Diet and disease

Several diseases are linked with diet. Diseases due to a deficiency are rare in developed countries, but many disorders are due partly to overconsumption of certain foods. A diet high in fats may contribute to atherosclerosis and heart disease. A high-fat diet has also been linked with cancer of the bowel (see colon, cancer of) and breast cancer. Obesity increases the risk of many other disorders, including diabetes mellitus and stroke. Overconsumption of alcohol can lead to various alcohol-related disorders. A high salt intake predisposes a person towards hypertension. Some components of the diet protect against disease. For example, fibre protects against diverticular disease, chronic constipation, and haemorrhoids. Many people’s diets contain too few natural vitamins. Pregnant women need high intakes of folic acid to reduce the risk of neural tube defects. Although many illnesses are commonly ascribed to food allergy, it is only rarely that a definite link is proved. (See also nutritional disorders).