It’s estimated that in the US, over 5.4 million people are living with Alzheimer’s disease and is the sixth leading cause of death among adults. Worldwide, there are around 50 million sufferers, and with 10 million new cases every year, it’s a disease that’s growing rapidly. There are many factors that are thought to influence the likelihood of an individual developing Alzheimer’s including smoking and cholesterol, and now, a new study has shown that there may also be a link with fitness levels.
The study found that the level of cardiovascular fitness could be associated with an increased risk of dementia. To assess the levels of fitness, researchers looked at 191 women in Sweden between 38 and 60 years old. They used an ergometer cycling test to evaluate over a 44 year period, and the women were categorised into “low fitness”, “medium fitness” and “high fitness.”
As a result, they found that in these women, those with high fitness had an 88% lower risk of developing dementia than those in the medium fitness group. In addition to this, the researchers found that having a high level of fitness increased the average age of dementia onset by eleven years. The researchers noted that “High compared to medium fitness decreased the risk of dementia by 88%,”
Helena Hörder, a professor in the Department of Psychiatry and Neurochemistry at the University of Gothenburg in Sweden and author of the study said: “I was not surprised that there was an association, but I was surprised that it was such a strong association between the group with highest fitness and decreased dementia risk. The level that you are so exhausted that you have to interrupt the test is a measure, in watts, of your work capacity.
She added: Cardiovascular fitness or endurance can also be tested in a submaximal test where you don’t push the person to maximal capacity. Many of those who interrupted the test at submax, very low watt level, probably had indications for a poor cardiovascular health status,” Hörder said. “This might indicate that processes in the cardiovascular system might be ongoing many decades before onset of dementia diagnosis.”
Keith Fargo, director of scientific programs and outreach for the Alzheimer’s Association in Chicago, who was not involved in the study noted that “the picture that is really emerging from the literature is a picture about the importance of fitness in midlife, not just old age, when it comes to protecting your brain health and preventing or delaying Alzheimer’s disease and other dementias.” This adds to the mounting evidence of the impact lifestyle has on the risk of dementia.
“There’s a very strong connection between cardiovascular health — so the health of your heart and your circulatory system — and the health of your brain,” Fargo said. He added: “The reason for that is because the brain actually is what we would call a highly vascularized organ, meaning that your brain has many blood vessels,” he said. “The demand for nutrient-, oxygen-rich blood in the brain is very high compared to other organs, and so anything a person can do to increase their cardiovascular fitness level is likely to have positive benefits on brain health.”