Myth 1: Dieting can prolong life.
First of all, it needs to be admitted that the relationship between dieting and prolonging life is indeed supported by some laboratory research results. To be exact, "dieting" here refers to strict calorie intake restriction, that is, reducing the calories taken from food while ensuring that other nutrients are sufficient.
Scientists have found that calorie intake does affect the life span and quality of life of experimental organisms. In nematodes, yeasts, fruit flies, some mice and rats, people have found the effect of limiting calorie intake to prolong life. For example, a study on Caenorhabditis elegans found that strict calorie intake restrictions can double the life span of model organisms in these laboratories. But it is worth noting that this "longevity effect" is not omnipotent. In other animal models, similar attempts were unsuccessful: dieting did not prolong the life span of wild mice, while in other strains of mice, calorie restriction even shortened the life span. Moreover, the biological model used in the above experiments is far from that of human beings, and these results can not reflect what kind of influence calorie restriction will have on human beings.
In order to further study the effect of calorie restriction on longevity, scientists have also conducted research in several primates that are closer to humans, but the results of these studies are inconsistent at present, and the final conclusion is still uncertain. At present, it is still unknown what impact strict heat control will have on human beings for a long time. The Institute on Aging of the National Institutes of Health also pointed out that "scientists don't know whether long-term calorie restriction is beneficial, safe or practical for human beings".
Myth 2: The live fish killed now is more nutritious.
It is unscientific to kill live fish now, because it is often too late to completely eliminate the toxic substances in the fish, and the parasites and bacteria on the fish have not completely died. These residual toxins are likely to cause harm to the body. In addition, the fish protein eaten alive is not completely decomposed, the nutrients are insufficient, and the taste is not the best.
In addition, fish should be eaten selectively. First of all, eat less or not eat fish heads, because the older the fish, the more mercury accumulated in the fish brain and skin, and excessive intake of mercury may cause poisoning. Secondly, the "three highs" crowd is not suitable for eating fish roe, because the fish roe rich in lecithin has higher cholesterol. Finally, don't eat fish on an empty stomach. If you eat a lot of fish containing purine on an empty stomach, but there is not enough carbohydrate to decompose it, the acid-base balance of the human body will be unbalanced, which will easily induce gout or aggravate the condition of gout patients.
Myth 3: Eating fat is harmful to health.
When it comes to fat, many people think of body fat first, which is mistaken for being harmful. In fact, fat is one of the essential nutrients and an important part of human body, which provides energy for life activities. But eating too much fat does increase the risk of obesity, as well as the risk of heart disease and cancer.
In daily diet, it is the key to control the intake of fat and learn to choose fat. Fat is composed of fatty acids, which can be divided into saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. Among them, monounsaturated fatty acids and polyunsaturated fatty acids are beneficial to lowering cholesterol and maintaining heart health. Most of them come from vegetable oils such as olive oil, sunflower oil, nuts and deep-sea fish oil, which can be eaten in moderation. Saturated fatty acids mainly come from animal fats, and trans fatty acids are mostly hidden in processed foods, so we should eat as little as possible.
Myth 4: Earth eggs are more nutritious.
There are many local eggs in supermarkets and food markets. They are expensive and are praised as "more natural and nutritious" original ecological food by merchants. Experts remind that there are few real earth eggs on the market, and the nutrition is almost the same as that of ordinary eggs. Don't be too superstitious.
Xu Guiyun, a professor at the College of Animal Science and Technology of China Agricultural University, said that although the nutritional value of native eggs and ordinary eggs is different, it can actually be ignored. The difference between native eggs and ordinary eggs is more reflected in the taste. The content of unsaturated fatty acids in soil eggs is high, which is very suitable for boiling eggs and frying eggs. Simple cooking methods can give full play to its excellent taste. If we don't investigate the difference, animal husbandry research data and food determination data show that the ratio of omega fatty acids to lecithin is slightly higher than that of foreign eggs, which is really good for promoting cholesterol metabolism and protecting cardiovascular system. But most importantly, don't buy ordinary eggs as earth eggs.
Xu Guiyun said that during the stocking process, most chickens need to be supplemented with full-price feed, and the sanitary conditions of the laying environment are not easy to control, and eggs are more likely to be contaminated by feces; The isolation belt around the chicken farm, epidemic prevention, sanitation and disinfection, immunity and immune monitoring all have strict requirements. If we consider it from this aspect, it is obvious that eggs in chicken farms are safer.
Myth 5 Sugar is the culprit of diabetes.
"I don't eat this. It's too sweet. I'm afraid of getting diabetes." We often hear this sentence, which represents a typical misunderstanding that sugar is the chief culprit of diabetes. Although the typical manifestation of diabetes is hyperglycemia, it is caused by islet dysfunction and has little to do with sugar intake. Of course, if diabetes has been diagnosed, it is necessary to strictly control the intake of "sugar" in the diet and control the blood sugar level within a reasonable range. If you don't have diabetes, sugar intake won't cause you to get diabetes.
When we say sugar, we mainly refer to carbohydrates in nutrition. It is an essential nutrient for human body, and many foods contain carbohydrates themselves. In addition, sugar will be added during food processing, which is called "adding sugar". What we need is "natural sugar" from food, mainly from grains, while "added sugar" in drinks, cakes, sweets and other foods should be eaten less.
Myth 6 Eating nuts will make you fat.
The fat content in nuts is really high, ranging from 44% to 70%, but the fatty acids in nuts are mainly unsaturated fatty acids, which are beneficial to human health and rich in protein and minerals. Many people are worried that eating nuts will make them fat, but many studies have confirmed that this kind of worry is unnecessary.
The researchers asked the subjects to eat 50 grams of nuts every day for nearly six months. The results showed that the intake of unsaturated fatty acids, vitamin E, magnesium and copper increased, which reduced the risk of cardiovascular diseases, but the weight changed little. This is because nuts are rich in dietary fiber, which is easy to feel full, and dietary fiber can also reduce the absorption of fat.
Myth 7 Wild vegetables are more nutritious.
Associate Professor He from the College of Food Science and Nutritional Engineering of China Agricultural University said that most wild vegetables in the market and restaurants are artificially planted, not wild. And "green food" refers to pollution-free, pollution-free, safe, high-quality and nutritious food produced with the approval of relevant state specialized agencies according to a specific production mode. Many cultivated wild vegetables may not meet this standard. In addition, according to the knowledge of modern nutrition, wild vegetables belong to vegetables, and their nutritional components are similar to those of ordinary vegetables, but they are not particularly prominent. They also contain more water. Green wild vegetables are rich in carotene, vitamin C, riboflavin, calcium, potassium, magnesium and other minerals, and are also rich in dietary fiber.
Some people like to pick wild vegetables in the wild, but natural wild vegetables do not mean that they are not poisonous. In order to adapt to the harsh environment in the wild, natural wild vegetables will produce some toxic substances in the long-term growth and reproduction process to resist foreign invasion. For example, the vast majority of wild ferns have prepared chemical weapons-cyanide, which is why we are recruited in our tongues. It is difficult for ordinary people to determine whether wild vegetables are suitable for eating. In order to be healthy, eat as little as possible.