How active you will be in your seventies depends partly on your genetic make-up, a team of US researchers reports. Scientists at the Wake Forest University School of Medicine in North Carolina investigated the link between the ACE (angiotensin-converting enzyme) gene and mobility in older people. Their findings, published in the Journal of the American Medical Association, show that individuals with a 'short' version of the gene are more likely to remain mobile, and to benefit most from exercise.
The ACE gene makes a protein called angiotensin-converting enzyme, which is important in heart strength and regulating blood pressure. Previous research revealed that the ACE gene comes in two versions: long (the 'I' form) and short (the 'D' form). The muscles of people who inherit two long copies of the ACE gene become more efficient after training, whereas the muscles of those with two short ACE genes hardly change. Athletes with two short forms of the gene tend to excel in sports that rely on short bursts of energy and power - such as sprinting, whereas those with two long forms are better at sports that require endurance.
The Wake Forest University team wanted to find out which form of the ACE gene, if any, was linked to fitness in the over seventies. 'We really didn't know whether the 'D' or the 'I' form would be most important in elderly people', said team leader Stephen Kritchevsky.
The scientists carried out a four-year study of 3,075 healthy people aged between 70 and 79. They found that those with two 'D' genes, the shorter version of the ACE gene, were most likely to remain mobile as they got older - possibly because they had extra strength that protected them from injury, say the team. However, the scientists stressed that genes were not the whole story: participants with two 'I' genes who exercised regularly were still less likely to have mobility problems than those who did not exercise. The team say that further studies are needed to understand the physiological basis of the findings.