Tomatoes can be cooked as a vegetable or eaten raw like a fruit, making them a common food on the people's tables, with both good taste and nutritional value. In addition, numerous studies at home and abroad have shown that tomatoes are rich in vitamins, lycopene, carotene, folic acid, and trace elements, making them an inexpensive "cancer prevention expert".
Reduces the risk of various cancers
"Just as carcinogens are classified, the cancer-preventing effects of food are also graded. The World Cancer Research Fund and the American Institute for Cancer Research, based on epidemiological studies and other relevant evidence, have classified the role of food in reducing the risk of cancer into four levels: 'sufficient', 'probable', 'limited', and 'unlikely'". Yu Changxuan, Deputy Director of the Oncology Department at Nanfang Hospital of Southern Medical University, told reporters from the Life Times that tomatoes can be classified as the second level, i.e., 'probable' cancer-preventing food. Existing evidence shows that some chemical components in tomatoes can protect the body from the damage of carcinogens, thereby playing a role in cancer prevention. In his opinion, the cancer-preventing substances in tomatoes mainly include the following:
Lycopene can prevent prostate cancer. Lycopene, abundant in tomatoes, is currently one of the strongest antioxidants found in plants. A Harvard University study found that men who ate 10 servings of tomatoes or tomato products per week had a 45% lower risk of prostate cancer than those who ate less than 2 servings of tomato products. Lycopene is found in foods such as tomatoes, watermelon, and citrus, but it is more easily absorbed when cooked, and since it is most abundant in tomatoes, tomatoes remain the main source of lycopene for the human body.
Vitamin C can prevent tumors of the digestive system. Vitamin C has antioxidant and anti-cancer effects, can prevent nitrates from turning into carcinogenic nitrosamines in the digestive tract, and can maintain the integrity of the cell matrix structure, preventing tumors of the digestive system such as esophageal and stomach cancer. A Zhejiang University study found that reasonable intake of vitamin C helps prevent stomach cancer. Every 100 grams of tomatoes contains 19 milligrams of vitamin C, five times that of apples and duck pears.
Carotene can prevent oral cancer. Tomatoes contain a relatively rich amount of carotene. An epidemiological survey published in the Journal of International Oral Medicine shows that from animal experiments and preliminary clinical trial results, carotene has a potential preventive effect on oral cancer.
Vitamin B6 can prevent bladder cancer. Tomatoes are one of the sources of vitamin B6. Studies have shown that vitamin B6 can inhibit the generation of cancer cells to a certain extent, help synthesize some important enzymes in the human body, and then regulate metabolism.
In addition to the above anti-cancer effects, a German study found that men with low lycopene intake had twice the risk of heart disease as those with high lycopene intake; Tomatoes contain lutein, which can protect the eyes and prevent the occurrence of age-related macular degeneration, making them suitable for office workers who often use their eyes; An American study found that eating more potassium-rich foods, such as tomatoes and bananas, can accelerate the excretion of sodium from the blood and help lower blood pressure.
Tomato and Egg Soup Preserves the Most Nutrients
Tomato and Egg Soup
"Tomatoes have a high 'appearance rate' on the people's tables, but different cooking methods have their own advantages," Yu Renwen said, "everyone should maximize the preservation of their cancer-preventing nutritional value while ensuring the flavor by choosing cooking methods that play to their strengths and avoid their weaknesses." He ranked the nutritional value of different ways to cook tomatoes.
1. Tomato and Egg Soup. Lycopene is essentially a fat-soluble vitamin and a "close relative" of carotene. Its health benefits can be maximized after heating and cooking. However, it is easily decomposed by light and heat, so it is not suitable for long cooking times. Tomato and egg soup has a short heating time, which can maximize the preservation of lycopene and avoid the loss of trace elements.
2. Scrambled Eggs with Tomatoes. Scrambled eggs with tomatoes is jokingly called the "national dish". Compared to tomato and egg soup, the stir-frying method is less healthy, and some lycopene is easily lost during the heating process. You can stir-fry the eggs first, then add the tomatoes to minimize the heating time for the tomatoes.
3. Stir-fried Tomatoes with Broccoli. A study by the University of Illinois found that broccoli contains natural antioxidants such as flavonoids and anthocyanins, which can inhibit cancer cells. The combination of tomatoes and broccoli, the "two brothers", not only doubles the nutritional value but also tastes very good. The broccoli can be blanched first to make it easier to stir-fry.
4. Braised Beef with Tomatoes. Beef is rich in heme iron, which is more easily absorbed, and can increase blood oxygen content. The fibers of beef are relatively thick and not easily digested and absorbed, while tomatoes can stimulate gastrointestinal peristalsis and promote digestion. However, stewing may lead to the loss of some vitamins. It is recommended to braise the beef first and add the tomatoes 5 minutes before serving.
5. Sugar-dressed Tomatoes. Cold dressing can best avoid the loss of vitamin C, but the absorption effect of lycopene is relatively poor, and it may also increase sugar intake. If possible, you can squeeze tomatoes to drink, which has lower calories and less nutrient loss.
Yu Renwen also reminded that the skin of tomatoes is rich in lycopene and dietary fiber. It is best not to peel them when cooking, as long as they are cleaned thoroughly. In addition, processed foods such as tomato sauce may have a high sodium content, so try to reduce their consumption.
Three tips for picking artificially ripened tomatoes
Nowadays, some tomatoes on the market are red as if they are "grinning", while others are green, and people are afraid of buying artificially ripened tomatoes. Yu Renwen said that artificially ripened tomatoes may contain tomatine, which interferes with the central nervous system. Naturally ripe tomatoes have very low or even no tomatine. When picking tomatoes, you can pay attention to the following 3 points:
1. Look at the color. Naturally ripe tomatoes have a red color with white sand spots, and the stem part is a bit green, while artificially ripened tomatoes are red all over. Under natural ripening conditions, the redder the color, the higher the lycopene content. According to data, yellow varieties of tomatoes contain only 0.3 milligrams of lycopene per 100 grams, while red varieties generally reach 2-3 milligrams, and can be as high as 20 milligrams. In addition, tomatoes sold in summer have a higher lycopene content than those sold in winter, because of abundant sunlight and longer daylight hours in summer.
2. Look at the shape. Choose tomatoes that are round and evenly shaped. Artificially ripened tomatoes are not round enough, and some may be oddly shaped. Also, do not choose tomatoes with green or yellow spots on their skin.
3. Squeeze them. The sign of a ripe tomato is that it is soft to the touch. When buying, you can gently squeeze or press them. The best ones have thin skin, are elastic, and feel firm but not soft.
Traditional peaches