Healthy lifestyle findings could help professionals and policymakers plan future health care
Men and women who adopt a healthy lifestyle appear to have a longer life expectancy and to live a larger proportion of their remaining years without Alzheimer’s disease.
That is the conclusion of a paper written by a team based in the US and Switzerland and led by Klodian Dhana, from the department of internal medicine in the division of geriatrics and palliative medicine at Rush Medical College in Chicago. It was published in The BMJ today (13 April). Dr Dhona and colleagues analysed the potential impact of a healthy lifestyle on the number of years spent living with – and without – Alzheimer’s.
They analysed data gathered from 2,449 participants aged from 65 years upwards (average age 76). The participants did not have a history of dementia and came from the Chicago Health and Aging Project (CHAP).
The participants, who completed detailed diet and lifestyle questionnaires, were given a healthy lifestyle score. This was developed from the following factors:
- a hybrid Mediterranean-DASH Diet (a diet rich in whole grains, green leafy vegetables and berries and low in fast/fried food and red meats)
- cognitively stimulating activities in later life (such as reading, visiting museums or doing crosswords)
- at least 150 minutes a week of physical activity
- not smoking
- low to moderate alcohol consumption
For each lifestyle factor, participants received a score of 1 if they met the criteria for healthy, and 0 if they did not. Scores from five lifestyle factors were summed to yield a final score ranging 0 to 5. A higher score indicated a healthier lifestyle.
After taking account of other potentially influential factors, including age, sex, ethnicity and education, the researchers found that, on average, the total life expectancy at age 65 in women and men with a healthy lifestyle was 24.2 and 23.1 years, respectively. But for women and men with a less healthy lifestyle, life expectancy was shorter – 21.1 and 17.4 years respectively.
For women and men with a healthy lifestyle, 10.8 per cent (2.6 years) and 6.1 per cent (1.4 years) of the remaining years were lived with Alzheimer’s respectively, compared to 19.3 per cent (4.1 years) and 12 per cent (2.1 years) for study participants with a less healthy lifestyle. At age 85, these differences were even more notable.
This investigation suggests that a prolonged life expectancy owing to a healthy lifestyle is not accompanied by living [longer] with Alzheimer’s dementia ... [the findings] could help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs [Klodian Dhana et al.]
While the study was population-based with long-term follow-up, this was an observational study, and therefore cannot establish cause. Other limitations highlighted by Dr Dhona and colleagues include the following: lifestyles were self-reported (possibly leading to measurement error) and their estimates should not be generalised to other populations without additional research and validation.
Despite these caveats, the team concludes: ‘This investigation suggests that a prolonged life expectancy owing to a healthy lifestyle is not accompanied by an increased number of years living with Alzheimer’s dementia.’ The life expectancy estimates presented here ‘could help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs', the team adds.
Linked editorial: 'important implications'
In a linked editorial, HwaJung Choi research assistant professor from the University of Michigan refers to the study’s ‘important implications for the wellbeing of aging populations and for related public health policies and programmes’.
Dr Choi argues that the development and implementation of intervention programmes to reduce the risk of Alzheimer’s disease and other dementias is critically important in global efforts to reduce pressure on stressed healthcare systems, healthcare workers, and both paid and unpaid carers.
Promoting greater engagement in healthy lifestyles may increase dementia-free life years – by delaying the onset of dementia without extending life years spent with dementia, she concludes.
by 2050, the number of people living with Alzheimer’s and other dementias globally is expected to treble (from an estimated 57 million in 2019 to 152 million)
a healthy lifestyle – consisting of adequate exercise, cognitive engagement and a healthy diet – may reduce the risk of dementia and extend life expectancy
reaching older ages is associated with a higher risk of Alzheimer’s. While a healthier lifestyle may delay the onset of Alzheimer’s dementia, it may increase the years spent with the disease
The research paper is titled Healthy lifestyle and life expectancy with and without Alzheimer’s dementia: population based cohort study. Visit: https://www.bmj.com/content/377/bmj-2021-068390
To see Dr Choi’s editorial, visit: https://www.bmj.com/content/bmj/377/bmj.o885.full.pdf