" Do stronger muscles lead to a stronger brain"

Gradually increasing muscle strength through activities such as weightlifting improves cognitive function as per a study led by the University of Sydney in Australia. The study was conducted in collaboration with the Centre for Healthy Brain Ageing (CHeBA) at the University of New South Wales and the University of Ade aide.  The results have been published in the Journal of American Geriatrics.

The trial involved a Study of Mental and Resistance Training (SMART) carried out on patients with mild cognitive impairment (MCI) between 55-68 years old. Patients with MCI have a higher risk of developing dementia and Alzheimer's disease.

Occurance of Dimentia and Alzheimer’s Disease
The findings are particularly significant given the high incidence of dementia and Alzheimer's disease among the ageing population. 47 million people worldwide have dementia and this number is expected to triple by 2050 according to the 2016 World Alzheimer Report. In the United States, the figure predicted for people with Alzheimer's disease in 2050 is 13.8 million.

The World Alzheimer Report recommends moving beyond specialist care due to the high cost of care for patients with dementia. The report suggests a holistic approach that focuses on improving the quality of life for people living with the condition.

It might be a step in the right direction in this context, to have a link between physical training and improving brain function for example, how a disciplined weightlifting schedule can improve cognition.The trial looked at progressive resistance training – such as weightlifting – and the functioning of the brain.

Research with old patients
The study examined 100 older adults living with MCI. Older patients not significant enough to interfere with their daily activities who have cognitive difficulties that are noticeable. "Mild cognitive impairment" refers to Eighty percent of patients diagnosed with MCI develop Alzheimer's disease after approximately 6 years.

For the trial, MCI patients were divided into four groups and assigned a range of activities. Weightlifting – and placebo resistance in the form of seated stretching included a combination of resistance exercise. Activities also included computerized cognitive training and its placebo equivalent.

Such activities did not yield cognitive improvements including cognitive training and placebo activities. A proportional relation between improvement in brain function and improvement in muscle strength, however, the study did demonstrate. "What we found in this follow-up study is that the improvement in cognition function was related to their muscle strength gains. The greater the benefit for their brain is the stronger people became, 

Lead author Dr Yorgi Mavros
Previous studies have shown a positive link between physical exercise and cognitive function, but the SMART trial led by Dr.Mavros provides the type, quality, and frequency of exercise needed to get the full cognitive benefits. It provides further information. In the trial, participants did weightlifting sessions twice a week for 6 months, working to at least 80 percent of their peak strength. 

Maintaining their peak strength at 80 per cent, the weights were gradually increased as participants got stronger, all the while. The more we can get people doing resistance training like weightlifting, the more likely we are to have a healthier ageing population," says Dr Mavros. 

This is also the first time a study has shown a clear causal link between increasing muscle strength and improving brain function in patients over 55 years old who have MCI.

Exercise and cognitive function
The onset of Alzheimer's disease and lowers the risk of cognitive impairment it has been suggested that exercise indirectly helps prevent these. Exercise helps with physiological processes such as glucoregulation and cardiovascular health. When these are sub-optimal, they increase the risk of cognitive impairment and Alzheimer's disease.

Exercise also improves other cognitive processes, such as selective attention, planning, organizing, and multitasking. Some studies have also suggested a connection between an increase in the size of certain brain areas and exercise training.

Cognitive impairment with age, the hippocampus is known to reduce in size. However, aerobic exercise has shown an increase in the size of the anterior hippocampus by 2 percent, which can improve spatial memory.

Dr Mavros and a team of researchers released a similar test earlier this year where they noticed cognitive improvement after weightlifting. 

Authors of this study pointed out that it remains unclear whether physical training in itself stops the degenerative effects of old age, or whether they boost some other mechanisms that support cognition

The mechanism behind muscle strength is still not entirely evident, although muscle strength seems to be clearly connected with cognitive impairment. In the future, Mavros and team hope to uncover it by connecting the increases in brain size to muscle strength and cognitive improvement.