Hidden fat in mid-life linked to dementia, study finds
A Monash University study of more than 17,300 people comparing mid-life abdominal fat and brain ageing later in life found that fat hidden around organs was associated with smaller brains, with the effect being more pronounced in men than women.
The findings suggest both the importance of keeping a healthy weight to ward off dementia, but also that hormones like oestrogen may protect brain health in older age.
The study, led by Associate Professor Chris Moran and Professor Velandai Srikanth from the National Centre for Healthy Ageing, and published in the journal, Diabetes Obesity and Metabolism, used abdominal and brain MRI data from a population-based cohort of people, aged 40-69 years of age, in the UK Biobank – looking at the total brain and grey matter volume; (controlling decision making, sensory perception); hippocampal volume (which controls learning and memory); and white matter lesions from small vessel disease (affecting speed of cognition).
The researchers found increased visceral abdominal fat (hidden fat) was associated with:
- reduced total brain volume, more so in men than in women
- lower hippocampal volume, similarly in men and women
- greater white matter lesion volume, similarly in men and women
According to Associate Professor Moran, the study findings “suggest that interventions targeting reductions in visceral abdominal fat may have the greatest benefit in men and in those before they reach older ages,” he said.
Professor Velandai said that how visceral abdominal tissue may contribute to brain atrophy is unclear, “but is probably the result of complex interactions between adipose tissue-driven inflammation and hormones,” he said.
“There is evidence that this complex relationship is further influenced by sex, and sex hormones may be neuroprotective, with oestrogen and oestrogen receptors potentially playing an important role in dampening the negative effects of inflammatory pathways in women. The loss of this protective effect of oestrogen following menopause also may explain the known increased risk of dementia in women compared with men in older age.”
Our results provide further support for The Lancet Commission, which highlighted the contribution of midlife risk factors (including obesity) to the risk of dementia in later life, and additionally highlights the mechanistic and potential therapeutic importance of visceral abdominal tissue.”
About Monash University
Monash University is Australia’s largest university with more than 80,000 students. In the 60 years since its foundation, it has developed a reputation for world-leading high-impact research, quality teaching, and inspiring innovation.
With four campuses in Australia and a presence in Malaysia, China, India, Indonesia and Italy, it is one of the most internationalised Australian universities.
As a leading international medical research university with the largest medical faculty in Australia and integration with leading Australian teaching hospitals, we consistently rank in the top 50 universities worldwide for clinical, pre-clinical and health sciences.
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