Doing aerobic exercise ‘can preserve brain function and health – and thereby reduce the risk of dementia’ according to a study of older individuals with slight but noticeable declines in memory and thinking, conducted by researchers from the University of Texas.

Their study ‘is the first to use an objective measure of aerobic capacity to assess the relationship between white matter integrity, cognitive performance, and cardiorespiratory fitness in older individuals with mild cognitive impairment (MCI)’ noted medicalnewstoday.com.

Lead author Professor Kan Ding commented: ‘This research (published in the Journal of Alzheimer’s Disease) supports the hypothesis that improving people’s fitness may improve their brain health and slow down the ageing process.’

People with MCI have ‘noticeable problems with memory and reasoning, but they are not serious enough to interfere with daily living
or the ability to take care of oneself’. Research suggests 15-20 per cent of people aged 65+ may have MCI.

The new study investigated people with amnestic MCI, which mostly affects memory (such as forgetting names, appointments, events, conversations or other information that would previously not have been difficult to recall).

The study involved 81 participants (43 female) aged 65 on average – 55 with amnestic MCI and 26 healthy individuals without MCI (the controls). The research team assessed participants’ cardiorespiratory fitness by measuring maximal oxygen uptake (VO2max) during an aerobic exercise test.

Participants also completed assessments of memory and reasoning and underwent diffusion tensor imaging (DTI) – a scan used to assess integrity of nerve fibers that make up the white matter in the brain. (White matter houses ‘millions of bundles of nerve fibers’ that connect brain cells, or neurons, in all parts of the brain and allow them to convey messages to each other.)

The results showed the MCI patients and healthy controls had no differences in global white matter fiber integrity and VO2max. But closer examination showed lower aerobic fitness was linked to weaker white matter in some parts of the brain.

The researchers noted the link ‘remained statistically significant after adjustment of age, sex, body mass index, [white matter] lesion burden, and MCI status.’

The study also found that, in the case of the people with MCI, DTI measures from the brain areas in which low white matter integrity was linked to poorer aerobic fitness correlated with performance on the memory and thinking tests.

The authors concluded higher levels of aerobic fitness are linked to better integrity of the brain’s white matter, ‘which in turn is correlated with better executive function performance in MCI patients’.
Sources: Journal of Alzheimer’s Disease and medicalnewstoday.com