Are we eating our way to poor mental health?

Disclaimer: First off I want to explain that Legacy Nutrition’s mission is about educating people so they can get their health and wellbeing back. No jargon or complicated explanations, just real discussion about why it’s vitally important that we sort our sh*t out and start to eat in a way that recognizes that our health, and the health of our families, depends on it. Some heavy topics are discussed around mental health and I am in no way dismissing the emotional trauma or realities of the people this affects. I am merely offering up what the latest research argues from a nutritional perspective.


There’s soooo much attention paid to the role poor nutrition plays in the global obesity epidemic, diabetes and heart disease, and so there should be it’s a serious issue. But very little attention is paid to the link between poor nutrition and depression, anxiety and suicide. Suicide rates are at an all-time with ‘the number of people who have taken their own lives in New Zealand [my home country] the highest since records began, with 668 dying by suicide in the past year(1). I myself have had a family member die of suicide and can attest to what devastating effects this has on the family left behind.

So how is it that we are not recognizing this link and talking more about what can be done!? Digging into the research, it’s clear that nutritional deficiencies affect the creation of neurotransmitters (feel good hormones), which means our neurochemistry is affected. If we are not giving our brain what it needs to function correctly, our neurochemistry can get seriously out of balance. This can lead to, among other things, depression and irrational thinking. When this occurs, a vicious cycle of nutritional depletion can be perpetuated.

The Indian Journal of Psychiatry had this to say about the role nutrition has on depression and mental illness. ‘Few people are aware of the connection between nutrition and depression while they easily understand the connection between nutritional deficiencies and physical illness. Depression is more typically thought of as strictly biochemical-based or emotionally-rooted. On the contrary, nutrition can play a key role in the onset as well as severity and duration of depression’(2). They go on to say, ‘Nutritional neuroscience is an emerging discipline shedding light on the fact that nutritional factors are intertwined with human cognition, behavior, and emotion’.


The research further explains there’s a direct link between a lack in essential nutrients (amino acids, omega-3 fatty acids, vitamins and minerals) and patients suffering from mental disorders due to a severe deficiency of these nutrients.


This is serious stuff! And, it’s important as we ALL know someone affected by mental illness: a family member, a friend or co-worker, or perhaps even ourselves at one point or another. So, with this new (or refreshed) understanding that what we consume has a profound affect on our mind, what can we do to ensure that we are getting the most out of our nutrition, to give our brain the fuel it needs to support us and function optimally? Well, a little understanding goes a long way! So here are my TOP 3 guidelines when it comes to supporting your brain health.


1.   Fruits and vegetables


Seems silly to have to remind everyone of the benefits of these nutrient dense foods, but with the now mainstream acceptance of the keto diet (often misinformed and implemented), carnivore diet, junk-food heavy vegan diets, as well as the typical Standard American Diet (or SAD diet for short), perhaps it’s time for a reminder of the amazing job fruits and vegetables do in the body and how they are so very important in supporting our brain health. Fruits and vegetables are rich in antioxidants, vitamins, minerals and fiber.


Great so what does that mean? Let’s break it down.


·      Antioxidants are molecules in fruit and vegetables that help your brain to fight off free radical damage (highly reactive rogue substances that can be found in the food we eat, the medicines we take, the air we breathe and the water we drink). So, getting colourful fruits and vegetables like berries, tomatoes, broccoli, spinach and things like nuts and green tea will all go a long way to reducing oxidative stress and helping your brain to function long into your senior years.


·      Vitamins and Minerals play a crucial role in neurotransmitter creation. Specifically,  B group vitamins and vitamin C, along with minerals such as zinc, magnesium and calcium are all important for normal brain functioning and protection against age-related degeneration, including Alzheimer’s disease, dementia, and stroke.(3) Best food sources of Vitamin B and C include fruits, berries, tomatoes, green leafy vegetables, and cruciferous vegetables.


·      Fiber is like the clean-up crew in your gut. It also keeps us fuller for longer, helping to improve our blood sugar levels, which means more consistent energy throughout the day without the crashes or the mood swings. Research shows everything in our bodies is interconnected and the gut functions like a second brain, meaning, insufficient fiber intake could be robing you of your mental wellbeing (4).


Fruits and Vegetables are vitally important for our brain health and we should be consuming 7-9 servings (handfuls) each day.


2.   Protein


We talk about protein all the time and we hear it’s important. But what exactly is Protein? Protein, once consumed, breaks down into amino acids which then creates the ‘structure’ and cellular expression from our DNA. These little molecules are often referred to as the ‘building blocks of the body’ turning food stuff into you stuff. Protein is crucial for building cells, tissues, organs and neurotransmitters (chemical messengers) such as epinephrine, norepinephrine, melatonin, serotonin and dopamine (5). Needless to say, without enough of these molecules we are not fueling our bodies for all important growth and repair, and we certainly won’t be able to create enough of those feel good chemical messengers to support our minds.


So, what’s ‘enough’? The current RDA is a modest 0.8g per kg of body weight (6). However, many believe this is far too low for today’s modern living. Protein requirement is very individualized (depending on physical demands, age, lifestyle and dietary factors), but if you were aiming for a minimum daily intake, I’d recommend no less than 1.2-1.4g per kg of body weight. On the flip side, if you were incredibly active, you may do well on anything upwards of 2-4g per kg of bodyweight. Protein requirement is one area I work with my clients on to get them to the right level based on their individual needs and goals.


