Scientists Identify Type of Exercise To Reduce Risk of Dying of Alzheimer's

Regular exercise has been associated with a reduced risk of dying from Alzheimer's. But how much exercise constitutes as regular, and what sort of exercise should we be doing?

In a recent study, published in the journal Lancet Health Longevity, researchers analyzed more than 90,000 adults to investigate how moderate and vigorous physical activity can impact an individual's chances of dying from Alzheimer's.

Alzheimer's affects an estimated 5.8 million Americans, according to the Centers for Disease Control and Prevention, with Alzheimer's-associated deaths in the U.S. increasing by more than 145 percent in the past two decades. Scientists do not yet know exactly what causes the disease, although both genetic and environmental factors appear to play a part.

One particularly interesting association has been found between Alzheimer's incidence and physical activity. However, exactly how much exercise is required to see these effects has been unclear. Until now.

By pooling data from 22 consecutive waves of the U.S. National Health Interview Survey from 1997 to 2018, a team from the University of Zaragoza in Spain, the University of Calgary in Canada, the University of Cadiz in Spain and the University of Sydney in Australia, explored how participants' physical activity levels were linked to their risk of dying from Alzheimer's.

In their study, moderate physical activity counted as anything that induced light sweating or a moderate increase in breathing and/or heart rate for at least 10 minutes. Vigorous activity was classed as anything that caused heavy sweating or large increases in breathing and/or heart rate for at least 10 minutes.

While moderate physical activity was associated with a lower Alzheimer's-associated death risk, this link was statistically insignificant. However, vigorous physical activity did appear to significantly reduce death rates after as little as 20 minutes of activity per week.

However, after a certain amount of exercise, this risk reduction association became less significant, and in some cases actually increased disease-associated mortality. Therefore, the team concluded that the optimum amount of vigorous activity to perform every week to reduce your risk of Alzheimer's disease was 140 minutes. Exercising for this time was associated with a 31 percent reduction in Alzheimer's deaths.

From these results, the team calculated that just 40 minutes of vigorous physical activity every week would prevent 12,238 deaths every year in the U.S., while 140 minutes a week would prevent 37,710 deaths a year, compared to a scenario in which no U.S. adults participated in the same activity.