Good nutrition is essential for mental health. There are a number of mental health conditions that may be influenced by dietary factors. Our food plays an important role in the development, management and prevention of depression, schizophrenia, attention deficit hyperactivity disorder as well as Alzheimer’s disease (AD).

By our 70’s one in five people will suffer from cognitive impairment and within 5 years half will progress to dementia. The earlier we can slow or stop this process, the better! Currently there is no effective treatment for AD unavailable, but there are interventions to control risk factors.

Over the past 60 years our intake of fresh, nutritious and local food has decreased and we care taking in more fat, sugar, alcohol and additives. In the UK there has been a 34% decrease in vegetable intake, with only about 13% of men and 15% of women meeting the required minimum of 5 portions of fruit and veg per day. The past 660 years has also shown a 59% decrease in our fish intake which ultimately means a lower intake inessential omega 3 fatty acids.

There are certain foods and nutrients that can help slow brain deterioration and atrophy and also play a vital role in prevention.


Be sweet on berries and cherries:

Berries, especially the dark ones such as blackberries, blueberries and cherries are a rich source of anthocyanins and other flavonoids which help to boost memory function. Individuals receiving bblueberry supplementation showed an improvement in memory in older adults. Consistent supplementation also helped to slow down brain degeneration with age.

The Harvard Nurse’s Health Study looked at cognitive function of over 16,000 women. They found that the higher, long-term consumption of berries showed significant slower rates of cognitive decline. Greater intakes of blueberries and strawberries showed slower rates of cognitive decline and not just by a little bit. The results were equivalent to cognitive differences one might observe in women up to 2½ years apart in age, meaning that a higher intake of berries could lead to delayed cognitive aging by as much as 2.5 years.


Omega 3 fatty acids:

The long-chain omega 3’s fatty acids, DHA and EPA are the most important fatty acids in omega 3 family. They are termed “essential” because the body needs them for healthy cellular functioning and this cannot be produced in-house and need to be ordered in from foods/supplements. We once ate a diet rich in DHA but now our intake is <100 mg/day. It is estimated that the gray matter are the brain is 50% fatty acids, which are polyunsaturated and 33% belong to the omega-3 family.

DHA is the most abundant fatty acid in brain and is essential for good brain health. The brain operates more efficiently with higher levels of DHA and supplements may help reduce symptoms of depression in individuals on antidepressant medication. DHA may be associated with a decreased risk of AD and lower DHA level are associated with an increased risk of AD.

There is no specific DRI for omega 3 fatty acids and the required amounts for brain health are a bit inconclusive, but the WHO recommends a general daily EPA + DHA intake of 0.3-0.5g.

Good sources of omega 3’s include seafood, algae, and fatty fish. It is a good idea to substitute fish for meat 2-3X/week. You could also add flaxseed powder into your morning breakfast. If you don’t eat fish, discuss a supplementation with your dietitian as you do get seaweed or microalgae omega 3 supplements.


B Vitamins:

In 1990 there was a small study of 22 Alzheimer’s patients and they found high concentrations of homocysteine in their blood. Homocysteine is a common amino acid and is one of the building blocks that make up proteins. Homocysteine is made from the amino acid methionine

Today homocysteine is considered a strong, independent risk factor for the development of dementia and AD. Blood levels of more than 14 may double our risk. One in six cases of AD may be attributable to elevated homocysteine. The body uses B vitamins (B12, B6 and folate) for conversion of methionine into homocysteine.

Lowering homocysteine levels by B vitamins helps to slow the rate of accelerated brain atrophy in people with mild cognitive impairment. As we age our brain slowly atrophies, but with AD the shrinking is greatly increased. If we could slow the rate of brain loss, could we could slow conversion to AD?

In a study, individuals were given B vitamins for 2 years. The results showed a slowed rate of brain shrinkage and the rate of atrophy in those with high homocysteine levels was cut in half. Ina follow up study it was demonstrated that B vitamin treatment reduces brain atrophy by as much as 7 times, in regions specifically vulnerable to AD process.

