The Role of Diet in Depression

I came across a new study last week that made me laugh out loud. Literally. It was one of those moments when you see research that is proving something that is so obvious and part of my known reality, that it seems comical that the research findings are showcased as if it is a new breakthrough in understanding.

The source of my latest moment of research happiness came when I read about Australian research intervention into teenage and young adult depression and diet. The researchers put a group of depressed teens and young adults (17-35yrs) on a healthy diet for just 3 weeks and found that by the end of the study, most had improved to the point that they no longer fit the diagnostic criteria for depression. Yep, that is it. Dietary change had a better statistical result than antidepressants and in only three weeks! The dietary recommendations to the study participants involved increasing their intake of a broad healthy range of fruit, vegetables, wholegrain and cereals, natural dairy products, lean protein, fish and other seafood, olive oil, nuts and seeds, olives or avocado and spices.

Although it seemed like a ‘no-brainer’ to me, I was actually happy to see this latest research show to the world how a simple dietary intervention for depression is plausible and effective. And despite my humour, my tongue is firmly in my cheek, because as well all know depression itself is no laughing matter and it is a growing concern. According to the WHO*, depression affects more than 300 million people worldwide. Depression rates in American teens have risen by over 50% in the past decade. According to Beyond Blue, one in sixteen Australians are currently experiencing depression.

Of course many different things contribute to depression and the alarming increase over the past decade in youth and young adults has been linked to social media, screen time, poor sleep and sedentary habits. A new theory has even found that antidepressants appear to work by attenuating our body’s use of light in neurotransmitter synthesis such as melatonin and serotonin. Using screens at night disrupts this natural circadian cycle and causes a chronic jet lag scenario, which includes depression as a side effect. Of course, if antidepressants are possibly working by increasing sensitivity to light, then we can invest in more sunlight, which is the most powerful enhancer of mood and circadian regulation, rather than need antidepressants. Many of you would know, I have a passionate interest in this topic and have been following the benefits of sunlight in human health and disease for some time….you can read further here.

Anyway, despite all this compelling and interesting research, I was happy to see more researchers expanding their criteria for depression to see if dietary habits played a role, however I was not at all surprised at their findings.

Having good mental health requires a whole swathe of nutrients including omega 3 fatty acids, B vitamins, zinc, and magnesium. In addition, the amino acids derived from protein are required to make neurotransmitters. Many brain pathways that impact on depression risk are modulated by nutritional intake. These pathways include everything from mitochondrial function and inflammation levels through to interactions with the gut microbiome. So it is no surprise that the research intervention found that a healthier diet was an effective treatment for depression!

The role of diet in different aspects of health continues to be examined across many research areas including mental health. However, while natural therapists like myself, have always known of the connection between depression and diet and have utilised it in our treatment strategies, oddly enough it has really only been examined in mainstream research for the past 10 years or so.

A recent study in the USA also found a link between fast food intake and depression in young adolescents. The Mediterranean style diet has also been shown in a number of studies to reduce depression risk. One large study examined populations consuming different diets and found that people following a more Mediterranean-like diet had a 33 percent lower risk of developing depression compared to those whose diet least resembled a Mediterranean diet. Other studies have examined the impact of inflammatory foods on the risk of depression and found that those who avoided inflammatory foods such as sugar, processed grains and unhealthy fats had a 24% reduced risk for depression.


Teenagers are known for their desire for freedom and independence and many parents have less control over what their teenagers eat. However, if you can ensure that at least breakfast and dinner are healthy, they will probably have less negative impact from any additional junk food consumed during their social activities. Educating them about the importance of healthy food starts young, but many teens will still listen and take in the message when they are suffering from mood changes, skin issues or poor energy…even if they appear to be ignoring you!

So the take home message if you have a teenager in your world, is to ensure that their diet is as nutritious as possible and create firm boundaries around phone use at night, and I am sure you will be rewarded with a happier teen! And of course if you are an adult suffering from depression, make sure you also follow this simple advice and please seek help from a healthcare professional if you need more support. 🙂