Can Nurture Trump Nature On Genetic Risks?

Genetic factors contribute to an increased susceptibility to major diseases. But lifestyle factors exercise a powerful influence on the extent to which that risk is expressed

- K SRINATH REDDY

THERE is considerable variation in life expectancy across different countries and even between different population groups and individuals within the same country. Socioeconomic factors related to the level of development explain much of the inter-country variation. However, even after adjusting for income levels, considerable variation remains between countries and among individuals in the same country. What explains this? Genetic predisposition to major diseases, contributing to early death in adult life, has often been incriminated as a key determinant of shortened life expectancy. Cardiovascular diseases, cancer and diabetes are among the common ones that reduce adult life expectancy. How much do our acquired living habits (frequently referred to as 'lifestyle') determine the risk of dying from such diseases, as compared to inherited genetic factors? The answer to this question will influence our efforts to reduce the risk of serious diseases that cut short life. Genetic predisposition is mostly non-modifiable, while living habits are amenable to change through a combination of personal effort and enabling public policies.