A few days ago, after three years of research and selection, the World Health Organization (WHO) rated six healthiest foods and ten junk foods. The healthiest foods included six categories: the best vegetables, the best fruits, the best meat, the best cooking oil, the best soup and the best brain-protecting food, and the familiar sweet potato was ranked as the champion of thirteen best vegetables.

Experts say that sweet potato not only has balanced nutrition, but also has little-known functions such as preventing sub-health, losing weight, bodybuilding and anti-cancer.

Sweet potato, also known as sweet potato, sweet potato, sweet potato and sweet potato, is an annual plant of convolvulaceae. It is a kind of health food with dual functions of medicine and food. Sweet potato contains dietary fiber, carotene, vitamins A, B, C and E, and more than ten kinds of trace elements such as potassium, iron, copper, selenium and calcium. The nutritional value is very high, and it is called nutrition by nutritionists.

Professor Zhang from the Health Room of Beijing University of Chinese Medicine said that eating sweet potatoes will not only make you fat, but also help you lose weight, keep fit, prevent sub-health, and relieve constipation and detoxify. Every100g of fresh sweet potato contains only 0.2g of fat, which generates 99 kilocalories of heat energy, about one third of that of rice. It is a good low-fat and low-calorie food, at the same time, it can effectively prevent sugar from transforming into fat, which is beneficial to weight loss and fitness. Sweet potato contains a lot of dietary fiber, which cannot be digested and absorbed in the intestine. It can stimulate intestinal tract, enhance peristalsis, relieve constipation and detoxify, especially for senile constipation.

Zhang particularly emphasized that sweet potato is an alkaline food and the most rare, just like many fruits and vegetables. Generally, food is acidic, and the PH value of human body is 7.34, so eating sweet potato is beneficial to the acid-base balance of human body. Eating sweet potato can reduce blood cholesterol and prevent "modern diseases" such as sub-health, cardiovascular and cerebrovascular diseases.

Professor Lin Hongsheng, director of the Oncology Department of Guang 'anmen Hospital of China Academy of Traditional Chinese Medicine and deputy director of the National Center for Oncology of Traditional Chinese Medicine, said that sweet potato is not only nutritious, but also ranks first among anti-cancer foods. There are many introductions in this document.

The list of 20 kinds of anticancer vegetables published by National Cancer Research Center of Japan is: sweet potato, asparagus, cauliflower, cabbage, broccoli, celery, sweet pepper, carrot, cauliflower, amaranth, shepherd's purse, kohlrabi, mustard, tomato, green onion, garlic, cucumber and Chinese cabbage, among which sweet potato ranks first. Japanese doctors found that the cancer inhibition rate of cooked sweet potatoes was higher than that of raw sweet potatoes through a dietary survey of 260 thousand people.

Medical workers in China investigated the hometown of centenarians in western Guangxi, and found that all the longevity elders here have a common feature, that is, they are used to eating sweet potatoes every day, even taking sweet potatoes as their staple food.

The anticancer mechanism of sweet potato is not very clear, and opinions vary. The hospital in Philadelphia, USA, extracted an active substance-androsterone from sweet potato, which can effectively inhibit the occurrence of colon cancer and breast cancer. Another American university study found that there is a substance called dehydroepiandrosterone in sweet potato, which has a definite effect on preventing and treating cancer.

Professor Zhang from the Health Room of Beijing University of Chinese Medicine believes that sweet potato has a certain anti-cancer effect, but its anti-cancer "ability" should not be exaggerated, and it should be treated dialectically, because its mechanism of action is not completely clear, and the greatest role of sweet potato should be to lose weight, keep fit, prevent sub-health, relax bowels and detoxify.

Regarding the anti-cancer effect, Chinese medicine theory holds that it can reduce the accumulation of garbage and toxins in the human body because of its catharsis and detoxification. In this regard, Professor Song Santai, director of the Cancer Center of China Academy of Military Medical Sciences and deputy director of the Cancer Committee of the whole army, also believes that the mechanism and reasons of sweet potato anti-cancer have not yet been scientifically tested. Theoretically, it is speculated that it is rich in dietary fiber, which can relieve constipation and is beneficial to prevent cancers such as colon cancer.

It is also important to eat sweet potatoes correctly. Be sure to pay attention to steaming and cooking thoroughly, because the cell membrane of starch in sweet potato is difficult to digest without being destroyed by high temperature, and the gasification enzyme in sweet potato will cause discomfort after eating; Excessive or unreasonable consumption of sweet potato can cause abdominal distension, heartburn, pantothenic acid, stomachache and so on. So you shouldn't eat too much. It should be used with caution for those diagnosed by TCM as dampness blocking the spleen and stomach, qi stagnation and blood stasis.

