Something to think about

FEW of us associate mental health with what we eat.

But research shows our psychology is profoundly affected by nutrition. Worryingly, many people aren’t getting the nutrients for optimal mental health — the ‘western diet’ is high in fatty and sugary processed foods and alcohol, and low in fresh fruit, vegetables and wholegrain cereals.

Mental health can refer to cognition, the ability to analyse a situation or task and formulate and express an appropriate, reasoned response. Performing a crossword puzzle, or recognising people, places, or the time, are examples of cognition. Part of cognition is memory, the lived experience that gives context to our thoughts.

Then there’s emotion, the feelings that can guide our actions irrespective of the rational response to a situation.

All the processes above — our thoughts, our memories, our feelings — are governed by chemical processes within our brain.

Like every biochemical process in our body, these reactions, which control the conscious and unconscious, are subject to manipulation by dietary nutrients.

Older Adults

Much of the research is based on older adults. Deficiencies of folate and vitamins B1, B2, B6 and B12 (in wholegrain cereals, fruits, green leafy vegetables, lean meat, chicken and fish), are associated with poorer cognition as we age.

These adverse effects arise from an inability to make and process chemicals, called neurotransmitters, in the brain. If you’re B vitamin activity gets disrupted, you won’t produce the correct balance of neurotransmitters, like dopamine and noradrenaline, required for normal thought and reasoning.

Other potential deficiencies in older adults include vitamin C (from fruit and vegetables) and tryptophan (found in milk, chicken, nuts, onions, broccoli and bananas). These two nutrients create serotonin, a potent feelgood chemical that influences our mood, sleep patterns and appetite.

Alcohol

Aside from our elderly population, the effects of folate and B vitamin deficiencies can be seen in younger adults when low intakes coincide with habitually heavy alcohol consumption. Alcohol disrupts the activity of these vitamins in the body, including their roles in normal brain chemistry. This is why high alcohol intake contributes to depression.

Brain building

In addition to its effects on neurotransmitter activity, diet and nutrition have a bearing on the structure of the brain. For example, children deficient in iron (available from lean meat, fresh fruit and vegetables, and fortified breakfast cereals) and vitamin D (in oily fish and fortified breakfast cereals) during infancy and early childhood have brains anatomically different to those of better-nourished children. These physical differences can lead to permanent deficits in brain function.

While it has been assumed that no new brain cells are created in adulthood, recent studies have shown that high intake of ‘polyphenols,’ chemicals from dark berry fruits, like blueberries and red grapes, can encourage the growth of new cells in an area of the brain called the hippocampus, a critical region controlling memory and resistance to depression and anxiety.

Additionally, the omega-3 oils we get from oily fish are integral building blocks of brain tissue. The evidence suggests that high intake of these omega-3 oils from early life builds a brain through which impulses travel more easily, and a brain more resilient to age-related degeneration.

Sharpen up

To optimise your mental health, the winning dietary formula is: a fortified, high-fibre breakfast cereal with fortified milk every morning; at least five servings of fresh or frozen fruit and vegetables (especially dark berry fruits, like blueberries) each day; a generous serving of oily fish, like salmon, mackerel, trout, sardines or pilchards, at least three to four times per week, and a strictly limited alcohol intake (i.e. a maximum of two to three drinks per week).

You might even consider a daily multi-vitamin and multi-mineral supplement containing those important B vitamins, if you’re over 40.

* For more on healthy eating, please visit www.dieticio.com

Dr Daniel McCartney, lecturer in human nutrition and dietetics at DIT.