Study claims weight training can help reduce dementia risk

By Stephen Beech

Weight training helps protect older people from dementia, according to new research.

Volunteers with mild cognitive impairment who practiced strength training showed improvements in memory and brain anatomy after six months, say scientists.

Weight training has been previously shown to improve strength and muscle mass, reduce body fat, and contribute to well-being and mental health.

Now, a new study conducted at the State University of Campinas (UNICAMP) in Brazil suggests it protects the brains of older people against dementia.

The study involved 44 people with mild cognitive impairment – a clinical condition between normal aging and Alzheimer’s disease in which cognitive decline is greater than expected for age, indicating a higher risk of dementia.

The results, published in the journal GeroScience, showed that strength training not only improved memory performance but also altered brain anatomy.

After six months of twice-weekly weight training, the participants showed protection against atrophy in the hippocampus and precuneus – brain areas associated with Alzheimer’s – as well as improvements in parameters that reflect the health of neurons.

Study first author Dr. Isadora Ribeiro, of UNICAMP’s School of Medical Sciences (FCM), said: “We already knew that there would be physical improvement.

"Cognitive improvement was also imagined, but we wanted to see the effect of weight training on the brains of older people with mild cognitive impairment.

"The study showed that, fortunately, weight training is a strong ally against dementia, even for people who are already at high risk of developing it,”

The research is the first to demonstrate what happens to the integrity of the white matter of people with mild cognitive impairment after weight training.

Study supervisor Dr. Marcio Balthazar said: “As well as neuropsychological tests, we also performed MRI scans at the beginning and end of the study.

"These results are very important because they indicate the need to include more physical educators in the public health system at the primary health care level since increased muscle strength is associated with a reduced risk of dementia.

"It’s a less complex and cheaper treatment that can protect people from serious diseases.

“For example, the new anti-amyloid drugs approved in the United States indicated for the treatment of dementia and for people with mild cognitive impairment, cost around US $30,000 a year. That’s a very high cost.

"These non-pharmacological measures, as we’ve shown is the case with weight training, are effective, not only in preventing dementia but also in improving mild cognitive impairment."

The study participants were divided into two groups: half underwent a resistance exercise program with weight training sessions twice a week, at moderate to high intensity and with progressive loads; the other half didn't exercise during the study period.

In the analyses carried out at the end of the six-month study period, the volunteers who practiced weight training had better performance in verbal episodic memory, improved integrity of neurons and areas related to Alzheimer’s disease protected from atrophy, while the control group showed a worsening of brain parameters.

Dr. Ribeiro said: “A characteristic of people with mild cognitive impairment is that they have volume loss in some brain regions associated with the development of Alzheimer’s.

"But in the group that did strength training, the right side of the hippocampus and precuneus were protected from atrophy.

"This result justifies the importance of regular weight training, especially for older people.”

The research team believe that a longer period of training could lead to even more positive results than those reported in the study.

Dr. Ribeiro said: “All the individuals in the bodybuilding group showed improvements in memory and brain anatomy.

"However, five of them reached the end of the study without a clinical diagnosis of mild cognitive impairment, such was their improvement.

"This leads us to imagine that longer training sessions, lasting three years, for example, could reverse this diagnosis or delay any kind of dementia progression.

"It’s certainly something to be hopeful about and something that needs to be studied in the future."

The researchers say weight training can protect the brain against dementia on two fronts: by stimulating the production of neural growth factor - an important protein for the growth, maintenance and survival of neurons - and by promoting disinflammation in the body.

Dr. Balthazar said: “Any physical exercise, whether weight training or aerobic activity, is known to increase levels of a chemical involved in brain cell growth.

"It can also mobilize anti-inflammatory T-cells. This is key.

"After all, the more pro-inflammatory protein that is released in the body, the greater the chance of developing dementia, accelerating the neurodegenerative process and forming dysfunctional proteins that eventually kill neurons."

To assess those issues, the volunteers’ levels of irisin and brain-derived neurotrophic factor (BDNF) – substances whose synthesis is stimulated by muscle contraction and which are associated with neural protection and synaptic plasticity – were measured.

The results are currently being analyzed.

Dr. Ribeiro added: “It’s a continuation of this study in which we’ll try to better understand how these factors are related to changes in brain anatomy.

"We believe that it’s a set of anti-inflammatory and neuroprotective factors that lead to these changes.”