How To Eat For Optimal Mental Health - Practical Tips

This is the third and final article in the Mental Health Nutrition Series. The first and second articles can be found here.

The gut can have considerable influence over a person’s mood and mental state. What you eat during your day will have a significant impact on your sense of wellbeing and your productivity and performance.

In the first and second article, we discussed in depth how your gut, your gut microbes, and your enteric nervous system (ENS), can have considerable influence over your mood and mental state. A healthy gut function has been linked to normal central nervous system (CNS) function and that hormones, neurotransmitters, and immunological factors released from the gut are known to send signals to the brain either directly or via autonomic neurons (1, 2).

Optimising our brain starts with optimising our body first.

In today’s article, we will talk about how we can optimise our mental health through nutritional and lifestyle interventions. It doesn’t have to be complicated. Just a few simple switches can make a big difference!


Our gut has a complex network of nerves in it that communicate directly with our brain. A number of studies have shown that people with various mental health issues have different species of bacteria in their guts, compared to healthy people. This suggests that the gut microbiome may affect brain health (3-5). Knowing which foods keep your gut healthy is key to improving gut health and subsequently improving your mental health.

1. Eat More Prebiotics and Probiotics

Friendly bacteria in the gut plays an important role in protecting the tissue in our gut that contains these nerves, which have a direct impact on brain activity. Maintaining a balance between friendly and pathogenic bacteria is essential for overall health, as well as mental health. A good way of keeping the not-so-friendly bugs at bay is by integrating prebiotics and probiotics into your diet frequently. Prebiotics and probiotics are essential to gut health and mental health.

Prebiotics are carbohydrates that humans cannot digest, but bacteria in our guts can.

Examples of prebiotics include:

  • Garlic

  • Onions

  • Leeks

  • Asparagus

  • Banana

  • Flaxseeds

  • Oats

Probiotics are live microorganisms, the best whole food sources of probiotics are:

  • Dairy: yoghurt, cheese, and kefir with live and active cultures

  • Fermented vegetables: pickles, sauerkraut, kimchi

  • Fermented soy: miso, tempeh

Evidence suggests that probiotics and prebiotics might improve mental function via several mechanisms (6-8).

2. Replace High-Processed & High-Sugar Foods With A Colourful Wholefood Diet

This can make a huge difference to a person’s overall health and wellbeing.

Highly processed food items include:

  • Vegetable, sunflower, corn, soybean, canola oil

  • White sugar, brown sugar, corn syrup

  • Cookies, cakes, muffins, crackers, chips, desserts

  • Fizzy drinks, sugar-sweetened drinks

  • Colourings, preservatives, flavour enhancers

Focus more on anti-inflammatory foods such as:

  • Vegetables especially green and bitter vegetables

  • Fruits

  • Preferably grass-fed and organic meats

  • Fatty Fish (e.g. salmon/mackerel), olive oil, nuts, and seeds

  • Cinnamon, turmeric, ginger

  • Whole grains and beans (if tolerated by your digestive tract)

  • Green tea

Foods like salmon and bone broth will help improve digestion and protect the intestinal wall, while high-fibre foods such as oats, pears, broccoli, and bananas also help with digestion. Flax seeds, mackerel, and salmon are high in omega-3s and can help reduce inflammation. Also, including prebiotics and probiotics into the diet feed the gut with good bacteria.

A diet that incorporates a varied and colourful rainbow of fruits, vegetables, whole grains, spices, and herbs provides essential minerals and vitamins, including antioxidants.

3. Consume Plenty Omega-3 Fatty Acids

Adequate healthy dietary fats (more importantly, omega-3) are important for our brain health. Omega 3 reduces inflammation as it down-regulates the inflammatory response in the body and in the brain, which can be a key driver to poor mental wellbeing (9). It also plays an important role in supporting cell membrane health, which is essential for optimal cell signalling in the brain (10). In order for neurotransmitters to communicate properly with cells, their membranes need to be receptive and ready to receive and transmit signals.

A good rule of thumb is to get 3 portions of oily fish in your diet on a weekly basis.

Rich Omega 3 sources can include:

  • Wild salmon

  • Mackerel

  • Anchovies

  • Sardines

  • Herring

If eating fish isn’t an option, there are many plant-based sources of omega 3 such as:

  • Chia seeds

  • Flaxseeds

  • Walnuts

  • Hemp seeds

Aim to have a serving of any of these on a daily basis to make sure you’re getting optimal amounts of omega 3.

4. Balancing Blood Glucose Levels

Balancing blood glucose levels prevents the development of hypoglycaemia (low blood glucose) and/or insulin resistance (and conversely to increase insulin sensitivity) which are central to improving mental wellbeing. Hypoglycaemia can cause feelings of anxiety and confusion. High blood glucose, on the other hand, can cause fatigue and low moods (11).

Ways to balance blood glucose levels:

  • Consume a protein source with every meal and snack. This helps normalise insulin secretion and reduces cravings (12, 13).