According to ancient documents such as Compendium of Materia Medica and Addendum to Compendium of Materia Medica, sweet potato has the effects of "tonifying deficiency and benefiting qi, strengthening spleen and stomach, and strengthening kidney yin", which makes people "live longer and have fewer diseases". It can also tonify the middle energizer, promote blood circulation, warm the stomach and nourish the five internal organs. "Contemporary Chinese Medicine" said: "Sweet taste, flat nature. Into the spleen and kidney. " , "tonify the middle and blood, replenish qi and be holy, broaden the stomach and relax the bowels. Indications: Spleen edema, sore and swelling, intestinal dryness and constipation.

Eating corn has many benefits.

Recently, a study by the German Nutrition and Health Care Association shows that corn has the highest nutritional value and health care function among all staple foods.

Can prevent heart disease and cancer.

In this study, which lasted 1 year, experts compared the nutritional value and health care function of many staple foods such as corn, rice and wheat. The results show that the vitamin content in corn is very high, which is 5- 10 times higher than that in rice and wheat.

At the same time, corn contains a lot of nutrients and health-care substances, which also surprised experts. Besides carbohydrates, protein, fat and carotene, corn also contains nutrients such as riboflavin and vitamins. These substances are of great benefit in preventing diseases such as heart disease and cancer.

The research also shows that the nutritional value of special corn is higher than that of ordinary corn. For example, the content of protein, vegetable oil and vitamins in sweet corn is 1-2 times higher than that in ordinary corn; The selenium content of "life element" is 8- 10 times higher; Among 17 amino acids, 13 amino acids are higher than common corn. In addition, the moisture, active substances, vitamins and other nutrients of fresh corn are much higher than those of old corn, because the cultivation branch of corn drops rapidly during storage.

Contains 7 kinds of "anti-aging agents"

Professor Rahman, a famous German nutritionist in charge of this research, pointed out that among the more than 50 kinds of nutritional and health-care substances that have been proved to be the most effective today, corn contains 7 kinds-calcium, glutathione, vitamins, magnesium, selenium, vitamin E and fatty acids.

It has been determined that every100g of corn can provide nearly 300 mg of calcium, which is almost the same as that contained in dairy products. Rich calcium can lower blood pressure. If you take 1 g calcium every day, your blood pressure will drop by 9% after 6 weeks. In addition, the carotene contained in corn can be converted into vitamin A after being absorbed by the human body, which has the function of preventing cancer; Plant cellulose can accelerate the discharge of carcinogens and other poisons; Natural vitamin E has the functions of promoting cell division, delaying aging, lowering serum cholesterol, preventing skin lesions, relieving arteriosclerosis and brain function decline. The researchers pointed out that lutein and zeaxanthin contained in corn can fight against eye aging. In addition, eating more corn can also inhibit the side effects of anticancer drugs on human body, stimulate brain cells and enhance people's brain power and memory.

Excellent eye anti-aging food

Chinese medicine believes that corn is flat and sweet, and has the functions of appetizing, strengthening the spleen, removing dampness and diuresis, and is mainly used for diarrhea, indigestion and edema. According to nutritional analysis, corn contains sugar, protein, carotene, lutein, zeaxanthin, phosphorus, magnesium, potassium and zinc. Age-related macular degeneration (AMD) is a disease caused by eye aging, which can lead to visual impairment in severe cases. Many epidemiological studies have found that lutein and zeaxanthin can prevent age-related macular degeneration.

According to the research done by Harvard Medical School and many research centers in the United States during the period of 1994, taking higher amounts of lutein and zeaxanthin can reduce the risk of age-related macular degeneration by 43%. Corn contains lutein and zeaxanthin, especially the latter. Therefore, corn can be said to be an excellent supplementary food against eye aging.

Carotene, lutein and zeaxanthin contained in corn are fat-soluble vitamins. Cooking with oil can help absorption, so it can play its health care role.

From the point of view of anti-free-radical, Cornell University's research in the Journal of Agricultural and Food Chemistry showed that the anti-free-radical activity of sweet corn increased by 22%, 44% and 53% respectively after heating at 15 degrees Celsius for 0, 25 and 50 minutes.

Canned corn on the market can provide different cooking purposes, but corn is easy to get damp and mildew, and it is easy to produce aflatoxin, so it should be stored in a cool and dry place.