How to get out of the misunderstanding of excessive pursuit of ＂polished rice and white flour＂
Yu yongchao
The General Offices of the General Office of the Central Committee of the CPC and the State Council recently issued the "Action Plan for Grain Saving", which specifically mentioned "improving moderate processing standards, reasonably determining processing accuracy and other indicators, and guiding consumers to gradually step out of excessive pursuit ‘ White rice flour ’ Misunderstanding of diet. "
So, why is there such a dietary misunderstanding? What can consumers do to get out of the misunderstanding?
Why is "polished rice and white flour" deeply rooted in people’s hearts?
Consumers are more likely to accept polished rice and white flour for three reasons.
One is sensory comfort. Refined grains are convenient for cooking, and the food made is easy to chew and lighter in color, which makes it more "clean". Because it can bring people soft, waxy, sticky, slippery and other comfortable tastes, white rice flour is often more popular than whole grains which are relatively harder, more elastic, more loose and rougher. Moreover, because the white flour of polished rice is easier to digest, the blood sugar rises rapidly, which makes the brain with glucose as the main energy source more pleasant.
The second is the cost advantage. At present, the price of whole grains on the market is higher than that of ordinary polished rice and white flour. Compared with whole grains, refined grains are simple in composition, stable in chemical properties, less prone to oxidative deterioration and lower in storage cost. Take flour as an example. If whole wheat grains are used to grind flour, because both germ and aleurone layer contain a lot of oil, if stored improperly, the oil will be easily oxidized and deteriorated, and even a "spicy taste" will appear after a few weeks. Therefore, refined grains are more competitive in terms of shelf life and the difficulty of home preservation.
The third is the inertia of thinking. In the period when productivity was relatively backward, white rice flour was "scarce", and most people were limited by their consumption power and had to eat whole grains which were cheaper at that time. Therefore, the impression that eating white rice flour meant improving their living standards was left in people’s minds.
Based on the above reasons, coupled with the factors of market economy, since consumers prefer to eat polished rice and white flour, manufacturers increase production to meet demand. After the output increases, the scale advantage appears, the cost further decreases, and the storage cost is relatively lower, so the market competitiveness of polished rice and white flour becomes stronger and stronger. Whole grains have become a minority choice. Over time, many consumers have a misunderstanding in cognition, that is, "polished rice and white flour is the staple food, and the staple food is polished rice and white flour." In this way, it is possible to inadvertently pass that "degree" and become "excessive pursuit of polished rice and white flour."
The so-called "degree" can refer to the Dietary Guide for China Residents. According to the advice of the guide, the daily diet should be mainly cereals, including 50-150g of whole grains and miscellaneous beans every day. In fact, the survey shows that more than 80% of the adult residents in China have a serious shortage of whole grains. The daily intake of whole grains for adult men is 13.9g and that for women is 14.6g, which is less than one third of the recommended lower limit.
In other words, polished rice and white flour seriously occupy the intake share of whole grains.
2 How does excessive grain refining affect health?
What exactly is polished rice and white flour? It is necessary for us to find out.
Cereals are the general term for food crops dominated by Gramineae, in which rice and wheat account for more than half of the world’s total grain output, and many coarse cereals well-known to China consumers also belong to cereals, such as corn, oats, buckwheat, millet and purple rice. Grain is an important basic component of diet and an important food source of dietary fiber, B vitamins, minerals and other nutrients.
According to the degree of processing, grains can be divided into whole grains and refined grains.
Whole grains retain the endosperm, germ, aleurone layer, husk and other structures of intact grains. It can be a complete grain or a product after simple processing such as grinding, crushing and tabletting. Taking rice and wheat as examples, the whole grain forms are brown rice and whole wheat grain (powder) respectively. After processed, refined grains are missing in the four structures of the whole grain to varying degrees. The most common one in the market is rice flour that only retains the endosperm part rich in starch, which is also commonly known as "polished rice white flour".
