Could obesity make Alzheimer’s worse?

World Health Matters – France – by Gary Finnegan – The detrimental effects of obesity are well-documented with public health specialists warning of a tidal wave of diabetes and cardiovascular diseases if obesity continues to rise. However, researchers in France are beginning to explore the negative impact of obesity on age-related loss of intellectual function.

The cognitive impairments observed in Alzheimer’s disease result from the accumulation of abnormal tau proteins in nerve cells undergoing degeneration.

Obesity has been linked to an increased risk of dementia during ageing but the effect of obesity on so-called ‘Taupathies’ – tau protein-related disorders – including Alzheimer’s disease have not been well understood.

A team of researchers led by Dr Luc Buée from the Inserm/University of Lille 2, are studying the relationship between tau proteins and obesity in animal models. The group has demonstrated that obese mice develop aggravated Alzheimer’s disease if they are also obese.

The scientists used young transgenic mice who developed tau-related neurodegeneration progressively with age, and put them on a high-fat diet for five months, leading to progressive obesity.

“At the end of this diet, the obese mice had developed an aggravated disorder both from the point of view of memory and modifications to the Tau protein” said Inserm research leader Dr David Blum.

This study uses a neurodenegeneration model of Alzheimer’s disease to provide experimental evidence of the relationship between obesity and disorders linked to the tau protein. Furthermore, it indicates that insulin resistance is not the aggravating factor, as was suggested in previous studies.

“Our research supports the theory that environmental factors contribute massively to the development of this neurodegenerative disorder” underlines the researcher. “Our work is now focussing on identifying the factors responsible for this aggravation” he adds.