Diet May Prevail Over Genes in Risk of Heart Disease

November 12, 2012

Diet May Prevail Over Genes in Risk of Heart Disease

A study conducted by researchers from McMaster University in Hamilton, Ontario, Canada has recently been published in PLoS Medicine and the study appears to indicate that even those at higher risk of heart disease because of their genes can also minimize their risk.

The study was carried out by Sonia S. Anand, MD, PhD, who is a professor of medicine and epidemiology, and colleagues. The researchers studied more than 27,000 people from five different ethnic groups and any effects their diets had on health and risks. The groups were European, Arab, Latin American, Chinese and South Asian and some of the people in the study had genes deemed to be high risk.

We are all conscious of the benefits of healthy eating which includes reducing the risk of heart disease but we are now aware that even if genes are the cause of the increased level of risk it can still be reduced.

Anand explains, “A diet high in fruits and vegetables appears to mitigate the genetic risk of a heart attack”.

The finding, if it can withstand academic scrutiny, will challenge the assumption that effects of genes cannot be altered. Because the study evaluated variants in the area of chromosome 9p21, which has just recently been identified as a gene with a bearing on the likelihood of having a heart attack further work will have to be carried out.

It was in 2007 that researchers from several different countries identified the increased risk of heart attack and heart disease was associated to variants in the 9p21 chromosome region. Anand and colleagues investigated if diet could overcome some of the effects of this variant.

Anand reports that within the general population around half of the people have one copy of the variant and around one person in five has two. It is believed that those having two copies of the variant are at even higher risk of disease than those with just one copy of the variant.

In addition to this report further studies have been published confirming the association. This has led Anand to say, “We are confident the gene associated with heart attack is real”.

The original findings were the result of research into two other studies. The studies evaluated over 27,000 people between them. The first study was named Interheart, here the researchers categorized the participants into two groups, those who had previously had a heart attack and those who had not. The groups were of almost the same size, with 3,820 people in the group who had experienced heart attacks and 4,294 in the other group.

The researchers then drafted a list of foods and scored them on their health attributes using different sources of information relating to the foods. The best scores going to fruit and vegetables and the worse, or riskiest, scores going to meat, salty snacks and fry-ups. Anand saw that those who ate more ‘risky’ (non prudent) foods and had the gene variant increased their risk by about 30%. This indicated to the research team that diet can influence risk factors caused by genetic variations. Anand says, “The risk [of heart attack] of those with the bad genotype who were in the high prudent diet group was not increased”.

The second study, called Finrisk was a large scale Finnish study involving 19,129 people and of that group 1,014 had heart disease. The Finnish study was similar to Interheart in that it rated different types of food from prudent to risky. It also required the participants to fill in questionnaires selecting which of the 130 food items they ate regularly. The highest scores went to those who ate more vegetables, berries and fruit, and if they ate food classed as prudent twice a day.

Lifestyle and Diet can Override Genes’ Influence

Eric Topol, MD, is a professor of translational genomics at The Scripps Research Institute and director of the Scripps Translational Science Institute in La Jolla, California. He says that the findings clearly indicate that lifestyle does have an effect. You can alter the risk factor produced by your genes.

He says of the report, “This suggests you may be able to do something about it [bad genes] if you follow a prudent diet that is rich in fruits and vegetables. I think this is a very sound report”. He also says. “It’s really one of the first solid evidence of this whole field of nutrigenomics”.

The study of genes, and the way they relate to nutrients is called nutrigenomics.

Topol rounds up by pointing out that the research found that if people eat an unhealthy diet then their risk of heart disease increases and with a healthy diet and lifestyle the risk decreases.

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