From a nutritional point of view, the health problems caused by excessive pursuit of polished rice and white flour are obvious.
One is the lack of nutrition. Due to over-processing, the nutritional value of polished rice flour decreased, and the loss of dietary fiber was serious. The loss of B vitamins and minerals accounted for about 60%-80%. Therefore, long-term consumption of polished rice white is not good for health, which may lead to insufficient intake of vitamins and minerals, and even lead to vitamin deficiency. For example, vitamin B1 deficiency may cause beriberi.
Second, it is easy to cause obesity. The finer the grain processing, the faster the blood sugar rises after eating, which will stimulate a large amount or even excessive secretion of insulin. One of the physiological functions of insulin is to promote the conversion of excessive glucose in blood into fat, that is to say, excessive consumption of polished rice and white flour is more likely to make the body weight or body fat rate exceed the standard, which may increase the risk of diabetes in the long run.
The whole grain is rich in dietary fiber, which makes the postprandial blood sugar reaction more stable, and at the same time can enhance satiety, thus reducing the intake of other foods. Therefore, compared with the same amount of refined grains, it is more helpful to control weight and reduce the risk of overweight and obesity. Replacing refined grains with whole grains can reduce the levels of total cholesterol, low-density cholesterol and triglycerides in blood.
In addition, whole grains can promote defecation and reduce the retention time of feces in the digestive tract, and the dietary fiber in them can produce beneficial short-chain fatty acids in the intestine, thus reducing the risk of intestinal cancer. For example, β in oats and highland barley; -Dextran can not only reduce the risk of cardiovascular disease, but also improve constipation, stimulate the growth of intestinal beneficial bacteria and promote the stability and diversity of intestinal flora.
Cooking whole grains is better this way.
Although we talked about the shortcomings of polished rice and white flour, it doesn’t mean that we can’t eat it, but we should pay attention to the combination of thickness.
The Dietary Guide for China Residents suggests that the intake of whole grains for healthy people is 50-150g per day, which accounts for 1/3 of the total staple food. It is commonly known as "the combination of coarse and fine grains", and it is not advisable to eat only whole grains without polished rice and white flour. In terms of varieties, we recommend that there are three kinds of staple foods (cereals, potatoes and miscellaneous beans) on average every day, and at least five kinds every week, which means that the types of whole grains should not be single, but diversified.
If you are worried about the poor taste of whole grains, you can try the following methods for processing.
1. Fully cook until soft and rotten
Some whole grains are hard in texture and have strong water resistance. You can soak them in clear water for 6-12 hours in advance to make the starch fully absorb water, and then cook them for a little longer as appropriate. Of course, you can also cook them directly in a pressure cooker. Using this cooking method, you can see the original shape of the whole grain when eating, and the taste is soft enough, similar to the prepackaged eight-treasure porridge.
2. Grind into powder or paste
The finer the grain particles, the larger the surface area, and the easier it is to cook and digest. In addition to grinding at home, you can also choose prepackaged whole grain powder or products ground on site. If you buy prepackaged foods, you should pay attention to the ingredient list, and choose whole grains as the first place or the first few are all whole grains. Comparatively speaking, whole grain flour is easy to carry, that is, it is ready to eat, but don’t grind it at one time or buy too much, and it is easy to oxidize and deteriorate if it is not stored properly. People who often cook at home can also mix a variety of coarse and fine grains in a suitable proportion and beat them into five-grain soybean milk with a soymilk machine.
Step 3 ferment
Fermented whole-grain foods such as whole-wheat steamed bread, whole-wheat bread, corn cake, etc., after milling and yeast fermentation, phytic acid, dietary fiber and other components in the whole grain are decomposed by microorganisms to some extent, and the taste and digestion difficulty are improved.
4 How to identify "pseudo coarse grains"
For the original form of whole grains, such as oatmeal, millet, brown rice, etc., we can easily distinguish them. But the words "whole wheat", "wheat bran" or "miscellaneous grains" are marked on the prepackaged foods packaging of whole wheat bread, coarse grain biscuits, whole wheat steamed bread or some cereals. Is it credible?
