It does not necessarily mean that if both your parents or a parent died of a heart attack in their forties you too are going to suffer one. Researchers have identified about 50 genes associated with heart disease. But even if you carry all the 50 genes you can still substantially reduce your risk of a heart attack by employing simple life style measures. Healthy life style behaviour that includes not smoking, not acquiring too much weight, moderate exercise and eating healthy food is terrific strategy to improve cardiovascular health in the general population.
A recent study (NEJM 2016; 375:2349) analyzed data for participants in 3 prospective cohort trials and one cross-sectional study to test the theory that life style modification despite high-risk genes can cut down rates of a heart attack.
The relative risk of coronary events was 91% higher in the people with high genetic risk than among those in low genetic risk. But a good life style (defined as at least 3 of 4 healthy life style factors – no current smoking, no obesity, regular physical activity and a healthy diet) was associated with a significantly lower risk of coronary events than an unfavorable life style (defined as no or only 1 healthy life style factor) regardless of genetic risk category.
Among participants at high genetic risk a favorable life style was associated with 46% lower r5ealtive risk of coronary events than an unfavorable lifestyle.
The researchers concluded that 4 studies involving more than 55,000 people genetic and lifestyle factors were independently associated with susceptibility to coronary artery disease. A healthy lifestyle was associated with greater absolute risk reduction in participants with high genetic risk. Life style modification can considerably reduce cardiovascular events despite bad genes.
More than 80 lakh people die of heart attacks globally. Bad genes can double the risk of a heart attack but reassuringly a good life style cuts the risk in half. The reverse is true too. A bad life style can washes away by half the advantages of good genes. Common sense mandates that one can to large extent control the chain of future cardiac events by moderate exercise and eating lots of fruits, vegetables, whole grain and nuts.
The first study analyzing (included in the NEJM paper) white and black American adults (45 to 64 years) found that a favorable lifestyle reduced the 10-year risk of coronary events from 11% to 5%. The 10-year risk dropped from 5% to 2 % in American health professional women, 45 years and older. while it fell 8% to 5% in middle aged people in Sweden. There was significantly less calcium observed in coronary arteries of middle aged Americans with genetic risk but adopting a healthy lifestyle.
The take home message is that if nature has dealt you a bad hand of high risk genes, you can successfully fight back by avoiding obesity, eating healthy food, not smoking, taking a brisk walk for 20-30 minutes,4-5 times a week. Actually,the researchers who published the NEJM study found that exercising merely once a week provided the beneficial effects.
The risk of a coronary event is halved by simply embracing a healthy lifestyle; the absolute reduction of 5% in the high genetic risk group suggests that life style changes are as powerful if not better than statins and other drugs costing lakhs and lakhs of rupees. The relative reduction in coronary events are the similar in people with high and low risk genes for heart attack. Crucially life style changes also reduce hypertension, development of diabetes and cancer. And all this at little or no cost plus without suffering the adverse effects of medicines.