Regarding food health preservation, the most widely circulated point is: eat hot food, not cold food.
Don’t drink cold and white water, drink warm boiled water; The yogurt just taken out of the refrigerator is too cold, wait until you eat it. Even if you eat fruit in winter, you have to heat it before eating it.
Many people are confused: Is there really a scientific reason for this? The same food, just different cold and hot temperatures, will have such a great impact on health? Maybe it’s a fool… … …
This time, let’s make it clear about hot and cold food.
For impatient friends, you can directly read the 4 suggestions given to you at the end of the article.
Cold rice is not easy to digest, but it is not necessarily a bad thing.
Whether food temperature affects health depends on what scientific research says.
A study published in < > in 2004 recruited nine young healthy male volunteers to eat the same amount of potatoes every day.
The only difference is:
On one day, I ate hot potatoes (the center temperature is 84 ℃) and on the other day, I ate cold potatoes (the center temperature is 26 ℃)
The results of the test, however, surprised people-
After eating hot potatoes, the postprandial blood sugar rise rate was significantly higher than that after eating cold potatoes. The postprandial blood lipid level is even more surprising:
Hot potatoes have brought about a significant increase, while cold potatoes have not only not caused an increase, but even a very significant decrease!
Why is this happening?
In fact, this is because the digestion difficulty of starch foods (such as rice and potatoes) is related to the gelatinization degree and aging degree of starch, which is greatly affected by food temperature.
Without sufficient temperature, starch cannot be fully gelatinized, that is, [unripe]. However, eating cold rice-once the cooked rice cools down, starch molecules will gather again, viscosity will decrease, and hardness will increase, which is called [aging retrogradation].
After starch retrogradation, more [resistant starch] will be produced, that is, starch molecules that are not easy to digest and absorb by human beings. They are somewhat similar to dietary fiber and can only be fermented by large intestine microorganisms after entering the large intestine.
There have been many studies showing that:
Compared with hot rice, cold rice after refrigeration has slower digestion speed.
Moreover, in addition to starchy foods, the digestion of meat and vegetables is similar:
- Meat: The fat of beef and mutton contains more saturated fatty acids, and the melting point exceeds the body temperature. After being cooled, the fat becomes solid and the digestion speed will also decrease. Vegetables: The cell wall of raw vegetables is not damaged and the digestion and absorption rate is low. After cooking and heating, the cell wall softens and the utilization rate of carotenoids increases significantly.
From this point of view, cold rice and cold food are really difficult to digest, but what Dr. Clove wants to say is that this is not necessarily a bad thing.
For people with too good digestion, obesity and three highs, eating some cool food and raw vegetables with slow digestion can help delay the rise of postprandial blood sugar and blood lipid, improve intestinal flora and be beneficial to health.
These people, really don’t eat cold food
However, there is another fact that cannot be ignored:
Warm food is conducive to promoting blood circulation in the stomach, while cold food will temporarily contract blood vessels in the stomach, affecting the secretion of digestive juice and gastrointestinal peristalsis.
For those who have poor digestion ability and thin body, the secretion of digestive juice is insufficient, and then using cold food to chill their stomachs is even worse.
Therefore, these people should not be greedy for cold food.
The experience of the ancients is not necessarily applicable to modern times.
The ancients said [avoid eating raw and cold] has been circulating for thousands of years. How can cold food be beneficial to health?
We must understand that almost all kinds of health preserving tips of the ancients were summed up under the conditions of malnutrition, physical fatigue and large changes in ambient temperature in ancient times.
In ancient times, there was no air conditioner or heating. The vast majority of people lived a life of shivering in winter and sweating in summer. Once willing to spend money to let a doctor see a doctor, they are often in a very weak and seriously ill state. Naturally, they should pay attention to the influence of food temperature on digestion and absorption.
Moreover, there was no refrigerator in ancient times and there was no food hygiene inspection. When food is first prepared, the hygiene level is the most reliable, but once it is left at room temperature for a long time, microorganisms multiply and there is a risk of food poisoning.
Therefore, in ancient times, advocating food to be eaten while it is hot is also a good suggestion to ensure food safety.
Cold or hot? Here are four suggestions
1. If I am healthy and have good gastrointestinal digestion function, I don’t need to pay too much attention to the temperature of food, as long as I don’t ice my teeth.
It’s no problem to eat some cold drinks such as ice cream and ice cream occasionally.
Three high patients may as well eat some raw vegetables. Diabetic patients can cool the staple food to room temperature before eating, which may be helpful to improve satiety and reduce the blood sugar and lipid reaction after meals.
2. If digestion is not good, there are gastrointestinal diseases, or people who are weak and recover from postoperative diseases, it is recommended to eat warm food.
Elderly people with weakened digestive function also need to pay attention to the temperature of food.
3. Don’t leave food at room temperature for too long.
Even in autumn, the daytime temperature is still not low, microorganisms multiply fast, and food is easy to deteriorate.
If you cool the food at room temperature and eat it after two or three hours, it is likely that the bacteria have exceeded the standard. The leftovers placed in the refrigerator should be thoroughly heated again before eating, and do not eat them directly because of laziness and greed for cold.
No one is recommended to eat hot food.
Hot and delicious food should also be eaten when it is not hot.
Otherwise, the mucosa of our mouth, esophagus and stomach, like those barbecued meat, will be scalded and degenerated, and there is also a risk of cancer. This is not to scare you. Recently, WHO suggested that hot drinks with too high a temperature (over 65 ℃) will increase the risk of esophageal cancer.