There's a new reason not to go on a low-fat diet. The signs of brain aging can be postponed in mice if placed on a high-fat diet, which opens up the possibility for treatment of patients with Alzheimer's and Parkinson's disease. 

When we get older, defects begin to develop in our nervous system and our brain loses some of its intellectual capacity. The risk of developing diseases such as Parkinson's and Alzheimer's also increases. Alzheimer's disease is currently the fastest-growing age-related disease.

Throughout our lives, it is important that our cells – to the extent possible – keep our DNA undamaged, and, therefore, the cells have a system that repairs the damage that occurs all the time. Humans age when the repair system ceases to function. In diseases such as Alzheimer's, the researchers also see damage to the DNA

A new research project headed by the Center for Healthy Aging, University of Copenhagen and the National Institute of Health has studied mice having a defect in their DNA repair system. In humans, this defect causes the disorder Cockayne syndrome, where patients prematurely age as children and die at an age of 10-12 years. The study shows that placing a mouse model of Cockayne syndrome on a high-fat diet will postpone aging processes such as impaired hearing and weight loss.

Fat putting a stop to premature aging

"The study is good news for children with Cockayne syndrome, because we do not currently have an effective treatment. Our study suggests that a high-fat diet can postpone aging processes. A diet high in fat also seems to postpone the aging of the brain. The findings therefore potentially imply that patients with Alzheimer's and Parkinson's disease in the long term may benefit from the new knowledge," says Professor Vilhelm Bohr from the Center for Healthy Aging, University of Copenhagen and the National Institute of Health, who has headed the study.

Our brain has a constant need for fuel in the form of either sugar or so-called ketones. Ketones are the brain's fuel reserve, and, in particular, play an important role in periods of low blood sugar levels, e.g. if you are fasting. This is because the body breaks down fat if it needs sugar, and during this process it produces ketones. The researchers see a particular positive effect when the mice are given the so-called medium chain fatty acids – e.g. from coconut oil.

Brain cells need extra fuel

"In cells from children with Cockayne syndrome, we have previously demonstrated that aging is a result of the cell repair mechanism being constantly active. It eats into the resources and causes the cell to age very quickly. We therefore hope that a diet with a high content of coconut oil or similar fats will have a beneficial effect, because the brain cells are given extra fuel and thus the strength to repair the damage," says postdoc Morten Scheibye-Knudsen from the National Institute of Health.