Autumn is the season of harvest, and fruits with rich varieties such as apples, citrus, and persimmons are also on the market one after another.
But while having a good time, there is also a saying around you that "eating too much fruit and eating it wrong will make people sick." For example, some people say that after eating fruit, they will suffer from diarrhea, allergies, stomachache, , etc. What's going on? How to eat fruits healthier?
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Eat pineapple “tick the mouth” because there are calcium oxalate crystals in pineapple. You can soak the pineapple in salt water before eating;
feel uncomfortable and diarrhea after eating fruits, which may be due to fructose intolerance. It is recommended to choose fruits with a higher proportion of glucose than fructose , such as bananas, oranges, grapefruits, strawberry , kiwi , etc.;
Do not eat lychees on an empty stomach or a large amount of lychees, otherwise it may lead to hypoglycemia;
After eating persimmons, abdominal pain is caused by " tannin ". It is recommended to wait until the persimmons are fully ripe before eating. For people with stomach diseases, it is not recommended to eat persimmons;
After eating mangoes, itchy around the lips and obvious swelling on the face is an allergic reaction, so it is recommended not to eat or touch it;
drinking juice cannot replace eating fruits, and it is recommended to have enough fruit intake every day. It is recommended to eat 200-300 grams of fruit every day, and choose different types of fruits to eat.
01
Fruit will make you "sick"?
1. Puncture the mouth
Many people feel uncomfortable when eating pineapples, such as puncture the mouth and throat. In the past, everyone thought it was because it contained bromelain . Bromelain can make us allergic, causing symptoms such as swelling and painful mouths and discomfort in the throat.
But later studies found that the culprit of 's "mouth" in eating pineapple is not bromelain, the real culprit is calcium oxalate crystal .
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protease in pineapple may also stimulate the mucosa, but it usually takes a longer time to feel it, and it will not feel sting immediately.
In fact, many plants contain oxalate . Oxalates are water-soluble, such as sodium oxalate and potassium oxalate , and some also form insoluble crystals, such as calcium oxalate and magnesium oxalate. At present, more than 200 plants' tissues, including leaves, stems, roots and even anthers, all contain calcium oxalate crystals.
Calcium oxalate crystals mostly exist in bundles in plant cells. When plant cells are damaged during chewing, moisture will enter and cause the cells to swell, thus vigorously pushing the calcium oxalate crystals into the oral environment, stinging sensitive tissues such as the tongue, gums and throat, creating a sensation of pricking the mouth. When we eat spinach, we feel that thorny on our mouth is also the influence of calcium oxalate.
The good news is that soaking salt water will dissolve the calcium oxalate needle crystals in water, and boiling and heating can dissolve the calcium oxalate in water. Therefore, before eating pineapple, soaking in salt water or boiling and heating will not be so "punching" the mouth.
2. Diarrhea
Many people feel uncomfortable after eating fruits, or even have diarrhea and diarrhea. In fact, this may be that fructose intolerance is "making trouble"!
Fructose intolerance is similar to that of drinking milk lactose intolerance. They are both categories of intolerance to "sugar" - one is tolerability to fructose, and the other is tolerability to lactose.
We know that there is a lot of fructose in fruits. When fructose reaches the intestine, it will not enter the blood circulation directly like glucose. Instead, it needs to be transported to the blood with the help of a protein on the intestinal wall - the "fructose carrier".
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, but some people are born with lack of this "fructose carrier", or its "fructose carrier" is too poor in working efficiency , which will cause fructose to not be absorbed in the intestine in time, resulting in a higher osmotic pressure of in the intestine, causing the water to be absorbed from the plasma, so that there is more water in the intestine.
Then when these unabsorbed fructose arrive in the colon, they will be metabolized by the bacteria there, producing gas, which will stimulate the peristalsis of colon . Because there is a lot of water, this peristalsis will cause diarrhea.
So some people will have bloating, uncomfortable, and even diarrhea after eating fruits.
If you are indeed intolerant of fructose, you should try to eat less fruits with high fructose content, including honey and food and beverages with fructose syrup . can choose to eat fruits with higher glucose ratio than fructose, such as bananas, oranges, grapefruits, strawberries, kiwis, etc. . You can also try eating various fruits to see which fruit will not feel uncomfortable or have diarrhea after eating them. Then you can choose to eat them later.
3. Hypoglycemia
Many people will experience hypoglycemia, dizziness and other discomfort symptoms after eating lychees. People have always called this phenomenon "lychee disease" . What's going on?
At first, people thought that this was caused by the fructose in lychees. Lychee tastes sweet and has a high sugar content, and a large part of it is fructose. After we eat lychees, fructose will directly start to stimulate the secretion of insulin and . Moreover, its effect is relatively strong, which often causes insulin to pull down and reduce blood sugar in time, which will lead to the blood sugar drop too low and cause symptoms of hypoglycemia.
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, but there are still many foods with a lot of fructose, such as dates, grapes, raisins, figs , pears, cherries, etc. We eat many processed foods and beverages now use fructose syrup, why don’t there be similar problems?
Later scientists discovered that the real reason for litchi disease is that there are two toxins in litchi: Hypoglycin-A (Hypoglycin-A) and α-Methylenecyclopropyl glycine (MCPG) . These two toxins will affect the body's sugar metabolism , leading to poisoning.
Moreover, the toxin content in lychees that are not fully mature will be higher. Because children have not yet fully developed their physical development, the risk of developing lychee disease is also higher.
However, there are two important prerequisites that cause lychee disease - "empty on an empty stomach" and "eat in large quantities". Most of the cases of poisoning found at present are children playing in the orchard. When they are tired and hungry, they pick up a lot of lychees that have fallen on the ground to eat. They eat a lot. They don’t eat dinner after returning home at night, and they will develop symptoms of “lychee disease” in the middle of the night.
