Healthy habits may offset risk of brain disease linked to biological ageing, study suggests

People with shorter telomeres — a sign of accelerated biological ageing — are more likely to develop stroke, dementia or late-life depression, but that risk appears to disappear in those who maintain a healthy lifestyle.

A large-scale study has found that individuals with short telomeres who follow good health habits, such as eating well and keeping their cholesterol and blood pressure in check, showed no increased risk of developing major age-related brain conditions.

Study author Dr Christopher D. Anderson, is a fellow of the American Academy of Neurology.

He said: “Our findings support the potential benefits of working to improve your risk factors such as maintaining a healthy weight, limiting alcohol and getting enough sleep and exercise in reducing the risk of age-related brain disease even in people who are already showing signs of damaging biological ageing.”

Researchers from Harvard Medical School analysed health records from 356,173 people in the UK, with an average age of 56.

The team focused on telomeres — protective caps on the ends of chromosomes that shorten with each cell division, serving as biomarkers of cumulative biological stress.

The study measured telomere length in white blood cells, or leukocytes.

Participants were divided into three groups — short, medium or long telomeres — and assessed using a modified Brain Care Score, which evaluates lifestyle factors associated with the risk of stroke, dementia and late-life depression.

The 19-point scale classified scores of 15 or more as good brain care, and 10 or less as poor brain care.

Over an average of seven years of follow-up, 25,964 participants developed at least one of the three brain diseases.

Among those with the shortest telomeres, the rate was 5.82 cases per 1,000 person-years, compared to 3.92 cases per 1,000 in those with the longest telomeres.

(Person-years account for both the number of participants and the length of time each was followed.)

After adjusting for other factors such as age, high blood pressure and smoking, researchers found that those with short telomeres were 11 per cent more likely to develop one or more of the brain diseases than those with longer telomeres.

However, that increased risk did not apply to people with short telomeres who had high Brain Care Scores. In this group, the likelihood of developing brain disease was no greater than in those with long telomeres.

Anderson said: “These results suggest that healthy lifestyle behaviours could delay the ageing of our cells and reduce the frequency of these diseases, especially in people who are at greater risk.”

The study was observational, meaning it does not prove that shorter telomeres cause these brain conditions — only that there is an association.

A limitation of the study is that it only included people of European ancestry, so the findings may not apply to other populations.