“The most important factors for a long life, I think, are partly in the genes; number two is lifestyle, which includes healthy diet and regular exercise. However, I think too much exercise is also unhealthy because of over-stress; sometimes people who exercise too many hours per day die early.” — John Gokongwei
Human genome has millions of times more germ genes compared to the small 23,000 human genes. Unlike what illiterate doctors (illiterate, today, is one who is incapable of unlearning the wrong things one has learnt, to re-learn new facts) and greedy biotechnology industry, which wants to amass wealth by selling genetic counselling, cord blood freezing, stem-cell therapy and what have you, tell—genes are the be-all and end-all of our inheritance. Doctors keep generating fear in the minds of healthy young people that, if their parents had suffered fatal diseases, they are likely to develop those diseases. Such disease-mongering is good for business but could ruin young lives and the mortal fear can, by itself, bring on such diseases.
It is now well known, for more than 25 years, that human evolution is not genetic but environmental; while a few of the dominant human genes (among the 23,000) might help transmit certain genetically inherited disorders, they are incapable of contributing to chronic lifestyle diseases like heart disease, diabetes and cancer. Evolutionary biologists have been shouting from housetops about the ascendency of environment, above genes, in evolution and disease inheritance. Unfortunately, most of our cross-sectional short-term small cohort studies generate false positive data mostly to appease the grant givers’ needs and they give us the false impression about disease inheritance.
The New England Journal of Medicine (12 November 2016) has published a milestone paper on this subject which looked at a very large set of human beings (more than 55,000 people) studied for genetic mapping and lifestyle. It was also significant in that all the 50-odd genes connected with heart attack have been studied in detail as were lifestyle factors, ranging from really horrible ones, to simple smoking, drinking and obesity. The study clearly brought out the importance of healthy lifestyle in preventing a heart attack even in those with a very bad genetic history and gene patterns. This was the first study that looked at genes and lifestyle in the same cohort—a brainchild of the leader of the research team, Dr Sekar Katiresan, the director of genetic research at The Mass General Hospital in Boston. This young man found that there were no studies in the past that looked simultaneously, in the same cohort; they looked at them individually. That did the trick for this study. Here are the take-home messages for lay readers:
1. The boss in inheritance is environment and not genes.
2. One does not need to be worried, even if one is dealt a bad hand in genetic play.
3. Even those with strong genetic background could avoid heart attacks, if they switch to a healthy lifestyle.
4. One does not have to undergo hardships in trying to change lifestyle. For those with extreme obesity, it is not easy to lose weight. If they just add regular exercise, hard work, avoided alcohol and tobacco, they could alter their genetic risks.
5. Even minor changes in lifestyle could bring significant benefits.
There was near unanimity among all sections of researchers in this area on the wonderful results of this study which used the best statistical methods. An on-going study of one million such people is in the pipeline. The leading researcher of that study feels that his outcomes might just reinforce the results of this study as he was very impressed by the rigours of this study. The results, he said, should quell the cries of those who emphasise that genes are above all as well as those who emphasise that elements of lifestyle are above all. “It’s not nature or nurture; it’s both,” says the study.
We can now safely say that heredity is not to be feared like in the past. Most diseases depend on the lifestyle (environment); to be healthy, one can follow a healthy lifestyle which is not difficult and is very inexpensive. An appeal through this article to practising doctors is that they should not scare patients about their bad heredity; it can now be mended by changing one’s lifestyle.