The sugar forms abnormal proteins that lead to the brain disease in most people
London: A diet, high in sugar, could lead to Alzheimers, as a study finds a link between sugar and the brain disease.
According to researchers from the University of Bath and King's College London, this is the first concrete evidence to explain why abnormally high blood sugar levels, or hyperglycaemia, have an impact on cognitive function, reports Telegraph.co.uk.
Unprecedented research has revealed the 'tipping point' at which blood sugar levels become so dangerous they allow the neurological disease to take hold. Once levels pass the threshold, they restrict the performance of a vital protein, which normally fights the brain inflammation associated with dementia.
"Excess sugar is well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer's disease is yet another reason that we should be controlling our sugar intake in our diets," said Dr Omar Kassaar. In Alzheimer's abnormal proteins aggregate to form plaques and tangles in the brain which progressively damage the brain and lead to severe cognitive decline.
Using brain samples of 30 patients with and without Alzheimer's and tested them for protein glycation, a modification caused by high glucose levels in the blood. They found that in the early stages of Alzheimer's glycation damages an enzyme called MIF (macrophage migration inhibitory factor) which plays a role in immune response and insulin regulation.
MIF is involved in the response of brain cells called glia to the build-up of abnormal proteins in the brain during Alzheimer's disease.It appears that as Alzheimer's progresses, glycation of these enzymes increases."We've shown that this enzyme is already modified by glucose in the brains of individuals at the early stages of Alzheimer's disease," said Jean van den Elsen from Bath's department of biology and biochemistry.
"Normally MIF would be part of the immune response to the build-up of abnormal proteins in the brain, and we think that because sugar damage reduces some MIF functions and completely inhibits others that this could be a tipping point that allows Alzheimer's to develop," Elsen added.