‘No firm evidence’ eating healthily prevents dementia

THERE is no firm evidence that a healthy diet protects against dementia, government advisers say.

The scientific advisory committee on nutrition said there was no proof that any specific nutrient or food supplement could ward off brain diseases.

The review considered dozens of trials examining the role of different types of diets and supplements.

Several studies found those eating the Mediterranean diet – a regime rich in fish, vegetables, fruit and legumes – were less likely to develop dementia. However, the review concluded that such evidence was “observational” – meaning it could not demonstrate that the healthy eating habits were the reason for the lower rates of disease.

Previous research has suggested omega-3 fish oils and vitamin B may ward off brain diseases. But the review said: “There is no evidence that specific nutrients or food supplements affect the risk of cognitive impairment or dementia”.

The committee advises the Department of Health and Public Health England (PHE) on health matters.

Dr Alison Tedstone, PHE’S chief nutritionist, said: “This report broadly supports existing advice to eat a healthy diet, as depicted in the Eatwell Guide.

“However, while the report indicates there isn’t currently enough overall evidence to support a relationship between diet and the prevention of dementia, a healthy balanced diet is vital in achieving a healthy weight and avoiding obesity-related health problems – including type 2 diabetes, heart disease and some cancers.”

Dr Matthew Norton, the director of policy and impact at Alzheimer’s Research UK, said: “The brain, just like other parts of the body, can be affected by the way we live our lives.

“While a balanced diet is one way to maintain a healthy brain, the best current evidence suggests supplements or nutrients offer no additional preventative value.

“Wider evidence points to a number of other lifestyle factors that can also play a role. Not smoking, staying mentally and physically active, only drinking in moderation and keeping blood pressure and cholesterol in check are all ways to keep the brain healthy into later life.”

♦ Taking fish oil during pregnancy cuts the risk of some child allergies by nearly a third, a government study suggests. A daily fish oil capsule taken after the 20th week of pregnancy and for the first three or four months of breastfeeding reduced the chances of a child developing an egg allergy by 30 per cent, the research showed.

Eczema risk was reduced by 22 per cent in children whose mothers took a probiotic supplement between 36 and 38 weeks of pregnancy. The research was commissioned by the Food Standards Agency, and carried out by scientists at Imperial College London.