A huge new study shows that aerobic exercise significantly reduces dementia risk.
**Study finds fitness may reduce dementia risk by 33%**
**by Mary McGorray, M.D., Medical News Today, March 11, 2022**
**Leveraging the vast breadth of people receiving care in the Veterans Health Administration (VHA), first author Dr. Edward Zamrini and his colleagues studied 649,605 military veterans ages 30–95 years. ...The scientists analyzed these individuals’ charts for the diagnosis of Alzheimer’s disease and related disorders (ADRD) over an average of 8.8 years....The scientists found that less fit individuals were at the highest risk of experiencing ADRD. Conversely, highly fit people were the least likely to develop ADRD....**
**Specifically, the researchers found that, compared with the least fit participants, the fittest were 33% less likely to develop ADRD. Similarly, the second most fit group was 26% less likely to develop ADRD, the third most fit group was 20% less likely, and the fourth most fit was 13% less likely....** [end quote]
Because of the huge data set, these findings are highly significant. I’m a little surprised that they included the young cohort who wouldn’t be expected to get ADRD in only 8.8 years. If I had designed the study I would have looked at people age 50 and above, maybe age 55.
The data set was skewed by the fact that they were all veterans so they must have been physically fit at some point, even if it was decades before. Today, seventy-one percent of young people are ineligible to join the military, according to 2017 Pentagon data. The reasons: obesity, no high school diploma or a criminal record. All of these factors are correlated with worse health. (Not to mention being terrible for national security.)
The study used Metabolic equivalents of task (METs) to track fitness. METs express the energy cost of physical activities as a multiple of the resting metabolic rate. For comparison, 1 MET is equivalent to sitting quietly, yoga requires 3.2 METs, a brisk walk at 3 or 4 miles per hour has a value of 4 METs and backpacking at 3.63 miles per hour would demand 11.6 METs <whew!>. I did yoga for a long time, which increases flexibility and some muscle strength, but I lost aerobic fitness and had to build back gradually. Now I do Zumba for an hour, 6 days a week, which keeps my heart rate at 110-135 beats per minute.
The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic exercise each week for optimal cardiovascular health. That’s equal to about 500 MET minutes per week, according to the Department of Health and Human Services.
The research shows that older Latinos are about 1.5 times as likely as older white people to develop Alzheimer’s disease and African Americans are twice as likely. Women are more likely to develop ADRD than men and also live longer (on average) than men.
According to the CDC, only 23.2% of adults aged 18 and over met the Physical Activity Guidelines for both aerobic and muscle-strengthening activity.
The Macroeconomic impact on the growing cost of taking care of people with ADRD is immense.