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Scientists say their studies show that some foods may help prevent, possibly even treat, some diseases such as cancer and disorders of the heart and blood system. The proof is not always clear. But researchers believe they have enough information to provide general advice about eating that may help people reduce the danger of suffering heart disease or cancer.

Health experts in many countries still are testing their ideas about the link between our food and our health. Thousands of persons are involved in the experiments. Doctors hope the tests will help prove which foods may help cause a disease and which may help prevent it. But such studies take many years.

Still, health experts believe they already can offer some advice, especially about heart disease and cancer. And their advice is similar for both. We would be much healthier if we sharply cut the amount of fatty, salty and sweet foods that we eat. We also should limit the amount of alcohol we drink. And we should eat more fresh fruit and vegetables, and foods that are high in fiber and in vitamins A and C.

The experts say they cannot yet prove this advice will prevent cancer. And even if the advice cannot halt cancer, it will cut the danger of developing heart disease.

Cancer and heart experts all agree. Eat less fat. This includes fatty red meats and poultry, eggs, milk and other dairy products, and cooking oils. Studies seem to show that people who eat large amounts of fat face an increased danger of suffering breast or colon cancers. Breast cancer is rare in Japan, where little fat is eaten. But in the United States, where much fat is eaten, breast cancer is a major killer. One study in England and Wales found a reduced rate of breast and colon cancer during World War Two when people did not eat foods rich in sugar, meat and fat. But the cancer rate rose after the war when such foods were available again.

Doctors also say eating less fat will reduce the amount of dangerous cholesterol in the blood. This cholesterol can stick to the wall of blood passages, blocking the flow of blood. In the arteries that carry blood to the heart muscle, such blockages cause a heart attack. Instead, eat more foods low in fat. This includes low-fat milk and dairy products, lean meats, poultry without the skin, and fish and shellfish. Experts also say cooking foods in olive oil and fish oil will help lower cholesterol. And they say it is best to steam, bake, roast or broil foods, not to fry. They also say eating dried peas and beans helps lower the amount of fat in the blood.

Health experts also say we should eat more fruit and vegetables, and foods high in fibers such as whole grain breads and cereals and brown rice. Some fibers help lower levels of dangerous cholesterol. This would help reduce the danger of heart disease. Most experts agree that fiber also can protect against cancer. They are not sure how fiber does this. Some believe it helps the body to quickly remove fat that may cause cancer to develop.

Medical experts also say some vegetables seem to contain agents that block cancer. These include asparagus, broccoli, Brussels sprouts, cabbage, cauliflower. Other studies show that persons who eat large mounts of foods that contain the substance beta-carotene are less likely than others to develop cancers in the skin, lung, bladder, breast and colon. Vegetables with beta-carotene include beet greens, bell peppers, broccoli, carrots, lettuce, spinach, sweet potatoes and tomatoes. Fruits that contain the substance include apricots, cantaloupes, cherries, papaya and watermelon.

The body changes beta-carotene to vitamin A. Some health experts say eating more foods with vitamin A may also help protect against cancer. These include liver, eggs and dairy products. Scientists are not sure how vitamin A and bet-carotene prevent cancer. But some research shows the substance interferes with the proteins that cancer cells need to reproduce and grow.

Health experts say we should drink only moderate amounts of alcohol. Usually, moderate means fewer than two alcoholic drinks each day. Researchers say large amounts of alcohol seem to increase the danger of cancers of the mouth, larynx, esophagus and lungs, and possibly the colon and rectum. This seems especially true if the person smokes cigarettes.

The experts also agree. Cut the amount of salt in your food. Salt helps raise blood pressure. High blood pressure is linked to heart disease. We also should eat much less smoked and salt-cured foods. This includes ham, smoked fish, sausages, bacon and bologna. Large amounts of these foods are eaten in parts of China, Japan and Iceland. These areas also have higher rates of stomach and esophagus cancers.

Two American scientists note much of this information tells that people in industrial nations would be healthier if they ate more of the same kinds of foods eaten by early humans more than 10, 000 years ago. The scientists say the human body has changed very little since humans first appeared on Earth. But the way we live has changed sharply. The scientists say our body has not been able to deal with these changes in lifestyle. And this has led to new kinds of sicknesses. These new sicknesses were not known in ancient times. So they are called diseases of civilization: many cancers and diseases of the blood system, including heart attacks and strokes.

The two doctors are from Emory University in Atlanta, Georgia based their report on studies in several different areas of science. Paleontology includes the study of fossil bone remains of ancient people. Anthropology includes the study of people who live today much the way ancient peoples lived. Epidemiology is the study of the spread of disease. And nutritional science is the study of the foods that people eat.

The scientists noted that early Stone Age humans used very little alcohol or tobacco, probably none. Ancient people also got a great deal of physical exercise. But a change in food is one of the major differences between ancient times and life today in an industrial nation. Stone Age peoples hunted wild animals for their met. Wild animals have much less fat than farm animals. Stone Age peoples also ate a lot of fresh wild vegetables, fruits and nuts. But they did not use milk and other dairy products. And they made very little use of grains.

Today, people in industrial nations eat a lot of dairy products and grain foods. We eat six times more salt than people in the Stone Age. We eat far more sugar but much less potassium, calcium, starch and fiber. We eat two times more fat but only one-third as much protein and much less vitamin C.

People today probably would not wish to live as Stone Age people of thousands of years ago. But the scientists say we would be much healthier if we ate more as those ancient people did – sharply cutting amounts of fatty, salty and sweet foods.