It’s often emphasized that a healthier lifestyle can lead to a longer life, but a recent study of participants from the UK Biobank showed that healthy lifestyle behaviors may help reduce the risk for age-related brain diseases.
Results of new research show participants with shorter leukocyte telomere length (LTL) were more likely to develop age-related brain diseases, including dementia, stroke, and late-life depression, than those who had longer LTL.
However, engaging in healthy lifestyle behaviors appeared to offset these risk factors. Although the study does not establish causality, the findings suggest that the association between shorter LTL and age-related brain diseases may be modifiable.
“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 aging,” senior author Christopher D. Anderson, MD, MMSc, of Harvard Medical School in Boston, said in a press release.
The results were published on June 11 in the journal Neurology.
Unhealthy Lifestyle and Age-Related Brain Diseases
Telomeres are often described as protective caps on the end of chromosomes, and shortened telomeres have been associated with age, race, sex, adverse environmental exposures, and genetic factors, as well as lifestyle factors such as physical activity, diet, alcohol, nutrition, sleep, stress, aerobic activity social interactions, and smoking using the Brain Care Score (BCS). A BCS of 15 or higher was associated with healthier lifestyle choices, while a BCS of 10 or lower signified less healthy lifestyle choices.
What has been less clear up to this point is the degree to which LTL affects age-related brain diseases, and whether changing an individual’s lifestyle habits could influence LTL, as opposed to LTL being a predictor of the risk for age-related brain disease.
Researchers evaluated 356,173 participants from the UK Biobank with a median age of 56 years. Recruitment of participants occurred between 2006 and 2010, and there were four follow-up assessments in 2012-2013, 2014, 2019, and 2023. Participants were included if they had data on biomarkers such as LTL and DNA, as well as clinical data to identify potential risk factors for age-related brain disease using the BCS.
The primary outcome was the association between LTL and the risks for stroke, dementia, and late-life depression, both as a composite outcome and as individual outcomes.
LTL was categorized into three tertiles, ranging from shortest to longest, and risk factors were compared across these groups using the BCS. A BCS of 15 or higher indicated healthier lifestyle choices — such as a nutritious diet, a low cholesterol level, and controlled blood pressure — while a BCS of 10 or lower reflected less healthy behaviors.
The results showed the shortest LTL tertile was associated with an increased risk for the age-related brain disease composite outcome (hazard ratio [HR], 1.11; 95% CI, 1.08-1.15), as well as increased risks for dementia (HR, 1.19; 95% CI, 1.12-1.26), late-life depression (HR, 1.14; 95% CI, 1.09-1.18), and stroke (HR, 1.08; 95% CI, 1.02-1.15).
When comparing participants with shorter LTL, those with a lower BCS were at a higher risk for the age-related brain disease composite outcome (HR, 1.11; 95% CI, 1.07-1.16), as well as for dementia (HR, 1.17; 95% CI, 1.08-1.28), late-life depression (HR, 1.13; 95% CI, 1.07-1.19), and stroke alone (HR, 1.10; 95% CI, 1.02-1.19).
Among participants with shorter LTL but a higher BCS, there were no significant increases in the risk for age-related brain disease as a composite or individual outcomes.
Reversing Risk
Limitations of the study included the evaluation of participants with only European ancestry, and measurement of LTL was conducted at baseline rather than over time. Future studies should include assessing the relationship between shortened LTL and age-related brain diseases in more diverse populations, as well as measuring LTL over time, the researchers said.
However, the findings suggest “healthy lifestyle behaviors could delay the aging of our cells and reduce the frequency of these diseases, especially in people who are greater risk,” said Anderson.
“Reducing risk factors like weight and alcohol consumption, as well as getting more sleep and exercise, can all help reverse the risk of age-related brain diseases, even for people who are already showing signs of biological aging,” lead author Tamara Kimball, MD, of the Center for Neurotechnology and Neurorecovery at Massachusetts General Hospital, Boston, said in the press release. “In short, it is never too late to start taking better care of your brain.”
This study was supported by the National Institutes of Health, American Heart Association, and the Massachusetts General Hospital McCance Center for Brain Health. The authors reported having no relevant financial relationships.