is unlikely to yield predictions of his individual risk of coronary artery disease. But, as they pointed out, a better understanding of this widespread association “could have important public health implications,” especially in attempts to assess the prevalence of the disease within a population. And further study should help “to decipher complex interplay between human Y chromosome, immunity and cardiovascular disease,” the researchers wrote.

“These findings are exciting,” Virginia Miller of the Mayo Clinic wrote in an associated Lancet essay (Miller was not involved in the new research). The new work also suggests that there could be another side to the genetic equation that is protective, she added.

Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news.
© 2012 ScientificAmerican.com. All rights reserved.

View the original article here

Heart Disease Risk Gene May Pass From Dads to Sons

WEDNESDAY, Feb. 8 (HealthDay News) -- An increased risk for coronary artery disease can be passed genetically from father to son on the male Y chromosome, a new study says.

The Y chromosome, a part of DNA present only in men, appears to play a role in the inheritance of coronary artery disease, according to researchers at the University of Leicester in England and their colleagues.

They analyzed DNA from more than 3,000 biologically unrelated men in the United Kingdom and found that 90 percent had variants of Y chromosomes belonging to one of two major groups -- haplogroup I and haplogroup R1b1b2.

Men with a Y chromosome from haplogroup I have a 50 percent higher risk of coronary artery disease than other men, and that risk is independent of risk factors such as smoking, high blood pressure and high cholesterol, the researchers found. Those men account for up to 20 percent of men in Britain, they said.

They attributed this increased risk to the effect of the haplogroup I Y chromosome on the immune system and inflammation.

"We are very excited about these findings as they put the Y chromosome on the map of genetic susceptibility to coronary artery disease. We wish to further analyze the human Y chromosome to find specific genes and variants that drive this association," principal investigator Dr. Maciej Tomaszewski, a clinical senior lecturer in the department of cardiovascular sciences, said in a university news release.

"The major novelty of these findings is that the human Y chromosome appears to play a role in the cardiovascular system beyond its traditionally perceived determination of male sex," Tomaszewski added.

The study appears online Feb. 8 in The Lancet.

Coronary artery disease is narrowing of the blood vessels that supply blood and oxygen to the heart. This can lead to angina symptoms and heart attacks. It develops in men about a decade earlier than in women.

More information

The American Academy of Family Physicians has more about coronary artery disease.

View the original article here

Y Chromosome Can Raise Heart Disease Risk by 50 Percent

y_chromosome_heart_disease Image courtesy of iStockphoto/luckyraccoon

Men tend to get coronary artery disease much earlier than do women. For some men, the reason for that might be in part because of their fathers and their father’s father according to a new study, published online Wednesday in The Lancet.

The study analyzed data from 3,233 unrelated white men enrolled in previous U.K. studies. From this information, the researchers took a close look at genetic markers on the Y chromosome, which is passed on from father to son. They found that 15 to 20 percent of the men fell into one of the 13 ancient ancestry branches known as haplogroup I.

Men in this haplogroup, who all showed a common variant on the Y chromosome, were 50 percent more likely to have coronary artery disease than those without it even when age, body mass, cholesterol, high blood pressure, smoking and other risk factors were taken into account. The genetic link is not entirely surprising, given that heart disease has been known to run in families, but the finding adds support to previously observed trends and insights into additional lines of research.

The finding follows well-described geographic distribution of coronary artery disease. Haplogroup I has been traced back to hunter-gatherers who arrived in Europe from the Middle East some 25,000 years ago and who today remain more prevalent in the northern areas of western Europe, where incidence of coronary artery disease is still higher than it is in the south where the haplogroup R1b1b2 is more common.

The genetic variant came with altered patterns of regulation in 19 key pathways all of which were linked to immune and inflammatory responses. These differences might play a role in atherosclerosis, or the hardening of the arteries, noted the researchers, who were led by Fadi Charchar, of Australia’s University of Ballarat. “Dysfunction of immune response is a well established contributor to atherosclerosis and coronary artery disease,” they wrote. Previous research had found other immuno differences in men from this haplotype, such as HIV-positive men in this group taking longer to show an immune response after getting antiretroviral therapy.

The findings do not suggest that heart disease risk for men is entirely or even mostly lodged on the Y chromosome. And the researchers noted that knowing which haplogroup a man is from is unlikely to yield predictions of his individual risk of coronary artery disease. But, as they pointed out, a better understanding of this widespread association “could have important public health implications,” especially in attempts to assess the prevalence of the disease within a population. And further study should help “to decipher complex interplay between human Y chromosome, immunity and cardiovascular disease,” the researchers wrote.

“These findings are exciting,” Virginia Miller of the Mayo Clinic wrote in an associated Lancet essay (Miller was not involved in the new research). The new work also suggests that there could be another side to the genetic equation that is protective, she added.

Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news.
© 2012 ScientificAmerican.com. All rights reserved.

View the original article here