A few days ago, a reporter from the Beijing Youth Daily told me that the Beijing Municipal Agriculture Bureau recently released a 10-year report on vegetable consumption, which showed that potatoes have always been the highest-selling vegetable in Beijing! Why is this humble potato so popular? From a health perspective, is it a good thing or a bad thing?
Why are potatoes popular?
This is not difficult to explain. It's not just people in Beijing who love potatoes. Potatoes are popular in half the world, and Europeans love to eat them as staple food! Although there has not been a comprehensive survey, in my opinion, people love potatoes for several reasons:
Firstly, the aroma of cooked potatoes is extremely rich, almost unmatched by other vegetables. Potatoes contain a large amount of free amino acids and have a high protein content. They also contain a small amount of sugar and a lot of starch, which are good at producing Maillard reaction, an important reason for the aroma of cooked potatoes.
Secondly, the texture of cooked potatoes is particularly rich. They can be made into cold shredded potatoes, crispy and slightly chewy stir-fried shredded potatoes, extremely delicate mashed potatoes, soft stewed potatoes, as well as the unique texture of fried french fries and potato chips...
Thirdly, the starch in potatoes can thicken and bind during cooking, making the broth thick and sticky. The thick sauce sticks to the surface of the ingredients, giving it a special taste. This is a magical effect that is difficult to achieve with other vegetables that do not contain starch.
Fourthly, potatoes are compatible with various seasonings. Whether it's soy sauce, vinegar, pepper, or curry powder, potatoes can present a very tempting taste.
However, from a health perspective, the high consumption of potatoes is a bit of a dilemma.
The nutritional value of potatoes themselves is not bad. They are rich in potassium, with a potassium content comparable to bananas. They also have a relatively high content of vitamin C, comparable to tomatoes. They are rich in vitamin B1, which is easily lacking in Chinese people, and their vitamin B2 content is higher than that of rice. They also contain dietary fiber and polyphenols. When not adding oil or salt, the starch content of roasted or steamed potatoes is not as high as rice or steamed buns, and the rate of blood sugar rise is not as fast as white rice or steamed buns, and they provide a strong sense of fullness. When eating 300 calories of food, potatoes are more filling than rice or steamed buns, and people don't feel hungry for a long time after a meal.
In conclusion, if potatoes are simply roasted or steamed, their health value is not disappointing. If used as a staple food to replace white rice or white flour, consuming more potatoes can improve nutrition and help control blood pressure. Europeans consider potatoes as staple food, and roasted potatoes are a common staple food for the French and Germans. Many doctors advise hypertensive patients to eat more roasted potatoes and less white bread. In the famous DASH diet, potatoes also have a place and become part of a healthy diet to prevent and control hypertension, hyperlipidemia, and hyperglycemia.
Potatoes are not suitable as a vegetable dish
If potatoes are used as a vegetable dish, the effect is reversed. Among vegetables, potatoes have the highest starch content, usually between 14% and 20%, while the carbohydrate content of most other vegetables is below 5%, and leafy vegetables are even lower. More starch means higher calories. If potatoes replace green vegetables, it will undoubtedly increase the risk of obesity and triglycerides.
What's more troublesome is that most Chinese people do not eat roasted or steamed potatoes, but cook them with a large amount of oil or stew them with meat. Potatoes are good at absorbing oil, and because of their starch content, if less oil is used, stir-fried shredded potatoes will stick to the pan. Although potatoes themselves have lower calories than rice, the high calorie content of the oil makes the potatoes soaked or coated with oil contain a considerable amount of calories.
Which cooking method of potatoes has less oil? Many people may say: it's the crispy stir-fried shredded potatoes, which looks refreshing and doesn't have much oil.
Unfortunately, that's not the case. According to our previous measurements, the popular Sichuan-style stir-fried shredded potatoes, which doesn't look greasy at all, actually contains a considerable amount of cooking oil (not counting the oil on the plate), with a fat content of 10% to 12%. Washing away the starch not only doesn't reduce the oil, but increases the fat content of the cooked potatoes. Comparatively, whole milk has a fat content of only 3%, and eggs have only 10%.
Therefore, pairing rice with stir-fried shredded potatoes or steamed buns with braised pork and potatoes is a fattening combination. Because shredded potatoes contain starch, theoretically, if you eat shredded potatoes, you should reduce the amount of rice, otherwise, you are eating two servings of staple food, which will surely promote weight gain. If you have fried potato chips or french fries after a meal, the fat content is much higher than that of stir-fried shredded potatoes (fried potato chips usually have a fat content of 25% to 35%), and it will be even more effective in causing weight gain.
