For the production of soybeans, the Chinese people can be said to have invented a variety of ways to eat.
As the most common soy product, tofu is not only a high-quality plant-based ingredient that provides protein, but also cheap in price and many ways to make dishes.
For the elderly and children, because tofu is soft and tender, and it is easy to digest and absorb, tofu is really a "convenient ingredient" without compromise.
Although tofu is said to be inexpensive, there are always picky eaters who point to it, claiming that eating too much tofu will xxx, the most common of which is kidney stones.
Kidney stones, are really caused by eating tofu?
Kidney stones are mainly stones that appear in the parts where the renal calyx, renal pelvis, renal pelvis and ureter are connected, and people who suffer from kidney stones are mostly due to abnormal metabolism of purines, calcium, oxalic acid and other components in the body.
The concentration of minerals in the urine is too high, exceeding the "saturation concentration", it will continue to crystallize and deposit in the kidneys, gradually becoming solid particles.
These solid particles can be large or small, petite can be excreted with the urine, and the larger may block the ureter, resulting in urine obstruction, resulting in low back pain.
Most of the stones that can cause stones are calcium oxalate, about 80% of the stones are caused by it, and some kidney stones are caused by calcium phosphate, urate or magnesium ammonium phosphate.
Tofu, purine composition is not high
The purines, oxalic acid and calcium in soy products are indeed related to stones.
It's just that soybeans are processed differently, and the ingredients related to the stones don't change much.
Although soybeans contain purine ingredients, they need to be soaked, cooked and pressed in the process of making tofu, and there are not many soybeans required for a piece of tofu.
In this process, most of the purine components in the beans have been removed, and there are not many purine components left, so it does not increase the risk of developing stones.
Tofu, oxalic acid content is also relatively small
The tofu itself contains very little oxalic acid, although the oxalic acid content in different soy products is relatively poor, but the general content of tofu is relatively small.
In 2015, the Journal of Agricultural and Food Chemistry published a study:
The researchers tested the oxalic acid content through more than 30 soy products, of which 18 of the 19 brands of tofu detected had a oxalic acid content of less than 0.10mg/g, which was a low oxalic acid food.
There are usually two reasons why oxalic acid is low---
On the one hand, before the tofu is made, a part of the oxalic acid of the soybean is dissolved in water when it is soaked, and then washed away;
On the other hand, the tofu tested is made of gypsum or tofu, which is squeezed or naturally placed to remove part of the water after condensation, and a part of the oxalic acid will be removed with this water.
However, compared to brine tofu or gypsum tofu, lactone tofu retains almost all the water in soy milk, so the oxalic acid content may be relatively high.
Combined with the above, people with a higher risk of stones can also eat tofu without worrying too much.
For healthy people, because the human body can handle oxalic acid and other ingredients by itself, there is no need to worry about stones caused by eating tofu or soy products.
For tofu, can we eat it in large quantities for a long time?
Tofu is delicious, and it is indeed necessary to pay attention to the amount of consumption, it is not recommended that you eat tofu every day or eat a large amount of tofu at a time. After all, tofu is also a soy product, with a certain gas production function, eating a large number of people will cause bloating, repeated farting.
Therefore, tofu can be eaten often, but it is best to control the amount every time, which will be more conducive to health.
Of course, there is a type of tofu or eat less, that is, oil tofu, although in the frying process, the water in the oil tofu will evaporate at high temperatures, but most of the calcium substances are still retained in it, maintained at about 147mg/100g.
After all, oil tofu is fried, the fat content is higher, and the calories of 100 grams of oil tofu are about 3 times that of ordinary tofu.
But then again, who can stand up to the delicious taste of oil tofu (especially stinky tofu)?
So it's okay to eat occasionally.