Fat consumption and schizophrenia.

This report describes the statistical association between the average ratings of course and outcome of schizophrenia in 8 national centres participating in the World Health Organization international 2-year follow-up study (1) and the amount of fat in the average national diets as published by the Food and Agriculture Organization of the United Nations (2). Highly significant correlations were found between favourable ratings of course and outcome of schizophrenia and a low percentage of total fat (r = 0.80-0.90; P less than 0.05) and of fat from land animals and birds (composed mainly of saturated fat) (r = 0.91-0.95; P less than 0.01). High percentage of fat from vegetables, fish and seafood (having a relatively high content of unsaturated fatty acids) tended to be associated with a favourable course and outcome (r = 0.23-0.50; P greater than 0.10). A multivariate analysis revealed that 97% (P = 0.0002) of the variation in the overall outcome of schizophrenia between the national centres could be explained by the combined variation in the percentages of fat from land animals and birds and from vegetables, fish and seafood, respectively, in the national diets. These results suggest that the course and outcome of schizophrenia may be influenced through diet. They should encourage investigators to perform controlled clinical trials of low-fat diets with a sufficient amount of essential fatty acids.