How can eating a few more bites of such delicious food become an accomplice of disease?

Contributing expert: Li Caihong, Urumqi First People's Hospital, Chief Technician (Nutrition), Member of Chinese Nutrition Society, Member of Xinjiang Nutrition Society

Review expert: Chen Xinle, former chief physician of food hygiene at the Autonomous Region Center for Disease Control and Prevention, popular science expert at the Autonomous Region Association for Science and Technology, Chinese registered nutritionist, and the fifth director of the Xinjiang Nutrition Society

Chen Peipei, executive director of Xinjiang Nutrition Society, deputy director of the Clinical Nutrition Department of the First Affiliated Hospital of Xinjiang Medical University, and expert in popular science education for Xinjiang youth

In daily diet, various nutrients play an important role in the human body. If they are not taken enough or taken in too much, they will affect human health. Therefore, it is very important to master the reasonable frequency and amount of dietary intake according to the Dietary Reference Intake (DRIS).

Professional knowledge popularization :

The Dietary Reference Intakes (DRIS) are a set of reference values ​​developed on the basis of recommended dietary nutrient supplies to ensure a reasonable intake of nutrients by the human body and avoid deficiency and excess. They include seven indicators of nutritional levels related to chronic non-communicable diseases: average requirement (EAR), recommended intake (RNI), adequate intake (AI), upper tolerable intake (UL), acceptable range of macronutrients (AMDR), recommended intake for prevention of non-communicable chronic diseases (PI-NCD), and specific recommended value (SPL).

Based on these parameters, people can better understand nutrient requirements and upper intake limits.

Now, let’s find out how to enjoy the happiness brought by delicious food without causing harm to your health.

1. Deep Sea Fish

Deep-sea fish are rich in high-quality protein and polyunsaturated fatty acids, among which DHA and EPA are the two most important polyunsaturated fatty acids for the human body. DHA is the abbreviation of docosahexaenoic acid, which has the effects of softening blood vessels, strengthening the brain, improving intelligence, and improving vision, and is commonly known as "brain gold". EPA is the abbreviation of eicosapentaenoic acid, which has the function of cleaning up garbage (cholesterol and triglycerides) in blood vessels, and is commonly known as "blood vessel scavenger".

However, with the acceleration of industrialization and urbanization in coastal areas, the offshore environment has been polluted, and the problem of seafood pollution has become increasingly prominent, among which heavy metals are one of the main pollutants. Heavy metals can exist stably in the water environment and then accumulate in organisms. Their pollution has the characteristics of high toxicity, environmental persistence, concealment, and bioaccumulation. Therefore, if you eat too much deep-sea fish, heavy metals such as lead, mercury, cadmium, and cobalt are likely to exceed the standard. Any of these heavy metals can cause headaches, dizziness, insomnia, forgetfulness, mental disorders, joint pain, stones, and even cancer.

Lin Yichen from the Chinese Academy of Sciences used the temporary maximum weekly intake of heavy metals recommended by the World Health Organization FAO/WHO to calculate the maximum limit of heavy metals that an average person can ingest per day. When copper is the maximum standard limit, an adult can avoid the risk of excessive intake of heavy metals by consuming no more than 99 g of oysters per day; when chromium is the maximum standard limit, the maximum intake of bivalves is 147.2 g; when cadmium is the maximum standard limit, the maximum intake combination is 327 g of seafood (147.2 g of bivalves + 180 g of fish). In particular, the degree of heavy metal pollution in wild fish is greater than that in farmed fish.

suggestion:

◆Eat less offal. The accumulation of heavy metals in the tissues or organs of aquatic animals is somewhat selective. The content of heavy metals in fish gills and offal is relatively high, while the content of heavy metals in muscles is relatively low.

◆In your daily diet, rationally combine different types of fish to reduce the health risks of heavy metal intake.

◆It is recommended to eat fish twice a week or 300-500g.

2. Liver

Animal liver is rich in iron and vitamin A, and has good blood-replenishing and eye-protecting effects.

However, eating too much liver may lead to an overdose of vitamin A, which may cause headaches, nausea, vomiting, irritability or drowsiness, conjunctival congestion, etc. According to the "Nutrition and Food Hygiene", if an adult continuously consumes 22,500 to 150,000 μg (75,000 to 500,000 international units) of vitamin A per day, chronic poisoning will occur after 3 to 6 months. Adults who consume 500,000 international units at a time and children who consume 300,000 international units at a time may also cause poisoning.

suggestion:

◆Choose animal liver that is reddish brown, smooth, shiny, soft and fresh.

◆Wash the liver thoroughly before cooking, rinse it and soak it in cold water for 30 minutes. If you need to eat it immediately, cut the liver into pieces, wash it gently with your hands in clean water, and finally rinse it under the tap.

◆It must be cooked thoroughly, not too tender. When cooking, avoid "quick frying and soaking", and don't "put it in the pot and take it out immediately" for the sake of freshness and tenderness. Cook and fry thoroughly to ensure food safety.

◆The amount of consumption should not be too much. It is recommended to consume it once a week at most, 30 to 50g at a time.

3. Corn

Corn is known as a longevity food and is rich in protein, fat, vitamins, etc.

