The idea that food affects our mood is something few of us would have any doubts about, but is it also responsible for the state of our mental health? Imagine a warm summer day at the beach. You rest back, close your eyes and somewhere, further down this sandy stretch, someone plays a song through a Bluetooth speaker that sounds vaguely familiar.

You try to ignore it for a moment because you came here for a rest. When you laid down, the intention was to just shut everything out of your mind. But now you can’t.

The problem is that song, it’s beginning to trigger memories from way back, and if an outside observer with an aerial view of this summer scene were present, they might be prompted to write the following note.

“Shortly after the music began, I noticed a slight smile on her lips followed by a physical reaction on the hand of her right arm. Her fingers began to tap.”

Few of us doubt the power of music to influence our mood or the fact that food can have a similar effect.

Both music and food get a bad rap from time to time, but let’s leave our imaginary sunbather on the beach for the moment and ask ourselves if food can actually have an impact on our state of mind.

There is a growing body of evidence which suggests that it can and, after some early pre-trial success, a team of researchers at Canterbury University are now calling for volunteers to put it to a much more in-depth test.

In two different studies soon to begin they’re researching whether plant-based micronutrients can have an impact on the mental state of women during pregnancy and, in another study, on whether or not micronutrients may improve symptoms of anxiety and depression in adults who are not taking medication for their mental health symptoms.

This is a double blind, placebo controlled, randomised controlled trial (RCT) which is viewed as the gold standard for testing whether treatments work.

Participants will be randomly assigned to one of two groups, either the treatment group (which will receive micronutrients) or the placebo group, which will receive an identical product that contains no micronutrients.

Both groups will take placebo or micronutrients for 10 weeks. Neither the participant nor the investigators will know which group participants are in until the end of the study.

At the end of the RCT phase (after 10 weeks), all participants will be offered the opportunity to take the micronutrients for a further 10 weeks, regardless of which group they were in.

The study is being led by Professor Julia Rucklidge whose department has been involved in research to find nutritional interventions that are effective in treating psychiatric / psychological illness for the last 10 years.

In the past she has been involved with people from the Christchurch earthquake looking at stress and anxiety, also with people who are ADHD, “and the issue of mood always comes up.”

In doing that work and through other studies involving insomnia she said that by supplementing with micronutrients people’s mood became much better and more stable “but we haven’t focused just on mood.”

“I had two graduate students that wanted to study mood. One inside of pregnancy and one outside. We’ve done a lot of clinical trials in the lab. We started with ADHD and the biggest effect was on mood.”

She said not only had nutrient studies shown positive effects in children with anxiety, but they had also benefited people that wanted to quit smoking and in aggression reduction.

On his highly popular web site, www.nutritionfacts.org, Dr Michael Gregor considers a plant-based diet the best treatment for depression.

In the wider sense he says depression presents a “baffling evolutionary puzzle” and wonders if it is an evolutionary strategy providing a defense against infection?

“Infection has been the leading cause of mortality throughout human history, making it a critical force in natural selection,” he says.

“When we become infected, there is a surge of inflammation as our body mounts a counter-attack. Our body responds by feeling lousy, sick, weak, tired, and slow. We don’t want to socialize. The only thing we do want to do is sleep.

“These symptoms are similar to the ones we experience during depression and are great for fighting infection.”

He says the connection between inflammation and mental health was first noted by Dr Julius Wagner-Jauregg, in 1887.

Over the century since Gregor says we now know that “people who are depressed have raised inflammatory markers, such as C-reactive protein and that inflammatory illnesses” which are associated with greater rates of major depression.

“Indeed, we find depression in even more benign inflammatory conditions such as asthma and allergies. This is important as it suggests that the mood symptoms may be directly tied to the inflammation and are not simply the result of “feeling bad about having a terrible disease.”

He says it also now known that depression can be induced by inducing inflammation.

“For example, when we give interferon for certain cancers or chronic infection, up to 50 percent of people go on to suffer major depression.”

He says that the studies, when taken together, were “strongly suggestive of inflammation being a causative factor of mood symptoms.”

Dr Gregor says the most anti-inflammatory diet is plant-based, “which is capable of cutting C-reactive protein levels by an impressive 30 per cent within two weeks, perhaps because of the anti-inflammatory properties of the antioxidants found in plants.”

In conclusion, he says we may be able to treat or even prevent depression by eliminating animal products and eating antioxidant-rich diets.

But where does all that leave our sunbather on the beach who, incidentally, has now been joined by her newly graduated daughter?

“That’s one crazy song, mum. Who on earth would write that? ‘There is no depression in New Zealand.’ Are they bloody joking?”

Impatient for an answer, she picked up her cellphone. “Don’t tell me. I’ll Shazam it.”

“OK. Blam, Blam, Blam. And according to Wiki … some dude called Richard von Sturmer wrote it. My God, he’s still alive! And he’s been Vegan since the age of 16.”

Vegan! Suddenly, her mother sat up.

“OMG Vegan. Food. I haven’t defrosted the steak for tonight’s BBQ”

She hurried away without properly finishing her sentence, and those invisible observers with their aerial view noted that the curious smile was now gone from her face.

Alison was proud of her daughter, but she frustrated her at times. As she walked up to the house, she wondered about food, kids, music, marriage, and somehow sensed that there was a hole in her wellbeing.

“Now what song was that?”