Could exercise be a potent weapon against neurodegenerative conditions?
ISLAMABAD: There is increasing evidence that regular physical activity may help preserve our cognitive function in old age. Studies are showing that not only can exercise reduce the risk of neurodegenerative diseases, such as dementia and Parkinson’s, but it might also slow the progress of these diseases after diagnosis. But how does it work? Medical News Today asked experts why and how exercise might help keep the brain young.
Share on PinterestHow might exercise help protect against dementia, Parkinson’s disease, and similar conditions? Image credit: Take A Pix Media/Stocksy.
On average, we are living longer, but we may not be living healthier. According to European Union figures, women can expect, on average, 64.5 healthy life years (HLYs), and men, 63.5.
But life expectancy in the EU is just over 83 years for women and 77.5 for men. So, on average, a person can expect to spend around 15-20 years with some sort of health problem.
And most of those years of ill health are likely to be the later years of life, and many people will develop a neurodegenerative diseaseTrusted Source.
Estimates indicate that 14–18%Trusted Source of people over the age of 70 years in the United States have some form of cognitive impairment. And some 10% of people in the same age group in the U.S. have dementia, a number that rises to 33% of those over 90.
But there are ways to help extend your HLYs, and evidence is increasingly suggesting that regular physical activity may be one of the most effective ways to help your body and brain stay healthy for longer.
Exercise for mental and physical health
Exercise makes us feel better — higher levels are associated with lower levels of depression, and it is thought this is due to a natural “high” from the release of endorphins and endocannabinoids, which can last for some time after exercising — but the physical effects last longer.
According to the Centers for Disease Control and PreventionTrusted Source (CDC), regular physical activity is “one of the most important things you can do for your health.”
Medical experts everywhere agree with that statement. Speaking to Medical News Today, Dr. Emer MacSweeney, CEO and consultant neuroradiologist at Re:Cognition Health, emphasized:
“Being physically active is one of the best things you can do for your body. Exercise helps protect against many diseases and keeps the heart, muscles, bones, and brain in optimum condition. Exercise promotes [the] oxygenation of the brain and stimulation of multiple neurochemicals.”
Exercise can reduce the risk of, among other conditions, cardiovascular diseaseTrusted Source, several types of cancerTrusted Source, and type 2 diabetesTrusted Source.
And, together with a healthy diet, it is a key part of maintaining a healthy body weight — another way to lower the risk of disease.
ResearchTrusted Source has shown that endorphins can relieve pain, and may reduce both inflammation and stress responses. Additionally, exercise can increase the beneficial effects of medications and other therapies for mental health conditions, such as depression.
“Exercise is particularly beneficial for mental health due to the chemical changes which occur in the brain and body, including the release of ‘feel-good’ chemicals, endorphins and serotonin,” Dr. MacSweeney explained.
Alzheimer’s disease is the most common form of dementia, affecting more than 5 million adults in the U.S. alone, and more than 55 millionTrusted Source worldwide. Around 1 million people in the U.S. have Parkinson’s disease, with a further 90,000 cases diagnosed each year.
As populations age, the numbers of people with both diseases are predicted to rise. The World Health Organization (WHO) states that by 2050 there will be almost 140 million peopleTrusted Source with Alzheimer’s worldwide.
And the number of people with Parkinson’s could rise to 17 million by 2040Trusted Source.
Both Alzheimer’s disease and Parkinson’s disease are progressive diseases that are, ultimately, fatal. Symptoms of Alzheimer’s disease include memory loss, confusion, cognitive changes, and personality or behavior changes.
Parkinson’s is characterized by tremors, impaired coordination, depression, and other changes in cognitive function.
Currently, both Alzheimer’s disease and Parkinson’s disease are currently incurable, but treatments can help to alleviate symptoms and slow their progress, improving the quality of life of people with the diseases.
Increasingly, research is showing that exercise may also be useful in both delaying onset and slowing the progression of these, and other neurodegenerative diseases. In addition, exercise may be effective as an add-on therapyTrusted Source alongside current medications.
Dr. Jamie Adams, associate professor in the Department Neurology and the Center for Health and Technology at the University of Rochester Medical Center, NY, told MNT:
“Unfortunately, we do not have any disease-modifying therapies or treatments to prevent or slow the progression of Alzheimer’s disease or Parkinson’s disease. However, there is growing evidence that shows that regular exercise can help slow [the] progression of [the] disease. Regular exercise also has therapeutic and other health benefits.”
“My patients that exercise, feel better and do better,” she added.
Exercise and the brain
“There are numerous studies assessing the link between exercise and reducing the risk of Alzheimer’s and other causes of dementia and it is imperative that this research continues. With every study, we learn more about the disease, which can lead to the development of new treatments,” said Dr. MacSweeney.
But why might exercise help prevent or slow these neurodegenerative diseases? There are several theories.
Inflammation, caused by the overactivity of immune cells — called microglia — in the brain, is a key featureTrusted Source of both Alzheimer’s disease and Parkinson’s disease.
This inflammation leads to the loss of nerve cells in the brain, with chronic overactivity of microgliaTrusted Source leading to a cumulative loss of neurons.
Exercise can reduce the activity of the microglia cells, which are the immune cells of the nervous system. A 2021 study in older people with Alzheimer’s showed that regular exercise protected cognitive functioning by limiting microglial activity.
Another possible mechanism may be that exercise changes how the brain metabolizes iron. Iron accumulation is associated with the development of beta-amyloid plaques, a characteristic of Alzheimer’s disease.
A study from Finland found that, in mice, regular exercise reduced iron storage in the brain by decreasing levels of a protein called interleukin-6Trusted Source, which is also linked to inflammation. The mice with lower iron levels also had fewer beta-amyloid plaques.
In Parkinson’s disease, exercise demonstrably reduces the alpha-synuclein clumps that are associated with neurodegeneration.
A study found that irisin, a molecule secreted into the blood during endurance exercise, reduced these clumps, but had no effect on alpha-synuclein monomers that are important for transmitting nerve impulsesTrusted Source.
Physical activity has also been shown to increase levels of two other important chemicals, as Dr. MacSweeney explained :
“Exercise stimulates the production of chemicals such as BDNF (brain-derived neurotrophic factor) and IGF (insulin growth factor) These help to stimulate new cell growth in certain areas of the brain and strengthen connections.”
Studies have shown that BDNFTrusted Source, administered externally, or produced via increased physical activity, may be useful as part of a therapeutic regime for Parkinson’s disease.
And the therapeutic use of IGF has been proposed for many disorders of the nervous system, including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis (ALS, or motor neuron disease), and multiple sclerosis (MS).
“Exercise is thought to encourage brain cell growth and survival, which may help reduce the risk of developing dementia. Studies have also shown that exercise increases the size of the brain structure linked to memory and learning.”