Physically fit individuals are at lower risk of developing Alzheimer’s disease compared to those who have lower fitness levels, according to preliminary findings from a study.

In this study, Zamrini et al at the George Washington University in Washington DC evaluated the link between cardiorespiratory fitness and new onset Alzheimers Disease and Related Disorders (ADRD) in nearly 650,000 military veterans in the Veterans Health Administration database. Their age ranged from 30-95 years of age (average 61 years) and most of them were male with women comprising 5.7% of the study population. None of the participants had Alzheimer’s disease or symptoms of dementia at the time of their enrolment in the study.

Based on their cardiorespiratory fitness levels on baseline exercise treadmill test, they were categorized into five groups: “lowest-fit (n=132,63; METs=3.8 ±), low-fit (n=129,493; METs=5.8 ±), moderate-fit (n=120,988; METs=7.5±,), fit (n=137,122; METs 9.2±) and highest-fit (n=129,368, METs=11.7±)”.

During the follow up period of nearly nine years (average), 44,105 participants were diagnosed with dementia.

The risk of developing incident Alzheimer’s disease declined by 33% among veterans in the highest fit group vis-à-vis the lowest fit group. The risk declined by 26% in the fit group and by 20% in the moderate-fit group. The low-fit group was 13% less likely to develop Alzheimer’s compared to the least-fit group.

The incident rates for the lowest-fit group was 9.5 cases per 1,000 person-years versus 6.4 cases per 1,000 person-years for the highest-fit group. The rate was 8.5 among the low fit group, 7.4 in the moderate-fit group and 7.2 in the fit group.

The adjusted hazard rates were 0.87,0.80,0.74 and 0.67 for the low-fit, moderate-fit, fit and the highest-fit groups compared to the lowest fit groups.

This study has demonstrated an inverse association between the risk of Alzheimer’s disease and related disorders and fitness levels. The incident rate declined as the fitness levels increased. According to a release from the American Academy of Neurology, Edward Zamrini said, “The idea that you can reduce your risk for Alzheimer’s disease by simply increasing your activity is very promising, especially since there are no adequate treatments to prevent or stop the progression of the disease.”

Physical activity has several health benefits. This study has demonstrated the beneficial effects of regular exercise on brain health in warding off dementia. Brisk walking is the best form of exercise, which requires no special equipment or training. Walking improves fitness.

Reference

1. Zamrini E, et al. Cardiorespiratory fitness is protective against Alzheimers and related disorders. https://www.aan.com/PressRoom/Home/PressRelease/4960