It would make sense then to try and prevent a deficiency in any of the 3 B vitamins used. Most people get enough B6 and B12 but most of us do not get in enough folate as this is found primarily in our dark green leafy veg and beans.

People with high homocysteine levels that were placed on a healthy plant diet decreased their homocysteine levels by about 20% due to the fact that methionine that is broken down to homocysteine is mainly found in you animal products.

Vitamin B12

  • This vitamin has been shown to delay the onset of signs of dementia if it is given before onset of the first symptoms.
  • The best sources are animal products: Meat, poultry, dairy, seafood and eggs.

Requirements depend on age and gender.

Amounts you can get in through your diet:

  • 1 cup of milk: 1.2-1.4mcg
  • 50g cheese: 0.7-0.9mcg
  • 75g chicken: 0.2-0.3mcg
  • Salmon 75g: 3.7mcg
  • Mackerel 75g: 13.5mcg

Vitamin B6:

  • The best sources for this vitamin are: Meat, fish, poultry, enriched cereals, nuts and lentils.

Amounts you can get in through your diet:

  • ¾ cup chickpeas: 0.84mg
  • ¼ cup sunflower seeds: 0.3-0.5mg
  • 75g chicken: 0.25-0.48mg


  • It has been seen that individuals suffering from depression had 25% lower blood folate levels. Low levels of folate are associated with a poor outcome with antidepressant therapy.
  • The best sources include: Dark green leafy veg, broccoli, legumes, beans and lentils.

Amounts you can get in through your diet:

  • Cooked spinach ½ cup: 121-139mcg
  • Broccoli ½ cup: 89mcg
  • Lentils 175ml: 265mcg
  • Mung beans 175ml: 234-238mcg



This is the compound that gives Indian spice curry its bright-yellow colour and may have the power to protect against AD. India –had one of the lowest rates of AD in the world.

Cucurmin slows the formation of and possibly destroys the accumulated plaque deposits  which are at the root of AD.


Dietary Damage

Some nutritional factors may actually enhance brain inflammation.


Obesity is on the top of list of concerns as higher levels of adiposity can lead to a higher risk for future Parkinson’s disease and AD. Central adiposity is related to cognitive decline and dementia. Body fat promotes inflammation and may store toxins. A fatter person even has a smaller hippocampus, thought to be the centre of emotion, memory and automatic nervous system in the brain.


Alcohol has a depressant effect on the brain and leads to a rapid worsening of mood. Alcohol is actually a toxin that has to be deactivated by liver. During the detoxification process the body uses thiamin, zinc and other nutrients and this may deplete reserves, especially if diet is already quite poor. Thiamin and other vitamin deficiencies are common in heavy drinkers and this causes low mood, irritability, aggressive behavior as well as more serious and long-term mental health problems.


The bottom line

  • Enjoy a varied diet and include the Mediterranean diet principles into your daily diet.
  • Focus on a good intake of a variety of vegetables. Think of a rainbow to ensure adequate antioxidant intake. Ensure half your plate is filled with veg and aim for at least 5 portions a day.
  • Boost your fish intake and focus on fatty fish, aiming for an intake of 2-3 times a week.
  • Add nuts and berries to your diet – especially walnuts and dark berries
  • Ensure adequate B-vitamin intake
  • Maintain a healthy weight
  • Avoid refined foods, focus on whole foods
  • Avoid sugar, sugary drinks, cakes, sweets etc. as these are loaded with calories, have little nutritional value and may trigger mood swings
  • Potential supplements would include:
    • Curcumin, vitamin B12 (vegans), omega 3 (poor fish intake)


Munchwize Dietitians are based in Claremont, Cape Town.

Contact us here for more info or to book a session. December is almost upon us – Vitality members in Cape Town don’t forget to book in for your Vitality Nutrition Consultations before the end of the year.