Golden apple in the morning, poisonous apple in the evening? An apple a day keeps the doctor away? The truth about apples

Expert of this article: Liu Jingjing, PhD in Food Biotechnology, China Agricultural University

We all know that eating apples is good for the body.

There is a saying that many people must have heard, "An apple a day keeps the doctor away", but is there any scientific basis for it?

There is also a saying that "golden apples in the morning, silver apples at noon, and poisonous apples in the evening". What is the truth? Let's take a look today.

An apple a day keeps the doctor away?

Although eating apples has many benefits, this statement is a bit exaggerated.

Common bulk fruits include apples, pears, hawthorn, strawberries, grapes, oranges, bananas, pineapples, etc. The comprehensive nutritional value of apples is not outstanding among these fruits.

For example, vitamin VC, the most important vitamin in human dietary nutrition, is only 4.46 mg/100g in apples, but can be as high as 298.90 mg/100g in kiwifruit. Therefore, eating apples can keep you safe and keep you away from doctors and prevent you from getting sick, which is an exaggeration of the health care effect.

However, apples do contain many ingredients that are beneficial to the human body, such as apple polyphenols and triterpenes. Apple polyphenols are the general term for polyphenolic substances contained in apples, including phenolic acids and flavonoids, which can be used as an effective inhibitor of hypertension, hyperlipidemia, and cardiovascular and cerebrovascular diseases.

Apple polyphenols also have a strong inhibitory effect on the transglucosylase of caries bacteria, thereby preventing the formation of dental plaque and are very effective in preventing caries.

Studies have shown that most triterpenoid compounds isolated from apple peel have a strong inhibitory effect on cancer cells, which is one of the reasons why apples have anti-cancer activity.

When is the best time to eat apples?

Golden apple in the morning, silver apple at noon, poisonous apple at night?

If the human digestive system is functioning normally, eating apples at any time will not cause any harm.

It's just that in the morning, the gastrointestinal function of the human body is in an activated state, the digestive ability is weak, and sufficient nutrients are needed. Eating some easily digestible fruits, such as apples, in the morning can supplement the nutritional needs of the human body; and the work and study activities in the morning are relatively large and consume a lot, so intake at this time is also more conducive to controlling blood sugar.

The sugar content of apples is about 11-13%, ranking high among all kinds of fruits. Moreover, the sugar in fruits is absorbed much faster than other foods. Therefore, eating apples at night or before going to bed can easily cause excess calories and lead to obesity. A full stomach and intestines will affect sleep, and it is even more harmful to health for people with poor gastrointestinal function.

Apples are artificially waxed. Is it harmful to eat them?

Artificial waxing of fruits after they are picked is an important part of the commercial processing of fruits. Apples are artificially waxed to prevent moisture loss and wrinkling of the skin, which leads to reduced freshness, and to prevent invasion of microorganisms in order to extend the shelf life. Fruit wax is a type of food additive allowed for use worldwide. As long as it is waxed in a regular manner, it will not cause harm to human health.

Moreover, during the natural growth process of apples, the skin will naturally secrete a layer of fruit wax to prevent harmful external substances from invading the flesh. This is a beneficial measure for apples to fight against the external environment and is harmless to the human body.

What should you pay attention to when eating apples?

It is best to choose fruits that are not too acidic or astringent when eating on an empty stomach, such as apples, pears, grapes, etc.

Try to peel the apple before eating it. Although a large number of studies have shown that the types and content of nutrients in apple peels are more than those in the fruit, eating only the peel of an apple will not have a significant effect on human health. In addition, there are more pesticide residues in the peel, so it is best to peel the apple thoroughly before eating.

Eat different kinds of fruits together. The nutritional structure of each fruit is unique. Some fruits have high protease content, some have many types of vitamins, and some are rich in trace elements. Long-term consumption of one or a few kinds of fruits can easily lead to nutritional deficiencies.

Apple tea, brewed with warm water. In recent years, it has become popular to dry apple slices to make fruit tea. After low-temperature drying, only some vitamins are retained in the apple slices. You can drink it anytime, but it is recommended to soak it in room temperature water. If the temperature is too high, it will accelerate the decomposition of the remaining vitamins and greatly reduce the nutritional value. Fruit tea cannot replace fruit.

The pictures in this article with the "Science Popularization China" watermark are all from the copyright gallery. The pictures are not authorized for reprinting.