A junior school in south London has been transformed since the staff banned fizzy drinks and crisps from the tuck shop and brought in crates of fruit instead. Two years on, according to the head teacher, the children are able to concentrate better, behaviour has improved and they achieved three times the pass rate in the English exam.
So, why are school tuck shops selling crisps and sweets and fizzy drinks in the first place? The fact that a school is regarded as unusual by encouraging healthy eating and seeing positive results in work and general behaviour is appalling.
The food we eat has a direct affect on health and behaviour, whatever our age. Any parent knows that, if you give small children a junk-food meal, say crisps, fizzy drinks, sweets, pizza and chips, you'll get first a great increase in noise and excitement, followed by tears and tantrums.
"Eating lots of foods full of refined sugar and flour is going to make it harder for kids to function effectively in class," says Dr Adam Carey of the Centre for Nutritional Medicine in Harley Street, London. "At first they get a rush as the glucose level in the blood goes up, then they begin to feel drowsy as it begins falling. That's disruptive enough, but finally to stop it falling too far, the body starts producing adrenaline, which makes them edgy and irritable."
Fizzy drinks are full of sugar so they contribute to this emotional see-saw, but they also contain phosphorus, which reduces the amount of calcium that you can absorb from your diet. That, in turn, can upset the balance of calcium in the brain essential for nerve cells to communicate with one another.
This has been known for years. The teachers at Wolsey Junior School in New Addington, south London, are simply following in the pioneering footsteps of Prof Stephen Schoenthaler, now at California State University, who nearly 20 years ago conducted large-scale trials involving children and diet in New York. Between 1980 and 1983, 803 low-achieving schools in the city simply reduced the amount of sugars, fats and additives in the children's meals. The exam pass rate overall rose from 11 per cent below the national average to 5 per cent above it.
In another study involving more than 8,000 delinquent youngsters in remand homes, Schoenthaler made similar changes in diet; that resulted in a 47 per cent drop in antisocial behaviour. Since then other researchers have looked at the effect of boosting vitamins and minerals in the diet. Increasing the amount of the essential fatty acid, omega 3, found in linseed oil and fatty fish, reduces the amount of hyperactive behaviour. Zinc, plentiful in whole-grain cereals and soybeans, reduces aggression as does iron and magnesium.
Two years ago, in the Journal of Paediatric Child Health, a review by Australian researchers of academic studies on the links between diet and behaviour concluded: "There is a clear relationship between the way children eat and how they act. Almost all studies have found a statistically significant change in behaviour with dietary intervention."
All this research has either been ignored or side-tracked into a sterile debate about food supplements. Schoenthaler and others, such as Dr David Benton of Swansea University, have run trials which, they claim, show that giving vitamin and mineral supplements to children can boost their IQ by several points.
But even those such as Schoenthaler, who advocate supplements, say that the first step in improving performance and behaviour is to reduce junk food intake as much as possible; and to ensure `nutritionally optimum' meals. "A vitamin supplement is just an insurance policy that can make up for poor eating," he says.
What's more, many people working with children are concerned about diets that often seem inadequate. Certainly Eileen Ewin, the teacher who initiated the ban at the Wolsey school was sufficiently worried to act. "We've got 40 per cent of the pupils on free meals and I know they eat a lot of beef-burgers, chips, crisps and sweets at home. We just felt they probably weren't getting the fresh fruit and vegetables they need."
There's no secret about what children should be eating. Ideally, they should have fresh foods, free of additives and preservatives, with plenty of whole grains, eggs and seafood, fruit and vegetables. They can then have a small amount of dairy foods and red meat. You could also consider adding wheat germ and nutritional yeast to meals. Snacks are fine, especially raw foods and nuts or seeds. Use ground-up raisins or other dried fruit as a substitute for sugar.
The brain is an energy-guzzling organ. It absorbs 20 per cent of the glucose taken into the body. It needs all the major vitamins and minerals to function at full capacity. Adequate doses of both A and B vitamins are vital for processing the energy from glucose, insulating the nerves and producing the chemicals and acids the brain needs to make protein. Vitamin C is needed for the brain to make use of iron, which in turn helps make the chemicals that carry messages between neurones.
Then, there are a couple of essential minerals such as magnesium, which helps extract energy from nutrients, potassium for chemical messengers and zinc, essential for nearly all the enzyme reactions in the brain. We get all these vitamins and minerals from a variety of sources but certain ones keep showing up on recommended dietary lists: red peppers and other red or yellow fruit and vegetables, whole grains including wheat, rye and rice, beans, oily fish, green vegetables, nuts and seeds, chicken and red meat.
So, for school children and anyone else interested in boosting their brain power, a typical day's menu might look like this:
Breakfast: Porridge with wheat germ and raisins, diluted fruit juice. Lunch: tuna salad, wholemeal bread, fresh fruit.
Dinner: steak, spinach salad, brown rice.