There are so many kinds of food in our daily life, each with its different nutrients and health effects on human body. And this article will mainly introduce you six kind of common food, which are very beneficial to human health.

First, whole-grain food
Whole-grain food contains nearly all the nutrients extracted from the refined grains. These nutrients include folic acid, vitamin B, selenium, etc., all of which are beneficial for the health of heart. At the same time, these elements can also control your weight, and reduce the risk of diabetes. In addition, whole-grain food is also rich in soluble fibers, which not only can reduce the level of blood cholesterol, but can promote the digestion of food. You should eat at least three kinds of whole-grain food every day, such as barley, rye, millet, brown rice, and so on.

Second, sweet potato
If you want to improve your diet, then you have to add sweet potato in the diet. This sweet food contains a large amount of antioxidants and plant chemicals, including beta-carotene, vitamin C and vitamin E, folic acid, calcium, copper, iron, potassium, and so on. The fibers contained in sweet potato can promote the health of the digestive tract. What's more, the antioxidants play an important role in the prevention of heart disease and cancer.

Third, tomato
Tomato contains a high content of lycopene--a kind of antioxidant which can help prevent certain kinds of cancer. At the same time, tomato also provides a lot of vitamin A, vitamin C, potassium, and other plant chemicals. It is especially beneficial to eat some tomatoes in summer. This is because tomato contains certain chemical ingredient, which can protect the skin from sunburn and prevent it from the harm of ultraviolet ray.

Fourth, vegetables
Vegetables (including spinach, kale, cabbage and lettuce) contain a lot of vitamins, mineral elements, beta-carotene, vitamin C, folic acid, iron, magnesium, carotenoid, plant chemicals, antioxidants, and so on. A study from Harvard University has found that, those who eat food rich in magnesium (such as spinach) can reduce the risk of diabetes. As a result, next time when you make a salad, you can add some of this kind of vegetables, which can help you fight against diseases.

Fifth, nuts
We all know that nuts contain a lot of fat. But nuts are also a kind of healthy food. Whether single unsaturated fat or poly unsaturated fat, both of them can help lower the level of cholesterol, and help to prevent heart disease. If you want to take in plenty of protein, fiber, selenium and vitamin A, vitamin E, nuts are also a very good choice. Small amount of nuts can increase energy and overcome hunger, so as to help those who are losing weight keep a normal diet. Of course, as nuts contain large amounts of calories, so if you eat too much at one time, it will easily make you fat. Generally speaking, you should not eat more than one ounce of nuts every day.

Sixth, egg
The results of research shows that, egg contains a large number of high-quality protein. At the same time, it also contains carotenoid, lutein, choline, and so on. In fact, egg is a good source of choline, while choline is a necessary nutrient--especially for pregnant women, which is much more important. Research shows that, some ingredients provided by egg can promote the health of eyes, so as to help prevent the blindness on elderly people. The American Heart Association recommends people to eat an egg every day. Of course, as egg is rich in cholesterol, so you'd better not eat too many eggs very day.