In fact, in order to cater to the needs of some consumers who pursue nutrition and health, many food manufacturers have marked various labels showing "whole grains" in eye-catching positions. However, due to the taste and cost reasons mentioned above, some foods are only "pseudo-whole grains" and "pseudo-coarse grains", and the main ingredients are polished rice and white flour, with little whole grain content.
We can identify true and false whole grains by looking at the ingredient list and nutrient composition list on the back of food packaging.
According to "General Rules for Labeling in prepackaged foods", the labeling principle of ingredient list is "descending order of ingredients", that is, the top ingredient in the ingredient list must be the ingredient with the highest weight proportion in this food. If the first ingredient in the ingredient list is "wheat flour" instead of "whole wheat flour", it can’t be regarded as a whole grain food. On this basis, try to choose foods with only whole wheat flour and no wheat flour, and the shorter the ingredient list, the better.
Other food ingredients are whole wheat flour (wheat flour, wheat bran) at the top of the list, followed by other ingredients such as wheat flour. Strictly speaking, this kind of food can’t be regarded as whole grain, because the proportion of wheat bran added may be lower than that of natural grain, and most of them will not add germ. However, compared with polished rice and white flour food, the nutrition has been strengthened to some extent.
In addition, it depends on the nutrient composition table. The General Rules for Labeling in prepackaged foods requires that the data of energy, protein, fat, carbohydrate and sodium be marked. If manufacturers want to highlight the nutritional advantages of food, they will also mark the dietary fiber content. Comparing several whole-grain foods, choosing the one with more dietary fiber in the same weight can indirectly show that the whole-grain ingredients content is more considerable.
There are also some bulk whole grain foods on the market without ingredient list and nutrient composition list, such as miscellaneous grains steamed bread and purple rice steamed bread, which can’t be judged only by the color depth. Even with the continuous innovation of technology, the taste of whole grain food will be more or less "rough" than polished rice and white flour food. Therefore, when you eat "whole grain" food whose taste and flavor are very close to refined grain food, you have to doubt its "gold content". We suggest that qualified consumers try to make whole grain food several times by themselves, so as to get a direct sensory experience, so as to know fairly well.
Doctor’s reminder
Who wants to cut down on whole grains?
Although whole grains have many benefits, the following people should pay attention to reducing the intake of whole grains.
Dietary fiber in whole grains of patients with digestive tract diseases, especially insoluble dietary fiber, will aggravate irritation to people with digestive tract injury or inflammation. For example, patients with esophageal varices, gastric ulcer, duodenal ulcer and inflammatory bowel disease, eating whole grains may cause pain or bleeding at the focus.
People with weak digestive function and weak gastrointestinal digestion or peristalsis, such as chronic gastritis, eating too much whole grains will delay gastric emptying, increase gastric acid secretion, and aggravate gastric acid reflux, heartburn and bloating. In addition, some elderly people’s digestive function is weakened. If they are already underweight or have reduced muscle mass, we should pay attention to reducing the intake ratio of whole grains.
Phytic acid, dietary fiber and other components in whole grains of immunocompromised people will reduce the absorption rate of protein and zinc. If a large number of whole grains are ingested for a long time, it may lead to malnutrition and reduce human immunity.
Phytic acid and dietary fiber in whole grains of people with iron deficiency or calcium deficiency will combine iron and calcium in the diet and reduce the absorption rate. Therefore, people with iron deficiency anemia or osteoporosis should appropriately reduce the intake ratio of whole grains.
Teenagers in the growth and development period of children and adolescents have a high demand for energy, protein, trace elements and other nutrients. A large proportion of the ingredients in whole grains that hinder food digestion will also hinder the absorption and utilization of nutrients, which is not conducive to growth and development.
(Author: nutritionist, China-Japan Friendship Hospital)