High-fat diet linked to risk of Alzheimer’s

EvEryonE knows that too much cheese and other rich foods are not good for the waistline.

But new research suggests a high-fat diet can also impair memory – after only one day.

It comes following an experiment that suggests daily recall of events and experiences could be compromised only 24 hours after eating a high-fat meal.

Luckily, switching to a low-fat diet can help repair the harm, according to experts.

The report adds further weight to previous findings that being obesely overweight is linked to memory-hampering conditions such as vascular dementia and Alzheimer’s disease.

Lead author of the report, Dr Fiona McLean of Aberdeen University, said: ‘Alzheimer’s disease is a leading cause of morbidity and mortality with no cure and only limited treatment available.

‘obesity and type 2 diabetes are positively associated with the development of premature cognitive decline and Alzheimer’s disease, linking diet with these conditions.

‘Here we demonstrate that in mice episodic memory, together with spatial and contextual associative memory, is compromised after only one day of a high-fat diet. This shows not only a more rapid effect than previously reported, but also that more complex memories are at higher risk of being compromised.

‘In addition, we show that these memory deficits are rapidly reversed by switching mice from a high-fat diet back to a low-fat diet.

‘These findings have important implications for the contribution of nutrition to the development of cognitive diseases.’

Episodic memory is made up of experiences and specific events that occur during our lives, while contextual memory is a basic process in long-term memory – where and when it happened.

Spatial memory helps with navigating.

In the study, mice were fed a lowfat diet – 10 per cent energy from fat – for eight days and then either remained on that diet for a further two weeks or were switched to a high-fat diet – 60 per cent energy from fat – for two weeks. others were fed a high-fat diet for one week then switched back to a lowfat diet for a week.

The high fat diet contained a mixture of vitamins, dairy, lard and soyabean – to reflect a human diet.

The animals were set memory tasks to discover what effect their food had on them.

Their experiments suggested that a high fat diet affects the brain directly.

Dr McLean said: ‘In our study the loss of ability to perform certain tasks while others are unaffected implies brain region specific effects of a high-fat diet.

‘If these deficits also occur in humans, this would support the theory that a high-fat diet may contribute to early cognitive decline leading to the development of Alzheimer’s disease.

‘The loss of episodic memory is a defining feature of early onset Alzheimer’s disease and the memory tasks which show deficits in our study utilise the entorhinal cortex and hippocampus, two areas of the brain which are affected early in Alzheimer’s disease.

The researchers, writing in the journal Scientific reports, said that to protect memory function people should eat a balanced diet of high and low fat meals.

yesterday Jim Pearson, director of policy and research for Alzheimer Scotland, said: ‘This adds to the increasing body of evidence that changes to our lifestyles can potentially reduce the risks of developing dementia.

‘These include keeping physically, mentally and socially active and maintaining a healthy diet.

‘Generally speaking what’s good for your heart can also be good for your brain.’