Researchers from Massachusetts General Hospital have found that higher levels of daily physical activity may protect against cognitive decline and brain tissue loss in adults who are believed to be at greater risk for Alzheimer’s disease. The best results were found among the research participants who took more than 8,900 steps per day.
Traci Pedersen, writing in PsychCentral:
“One of the most striking findings from our study was that greater physical activity not only appeared to have positive effects on slowing cognitive decline, but also on slowing the rate of brain tissue loss over time in normal people who had high levels of amyloid plaque in the brain,” said Jasmeer Chhatwal, M.D., Ph.D. of the MGH Department of Neurology, and corresponding author of the study.
The results suggest that physical activity might reduce b-amyloid (Ab)-related cortical thinning and preserve gray matter structure in regions of the brain that have been associated with episodic memory loss and Alzheimer’s-related neurodegeneration.
The underlying processes of Alzheimer’s disease can begin decades before clinical symptoms appear and is characterized by early accumulation of b-amyloid protein.
The new study is among the first to demonstrate the protective effects of physical activity and vascular risk management in the preclinical stage of Alzheimer’s disease, while there is an opportunity to intervene prior to the onset of substantial neuronal loss and clinical impairment.
“Because there are currently no disease-modifying therapies for Alzheimer’s disease, there is a critical need to identify potential risk-altering factors that might delay progression of the disease,” Chhatwal said.
The new research published in the journal JAMA Neurology.
Aaron Reuben, writing in Mother Jones:
Of all the new research, three studies in particular paint a stark picture of the extent to which the quality of our air can determine whether we will age with our minds intact. In one from 2018, researchers followed 130,000 older adults living in London for several years. Those exposed to higher levels of air pollutants, particularly nitrogen dioxide and fine particulate matter released by fossil fuel combustion, were significantly more likely to develop Alzheimer’s disease—the most common kind of dementia—than their otherwise demographically matched peers. In total, Londoners exposed to the highest levels of air pollution were about one and a half times more likely to develop Alzheimer’s across the study period than their neighbors exposed to the lowest levels—a replication of previous findings from Taiwan, where air pollution levels are much higher.
Another, a 2017 study published in the Lancet, followed all adults living in Ontario (roughly 6 and a half million people) for over a decade and found that those who lived closer to major high-traffic roads were significantly more likely to develop Alzheimer’s disease across the study period regardless of their health at baseline or socioeconomic status. Both of these studies estimated that around 6 to 7 percent of all dementia cases in their samples could be attributed to air pollution exposures.
Those studies from Canada and the UK are certainly intriguing. But the most compelling, and least reported on, study comes from the United States. It was also, incidentally, inspired by our previous reporting.
There is no magic shield against Alzheimer’s disease and other dementias. Supplements don’t work. Yet there is evidence that some strategies may help.
Paula Span at the New York Times writes:
- Increased physical activity;
- Blood pressure management for people with hypertension, particularly in midlife;
- And cognitive training.
That last recommendation doesn’t necessarily refer to commercial online brain games, said Dr. Kristine Yaffe, a neuropsychiatrist and epidemiologist at the University of California, San Francisco, who served on the panel.
“It’s really the concept of being mentally active,” she said. “Find something you enjoy where you’re learning something new, challenging and stimulating your brain.”
Though the evidence to date doesn’t establish which mental workouts have the greatest impact or how often people should engage in them, “they’re not expensive and they don’t cause side effects,” Dr. Yaffe pointed out.
The blood pressure recommendation got a boost in January with the latest findings from the Sprint trial, a multisite study stopped early in 2015 when intensive treatment of hypertension (a systolic blood pressure goal of less than 120, compared to the standard 140) was shown to reduce cardiovascular events and deaths.
A study was conducted to evaluate the relationship between apathy, depression, and pharmacological treatment of depression in 11,780 patients, 45 years-old and up.
Dr Wyman concluded, “Apathy at baseline was related to increased risk of conversion accounting for depression severity and treatment, confirming the potential clinical importance of this neuropsychiatric symptom for assessing risk.”
In a seperate study published in the JAMA Psychiatry journal, researchers found apathy to be associated with an increased risk for incident dementia in patients with mild cognitive impairment (MCI).
These findings have high clinical relevance because patients with apathy are likely to withdraw from care. The risk for dementia among patients with apathy appears to be independent of concurrent depression, greater in the short term, and less strong with higher age and greater cognitive impairment. Apathy may be a powerful marker of increased risk for incident dementia.
This study was different from most, in that it looked at the participants’ maximum oxygen consumption during aerobic exercise — known as the V02 max.
Yet again another study indicates exercise, this time aerobic exercise, is important in slowing the brain’s aging process.
David DiSalvo, Forbes:
What these results tell us about the role exercise might play in slowing the development of Alzheimer’s is difficult to nail down. While studies like this suggest that exercising more strengthens the brain against the debilitation leading to severe dementia, definitive answers are still elusive. We don’t know, for example, the amount of exercise that makes a difference, if specific types of exercise are better than others, or whether starting exercise later in life can forestall the progression of dementia.
What we do have are solid indications that we should think of exercise and brain health in a similar way to exercise and heart health. Some of the same benefits exercise provides the heart—like improved blood flow and lower inflammation—also benefit the brain. More evidence along those lines keeps coming, further supporting the case that staying active is a better policy for brain health than the alternative.