Muscular strength, measured by handgrip, is an indication of how healthy our brains are, a study of nearly half a million people suggests.
Using UK Biobank data from 475,397 participants, the new study showed that on average, stronger people performed better across every test of brain functioning used.
Tests included reaction speed, logical problem solving, and multiple tests of memory. The study shows the relationships were consistently strong in both people aged under 55 and those aged over 55.
Previous studies have only shown this applies in elderly people.
Better Functioning Brains
Lead author Dr. Joseph Firth, an Honorary Research Fellow at The University of Manchester and Research Fellow at NICM Health Research Institute at Western Sydney University, said:
“When taking multiple factors into account such as age, gender, bodyweight and education, our study confirms that people who are stronger do indeed tend to have better functioning brains. We can see there is a clear connection between muscular strength and brain health. But really, what we need now, are more studies to test if we can actually make our brains healthier by doing things which make our muscles stronger – such as weight training.”
The study also showed that maximal handgrip was strongly correlated with both visual memory and reaction time in over 1000 people with psychotic disorders such as schizophrenia.
The relationship between grip strength and cognitive domains in (a) schizophrenia sample and (b) general population. Y-axis denotes the cognitive measure considered. Credit: Joseph Firth, et al. CC-BY
Previous research by the group has already found that aerobic exercise can improve brain health. However, the benefit of weight training on brain health has yet to be fully investigated.
“These sorts of novel interventions, such as weight training, could be particularly beneficial for people with mental health conditions. Our research has shown that the connections between muscular strength and brain functioning also exist in people experiencing schizophrenia, major depression and bipolar disorder – all of which can interfere with regular brain functioning.
This raises the strong possibility that weight training exercises could actually improve both the physical and mental functioning of people with these conditions,”
The study does have some limitation. There is a lack of information on factors specific to schizophrenia that may or may not have an effect upon the link between grip strength and cognition. For example, negative symptoms and extrapyramidal symptoms could potentially impair performance in grip strength and/or cognitive tasks for some patients with schizophrenia.
Also, because of the UK Biobank’s middle- to older-age range, associations between muscular and cognitive functioning in younger people with schizophrenia were not studied.
It is emerging as a useful clinical marker of mortality risk, as grip strength can be an even stronger predictor than either systolic blood pressure or obesity for both all-cause and cardiovascular mortality.
Support for the researchers came from a Blackmores Institute Fellowship and an MRC Doctoral Training Grant (J.F). J.S. is funded by an NHMRC Research Fellowship. B.S. is supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South London at King’s College Hospital NHS Foundation Trust. B.S. is also part funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. S.R. is funded by an NHMRC Early Career Fellowship.