However, long-term use of corn as the staple food is prone to dermatitis. Its typical symptoms are dermatitis, diarrhea, and dementia. Dermatitis often occurs on the cheeks, backs of the hands, and backs of the feet, and is symmetrical. Gastrointestinal symptoms are mainly loss of appetite, indigestion, diarrhea, and erosion of the oral mucosa and tongue. Neuropsychiatric symptoms include depression, anxiety, memory loss, emotional indifference, and dementia, and some people experience mania and hallucinations.

suggestion:

◆Adding alkali can convert the bound niacin in corn into free niacin, which is easily utilized by the body.

◆The nutrients in cooked or steamed corn are easier to absorb.

◆People with poor stomach should not eat too much.

◆It is recommended to eat no more than one corn per day, and it cannot completely replace the staple food.

4. Milk

Milk is a good food source of dietary protein, calcium, phosphorus, vitamin A, vitamin D and vitamin B2. However, drinking too much milk can lead to iron deficiency and easily induce anemia.

suggestion:

◆More than 300 ml of liquid milk per day is enough. 600-800 ml of daily calcium supplement is sufficient, no more is needed.

◆It is not advisable to eat too much fruit one hour before and after drinking milk.

◆It is not recommended to add sugar to milk, especially when it is just boiled, as this can easily produce toxic hydroxyl lysine.

◆Milk cannot replace water, and you cannot take medicine with milk.

5. Fruit

Fruits are not only rich in vitamins, but also can promote digestion. However, if you eat too much, you will easily gain weight, and your blood sugar and blood lipids will also increase.

suggestion:

◆Consume 200-350g of fresh fruit every day. Juice cannot replace fresh fruit.

◆It is best to eat fruits at room temperature. Do not eat fruits that are too cold. For example, fruits just taken out of the refrigerator should be left at room temperature for a while before eating.

◆ Wash or peel the fruit before eating to avoid diarrhea. Rinse your mouth immediately after eating the fruit to prevent tooth corrosion.

◆Fruit cannot replace staple food, especially should be eaten less before going to bed.

6. Eggs

According to analysis, every 100 grams of eggs contains 12.58 grams of protein, mainly ovalbumin and ovomucoid, which contain 8 essential amino acids for the human body and are very similar to the composition of human protein. The absorption rate of egg protein by the human body can be as high as 98%. Egg yolk is rich in lecithin, sterols, yolk, calcium, phosphorus, iron, vitamin A, vitamin D and B vitamins.

Recently, researchers from the National Center for Cardiovascular Diseases and the Fuwai Hospital of the Chinese Academy of Medical Sciences found that the association between egg intake and cardiovascular disease (coronary heart disease, stroke, etc.) and total mortality risk showed a U-shaped relationship. Eating too many or too few eggs is not good for cardiovascular health. The study found that people who eat 3 to 6 eggs a week have the lowest risk of cardiovascular disease and total mortality. In comparison, people who eat less than 1 egg a week have a 22% and 29% higher risk of cardiovascular disease and total mortality, respectively; while those who eat 10 or more eggs a week have a 39% and 13% higher risk, respectively.

suggestion:

◆A normal person only needs 300-350g (about 3-6 eggs) per week. The egg yolk is rich in nutrients and should not be discarded.

◆Do not eat eggs with boiling water. Do not eat hairy eggs or rotten eggs.

◆When beating eggs, you must also be careful not to get contamination from bacteria on the eggshell.

◆It is better for infants, the elderly and the patients to steam or boil eggs.

7. Walnuts

Walnuts are known as "longevity seeds", "longevity fruits" and "health treasures" because they are rich in unsaturated fatty acids. 86% of the fat in walnuts is unsaturated fatty acids. Walnuts are also rich in micronutrients such as copper, magnesium, potassium, vitamin B6, folic acid and vitamin B1. However, walnuts are goitrogenic substances, and excessive consumption can easily increase the risk of hypothyroidism and hyperlipidemia.

suggestion:

◆Eat a moderate amount of nuts every day, and no more than 1 walnut is recommended.

◆Patients with hypothyroidism should not eat walnuts, especially pregnant women should pay special attention.

◆It is not recommended to eat before going to bed as it can easily lead to excessive energy and fat accumulation.

8. Century Egg

Preserved eggs, also known as Songhua eggs and changed eggs, are a unique food in my country with a special flavor that can stimulate appetite. Preserved eggs are made by wrapping duck eggs with a mixture of soda ash, lime, salt and lead oxide, which contain lead. Frequent consumption may cause lead poisoning. This can lead to symptoms such as insomnia, lack of concentration, anemia, joint pain, slow thinking, and impaired brain function. In addition, lead can replace calcium, affecting calcium intake, which may cause calcium deficiency.

suggestion:

◆Choose preserved eggs that meet safety standards. Do not eat too many at one time. 1 to 2 is appropriate.

◆Do not eat preserved eggs after peeling them overnight.

◆Children should not eat preserved eggs as it is not conducive to their growth and development.

Although food is good, eating too much is not good. Therefore, eating a balanced diet, not being picky or overeating, and mastering the correct frequency and amount of consumption according to the recommended standards of the Dietary Guidelines for Chinese Residents (2022) will make you safer and healthier.