Entering the 21st century, human life expectancy is getting longer, which is not only due to the advancement of medicine but also because people are paying more attention to health preservation. "Eat well, live well, and maintain a cheerful mood" naturally contributes to physical and mental well-being and a long life. Therefore, people's demands on food have long gone beyond simply satisfying physiological needs to a focus on nutrition. Today, the topic naturally turns to the most nutritious foods.
In 2002, the American magazine *Time* featured a special issue on the top ten most nutritious foods, which were tomatoes, spinach, nuts, broccoli, oats, salmon, garlic, blueberries, green tea, and red wine (in no particular order).
A survey published last year by the World Health Organization pointed out that Japanese people are the longest-lived group in Asia. This honor is undoubtedly due to the Japanese preference for a low-fat diet, their habit of eating more salmon, and drinking more green tea. The fat in salmon is Omega-3 fatty acid, which is a beneficial type. The catechins in green tea are phytochemicals. Both are beneficial to the body and help prevent cancer and heart disease.
Oats, on the other hand, are rich in soluble fiber, which can effectively lower blood cholesterol and reduce the chance of arteriosclerosis. As for spinach and broccoli, they are both dark green vegetables that provide folic acid to assist in the normal growth of red blood cells. They also contain antioxidants that have a protective effect and can reduce the chance of developing diseases. Additionally, tomatoes contain carotenoids (including beta-carotene and lycopene), which also play an anti-cancer role and maintain physical health.
When it comes to the benefits of nuts, it is certainly their unsaturated fatty acids. These fatty acids are similar to Omega-3 fatty acids and help lower total cholesterol and low-density lipoprotein (LDL) cholesterol. In addition, drinking a small amount of red wine can help reduce the chance of developing heart disease. Finally, garlic contains the phytochemical allyl sulfides, which are greatly helpful in maintaining good health.
The foods listed above each have their own unique characteristics, and being selected as the top ten most nutritious foods is certainly well-deserved. However, by synthesizing the arguments above, we can summarize the four basic principles of how food affects health.
The Antioxidant Theory Scientists believe that two great forces work together in the human body: one is the destructive oxidant, a large amount of oxides produced from the external environment, which can oxidize the plasma membranes inside and outside the cells, causing damage to the body and serving as a prelude to cancer; the other is the protective antioxidant, which exerts a powerful antioxidant effect, preventing and compensating for the damage caused by oxygen free radicals, thus preventing aging and extending human life.
Antioxidants include the familiar vitamins C and E, as well as the trace element selenium. From food, especially plant-based fruits, vegetables, and grains, a variety of rich antioxidants are available to meet the body's needs.
The Effects of Phytochemicals In addition, scientists began studying elements called phytochemicals many years ago. These phytochemicals exist in natural foods and can prevent the occurrence of cancer and heart disease. More well-known phytochemicals include beta-carotene, flavonoids, indole, isoflavones, lycopene, catechins, and allicin. Different plants contain different amounts of phytochemicals, which produce different effects in the body. Broccoli contains indole, which can start the enzyme system, help inhibit the DNA in the cell nucleus from being damaged, and cause tumor cells to shrink. As for garlic, its allicin can enhance the immune system, increase enzyme secretion, and thus clean up carcinogens.
The Principle of Lowering Fat Lipids play an extremely important role in the human body; they can suppress certain diseases, such as preventing and controlling coronary heart disease. This effect is mainly through the subtle effects of different fat molecules. The well-known Omega-3 fatty acid can lower low-density lipoprotein (LDL) cholesterol (known as "bad cholesterol") in patients with high blood cholesterol and triglycerides, reducing the incidence of coronary heart disease. Moreover, fish oil also helps to improve hypertension. Another beneficial fat is the Omega-6 fatty acid, found in corn oil, soybean oil, and sunflower oil. It effectively removes "bad cholesterol" from the circulatory system by increasing the activity of LDL receptors. However, research indicates that excessive Omega-6 fatty acid, i.e., more than 10% of total calories, can simultaneously lower high-density lipoprotein (HDL) cholesterol.
Fiber With the advent of refined foods, the amount of fiber people get from their food has become less and less. Dietary fiber is divided into soluble and insoluble types. The former helps to lower blood cholesterol, while the latter stimulates intestinal peristalsis to remove waste.
From this, it can be seen that nutritious foods all have the advantages of antioxidants, phytochemicals, Omega fatty acids, or fiber. By following this path, one can naturally discover other nutritious foods beyond the top ten:
1. Red Rice For generations, Chinese people have relied on grains as their staple food. Generally, red rice is more nutritious than white rice because it retains the fiber from the husk.
2. Oranges Among the many types of fruits, acidic fruits contain more vitamin C. Today's nutrition science consistently recommends vitamin C as an antioxidant:
a. It prevents free radicals from damaging cells, reducing aging;
b. It prevents the preservatives sodium nitrate and sodium nitrite from converting into carcinogenic nitrosamines, which is highly protective for cancer patients, especially those with stomach and esophageal cancer;
c. It inhibits the oxidation of "bad" cholesterol and protects "good" cholesterol, maintaining vascular and heart health.
3. Carrots Carrots are rich in the phytochemical beta-carotene, which can scavenge free radicals, prevent the oxidation and mutation of the cell surface, and exert an anti-cancer effect.
4. Soybeans Soybeans are inexpensive and nutritious. The isoflavones they contain can produce effects similar to the estrogen hormone, lowering blood cholesterol, protecting the heart, and preventing breast cancer, prostate cancer, and osteoporosis.
5. Mushrooms As is well known, mushrooms are rich in dietary fiber, which can enhance the immune system, help in anti-cancer efforts, and are a food worth recommending.
In conclusion, there are thousands of foods in the world, each providing different nutrients to meet different needs, and thus each has its own value. Especially in medicine, knowledge of dietary nutrition is constantly advancing and seeking new frontiers. While nutritious foods are certainly worth recommending, other foods can also be chosen. Looking ahead, there are far more than ten nutritious foods.