Broccoli
Eat healthy.
Over the next few weeks, the Quadram Institute will be showing us how to eat healthy. Today it's the turn of cauliflower, broccoli and many other vegetables from the cruciferous family. It's about to get scientific. If you want the short version of why you should eat the so-called cruciferous vegetables:
They reduce the risk of cancer, they reduce your cholesterol and they help your digestion.
The last part contains a recipe and important cooking recommendations.
We're already saying meal time!
What does science say?
What are cruciferous vegetables and why are they so special?
Anyone who has ever cooked cauliflower or cabbage will be familiar with the unmistakable smell. This is due to the fact that sulphur molecules are broken down by the cooking process. Several vegetables belong to the cruciferous family: Broccoli, cabbage sprouts, cauliflower, cabbage and kohlrabi. Like many other vegetables, they are rich in vitamins, minerals and fibre.
Their unique selling point, however, is their production of mustard oil glycosides: Substances that the plant produces to ward off insects and pests. Mustard oil glycosides consist of sulphur atoms, which are responsible for the characteristic smell. (Fahey et al., 2001).
The cooking process converts the mustard oil glycosides into isothiocyanates. (Herr and Buchler, 2010) and these in turn are being studied for their cancer-reducing effect and therapeutic effects. It is important not to overcook them!
A very good example is the ever-popular broccoli, whose glucoraphanin (a mustard oil glycoside) breaks down into sulforaphane, which in turn plays an important role in health. (Traka and Mithen, 2008). Sulforaphane was discovered in the 1990s and has since been intensively studied for its role in the human body. The area of expertise of our original author Frederico Bernuzzi is to understand what role it plays in metabolism. So far we know that sulphopharan is the most potent activator of the so-called NRF2 factor, which inhibits inflammation. (Houghton et al., 2016). Sulforaphane, in summary, can be considered a very important antioxidant in the body. (Zhang, 2000).
Further leading research at the Quadram Institute
Over the past 20 years, the Quadram Institute has been investigating how certain foods affect our well-being. The aim of this basic research is to understand how cruciferous vegetables regulate metabolism at the molecular level. The results are then validated through studies with humans.
Over the past 10 years, Quadram has conducted several small studies with men who had an increased risk of developing prostate cancer. Two groups were formed in which the control group received an ordinary broccoli soup and the intervention group received a soup with about three times the amount of glucoraphanin (the precursor of sulforaphanin).
It was found that those who had received the "super soup" had increased GSTM1 expression. This gene is responsible for the elimination of toxins, carcinogens and the by-products of oxidative stress. (Traka et al., 2008).
Furthermore, it was observed that concentrated intakes of glucoraphanin were able to reduce LDL cholesterol by six percent after 12 weeks. (Armah et al., 2015). The latest study by Maria Traka and her group was able to show that the increased intake of mustard oil glycosides alone reduced the number of genes responsible for cancer. (Traka et al., 2019). However, these results must be seen in the light of a small number of participants.
Recipe and cooking recommendation
What is the best way to cook the vegetables?
When cooking cruciferous vegetables, there is essentially one rule: As long as necessary and as short as possible. One should avoid overcooking, as this destroys the substances mentioned above. The vegetables should still remain crunchy.
An Italian recipe, for example, calls for putting broccoli in a pan with a tablespoon of olive oil, two three cloves of garlic and just enough water and white wine to prevent it from burning, and steaming it for five minutes.
So next time you're in the supermarket, give broccoli, cauliflower and cabbage a chance.