  • Minimise the consumption of refined carbohydrates, such as pastries, bread, pasta, chocolates, sugary drinks and sweets to minimise dips and spikes in blood glucose levels.

  • Consume complex carbohydrates such as whole grains (e.g. brown rice, oats, quinoa and sweet potatoes), beans, lentils, fruits and vegetables, which help stabilise blood glucose levels since they are high in fibre and are nutrient-dense.

  • Sprinkle some cinnamon on foods as it may have the ability to reduce blood glucose levels and increase insulin sensitivity (14).

5. Rest and Digest

To have good gut health, you need to be able to digest food effectively — for which you must be in a parasympathetic state, also known as ‘rest and digest’. When the body is not in this relaxed state, it cannot produce the gastric juices it needs to be able to adequately absorb food. This means that it won’t be able to absorb vitamins, minerals, and nutrients required to be able to support a healthy body and brain. To achieve this restful state, practising deep breathing before eating is highly recommended.


Micronutrient malnutrition, or deficiencies in one or more crucial vitamins or minerals, may negatively impact both physical and mental health and potentially lead to chronic illness.

In addition, chronic psychological and environmental stress may negatively impact micronutrient concentrations in the body which can lead to micronutrient depletion. Therefore, a nutrient-dense diet made up of foods full of vitamins, minerals, and phytonutrients can be a powerful tool in promoting mental wellness.


Low levels of magnesium intake have been associated with depression (15, 16) and recently a study found a positive correlation between lower serum magnesium levels and depressive symptoms (17). Beneficial effects of magnesium supplementation on anxiety and stress-related symptoms have been suggested, though further trials may be required to confirm efficacy in all populations (18, 19, 20).

Magnesium-rich foods such as dark leafy greens, nuts, and cacao.

B Vitamins

The B vitamins, particularly folate, vitamin B6, and vitamin B12, are essential cofactors in neurotransmitter production (21). A deficiency of any one of these nutrients may impair mental health, so make sure your patients are eating foods rich in these nutrients.

Folate is found in:

  • Dark leafy greens

  • Beef liver

  • Brussels sprouts

  • Avocado

Vitamin B6 is found in:

  • Poultry

  • Fish

  • Eggs

  • Bananas

  • Spinach

  • Sweet potatoes

Vitamin B12 is found almost exclusively in animal foods.


1. Move Move Move

Consistent physical activity is linked to good mental health, whereas a sedentary lifestyle is linked to anxiety and depression in people of all ages. (22, 23) Exercise increases the body’s production of anti-inflammatory signalling molecules and brain-derived neurotrophic factor (BDNF), which supports neuroplasticity and a healthy mood (24).

2. Optimise Sleep

Sleep deprivation can exacerbate pre-existing mood disturbances, such as anger, depression, and anxiety, and can lead to confusion and fatigue (25) (27). Even just one sleepless night correlates with these changes in function (26) (28). Optimising sleep can do wonders for your mental health.

Ways to implement healthy sleeping habits:

  • Develop a ‘winding down’ routine before bedtime: Shut off all electronics 1 or 2 hours before sleep. The light from laptop screens, televisions, and phones can affect the production of melatonin, which means your body isn't preparing the hormones it needs to enter the sleep phase.

  • Enhance your sleeping environment: The ideal sleeping environment is dark, cool, and quiet.

  • Get outside: Aim for at least 30 minutes of sun exposure each day.

  • Relaxation techniques before bed: Proven methods include daily journaling, deep breathing exercises, prayer, meditation, hot bath or keeping a gratitude journal where you can write down something you are grateful for each day.

  • Exercise 20-30 mins a day: But no later than 2 to 3 hours before going to bed (performing it too late in the day may cause sleep problems due to the stimulatory effect of exercise, which increases alertness and hormones like adrenaline).

  • Avoid caffeine late in the day: ideally no caffeine after 2pm as it can have disruptive effects on sleep.

  • Set a schedule: Going to bed and waking up at the same time every day creates consistency which can improve the quality and duration of your sleep as our bodies become accustomed to the schedule. Staying up late and sleeping in late on weekends can disrupt our body clock's sleep-wake cycle.

3. Spend More Time In Nature

Spending time in nature is absolutely essential for our mental health. Research shows that exposure to natural places can lead to positive mental health outcomes, even with just a view of nature from a window, being within natural places, or exercising in these environments (29, 30). Furthermore, the practice of ‘forest bathing’ or shinrin-yoku in Japanese, has been found to significantly decrease depression and anxiety. (31, 32).

Nutrition provides the building blocks and the fuel for our brain, as well as our body. Our mental wellbeing is very complex and it depends on many factors such as toxic burden, sleep, nutrients, gut health, inflammation, trauma, or exposure to microorganisms. These items influence physiology which is also affected by genetics and an individual’s attitude and beliefs.

The key insight is that your brain is an organ that’s connected to everything else happening in your body. Optimising your brain starts with optimising your body first.

This is the third and final article in the Mental Health Nutrition Series. The first and second articles can be found here.



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