This doesn’t suddenly mean you must become a carnivore either, of course meat is a great source of essential amino acids, so too is dairy, fish, nuts, seeds and vegetables. The idea is that you include a wide variety of these nutrient dense foods to fuel the body and mind appropriately.


3.   Fats


Some of us still have a lingering fear around ‘fat’ thanks to the low-fat revolution, but if we break it down and again put some understanding around the role fat (or more appropriately termed lipids) has in the body, then we begin to understand that avoidance of good fats is damaging our bodies and minds more than we would have ever thought.


Much like protein, fat also provides building blocks for the body, including various cell components and steroid hormones like testosterone, estrogen, progesterone, cortisol, DHEA and others. The brain is made up of approximately 60% fat with half of that fat being Omega-3s (5). Omega-3s consumptions leads to more gray matter in the brain which is the brain tissue involved in muscle control, memories and emotions. Omega-3s also have additional benefits for your brain: slowing age-related mental decline and helping to ward off Alzheimer's disease (8–11). It can help to reduce ADHD in kids, lower triglycerides, keep eyes healthy, fight off symptoms of depression, provide better sleep (as well as depth and length of sleep), it can reduce PMS symptoms and also has benefits for heart health, skin, hair, psoriasis, eczema and even sunburn! (but that’s a subject for another day).


The facts are in. Fat is good for our health and crucial to support our brain function. But again, how much do we need? Well, with my clients I recommend no less than 1.5g of fat per kg of bodyweight per day. This is of course dependent on your goals. You can get adequate Omega-3 fats into your diet by consuming fish (salmon, mackerel, tuna, sardines etc),  avocado, macadamias, walnuts, chia seeds, flaxseeds, oysters, hemp seeds and cod or fish oils. There are other healthy fats that you could include such as MCT oils. There are plenty of other ways that you can optimize brain function, with the use of Ketones and Medicinal Mushrooms, but I’ll save those for future Blog posts.


I’ll leave you thinking about how your own cognition is going? If you are suffering from depression or anxiety symptoms, mood disturbances or feeling completely overwhelmed by life, there could be an underlying nutritional deficiency. Can I just encourage you, don’t leave it thinking ‘this is my lot, this is just how it is for me’. Reach out and get help from someone you trust. There’re ways through. You can call any of the numbers below if you would like to talk to someone anonymously. And, if you need help with your nutrition, or if you want to find out more about how nutrition can help with your brain function please don’t hesitate to contact me.


Lifeline                                                                        0800 543 354

Suicide Crisis Helpline                                                0508 828 865

Healthline                                                                    0800 611 116

Samaritans                                                                   0800 726 666



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5.        Cliff Harvey. The Carbohydrate Appropriate Diet: Go beyond low-carb diets to lose weight fast, and improve energy and performance, without counting calories - Kindle edition by Cliff Harvey. Health, Fitness & Dieting Kindle eBooks @ [Internet]. [cited 2018 Sep 15]. Available from:

6.        Pendick D. How much protein do you need every day? - Harvard Health Blog - Harvard Health Publishing [Internet]. [cited 2018 Sep 15]. Available from:

7.        Murray C] L, Boston MA, Tt.’· ,~ ~ Lijio W ~ :I ~ ~ ’i U. BURDEN OF DISEASE A comprehensive assessment of mortality and disability from diseases, injuries, and risk factors in 1990 and projected to 2020 EDITED BY Library of Congress Cataloging-in-Publication (CIP) Data applied for [Internet]. 1996 [cited 2018 Sep 15]. Available from:;jsessionid=19A51E0114D353941CCB7B6B57E56AD9?sequence=1

8.        Devassy JG, Leng S, Gabbs M, Monirujjaman M, Aukema HM. Omega-3 Polyunsaturated Fatty Acids and Oxylipins in Neuroinflammation and Management of Alzheimer Disease. Adv Nutr [Internet]. 2016 Sep 1 [cited 2018 Sep 15];7(5):905–16. Available from:

9.        Belkouch M, Hachem M, Elgot A, Lo Van A, Picq M, Guichardant M, et al. The pleiotropic effects of omega-3 docosahexaenoic acid on the hallmarks of Alzheimer’s disease. J Nutr Biochem [Internet]. 2016 Dec [cited 2018 Sep 15];38:1–11. Available from:

10.      Cole GM, Ma Q-L, Frautschy SA. Omega-3 fatty acids and dementia. Prostaglandins, Leukot Essent Fat Acids [Internet]. 2009 Aug [cited 2018 Sep 15];81(2–3):213–21. Available from:

11.      Morris MC, Evans DA, Tangney CC, Bienias JL, Wilson RS. Fish Consumption and Cognitive Decline With Age in a Large Community Study. Arch Neurol [Internet]. 2005 Dec 1 [cited 2018 Sep 15];62(12):1849. Available from:

Kirstie Vesseur

Food blogger, Cat Lover, Studying Clinical Nutritionist