Have you ever wondered if what you eat affects your mood? Or if your mother's advice to eat fish because it's a "brain food" was just a way to get you to clean your plate? With the growing incidence of depression and aging of the " baby boomer" generation, scientists are now looking into the area of diet and brain function. AFIC looks at what's on the menu to help with memory and improved mood.

B vitamins

A study by the Centre for Scientific and Industrial Research Organisation (CSIRO) in Australia in women aged 20 to 92 years, found that supplementation with folate and vitamin B12 improved memory and mental performance in women in their 20s and in those over 65 years of age. Vitamin B6 (found in soybeans, chicken and bananas) improved word finding ability in women of all ages. The researchers noted that the normal diets of women were low in some of these nutrients. Folate can be found in fortified breakfast cereals, fruits and vegetables while good sources of vitamin B12 are meat, fish, dairy products and eggs.

It is thought that the B-vitamins may help chemicals involved in thinking and improve blood flow to the brain.

Iron to the rescue

Teenage girls who are having trouble with their schoolwork, are irritable or constantly tired, may find that iron deficiency is their problem. According to Dr Tony Helman, Chairman of the Australian Iron Advisory Panel, iron deficiency is found in I in 9 teenage girls in Australia.

A recent study in the Lancet of 76 teenage girls found that those who took iron supplements for eight weeks did significantly better on verbal and memory tests than the group that took the placebo. The researchers concluded that even in the absence of anaemia, iron deficiency might impair learning in adolescent females.

Dr Helman says 'teenage girls are particularly prone to iron deficiency because they are losing iron rich blood through menstruation, they are growing fast, and they often don't eat enough food rich in iron. Parents should think about the possibilities of iron deficiency if their teenage daughters are having difficulties with their schoolwork, complain of tiredness, are eating poor meals or are having heavy periods."

"Red meat, chicken and fish are all good sources of iron, with red meat being the richest source," said Dr Helman. "Breads, cereals, vegetables, nuts and eggs contain iron in a less available form but absorption can be boosted by combining them with vitamin C-rich foods such as broccoli or orange juice" Iron is important in other age groups too:

In infants, iron deficiency is associated with intellectual and psychomotor impairment such as poor eye-hand coordination. This may not always be completely reversed when iron status is corrected.

Iron deficiency in adults can lead to an inability to concentrate, which in turn can hinder verbal learning, memory, mood and energy levels. Tiredness and irritability are both symptoms of iron deficiency.

Want to relax? Bring on the carbohydrates

Some foods are thought to have the potential to aid relaxation by their effects on brain neurotransmitters. Neurotransmitters are chemical messengers that are produced from nutrients in foods. The manufacture and release of certain neurotransmitters can be affected by the type of foods eaten. Diet can therefore, at least to some extent, affect behaviour although other factors such as the environment, age, gender and medication are also important. The amino acid, tryptophan, found in meat, milk and eggs, is a component of the neurotransmitter serotonin (the "feel good" neurotransmitter). Serotonin is needed for normal sleep. Hence the old advice to take a glass of warm milk to help get to sleep.

Meals that are high in carbohydrates have been shown to increase serotonin levels resulting in calmness and drowsiness. Many people erroneously believe that sugar causes hyperactivity in children when in fact sugar, as a carbohydrate, seems to have the opposite effect!

The FAO/WHO Expert Consultation on Carbohydrates in Human Nutrition (1997) makes the following comment on sugar and hyperactivity; "However, an extensive review of the literature in this area concluded that there is no evidence to support the claim that refined sugar intake has any significant influence on behaviour or cognitive performance in children."

Studies looking at "seasonal affective disorder" in which people get depressed during the long dark winter months in Northern climates, suggest that lower levels of sunlight in winter decrease production of serotonin. To make up for this, people turn to "comfort foods" that are high in carbohydrates to boost serotonin levels. Findings from the studies are mixed, however, with some studies suggesting that an excess of carbohydrates can make subjects too lethargic.

Soothing chocolate

The good mood that comes after eating chocolate is not just due to its great taste. The cocoa, used in chocolate contains phenylalanine. Phenylalanine occurs naturally in the brain and is released when emotions are aroused. Chocolate also contains theobromine and caffeine, both of which have been shown to increase alertness.

Caffeine alert

Moderate levels of caffeine have been shown to increase performance, alertness and concentration. That mid-morning cup of tea or coffee, or a lunchtime cola drink can help you plough through that loaded in-tray.

Enjoy your food

The area of diet and brain function is in its infancy and further research needs to be performed before any recommendations can be made. One important facet of eating that is often forgotten though, is the need to take time to savour and enjoy foods. Too often, people rush through meals with little thought as to how the food actually tastes. Not only can this lead to overeating, it also takes away one of life's simple pleasures.

One of the Japanese dietary guidelines is to make all activities pertaining to food pleasurable ones and to use mealtimes as occasions for family communication. It's a good recommendation to remember as we rush through life.

Give your brain a better diet!

Eat more fish - an omega-3 fatty acid found in fish called DHA might play a role in preventing dementia. A Dutch study reported that elderly men who ate the largest amounts of fish were the least likely to suffer from dementia. Research also suggests that fish oil may help prevent depression.

Skip fad diets - Restricting food intake interferes with concentration and mental performance not to mention the irritability associated with hunger pangs. It's still unclear whether the effects of dieting are due to a lack of food or the dieters preoccupation with weight.

Eat more fruits and vegetables - these are great sources of antioxidants to help protect brain cells against the effects of aging.

Eat breakfast - Studies show that breakfast eaters perform better on tests of concentration than non-breakfast eaters. One theory is that an overnight fast depletes the brain of glucose, the only fuel it can utilise and which also helps the brain to store information.