Do you believe in the pseudoscience of ＂drinking oil to detoxify＂
Recently, "drinking oil" has become a hot search term. Some anchors died because of "drinking oil+drinking"; Some stars say that drinking oil to detoxify can treat diabetes, hypertension, liver cirrhosis and other diseases; Some people say that drinking oil can reduce weight, and some people say that drinking oil can lower blood fat and blood sugar … …
In fact, so far, there is not enough scientific evidence to prove that swigging oil and eating oil in a big bowl are good for health.
High-fat diet has adverse effects on intestinal flora.
Some people say that primitive people did not eat grains, but ate low-carbon water meals. However, archaeological research shows that even in the Stone Age, the energy supply ratio of carbohydrates was around 40%. Moreover, there was no technology to extract oil at that time, so oil was not the food of ancient humans.
Two or three thousand years ago, oilseeds such as hemp seeds and soybeans were eaten directly, so there were "hemp" and "glutinous rice" (soybeans) in the "five grains" at that time. It was not until after the Song Dynasty that oil became a common food raw material in China.
Although in recent years, scholars have disputed the question of "what is the best ratio of fat to energy in diet", more than one recent study has found that high-fat diet has adverse effects on intestinal flora.
Recently, Gut, an authoritative scientific journal, published the new findings of Chinese scientists, which once again proved that eating too much fat increases the harmful flora in the intestine and decreases the beneficial flora.
In this randomized controlled human dietary intervention study, the researchers recruited 217 healthy people aged 18-35. They have no chronic diseases and no obesity problems. These volunteers ate three different kinds of meals as required for half a year.
Then, the researchers collected their blood and measured the indexes related to inflammatory reaction, such as IL-1β 、IL-6、IL-8、TNF-α Cytokines, such as PGE2, TXB2, leukotrienes, LTB4, etc. Their feces were collected, and 16S rRNA was sequenced to analyze the flora. During the experiment, all the food and most drinks were provided by the researchers.
The calorie levels of these three diets are completely consistent, with an average of 2080~2100 kcal, and the dietary fiber intake is also consistent. However, the proportions of the three nutrients are different, and their nutrient energy supply ratios are as follows:
Type I: the energy supply ratio of fat is 20%, that of carbohydrate is 66%, and that of protein is 14%.
Type II: The energy supply ratio of fat is 30%, that of carbohydrate is 56%, and that of protein is 14%.
Type III: Energy supply ratio of fat is 40%, energy supply ratio of carbohydrate is 46%, and energy supply ratio of protein is 14%.
Maybe non-professionals can’t understand what this means, so they have to explain it.
The so-called nutrient-to-energy ratio is how much of the calories (calories, energy) gained in a day come from fat, carbohydrates and protein.
Type I, the so-called fat-to-energy ratio of 20% and carbohydrate ratio of 66%, is a fairly low-fat diet similar to that eaten in poor times before the reform and opening up.
Food energy mainly comes from grain, and a large proportion of cooking is cooked in cold salad. Basically, there is no oil flower and little meat in the serving.
There are few kinds of nuts, peanuts and melon seeds, such as boiled fish, fried meatballs, hand-torn bread, egg tarts, fried dough sticks, crispy rice, potato chips and so on … … Just don’t even think about it
Type II, the ratio of fat to energy is 30%, and the ratio of carbohydrate is 56%, which is recommended by the Nutrition Society of China, and it is slightly lighter and less oily than the current diet of most residents in China. There are nuts, but the quantity should be controlled; There is fish, but you can’t always fry it in oil.
Type III, the ratio of fat to energy is 40%, and the ratio of carbohydrate is 46%, which is the daily life of many wealthy families in China.
The fat energy supply ratio of fried instant noodles is about 40%~45%. Cooking with more oil, often eating out, often eating fried dishes, often eating fried cakes and fried dough sticks, and often eating cake biscuits will all increase the fat energy supply ratio.
The latest experiment proves that high-fat diet can promote inflammatory reaction.
Okay, let’s get down to business. Eating these three kinds of meals is naturally a world of difference in taste enjoyment. So, what is the change of the body?
The researchers found that after six months, there were no significant changes in the weight, waist circumference, blood sugar and blood lipid of the three groups. However, the intestinal flora has changed significantly.
First of all, the low-fat diet group with 20% fat has the most diverse fecal flora. High-fat diet reduces the diversity of flora.
Secondly, the quantitative proportion of flora has changed. High-fat diet increased the number of Alistipes and Bacteroides, and decreased the number of fecal bacteria. Low-fat diet increased bacteria of Blautia and fecal Bacillus. The simple explanation is that the bacteria increased by high-fat diet are mostly varieties that are easy to increase in patients with metabolic diseases such as diabetes; Most of the fungi it reduces are those that are easily lacking in diabetic patients, which produce beneficial components such as butyric acid and reduce intestinal inflammatory response.
The third finding is that the short-chain fatty acids in the feces of subjects in the 40% fat diet group are significantly lower than those in the other two groups. This is not good news, because butyric acid produced by large intestine fermentation is beneficial to control blood lipids, and recent research has just found that it is beneficial to reduce the risk of diabetes.
The fourth finding is that in the low-fat diet group, the contents of cresol and indole in feces are relatively low, and these components are less, indicating that it is far from various chronic diseases. Conversely, there are more arachidonic acid and lipopolysaccharide in the feces of high-fat diet groups, and more of these components represent higher risk of inflammatory reaction.
The analysis of blood samples shows that many proinflammatory factors in plasma of high-fat diet group are relatively high. In the 40% fat group, the content of TXB2 was significantly higher than that in the 20% low-fat group, and the content of C-reactive protein was significantly higher than that in the middle-fat diet group with 30% fat. Conversely, in the low-fat diet group with 20% fat, the contents of LTB4 and PGE2 were lower than those in the other two groups. In a word, a high-fat diet will obviously promote the inflammatory reaction.
This means that those who are prone to acne and inflammation should avoid eating high-fat meals.
Too much fat can lead to obesity and various chronic diseases.
In fact, the results of this study are not too surprising.
In fact, as long as Chinese people recall the past a little, they have to admit that in the past, when food was the mainstay and they could not eat much oil, people were very thin, and chronic diseases such as diabetes, fatty liver and coronary heart disease were rare, and intestinal cancer was also rare. With the development of economy, the only thing that keeps pace with the income level is fat. At the same time, obesity and various chronic diseases have increased. In addition to the decrease of infectious diseases and infectious diseases (which are related to malnutrition and poor sanitation), diseases related to chronic inflammation have also increased.
In this study, although the ratio of fat to total calories is different among the three groups, the total calories and total dietary fiber intake are strictly consistent. In real life, eating more high-fat foods will inevitably bring more calories and less dietary fiber, which is even more unfavorable for preventing fertilizer, disease and intestinal cancer.
In short, rational friends, don’t be fooled by stars, anchors and people who sell all kinds of oil. The recommendations of dietary guidelines for China residents are still very reliable. Cooking oil can be used, but it must be limited. Cooking can’t be "oily" and fried food can’t be eaten freely. Steak, fat sheep slices, pork belly and other high-fat meats are not inedible, but they can only be eaten occasionally, and they can’t be enjoyed every day.
Text/Fan Zhihong (Director of China Nutrition Society)