Everyone knows that iron is essential for the formation and maturation of red blood cells, primarily found in hemoglobin, and performs important physiological functions. However, iron deficiency remains a widespread problem among both urban and rural residents in China. This is firstly determined by physiological characteristics: adolescent girls experience rapid growth and development, leading to a high demand for iron in the body. Coupled with the onset of menstruation, they are prone to iron-deficiency anemia. Women during pregnancy and lactation need to supply nutrients to the fetus or infant, which also significantly increases their iron requirement. Elderly women often have impaired gastrointestinal absorption and weakened hematopoietic function, which can also lead to anemia. Secondly, the diet of China's urban and rural residents is still predominantly plant-based, with animal foods playing a supplementary role.
The daily iron requirement for adult women aged 18-50 in China is 20mg, and for those over 50, it is 15mg. However, more iron is not always better; excessive intake can lead to acute poisoning. The main symptoms include discomfort in the upper abdomen, abdominal pain, nausea, vomiting, diarrhea, and other symptoms of gastrointestinal bleeding. In severe cases, acute intestinal necrosis, shock, or even death may occur. Chronic poisoning mainly involves organ fibrosis, with significant iron deposition in the liver and spleen, which can manifest as cirrhosis, osteoporosis, etc. Therefore, the daily intake should not exceed 50mg.
It is necessary for everyone to understand the iron in our bodies and the iron in food.
There are two forms of iron in the human body: one is "functional iron," which primarily exists as hemoglobin, myoglobin, and iron-containing enzymes; the other is "storage iron," such as ferritin and hemosiderin, stored in the liver and bone marrow. All forms of iron in the body are bound to proteins.
The iron in food can also be divided into two forms: heme iron and non-heme iron. Heme iron is mostly found in meat foods, with an absorption and utilization rate as high as 15%-20%, whereas the absorption and utilization rate of plant-based non-heme iron does not exceed 5%.
From this, everyone can understand that the main sources of iron are animal blood, liver, and red meat. The iron in these foods is mainly in the form of heme iron, which is easily absorbed and utilized by the body. Dark green vegetables and other deeply colored vegetables are also rich in iron, but its absorption is poor.
Have you been doing it this way before? For example:
1. Using spinach to supplement iron
The older generation likes to use spinach to supplement iron. However, according to the "China Food Composition Table," every 100g of spinach contains 2.9mg of iron. The iron in spinach is non-heme iron, which is difficult to absorb, and it is also affected by oxalic acid. Because spinach itself contains a large amount of oxalic acid—606mg per 100g—and oxalic acid inhibits iron absorption, the absorption rate of iron from spinach is only 1.3%. Therefore, eating spinach does not supplement much iron. Although blanching spinach reduces oxalic acid, the content is still high. It not only interferes with the absorption of iron from spinach but also interferes with the absorption of non-heme iron from other foods. Therefore, in terms of iron supplementation, spinach is not a good choice. However, it is still a nutritious food rich in various vitamins and minerals, especially VA, VC, VE, folic acid, VK, and magnesium. It is also rich in lutein and flavonoids, making it a recommended food, but not a good choice for iron supplementation.
2. The current internet hype about "cherries" claims they are a high-iron fruit that prevents anemia and is good for blood replenishment.
This is how it is described on the internet: "Cherries are rich in iron, making them an excellent fruit for women to supplement iron," "Cherries have been called 'beauty fruit' since ancient times," "Ancient Chinese medical texts describe them as 'moisturizing the skin' and 'making one look good and beautiful'," "Regular consumption can make the skin smoother and more radiant," "The iron content in cherries is extremely rich; every 100 grams of flesh contains six times the iron of strawberries, ten times that of jujubes, thirteen times that of hawthorn, and twenty times that of apples, ranking first among all fruits."
In fact, every 100g of cherries contains 0.4mg of iron, strawberries have 1.8mg, dried jujubes have 2.3mg, hawthorn has 0.9mg, and apples have 0.6mg. Thus, the data circulating online is easily debunked.
Therefore, we must have a discerning eye. We must learn to question and think critically so that we can make correct judgments.