Spinach, a green vegetable, is a frequent guest on the dining table. It can be stir fried, cold mixed, and made into soup, providing rich nutrients such as dietary fiber, vitamin C, vitamin K, potassium, magnesium, folate, and carotenoids. But there are also many rumors among the public about it. Some people say that spinach cannot be eaten with tofu, otherwise it will get stones; Spinach with high purine content is contraindicated for gout patients; Some people also say that spinach can supplement iron and blood. Are these claims reliable or not? Let's make it clear now. 1、 Spinach cannot be eaten with tofu, which can easily lead to stone formation. Rumor: Oxalic acid in spinach will combine with calcium in tofu to form calcium oxalate, causing stones and affecting calcium absorption. Truth: Spinach and tofu can be eaten together, the key is to blanch them in water! The oxalic acid content in spinach is indeed not low, reaching nearly 600 milligrams per 100 grams, with some spinach even higher, possibly reaching over 1000 milligrams per 100 grams. Tofu is rich in calcium, for example, the calcium content of northern tofu and southern tofu is 105 milligrams per 100 grams and 113 milligrams per 100 grams, respectively. Although the oxalic acid in spinach can form a calcium oxalate precipitate with the calcium in tofu, hindering the body's absorption of calcium, everything has its two sides. If spinach is frequently consumed in large quantities alone, the oxalic acid in it can affect the absorption of nutrients such as iron, zinc, and calcium in other foods consumed in the stomach. Moreover, oxalic acid can also be absorbed into the blood and then into the urine, increasing the risk of calcium oxalate stones. Eating tofu with spinach, the calcium in tofu will combine with oxalic acid in spinach in the gastrointestinal tract to form calcium oxalate, which is excreted through feces and further reduces the amount of oxalic acid absorbed into the bloodstream. If you want to eat spinach and tofu together, the most crucial thing is to blanch spinach in boiling water for at least 1 minute in advance, which can remove 43% of oxalic acid. With the increase of time, the oxalic acid removal rate can increase to 58.9% by 4 minutes; Adding tofu and cooking for more than 3 minutes can achieve a 60% removal rate of oxalic acid. After this treatment, the remaining oxalic acid in spinach can only affect the absorption of a small amount of calcium, and the formation of calcium oxalate precipitation is not significant. It is rarely absorbed into the bloodstream and forms stones in the urinary system. Healthy individuals do not need to worry about this issue. 2、 Spinach is an unfriendly vegetable for gout. Rumor: Spinach has high purines and gout patients should not eat it. Truth: Spinach has a low purine content, and gout patients can eat it in moderation after blanching. According to the data in the "Chinese Food Composition Table" and the "Chinese Nutrition Science Encyclopedia", the purine content of spinach varies among different varieties and regions, roughly ranging from 8-23 milligrams per 100 grams, making it a low purine vegetable. Therefore, in terms of purine content, gout patients do not need to deliberately avoid spinach. However, spinach has a high content of oxalic acid, and our kidneys are important organs for excreting metabolic waste from the body. Both uric acid and oxalic acid need to be excreted through the same "excretion system" in the kidneys, and the two will affect each other. High intake of oxalic acid may affect the excretion of uric acid. So for people with gout, before eating spinach, it is necessary to blanch it to remove oxalic acid, discard the soup before consumption, and do not eat in large quantities. Vitamin C and folic acid in vegetables have a protective effect on gout. Spinach has excellent vitamin C and folate content among vegetables! 3、 Rumor that eating more spinach can supplement iron: Spinach has a high iron content and can supplement iron and blood. Truth: Spinach contains iron, but its absorption rate is low and cannot be used as the main source of iron supplementation. Although the iron content of spinach is not low in vegetables, at 2.9 milligrams per 100 grams. But the problem is that the iron in spinach is non heme iron, with a relatively poor absorption and utilization rate of only 2% to 20%, usually less than 5%, and is easily interfered by other dietary components such as oxalic acid and phytic acid. In contrast, meat and animal liver have higher iron content, such as pig lean meat, pig liver, and duck blood, which have iron contents of 3 milligrams/100 grams, 23.2 milligrams/100 grams, and 30-39 milligrams/100 grams, respectively. They are heme iron with an absorption rate of 15% -35%, and are not easily affected by other dietary factors, making them a high-quality source of iron supplementation for the human body. So, relying on eating spinach to supplement iron is not very effective. If there is a special need, it can be paired with foods rich in vitamin C (bell peppers, kiwifruit, oranges, etc.) to improve the absorption and utilization of iron. 4、 Since the rumors about spinach are not reliable, we can eat spinach with peace of mind! In order to keep spinach as fresh and nutritious as possible, it is important to pay attention to storage and consumption methods. How to store fresh spinach: It is recommended to store fresh spinach in a refrigerator at 4 ℃ for no more than 24 hours. As for stir fried spinach, it's best not to leave it behind, it's best to finish it as a meal. A study published in Food Research and Development in 2016 found that even when stir fried spinach was refrigerated at 4 ℃ for 16 hours, nitrite levels exceeded the national limit. What is the healthiest way to eat? Whether it's cold dishes, stir frying, making soup or vegetable juice, you need to blanch with enough boiling water for about 1 minute to remove most of the oxalic acid, then remove it from the supercooled water and drain the water. Remember not to cut before blanching to avoid excessive loss of water-soluble vitamins; To maintain color, you can add a few drops of cooking oil while blanching. It is better to pair with foods rich in vitamin C, such as bell peppers, to promote iron absorption. According to the Chinese Dietary Guidelines, it is recommended to consume 300-500 grams of vegetables throughout the day, with more than half of them being dark colored vegetables. Spinach, as an excellent dark vegetable, can be eaten around 200 grams a day, which is about 2 big scoops. (New Society)