We must not forget that when potatoes are used as a vegetable dish, there is another serious drawback.
In the field of nutrition, vegetables are often divided into "dark-colored vegetables" and "light-colored vegetables," and potatoes belong to the latter. Light color means low carotenoid content and low anthocyanin content. In terms of carotenoid content, folic acid content, vitamin K content, calcium content, dietary fiber content, antioxidant content, and many other aspects, potatoes are far behind dark green leafy vegetables. Nutrition studies often find evidence that eating more vegetables and fruits is beneficial for preventing cardiovascular and cerebrovascular diseases. Unfortunately, this does not include potatoes. In other words, potatoes cannot replace the benefits of tomatoes and carrots, let alone spinach and rapeseed.
With that said, the conclusion is clear: if potatoes are evaluated as a staple food, they are better than white rice. However, if evaluated as a vegetable, they are a vegetable with low scores. They have low antioxidant content, few health-promoting ingredients, and a much higher calorie content than ordinary vegetables.
Food safety research has also found that potatoes are the most likely vegetable ingredient to produce acrylamide (a suspected carcinogen) during cooking. Acrylamide often accompanies the Maillard reaction that produces aroma, which means that the stronger the aroma of the potato cooking method, such as frying or deep-frying, the more acrylamide is produced. Fried potato chips are the top food in terms of acrylamide content. Researchers have found that this is because potatoes are rich in glutamine and asparagine, which are prone to produce acrylamide under common cooking conditions between 120 and 190 degrees Celsius. However, this is not a problem when steaming potatoes because even when using a household pressure cooker, the cooking temperature is less than 120 degrees Celsius, and these reactions are unlikely to occur rapidly.
In summary, it is recommended for people in Beijing to change the way they eat potatoes and steam them to replace some of the rice. What is concerning is that if they don't make dishes like stir-fried shredded potatoes, fried potato chips, or braised pork and potatoes, they may not like them as much. In fact, steamed potatoes are really delicious (many people have never tasted the natural flavor of potatoes in their lifetime, which is a pity). They are fragrant and slightly sweet, and taste especially good with a little salt and pepper. They can even be eaten without salt! It is also not difficult to use potatoes as a staple food. Cut the steamed potatoes into small pieces, put them in a rice bowl, and then eat them normally, one bite of potato and one bite of vegetables. The taste is very good, try it and see!
Postscript
Some people have a bad impression of potatoes, saying that they have a high glycemic response, low antioxidant content, and are as harmful as white rice. However, this is slightly biased, as it only applies to the potato varieties used in fast food chains and does not apply to all potato varieties in the world.
In thousands of years of agricultural production, various countries and regions have preserved and developed many distinctive potato varieties, and their appearance, texture, and nutritional value are not like French fries in fast food chains. There are red-skinned, yellow-skinned, purple-skinned, and white-skinned varieties, as well as varieties with white, yellow, and purple flesh. A Canadian potato breeding expert told me that they have more than 200 potato varieties, some of which have very high antioxidant content, some have slow digestion and low glycemic response, some are rich in fiber, and some have high vitamin C content... So, don't be surprised and cry out "GMO" just because you see a potato that looks a little different.
Yellow-fleshed potatoes are rich in vitamin B2. Purple-fleshed potatoes contain a large amount of anthocyanins (which are not yet available on the market, but let me introduce them in advance, maybe we will see these varieties in the future). White-fleshed potatoes, relatively speaking, have slightly lower nutritional value. Some potatoes may change color during storage, and you can see some purple in the flesh (this often happens with sweet potatoes and yams), and many potatoes will turn yellow after cooking. However, don't think it's someone coloring them. It's just that some colorless phenolic substances transform into colored anthocyanins, or flavonoids undergo structural changes when they encounter alkaline water, resulting in yellowish chalcones.
If you want to find potatoes with slow digestion and low glycemic response, it's actually not difficult. Just taste them with your mouth. Generally speaking, potatoes with a powdery texture have a higher starch content, while potatoes with a fine texture are digested faster, which is not suitable for people who need to control blood sugar. However, some potatoes are crispy and require careful chewing, which is more suitable for people with hypertension, hyperlipidemia, and hyperglycemia.
