What color of fruits and vegetables are the most nutritious? If you don't know, you'll be at a big loss!

Vegetables and fruits are essential in a healthy diet. They are not only juicy, light and refreshing, but also rich in nutrition. People often have trouble buying vegetables and fruits: there are so many kinds of vegetables and fruits, what should I eat?

Don’t worry about it anymore! This article will tell you some tips on choosing fruits and vegetables, so that you can get more “good nutrition” while eating fruits and vegetables.

Image source: pixabay

If fruits and vegetables are classified based on color, they can be divided into dark-colored fruits and vegetables and light-colored fruits and vegetables.

This is easy to understand. The dark-colored fruits and vegetables are naturally dark-colored. When choosing fruits and vegetables, be sure to choose dark-colored fruits and vegetables! Compared with light-colored fruits and vegetables, dark-colored fruits and vegetables are not only brighter in color, but also more nutritious.

Why are dark-colored fruits and vegetables more nutritious?

Dark-colored fruits and vegetables not only contain nutrients such as vitamins, minerals, dietary fiber, but also contain rich natural pigments, such as beta-carotene, lutein and zeaxanthin, lycopene, anthocyanin, chlorophyll, etc. Generally speaking, the higher the content of these substances, the darker the color of fruits and vegetables.

Don't underestimate these natural pigments, they have antioxidant effects and are very beneficial to health.

1. Beta-carotene, lutein and zeaxanthin

They are carotenoids, a type of substance that makes food appear orange-yellow. Of course, they are not only found in yellow fruits and vegetables, but also in green leafy vegetables, but are masked by the green color.

β-carotene, lutein and zeaxanthin are all important nutrients related to the retina. Among them, β-carotene is an important source of vitamin A, which can be converted into vitamin A in the body, can protect eyesight, prevent dry eyes, prevent night blindness and other eye diseases, and is also beneficial to our skin health; lutein is a derivative of α-carotene, and zeaxanthin is a derivative of β-carotene. These two can help us resist the damage of blue light to the eyes, prevent retinal damage, anti-oxidation, and help prevent retinal macular degeneration.

The "Dietary Reference Intakes of Chinese Residents (2023 Edition)" only gives a specific recommended value for lutein, which is 10 mg/d. Foods rich in lutein include marigold, leek, amaranth, pumpkin, spinach, and pakchoy. Among them, marigold and leek have the highest content, at 18.74 mg/100g and 18.23 mg/100g, respectively.

2. Lycopene

Lycopene is also a carotenoid. It is the main pigment in ripe tomatoes and gives food its tomato-like red color.

Lycopene has antioxidant properties that can help us eliminate excess free radicals in the body, help our body fight inflammation, enhance the body's ability to resist oxidative stress, and improve immunity; it can also protect cardiovascular health and lower serum total cholesterol and low-density lipoprotein cholesterol, commonly known as "bad cholesterol."

In addition, intervention studies mainly using lycopene products have found that they have a certain effect on improving blood pressure, especially lowering systolic blood pressure.

Some large-scale prospective studies in Europe and the United States have found that lycopene levels in the body are negatively correlated with the risk of cardiovascular diseases, such as coronary heart disease and stroke. Some studies have also mentioned that lycopene intake has a protective effect on prostate cancer (especially advanced prostate cancer).

The specific recommended value of lycopene for adults in my country is 15mg/d. Foods rich in lycopene include tomatoes, guava, watermelon, red grapefruit, red pepper, purple cabbage, etc. The most recommended is tomato sauce, which contains 29.3mg/100g.

Image source: pixabay

3. Anthocyanins and anthocyanins

Everyone is familiar with "anthocyanidin", which is combined with different sugars to form anthocyanins. Both of them can give food color, such as red, purple, black, and blue, but the color of anthocyanidin will change due to the pH of the environment. Because anthocyanidin is unstable, it generally exists in the form of anthocyanins in nature, and anthocyanins are more stable than anthocyanidins.

Anthocyanins have antioxidant properties, strong free radical scavenging ability, and can inhibit the body's inflammatory response. Eating foods rich in anthocyanins can significantly improve dyslipidemia and reduce triglycerides. In addition, the results of Meta-analysis also show that anthocyanins can significantly improve eye symptoms such as glaucoma, high intraocular pressure, and dry eye syndrome.

my country's specific recommended value for anthocyanins is 50 mg/d. Foods rich in anthocyanins include mulberry, bayberry, black plum, blueberry, purple cabbage, hawthorn, perilla, black rice, black beans, etc., among which mulberry is the richest, with a content of 668 mg/100g.

Image source: pixabay

4. Chlorophyll

Most green leafy vegetables are rich in chlorophyll, and many green-fleshed fruits also contain chlorophyll, which is also an antioxidant. Moreover, chlorophyll is the main complex of magnesium, so foods rich in chlorophyll also contain magnesium. The darker the color, the higher the magnesium content.

Epidemiological surveys have shown that magnesium intake is negatively correlated with hypertension, and magnesium supplementation can reduce vascular tension and vascular tightness. In addition, magnesium can help lower serum cholesterol levels, lower blood triglyceride levels, lower bad cholesterol, and raise good cholesterol, which can prevent the occurrence of atherosclerosis.

