Schizophrenia is not caused by a nutritional deficiency. On the other hand, people with schizophrenia are just as much in need of good nutrition as anyone else. Poor nutrition can therefore make things worse and also make it difficult for people to respond to treatment. Many people with schizophrenia fail to eat properly.
Essential nutrients (vitamins and minerals) are required to enable the body’s biochemical machinery to work effectively. Without appropriate amounts of vitamins and minerals, the body cannot function. Essential nutrients are relatively more important for the brain than for any other tissue. This is because the brain uses up so much energy and metabolises so quickly. Although the brain is only around 2% of the body by weight, it uses up about 20% of the body’s energy. Thus, on average, its biochemical activity per unit weight is ten times higher than that of other organs.
Like anyone else, people with schizophrenia may develop specific deficiencies of particular essential nutrients. Such deficiencies can really only be identified by careful clinical examination and biochemical tests in a particular individual and cannot be the subject of general instructions applicable to everyone. If you think that you or someone close to you may have a specific nutritional deficiency the best thing to do is to consult a nutritionist or a doctor with a special interest in nutrition.
However, there are some useful general instructions which can be given and which may be particularly helpful for people with schizophrenia or related problems.
- Multinutrient supplementation. Ideally, we should get all our essential minerals and vitamins from food, in practice, this is often simply not possible. It is therefore sensible to take each day a good quality universal supplement which provides all the known essential minerals and vitamins. There are several of these available and assistants in chemist’s shops or health food stores will usually be able to point them out. Many people with schizophrenia have poor gastrointestinal absorption, especially if they are sensitive to gluten. In this case, an extra multivitamin or multimineral supplement each day, which provides twice the usual amount may be appropriate. It is particularly important to take enough B12, folic acid, and B6. These all help control the levels of homocysteine which may be harmful to nerve cells and which is so often elevated in people with schizophrenia.
- Antioxidants. Oxygen is essential to life, but under some circumstances it may be too active, damaging cells by oxidizing their components. There is increasing evidence from many different directions that, in schizophrenia, nerve and other cells are oxidized more readily than usual. This suggests an increased need for antioxidant intakes which are higher than those provided by ordinary multivitamin or multimineral tablets. It is important to use two antioxidants, one which will work in the watery parts of the body and one which will work in the cell membranes. Much more work needs to be done to work out exactly the levels of antioxidants required. However, a reasonable proposal in the light of current knowledge is that around 500mg/day of vitamin C and 100 IU of vitamin E should be taken in addition to the multi-nutrients.
Vitamin C works best in the watery parts of the body and vitamin E in the cell membranes. Together they produce a co-ordinated effect.
- Total fat. A major World Health Organisation (WHO) study has shown that all races and countries are about equally affected by schizophrenia with regard to the numbers of patients/1000 population (1). However, the same study showed that the severity of the illness is considerably worse in some countries than others. Danish investigators have shown that this is best explained by the total amount of fat in the diet, especially saturated fats, the types found in meats, dairy products and hard margarine (2). The higher the intake of this type of fat, the higher the risk of a poor outcome of schizophrenia. It, therefore, makes sense to cut down on fat intake as much as possible. This is likely to have general health benefits.
- Good fats. Not all fats are bad. While the WHO study showed that high levels of saturated fats were associated with a poor outcome of schizophrenia, it also showed that vegetable and fish fats were associated with a relatively good outcome (2). People with a low intake of saturated fats and a high intake of vegetable and fish fats did well.