More seafood the key to NZ's mental health

By ANGELA GREGORY

A British brain and nutrition expert warns that New Zealand is at risk of rising rates of mental illness because people eat too little seafood.

Professor Michael Crawford, of the London Metropolitan University, said that despite huge coastal resources, the bulk of the population consumed relatively little seafood.

Seafood, particularly oily fish, was a good source of a fatty acid linked to brain growth and function, he said.

Professor Crawford, director of the university's Institute of Brain Chemistry and Human Nutrition, said New Zealanders were at risk of increasing rates of depression and other mental illnesses.

Oily fish, which were rich in a fatty acid essential to brain structure and function, were not widely available in New Zealand, he said.

The nutrient Omega-3 DHA made up just under 20 per cent of the human brain but the body could not produce it in sufficient quantities, so it had to come from diet.

Professor Crawford said seafood consumption should be encouraged by the Government, which should ensure it was available at affordable prices and not treated as a luxury.

He supported alternative sources of Omega-3 DHA products.

Tip Top, which invited Professor Crawford to New Zealand, is about to launch a white bread enriched with Omega-3 DHA.

Professor Crawford said the American National Institute of Health had attributed rapid rises in mental ill-health over the past two decades to a decline in the availability and consumption of fish and seafood.

The increase had been shown to follow high rates of heart disease in countries such as New Zealand.

The American research had shown New Zealand rated high for rates of major depression and low for fish consumption.

He said mental ill-health was predicted to become one of the top three health burdens in the world by 2020.

Dr Laurie Jo Moore, Auckland District Health Board clinical director mental health service, said some studies showed Omega-3 consumption was a factor that warranted further investigation in relation to mood disorders.

But Dr Moore said many causes of depression and mental illness were not diet-related.

Examples included trauma and genetic predisposition.

Christchurch Medical School senior lecturer in psychological medicine Richard Porter said the Omega 3 theory was interesting but a lot more work was required.

The use of fish fatty acids in the treatment of bipolar disorders was currently being investigated, he said.

Crop and Food Research scientist Dr Karen Silvers said she was studying the effects of fish oil consumption in the treatment of depression.

It was too early to discuss results, but other data indicated that the consumption of fish oil was beneficial to brain health and well-being.

Dr Silvers said that people who reported a long-standing consumption of fish appeared less likely to have mental health problems.

nzherald.co.nz/health