Alzheimer´s Disease and Yoghurt - a Physicist´s Exploration of Proteins

14 April 2011

On 30 March Professor Dame Athene Donald DBE FRS explained that the link between yogurt and Alzheimer's disease was that both depend on protein aggregation.

Institute of Physics News

In the food industry changes in proteins are often caused by a temperature change, for example boiling an egg or in yoghurt proteins are denatured so they can stick together in different way.

Amyloid plaques found outside neurons in the brain are mainly made up of beta amyloid protein and stick together in a way that disrupts brain function and indicative of Alzheimer's disease. 

In the cases of yoghurt and amyloid protein the sticking together to form aggregates is a similar process. 

Haemoglobin for example has a specific shape for an intended function, as do other proteins. If the appropriate proteins unfold from their usual shape they can be responsible for BSE/vCJD as well as Alzheimers.

Beta-lactoglobin is a small globular protein in whey and often used as a gelling agent is readily available for study.

 Below a pH of 4 there is a fine stranded structure as there is above a pH of 6, in-between there is a globular structure. 

All proteins behave similarly if allowed to denature around their iso-electric point and microscope and other studies show that proteins behave in an apparently universal way. 

Unfolded proteins can link chain structures together forming spherulites resembling synthetic polymers.

Professor Donald had recently been invited to Andrew Marr’s Start the Week radio program to explain the link between yoghurt and Alzheimers.