Foods rich in chlorophyll include Chinese cabbage, rapeseed, leeks, kiwi fruit, etc.

Image source: pixabay

Nutritional comparison of common dark-colored fruits and vegetables

-Dark green vegetables and fruits: rapeseed, spinach, leek, celery, water spinach, lettuce, spinach, broccoli, chrysanthemum, radish leaves, lettuce, green pepper, kiwi, etc.

-Orange and yellow fruits and vegetables: carrots, pumpkins, yellow bell peppers, mangoes, oranges, tangerines, grapefruits, cantaloupes, persimmons, etc.

-Red, purple and black fruits and vegetables: tomatoes, red peppers, red bell peppers, red amaranth, purple cabbage, purple lettuce, purple onions, seaweed, mulberries, black wolfberries, blueberries, bayberries, cherries, watermelons, etc.

Generally speaking, dark-colored vegetables are more nutritious than light-colored vegetables. Below is a nutritional comparison of 6 vegetables that look similar but have large differences in color depth. Let’s take a look.

Nutritional comparison between Chinese cabbage and pakchoi[4]

Nutritional comparison between broccoli and cauliflower[4]

Nutritional comparison between purple cabbage and Chinese cabbage[4]

Nutritional comparison of three colors of onions[5]

Nutritional comparison between red radish and white radish[4]

Nutritional comparison between black fungus and white fungus[4]

It’s not difficult to eat enough, just 7 tips to do it!

The "Dietary Guidelines for Chinese Residents" recommends that you eat 200-350 grams of fruit every day, which is equivalent to (an "or" relationship) 1-2 apples, 2-3 kiwis, 2-3 large oranges, and eight or nine large strawberries. This is easy for most people to do.

As for vegetables, the "Dietary Guidelines for Chinese Residents" recommends that we consume no less than 300g of fresh vegetables every day, of which dark vegetables should account for more than 1/2. If you can eat 500g a day, it would be even better! Many people think that this is 0.6 catties to 1 catties, a lot of vegetables, and it is too difficult to eat enough! In fact, it is not difficult. Master these 7 tips to help you eat enough vegetables.

① Eat for all three meals: Set rules for yourself in terms of diet structure. Every meal must have vegetables. This will make it easier to achieve the goal of eating 300-500g of vegetables every day.

② Cook before eating: Cooking vegetables is not only for safety, but also for eating more. Although 300-500g of vegetables may seem like a lot when raw, it is not much when cooked. The fiber of vegetables softens and becomes limp after being heated and cooked. 100g of green leafy vegetables weighs less than 1 fist after being cooked. It is enough to eat 3 to 5 fists of cooked vegetables every day, which is equivalent to 1 to 1.5 fists of vegetables in each of the three meals.

③ Eat as a snack: If you feel that you don’t eat enough vegetables at your regular meals, you can eat as a snack. You can also choose vegetables such as tomatoes and cucumbers that are easy to eat as snacks in the morning and afternoon.

④ Place in a conspicuous place: Don’t place vegetables at the innermost part of the refrigerator, as this will not only cause them to freeze, but also make them easy to be forgotten. Usually, the food that is most conspicuous when you open the refrigerator door is more likely to be chosen and eaten.

⑤ Make the table colorful: Choose vegetables of different colors and put them on the table together. This can visually please the mood and promote appetite.

⑥ Make it into food with stuffing: In terms of the way of eating vegetables, in addition to the common stir-fry and cold salad, for those who don’t like to eat vegetables directly, making them into dumplings and buns with stuffing is the most delicious and a good way to increase vegetable intake.

⑦ Don’t throw away the residue when drinking vegetable juice: If you really don’t like eating vegetables directly, then make them into fruit and vegetable juice (without removing the residue). This is also a good way to increase your vegetable intake. Remember to rinse your mouth in time after drinking to maintain oral health.

When it comes to choosing fruits and vegetables, you really have to be "colorful"! Choose more dark-colored fruits and vegetables to get more nutritional benefits. It's actually not difficult to eat more vegetables every day. You can do it with a little thought.

References

[1] Chinese Nutrition Society. Dietary Reference Intakes of Nutrients for Chinese Residents (2023 Edition) [M]. People's Medical Publishing House. 2023.8

[2] Zhang Bing, Lei Shengjiao, Zhang Lei, Shi Songsong, Xia Xinke. Structural identification and antioxidant activity of chlorophyll in Yichang green kiwifruit pulp[J]. Food Industry Science and Technology, 2019, 40(23): 31-3541

[3] Sun Changhao. Nutrition and Food Hygiene. 8th edition. People's Medical Publishing House. 2018

[4] Yang Yuexin. Chinese Food Composition Table 6th Edition Volume 1[M]. Peking University Medical Press, 2018

[5] Li Jinwei, Wang Liang, Fan Liuping. Analysis of nutritional components of three kinds of onions[J]. Food Industry Science and Technology, 2010, 31(05): 345-347. DOI: 10.13386/j.issn1002-0306.2010.05.089.

This article is a work of Science Popularization China-Starry Sky Project

Produced by: Science Popularization Department of China Association for Science and Technology

Producer｜China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author: Xue Qingxin, member of Chinese Nutrition Society, registered nutritionist, health manager, public nutritionist

Review | Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center