Food and Our Brains

15 June 2021

Food and Our Brains – the following article has been written by Joanna Instone, in-house Dietitian at NHS Supply Chain: Food.

Joanna poses the following questions:

Are you aware that the brain is a complex and delicate organ that is sensitive to what we eat and drink?

Did you know what we eat can affect our brainpower?

It can also affect our chances of later suffering from dementia, and our chances of having a stroke.

In Joanna’s short article, she breaks down some of the key research looking into the role of certain foods and nutrients in the healthy functioning of the brain, and reviews the above claims.

Joanna Instone


At least 50% of our brain is made up of fat1. So making sure we eat the right fats and fatty foods are important to promote brain health1.

Omega 3 fatty acids are essential for maintaining a healthy brain cell structure2. They are typically found in oily fish such as salmon, mackerel, trout, sardines and pilchards. It is advised that the general public3 and patients in hospital4 eat these types of fish at least once a week.

If you do not eat fish then cooking with vegetable oil (based on rapeseed oil) and eating small amounts of omega 3 rich linseed, hemp seeds or walnuts (6 halves per day) is recommended5.


Fibre rich carbohydrate foods such as wholegrain bread, breakfast cereals, brown rice and brown pasta all help to promote a rich and diverse gut microbiota. Which in turn helps to promote a healthy brain via the gut-brain axis6.

Glucose is the preferred energy source of the brain. Fibre rich carbohydrate foods are broken down slowly in the gut to produce glucose.

This means that the brain will receive a slow and steady supply of energy to sustain brain activity throughout the day. Including whole grains with each meal, at least three times a day is the best way to achieve this.

Fruit and vegetables (fresh and frozen)

Fruit and vegetables contain vitamins that are linked to mood and brain health. Fresh or frozen green leafy vegetables such as broccoli, kale, cabbage and sprouts contain folate – a B vitamin. Low levels of folate have been linked to depression in the elderly7.

Oranges and orange juice are great sources of vitamin C, as are tinned mandarins and fresh or frozen strawberries. Inadequate vitamin C intake has been liked to depression and cognitive impairment8.


Protein rich foods include meat, fish, eggs, cheese, beans, pulses, nuts and seeds. Meat and milk-based foods like cheese, contain an amino acid called tryptophan which is used by the body to synthesize serotonin, a brain neurotransmitter. Low serotonin levels are linked to depression9.

Not eating enough iron rich foods (found in red meats, beans and pulses) results in weakness and tiredness which affects our mood and performance10.


Our brains are sensitive to fluid levels in our body. Dehydration can quickly impair brain functioning particularly in the elderly 11.

Tea and coffee do count as ‘fluid’ but sudden withdrawal from caffeine drinks may result in fatigue and headaches12 which may contribute to a low mood.

The great news is that looking after our brains by eating healthily will not only help our current mood and mental performance, but it will also help to prevent developing stroke13 and dementia13 (for example Alzheimers disease) in the future.


  1. British Dietetic Association (BDA) (2021) Food Fat Sheet Depression
    Accessed 2 June 2021.
  2. Dyall, S. C. (2015). Long-chain omega-3 fatty acids and the brain – a review of the independent and shared effects of EPA, DPA and DHA. Frontiers in aging neuroscience, 7, 52.
    Accessed 2 June 2021.
  3. PHE (2016) The Eatwell Guide
    Accessed 2 June 2021.
  4. BDA (2019) The Nutrition and Hydration Digest. 2nd ed. Birmingham.
  5. Vegan Society (2021) Omega 3 and Omega 6 fats
    Accessed 2 June 2021.
  6. S., Butler, M.I., Holl, A. et al. (2020) Probiotics and the Microbiota-Gut-Brain Axis: Focus on Psychiatry. Curr Nutr Rep 9, pp.171–182.
    Accessed 4 June 2021.
  7. Reynolds, E. H. (2002). Folic acid, ageing, depression, and dementia. BMJ (Clinical research ed.) 324(7352), pp. 1512–1515.
    Accessed 2 June 2021.
  8. Plevin, D., Galletly, C. (2020) The neuropsychiatric effects of vitamin C deficiency: a systematic review. BMC Psychiatry 20, 315. Doi: 10.1186/s12888-020-02730-w
  9. Jenkins, TA, Nguyen, JCD, Polglaze, KE, Bertrand, PP.(2016)  Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis. Nutrients. 8(1) pp.56.
    Accessed 2 June 2021.
  10. Gandy, J. (2014) Appendix A2 Micronutrients, in Gandy, J. (ed) Manual of Dietetic Practice Chichester: Wiley, pp.927.
  11. British Nutrition Foundation (2021) Dehydration in the Elderly
    Accessed 2 June 2021.
  12. Sajadi-Ernazarova, K.R, Anderson. J., Dhakal, A., et al. (2020) Caffeine Withdrawal
    Accessed 2 June 2021.
  13. NHS (2021) Dementia Prevention.
    Accessed 2 June 2021.