Food Nutrition and Cancer
The American Cancer Society signaled a change in its approach to fighting cancer when it announced that it will support more research studying the role of diet in cancer prevention. This shift reflected the findings of recent studies showing that some foods or nutrients seem to play a protective role against cancer, while others appear to promote the disease.
Diet and colon cancer.
The men who consumed diets high in fat and low in fiber were 3.7 times more likely to develop adenomas than those who ate a low-fat, high-fiber diet. Men who ate more red meat than chicken and fish also had greater risks of developing adenomas.
The Harvard researchers had found similar results in previous studies of fiber and fat intake among women. The findings also supported research by other scientists that related high fat intake and low fiber consumption with an increased risk for colon cancer, which claims the lives of 58,000 Americans each year.
Folate and cervical cancer.
Researchers led by nutritionist Charles E. Butterworth at the University of Alabama in Birmingham discovered that folate deficiencies in the blood increased the incidence of a precancerous condition known as cervical dysplasia (abnormal cell growth in the cervix, the opening to the uterus) in women who were already at risk for the disease. Cervical cancer is the ninth leading cause of cancer deaths in the United States.
Low folate levels seem to magnify the harmful effects of such risk factors as smoking, having multiple sexual partners, and infection with a sexually transmitted virus called human papilloma virus (HPV).
In the study, the researchers compared folate levels in 294 women who had cervical dysplasia with 170 women who did not. Among both groups, the level of folate in the blood did not by itself seem to increase the risk of cervical dysplasia. But women who had both low folate levels and other risk factors were up to five times more likely to have cervical dysplasia than were women with normal folate levels.
The researchers hypothesized that folate may protect cells from cancer-causing agents by making the cells’ genetic material less vulnerable to HPV infection. Folate is a vitamin found in such foods as leafy, green vegetables and some meats.
Children’s cholesterol levels.
Total dietary fat intake for children over age 2 should not exceed 30 per cent of the total daily calories consumed, and saturated fats should make up no more than 10 per cent of those calories. Thus concluded the Expert Panel on Blood Cholesterol Levels in Children and Adolescents in its September 1991 report. The panel, which was sponsored by the United States National Institutes of Health, also recommended that children consume no more than 300 milligrams of dietary cholesterol per day. These guidelines paralleled those that a similar panel recommended for adults in 1990.
The group reached its conclusions after reviewing numerous studies indicating that high blood-cholesterol levels in children play a role in the development of coronary artery disease later in life. Coronary artery disease-the leading cause of death among Americans-occurs when cholesterol builds up on the inner walls of the arteries and restricts the flow of blood to the heart. Research has found that this build-up can start in childhood. Saturated fats, which are found mainly in animal products, seem to contribute to this process.
The panel called on schools and the food industry to provide children with appetizing alternatives to high-fat and high-cholesterol foods. It also suggested that health professionals, government agencies, and the media take a more active role in educating the public on healthy dietary habits.
Diet and mental development.
A British study of malnourished children in Jamaica found that developmentally stunted children’s mental capacities could become equivalent to those of healthy children after they received proper nutrition and the stimulation of playing with their mothers.
For two years, the researchers studied 129 stunted infants and toddlers who ranged from 9 months to 24 months in age. Thirty-two healthy children served as a basis for comparison. The stunted children were examined to make sure that their poor growth was due to malnutrition rather than to illness or some other disorder. The researchers then assigned the children to one of four groups.
The first group received no intervention at all. The second group received food supplements only. The mothers of the third group received special instruction and encouragement for one hour each week in playing with their children. The fourth group received both nutritional supplements and the weekly play sessions.
At the beginning and the end of the study, the researchers administered tests to measure the children’s development in such areas as hand-eye coordination and the ability to recognize shapes and use building blocks. Initially, the stunted children’s test scores were lower than those of the well-nourished children. At the end of the two years, the scores of the children who had either received extra food or extra attention were higher than the scores of the children who received no intervention. The group that received both food and play showed the greatest increase in mental development, and they performed almost as well on their tests as did the healthy children.