So, don’t eat a lot of lychees on an empty stomach. Try to eat cooked lychees thoroughly, so don’t worry about lychees coming to you.
4. Gastrostone
Many people say that persimmons cannot be eaten on an empty stomach, otherwise they will get gastric stones (gastrostone). Can you still eat persimmons?
Persimmons contain tannic acid. Combining tannic acid with saliva protein in the human mouth will make people feel "astringent", so they will feel numb when eaten.
Tannic acid can bind to protein to produce insoluble precipitates, and cannot be decomposed in the gastrointestinal tract. If you eat tannic acid in large quantities, and there are also a lot of protein in the stomach. On the one hand, tannin will form an insoluble complex for the protein. At the same time, tannins can also make pepsin inactive. In addition, other ingredients such as pectin and fiber in persimmons may be mixed together and form "gastric persimmon stone" , causing digestive tract obstruction and abdominal pain.
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, but this does not mean that we cannot eat persimmons. In fact, not all persimmons are high in tannin.
There are very few persimmon tannic acid sold on the market now, because commercial persimmons must be removed before they can be sold on the market. After all, if the taste is too astringent, consumers will not buy it, and merchants will face huge risks if they really eat something wrong. can be eaten with little tannin as long as it has been treated with astringent treatment.
If you are worried about eating persimmons, you are advised to:
Immature persimmons have a high tannic acid content and astringent taste. If you are not delicious, don’t eat it. Try to wait until it is ripe before eating ; when eating, it is best not to be on an empty stomach.
If it is a persimmon planted by your own home, it is best to keep for a few days and then eat after it becomes soft, because during the ripening process of persimmons, the tannin content will gradually decrease, and the tannin content of fully mature persimmons is very low, so they can only be eaten.
Don’t buy or eat some persimmons sold on the roadside or grown by yourself, as they may not have been treated with astringent treatment.
People with excessive secretion of gastric acid and poor stomach motivation, or those with stomach diseases such as gastric ulcers and , try not to eat persimmons , especially those with too astringent and immature persimmons.
5. Allergic
Some people have a large area of erythema around their lips after eating mangoes, which feels burning and itchy, and their faces are obviously swollen. This is actually an allergic reaction.
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Research has found that there are 9 common allergens in mango, and these allergens can cause allergic reactions in the human body, including contact dermatitis , oral allergies, cross-allergies , etc.
For example, mango allergies can cause skin and mucosal lesions (such as angioedema , urticaria, facial swelling, etc.), digestive system lesions (such as oropharyngeal syndrome, diarrhea, abdominal pain, etc.), respiratory lesions (such as asthma , dyspnea, allergic rhinitis , etc.), and in severe cases, symptoms of systemic allergies and shock and other life-threatening symptoms. How to prevent
? The only way to prevent allergies is to avoid exposure to allergens. If you are really allergic to mangoes, try not to eat or touch them.
For example, if you just eat mangoes, you will experience some mild allergic symptoms, such as corner inflammation of the mouth, itchy skin, etc., it means that you are allergic to mangoes. You should try to eat less or not eat mangoes, and you should also avoid contacting the trunks, stems and leaves of mangoes, especially avoiding the juice of mango tree , because it will also contain allergens.
02
How to eat fruits healthily?
1. Eat enough
1. In 2019, the Lancet released an analysis of the mortality rate and disease burden caused by dietary structure in 195 countries and regions around the world. The results show that the mortality rate caused by dietary problems in China is in the second to last in the world. One of the problems is: eating too little fruit.
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fruits are rich in dietary fiber, vitamins, minerals and a variety of plant active substances and other nutrients. Increasing fruit intake can reduce the risk of cardiovascular disease, esophageal cancer, colorectal cancer and other chronic diseases.
But at present, our country's per capita fruit intake is less than 50 grams per person per day, while our country's dietary guide recommends that we eat 200-350 grams of fruit every day, and don't eat too much, as too much will affect eating other foods and lead to malnutrition.
So, our top priority is to eat enough to ensure that we can eat 200-350 grams of complete fresh fruit every day. Generally, a medium-sized Fuji apple core is about 200 grams, a medium-sized persimmon is about 100 grams, a banana is about 120 grams, an orange is about 150 grams, and a kiwi is about 100 grams.
I would like to remind everyone here that juice cannot replace fruits. Try to eat complete fruits and drink less juice. Even pure juice should be drunk less.
2. Eat fruits by changing the type
Many people like certain fruits and only eat one, staring at it. In fact, the basic principle of nutrition and health is a balanced diet. The most basic thing is to make food diverse and eat different types of food.
fruits are the same. Different types of fruits contain different nutrients. The dietary guide recommends that we eat 12 foods a day and 25 foods a week. It is recommended that everyone try to eat different types of fruits every day, and cut each fruit into small pieces to share with family and friends.
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3. Adjust
According to your own situation, everyone's physical condition and digestive ability will be different. If you are allergic to a certain fruit, or if you feel uncomfortable eating a certain fruit on an empty stomach, try not to eat it and change to other fruits.
If you are worried about gaining weight by eating fruits, you can eat fruits before meals, which is conducive to controlling the total amount of meals; eating fruits between meals can not only replenish moisture, but also obtain rich nutrition.
Overweight, obese, hypertensive , and patients with hyperlipidemia are suitable for eating fruit before meals; if they are diabetes patients, it is recommended to treat fruit as an extra meal between meals.
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Author: Ruan Guangfeng Kexin Food and Nutrition Information Exchange Center Director of the Science and Technology Department
