Is the popular vegetable juice really healthy? Can it replace vegetables?

In recent years, many vegetables have been sold in milk tea shops from vegetable markets. Kale, bitter melon, celery, coriander, etc. are often on the menus of milk tea shops. Many milk tea shops have launched various "vegetable juices" to promote the concept of health and wellness.

But what is the nutritional value of vegetable juice? Is it really healthier?

Are vegetable juices healthier?

Numerous studies have shown that eating enough vegetables has many health benefits, and the evidence is strong. That’s why dietary guidelines around the world recommend eating vegetables every day. The Chinese dietary guidelines recommend eating one pound of vegetables every day.

However, drinking vegetable juice does not show the same health properties, and 100% pure vegetable juice does not have obvious health benefits in many aspects.

In 2024, a systematic review and meta-analysis analyzed the relationship between 100% fruit and vegetable juice and health, including anthropometric parameters, body composition, blood pressure and vascular function, blood lipids, blood glucose homeostasis, inflammation and oxidative stress markers, cognitive function, exercise performance, intestinal microbiome composition and bacterial infection. The final result is that the effect of 100% fruit and vegetable juice on human health is very limited and further research is needed.

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In general, eating vegetables is healthy, but drinking vegetable juice is not healthier, and drinking vegetable juice is not as healthy as eating vegetables.

What's wrong with vegetable juice?

Eating vegetables is healthy, so why isn't drinking vegetable juice so healthy?

This is because drinking vegetable juice is different from eating vegetables.

Compared with fresh vegetables, some nutrients are lost during the juicing process.

The first is dietary fiber. When juicing, most of the water-soluble nutrients go into the juice, while the insoluble dietary fiber remains in the residue. Data show that the fiber content of 100 grams of carrots is 2.8 grams, while the fiber content of 100 grams of carrot juice is 0.8 grams. Considering that many people filter out the residue when juicing vegetables, a lot of dietary fiber will be lost.

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In addition, some vitamin C and polyphenol antioxidants will also be lost. Polyphenol antioxidants are sensitive to oxygen and will be fully released and oxidized during the juicing process. Juicing destroys tissue cells during pulping, releasing oxidases in them. The high-speed rotation during pulping will introduce a large number of bubbles, allowing vitamin C to "efficiently" contact oxygen, oxidizing very quickly, and even causing more than 80% of vitamin C loss.

Compared with fruit juice, vegetable juice or vegetable pulp usually does not taste that good. In order to make it "taste good", many people will add sugar and other flavoring ingredients, or add sweeter fruits, which increases the intake of these other ingredients. For example, sugar should be limited for most people. The sugar content in fruit and vegetable juices sold in many milk tea shops and fresh fruit and vegetable juice shops on the market is usually 8%~10%, which is not much different from fruit juice and sweet drinks, so it is not very good for health.

Vegetable juice is in liquid form and does not need to be chewed. It is quickly emptied from the stomach. Therefore, after drinking fruit and vegetable juice, it is difficult for people to solve the problem of hunger and it is impossible to ensure the stability of blood sugar levels throughout the day. If hunger is not solved, it will always be there. Therefore, many people will eat more other things to solve the problem of hunger, which is not good for health.

Because of this, drinking too much vegetable juice is not good for your health.

Eating vegetables is the best choice

From a health perspective, eating vegetables is a better choice than drinking vegetable juice. The Chinese Dietary Guidelines recommend eating 200 to 400 grams of vegetables every day. Therefore, it is recommended that you drink less vegetable juice and eat as many vegetables as possible. It is best to eat different types and colors of vegetables to increase food diversity.

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For some elderly people over 65 years old, especially those with bad teeth, they can also drink vegetable juice appropriately. Because they cannot eat vegetables due to bad teeth, drinking vegetable juice in moderation can still help these elderly people fully absorb the nutrients in vegetables, such as drinking 1 to 2 cups a day. Moreover, after the vegetables are made into juice, since no oil or salt is added, it is also beneficial for these elderly people.

References

[1]RossiI,MignognaC,DelRioD,MenaP.Health effects of100%fruitandvegetablejuices:evidencefromhumansubjectinte rventionstudies.NutrResRev.2024Jun;37(1):194-238.doi:10.1017/S095442242300015X.Epub2023Sep1.PMID:37655747. ↑

[2]MicekA,CurrentiW,MignognaC,RosiA,BarbagalloI,AlshatwiAA,DelRioD,MenaP,GodosJ.Are(poly)phenolscontainedin100%fruitjuicesmediatingtheireffectson cardiometabolicriskfactors?Ameta-regressionanalysis.FrontNutr.2023Jun16;10:1175022.doi:10.3389/fnut.2023.1175022.PMID:37396131;PMCID:PMC10311565. ↑

[3]Dietary Guidelines for Chinese Residents 2022 ↑

Planning and production

Author: Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Review丨Zhong Kai, Director of Kexin Food and Health Information Exchange Center