[Nutrition and cancer].
The complex process of carcinogenesis is mainly due to environmental factors and therefore preventable. Diet may account for about 35% of cancer. This review presents the nutritional evidence for the development of the four most common cancers in Switzerland. The clearest risk factors for breast cancer are those associated with hormonal and reproductive factors. In relation to dietary factors, high alcohol intake, weight gain and adipositas (postmenopausal breast cancer) probably increase the risk of breast cancer. The evidence is less clear for the consumption of (animal) fat, meat, fruit and vegetables (inverse association). Hormones may also play an important role in the development of prostate cancer. There is no convincing evidence that any dietary factors modify the risk of prostate cancer. Diets high in vegetables are possibly protective, regular consumption of fat and meat possibly increase the risk. Intervention trials revealed protective effects of supplementation with selen or alpha-tocopherol. The main cause of lung cancer is cigarette smoking, and smokers whose diet is protective nevertheless remain at high risk. The evidence that diets high in vegetables and fruit protect against lung cancer is convincing, but it is not clear what constitutents are responsible for this effect. Intervention trials revealed no protective effect of beta-carotene, and in high risk groups, lung cancer risk was even increased. There is convincing evidence that diets high in vegetables decrease the risk of colorectal cancer. The same is true for regular physical activity. Alcohol and consumption of diets high in (red) meat, probably increase the risk of colorectal cancer. For cancer prevention it is recommended to choose a predominantly plant-based diet, to avoid obesity, to reduce the intake of fat, (red) meat, alcohol and salt, not to smoke and to be physically active. The main aim of nutritional therapy of cancer patients is to improve quality of life, whereas the effect on life expectancy is very limited.
Eichholzer
M
M
Institut für Sozial- und Präventivmedizin, Universität Zürich. eichholz@swissonline.ch oder
D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D009369:Neoplasms / Q000209:etiology* / Q000517:prevention & control; D009376:Neoplasms, Hormone-Dependent / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors