You are what you eat, so if you want to feel happier and less stressed, pay attention to what you plate up!
Imagine you served up last night’s dinner to a hunter-gatherer ancestor. Would they recognise it as food? If they did the same to you, would you be willing to take a bite? The modern-day diet has changed considerably in the last few decades, with much of it passing through a manufacturing plant, rather than just the farm gates. This increase in processed food consumption is among the many factors fuelling our rates of obesity, type 2 diabetes and heart disease, but what effect is it having on our mental health? Is there a link between food and mood?
Deakin University’s Food & Mood Centre’s Dr Hajara Aslam and Dr Samantha Dawson, plus Jean Hailes for Women’s Health naturopath Sandra Villella, have been researching the best foods for health and happiness. We reveal their findings.
The link between food & mood
Based in Victoria, the Food & Mood Centre is a world-leading research hub dedicated to exploring how diet impacts mental health. Post-doc Research Fellow Dr Aslam says there is consistent evidence to show people with a healthier diet have a lower risk of depression than those who don’t eat well.
“This trend is visible right across the lifespan, from early childhood to older adults,” explains Dr Aslam. She also adds there’s a correlation between a mother’s diet during pregnancy and the mental health of her children.
Gut microbiota (the microorganisms in the gut) is of particular interest to researchers at the Centre, who are examining how diet can affect it, and how gut microbiota improvements can influence mental health.
Meet your microbiota
The gut (or intestinal tract) is teeming with microscopic life — both good and bad. Your gut microbiome is home to trillions of bacteria, viruses and fungi. While it might sound a bit frightening to know there is a mini-universe of bugs living in your digestive system, these microbes can actually exist harmoniously. And when their population balance is strong and healthy, there are many associated health benefits.
Interestingly, gut microbiota changes — sometimes very rapidly — in response to what we eat. Dr Samantha Dawson, another Mood & Food Centre post-doc Research Fellow, highlights two studies that looked at the impact different diets (an animal-based diet rich in meat, cheese and eggs, compared to a plant-based diet, for example) have on gut microbiota.
“Within that first 24-hour period of starting a different diet, they [the studies] could detect a change in gut microbiota,” she says.
The fact that gut microbiota responds so well to what we eat is heartening. “It means there’s a bit of a hope. If you’re not happy with your diet, you can change it, and that might influence your gut,” says Dr Dawson.
Microbes and mood
According to Dr Aslam, “The gut microbiome is increasingly being understood as a separate organ.” The relationship between your gut microbiota and your brain is complex and, as Dr Aslam puts it, “bi-directional”. This means the two organs communicate with each other
by various biological pathways.
Not only is gut microbiota involved in pathways related to producing serotonin and dopamine — the brain chemicals associated with good mood, motivation and feelings of reward — gut microbiota can also influence inflammation and stress responses in the body. “So, by all these means, the gut microbiota is communicating with the brain,” Dr Aslam concludes.
Other studies reveal another key connection: a differing gut microbiota profile exists in people with depression compared to people without.
Chicken or egg?
While there’s a clear link between gut microbiota and mental health, Dr Dawson stresses it’s not known which comes first. “We often see two different gut microbiota profiles in people with and without mental health disorders — but we don’t know if it’s the depression that changes the microbiota, or if the microbiota is a certain way and then people get depression,” she says.
“Even so, there is still evidence to suggest healthier diets are associated with better mental health and better gut microbiota profiles,” she adds.
The secret’s out
Eating for good health and optimal happiness is, in fact, no secret at all. The same food groups that appear time and time again for encouraging good physical health also support your mental health.
“[Focus on] whole grains, vegetables, fruits, legumes, nuts and healthy fats,” says Dr Dawson. “In particular, you want the fibre. That seems to be really good for your gut.”
Jean Hailes naturopath Sandra Villella recommends the Mediterranean diet, with its focus on plant foods and healthy fats from olive oil, fish, nuts (especially walnuts) and seeds, for good mental health. While the Mediterranean diet has a significant amount of published research backing it, other cuisines like the traditional Costa Rican and Japanese diets, also follow principles that are similar to the Mediterranean diet.
A ‘good-mood diet’ is also about what we should be eating less of. In a nutshell, this means less highly refined foods and foods that don’t contain fibre. “That’s the packaged, highly processed foods [store-bought chips, commercially baked goods, takeaways] which are pretty common in people’s diets,” says Dr Dawson.
Know the why
Naturopath Sandra Villella promotes the Mediterranean diet because it’s low in refined carbohydrates and “unhealthy trans fats found in fast food and commercial bakery goods, which are associated with a higher depression risk.”
“We know the Mediterranean diet plays a role in reducing the risk of cardiovascular disease and metabolic syndrome and, in fact, depression shares several mechanisms that are similar to these diseases,” she says.
According to Villella, whole and plant-based foods fight inflammation and may help to protect brain and nerve cells from damage via their antioxidant action. Whole grains (brown rice, oats, wholemeal bread) are rich in B vitamins, “which play important roles in the making of neurotransmitters (or brain chemicals) that affect mood,” she explains.
Dr Aslam adds it’s the compounds in these whole foods that benefit mood. “Vitamins, minerals, omega-3 fats, pro- and prebiotics are all functionally active ingredients that can affect our physical and mental health overall,” she says.
Start simple and small
Less than four per cent of Australians are eating the recommended daily amount of vegetables and legumes, and fare only slightly better in the fruit and grains department. With only about 30 per cent of us meeting the recommended daily intake of these food groups, we’ve some way to go.
Both Drs Dawson and Aslam agree that adopting a new diet can be challenging. “It might appear costly, and it might need a bit of dedication,” says Dr Aslam. But the key is to start small. If you don’t eat any veg at all, start by including just one serve a day, then gradually increase it to two, and so on.
When it comes to feeding gut microbiota, variety is as important as quality. Dr Dawson suggests including a wide range of colourful vegetables in meals. Cooking with spices also pays dividends in terms of both flavour and health benefits. “Certain spices, like cumin and turmeric, have really good anti-inflammatory and antioxidant properties,” adds Dr Aslam.
It’s important to remember that eating to support good mental health is not out of reach — for anybody. It doesn’t involve elusive and expensive superfoods, strict rules or striving for perfection. “It’s about what you do most of the time. If you’re following a healthy diet pattern with good habits for most of the time, that is a good way forward,” concludes Dr Dawson.
This is an edited extract from Jean Hailes for Women’s Health. Visit jeanhailes.org.au for more about this non-profit, national organisation dedicated to improving women’s health. Read the original article.