We’ve all heard that you are what you eat. But research in the last decade has begun to show that what we eat is actually a huge part of how we feel. In the past several years especially we have seen in increase in the interest of the public in probiotic food and drinks, as well as plant based and vegetarian diets. Moral and ethical reasons aside, studies have begun to unequivocally establish a link between what we put in our bodies and the overall function of our brains, and in turn, our mental health.

It has been known for some time that what you eat has an effect on your mood and your risk for depression. Diets high in fatty, fried, sugary, and processed foods have been linked to an increased risk for depression. Likewise, diets high in vegetables, fruits, legumes and whole grains have been linked to a decrease in risk for depression and other mood disorders.

Scientific studies have now proven that you can treat many forms of mental illness through diet, and side effects such as weight loss are treated as that – a side effect, rather than a primary goal. This new field of research is being called Nutritional Psychiatry, and the International Society for Nutritional Psychiatry Research has actually been established right in Frederick, Maryland.

Many of us are already eating plant based and drinking kombucha and other probiotic beverages, aware that regulating our gut health just makes us feel good. But how? We now know that the bacteria that make up our microbiome – a complex microbial ecosystem containing some 100 trillion microorganisms which function to establish the intestinal lining and aid in its maintenance – directly communicate with the brain. A link between mood disorders and GI disorders such as irritable bowel syndrome and Crohn’s has been long established, but for decades scientists didn’t know why. Evidence has now begun to show that our microbiome is actually directly affected by stress, and that, conversely,  it can modulate and influence emotional behavior.

The Deakin University in Australia conducted the first ever trial that proved that diet – specifically a Mediterranean diet – can treat major depressive disorder. Professor Felicia Jacka, president of the International Society of Psychiatric Research and the clinician who led the trial said, “Mental disorders account for the leading cause of disability worldwide, with depression accounting for the large proportion of that burden. While approximately half of sufferers are helped by currently available medical and psychological therapies, new treatment options for depression are urgently needed. Importantly, depression also increases the risk of common physical illnesses such as obesity, type 2 diabetes and heart disease. Successfully improving the quality of patients’ diets would also benefit these illnesses.”

So, knowing that our diet can successfully lead to not just a healthier body but more importantly, mind, what can we do to eat differently? What should we be doing? The question of what the “real” human diet is is still (hotly) up for debate – and likely will be for many, many years to come. But there are ways we can modify our diets that are now scientifically shown to improve mood and overall brain function, as well as successfully treat mental illness.


To explore how you can implement nutritional psychiatry to better your life, we’ll look at probiotics, a maintenance in levels of Omega-6 and Omega-3 fatty acids, and a Mediterranean diet that researchers are proving treats depression and other physiological illnesses.



photo courtesy of Theonista Kombucha

Multiple preclinical trials on the effects of probiotics have found overwhelming evidence of their impact on several neurotransmitters that affect a wide variety of mental processes. A study published in the National Library of Medicine states, “There is robust evidence of this in preclinical studies that have demonstrated probiotics’ ability to change behavior and improve the mood, anxiety, and cognition of rodents by altering neurotransmitter activity”.  A 2007 double-blind randomized control trial with 124 healthy individuals concluded that after only 20 days of consuming a probiotic-containing milk drink, those who initially reported a low mood had improved. This study was repeated ten times with several different age groups that proved the same results. Seven of the ten studies also observed anxiety and stress, and all but two reported improvement with the treatment of a probiotic. Studies on cognition proved profoundly positive results, increasing cognitive function across the board in every test administered.

These days, access to probiotics is as simple as looking in your fridge. Scientific studies are still being done on what the actual dosage should be. We’re finding that some may be strain-specific, as there are billions of bacteria that make up our microbiome. The majority of the studies done so far have been in relation to GI disorders, so it will still be some time before we know just how much is enough.

But a good place to start is with a cup of a probiotic milk drink of some kind, yogurt, or about two cups of kombucha a day. Probiotic capsules and powders are also readily available. It is important to note that taking a probiotic will not change your microbiome overnight – you have to stick to a daily regime, and keep it routine.



Photo courtesy of Katie Emmitt

There are many nutrients that are necessary for brain function, but our bodies can’t produce all of them on their own. An incredibly crucial one is Omega-3, intake of which has plummeted in the American population. Our brains use Omega-3 fatty acids to build nerve-cell membranes and for nerve-cell signaling. The changing of omega-6/omega-3 polyunsaturated fatty acids in the food supply of Western societies is believed to have promoted the pathogenesis of many inflammatory-related diseases, including depressive disorders. Studies of men in Japan as well as U.S. service members concluded that those with the lowest omega-3 acid levels had the highest rates of suicide. We are pouring Omega-6 fatty acids into our food supply, and these two fatty acids fight each other for their place in the brain.

Since our brains cannot produce Omega-3’s on their own and are being largely overwrought by Omega-6’s, we have to mitigate what we put into our bodies in order to get the balance back to where it needs to be. This is where Felicia Jacka’s study in Melbourne becomes so important and profound, which treated depression by implementing a Mediterranean diet. We have seen from several population studies that people with a Western diet have higher rates of depression and suicide compared to those with a traditional, Mediterranean diet.

The main difference between a Mediterranean diet and a Western one is the consumption of processed foods. The processed foods that we are eating are heavily laced with trans fats and are high in omega-6’s, promoting depression and overall impaired cognitive function.

A typical Mediterranean diet includes lots of vegetables and fruits, averaging about twelve and nine servings respectively. Whole grains are eaten instead of white bread that has added trans fats and sugars, legumes heavily incorporated in foods. Red meat is cut down to only a few times a month, with fish and poultry eaten a few times a week. Processed sugars and corn syrup are a no-go, and butter is substituted with olive oil, salt replaced with herbs and spices.

And of course, a little red wine.


A healthy lifestyle treating mental illness is not out of reach, and is the frontier in psychological research for the treatment of disorders that plague so much of the population. Pioneers of nutritional psychiatry are hoping to push nutraceuticals – food/supplements containing health-giving additives as well as medicinal effects – instead of pharmaceuticals. As stated in the British medical journal The Lancet Psychiatry, “Although the determinants of mental health are complex, the emerging and compelling evidence for nutrition as a crucial factor in the high prevalence and incidence of mental disorders suggests that diet is as important to psychiatry as it is to cardiology, endocrinology, and gastroenterology.”

So, cut out the sugars and processed foods, say goodbye to corn syrup, eat your veggies, and drink your ‘booch. Pretend you’re living in a seaside Grecian village (why not even throw a siesta in there?). The new wave of the American diet is here, and the ability to harness the full capability of our bodies and minds is as close as our own pantries. It already intuitively feels to many of us that eating locally sourced, unprocessed, real food is better for us, for our communities, for our planet. Many of us feel revived after doing so. But now we know, beyond a doubt, that we are truly nourishing our bodies and our minds by controlling what we put into it.