Broccoli is a common vegetable on every family’s table, and it is also a class of food that is beneficial to human health. A common way to cook broccoli is to boil it in water, but this method causes the loss of a lot of water-soluble vitamins, so it is not favored by nutritionists.
However, a recent study found that boiling broccoli not only causes vitamin loss, but also more serious nutrient loss. The study found that boiling affects the body’s absorption of a group of compounds in broccoli called “mustard oleoresins”. This compound reduces the risk of lung and rectal cancer.

In 2011, researchers compared the levels of cancer-fighting “carrageenosides” in two different groups of people (those who ate broccoli or consumed nutrients purified from broccoli). They found that: vegetable broccoli contains a special class of protein, the protein can help the body break down the “mustard oil glycosides”, so as to facilitate the absorption; while the purified nutrients do not have this protein.
Specifically, broccoli consumption of people in the blood and urine “mustard oil glycosides” in the content of the other group of people eight times.

Additionally, the lead researcher on the subject believes that excessive cooking, such as boiling, severely reduces the enzymatic activity of this protein in broccoli. In other words, consuming boiled broccoli is essentially no different than consuming a broccoli purification supplement.
Fortunately, they found a way to salvage the consequences of this cooking mistake: drinking the water in which the broccoli was boiled properly.

Broccoli water is not a new concept. In fact, the 1999 Family Health Guidebook written by Harvard Medical School recommended preserving broccoli water for soups, flavoring, stews, and more. However, broccoli water is not easy to keep, and parasites are a big problem. Practice has shown that water is prone to harbor the bacteria and parasites that cause spoilage to occur.

So what should we do? If boiling causes nutrients to diffuse into the water, then switching to steaming can effectively avoid this problem. In this recently published study, the authors advocate: “In order to preserve as much as possible the mustard oleoresin in broccoli, the best cooking method should be steaming. The same applies to other green vegetables.”