And it starts in the womb.

Associate Professor Felice Jacka from the School of Medicine at Deakin University explained the link to an audience of Rotary District 9520 conference members in Warrnambool yesterday.

Addressing the question “Can we prevent depression by improving diet?”, she provided evidence from numerous studies she has been involved with in what is a relatively new field of scientific research.

Professor Jacka said there was a clear correlation between early-life nutritional exposure and the risk of depression and anxiety.

A major study funded by American foundation NARSAD looked at 23,000 mothers and children.

“We looked at the pre-natal diets and children in their first few years,” Professor Jacka said.

“Mums with a high intake of junk food (while pregnant) led to their children having more externalised behaviours,” such as tantrums.

“Children who ate more wholesome foods in their early years showed lower externalising behaviours.

“What you eat and feed you child is really important to their physical and mental health.”

She said obesity-related illnesses now accounted for more deaths than infectious diseases such as Aids and malaria.

“Obesity also kills more people than smoking worldwide,” she said.

She said there were two main dietary patterns: traditional/healthy, with a higher intake of nutrient- dense foods; and Western, with many unhealthy foods.

While it has long been known that a Western diet is responsible for a range of physical health problems, a link to mental health was relatively new, Professor Jacka said.

“High scores of the Western diet means someone is much more likely to have a depressive disorder,” she said.

“A traditional diet shows they are 35 per cent less at risk.”

She said adults often thought they could continue to eat a Western diet and compensate with supplements.

“In fact, there is not good evidence for supplements being particularly useful and in some cases actually harmful.”

She said there was no evidence of an improved diet relieving depression because it hasn’t been researched, but there was confirmation that prevention could work.

“But the government won’t invest in prevention because the costs are too high and the results are too far down the track. It only will if the community asks for it.

“This year we hope to join with Rotary and ask the government to get behind prevention.”