Ever heard that broccoli and cabbage can help prevent cancer? Ever wonder if those statements were true? Read on to find out what research has to say.
The umbrella term for vegetables that belong to the Brassica plant family.
- Bok choy
- Brussels sprouts
- Chinese cabbage
- Collard greens
- Daikon radish
What are they rich in?
- Act as antioxidants, which protect our cells from damage and promote anti-aging
- Some turn into vitamin A, which helps keeps our eyes, skin, and immune system healthy
- Insoluble fibre helps keep your bowels regular
- Soluble fibre can help lower blood cholesterol and control blood sugar
- Plays a large role in heart health
- Helps make healthy red blood cells
- Helps keep the heart healthy
- Reduces the risk of birth defects
- Keeps our immune system healthy
- Keeps our bones, teeth, gums and skin healthy
- Helps with wound healing
- Helps us absorb iron from plant-based foods
- Acts as an antioxidant
The chemical structure of glucosinolates
To save us both some trouble, we’ll abbreviate glucosinolates (prounounced glue-co-SIN-o-lates) as GLSs. These are substances found in cruciferous vegetables that give them their pungent aroma and that somewhat spicy, or bitter taste. GLSs become beneficial to our health once they start breaking down through food preparation (eg. chopping your veggies), chewing, and digestion. These actions release myrosinase, a plant enzyme that breaks down GLSs into biologically active compounds. In addition, our intestines have bacteria that help break down GLSs. Two key breakdown products, indoles and isothiocyanates (let’s call them I & I), have been studied for their anticancer effects. What have studies shown?
- I & I have stopped the development of bladder, breast, colon, liver, lung, and stomach cancers in rats and mice
- Cohort studies have shown little or no association between consuming cruciferous vegetables and cancer development
- These are studies where groups of people are followed over a period of time to see who develops a disease. Certain factors (eg. how many servings of cruciferous veggies they eat in a week) are looked at to see if there is a correlation between factor and disease
- However, one cohort study showed that women who ate more cruciferous veggies had a lower risk of colon cancer
- Case-control studies have mixed results
- These are studies where one group with the disease is compared to a second group that does not have the disease but is otherwise similar
- In one study, lower risk of prostate cancer was found in the group who ate greater amounts of cruciferous veggies. Similarly, another study showed lower risk of breast cancer with greater intake
- One analysis of various studies showed that women who ate more than 5 servings of cruciferous veggies each week had a lower risk of lung cancer
- When 28 human volunteers aged 50+ were asked about how many cruciferous veggies they ate each week, the colonoscopies of those who ate more servings were found to have higher levels of a tumour suppressor gene
- There is some evidence that genetic factors may play a role in how cruciferous veggies affect cancer risk. These factors would be related to the production or function of enzymes that break GLSs down
How might I & I help protect against cancer?
- By protecting cells from damage
- By inactivating carcinogens (things that cause cancer)
- By inhibiting the formation of tumor blood vessels
- By inhibiting migration of tumor cells (which is how cancers spread)
- By increasing levels of tumour suppressor genes
- By causing death of tumor cells
What’s the best way to cook cruciferous vegetables?
According to studies, GLS levels are affected by storage and preparation. Here are some tips to keep the GLS levels high.
- Store veggies in the fridge rather than at room temperature
- Eat veggies raw. Myrosinase, the enzyme that breaks GLSs down, is destroyed by heat. Remember, our intestinal bacteria can still break GLSs down, but there will be less I & I formed/absorbed
- Cook with minimal water. GLSs are water-soluble and can be leached into cooking water. This will also help retain water-soluble vitamin C.
- Use short cooking times
- Steaming, stir-frying, and microwaving on low power for short times seem to maintain GLS levels
- Canning, blanching, boiling, and freeze-thawing tend to decrease GLS levels
What’s the conclusion?
While more human studies are needed to confirm that the active compounds in cruciferous vegetables help with cancer prevention, cruciferous vegetables are a rich source of vitamins and nutrients, and adding them to your diet will help…
- Promote anti-aging
- Keep your immune system, heart, skin, bones, teeth, and eyes healthy
- Lower blood cholesterol
- Control blood sugar
- Keep your bowels regular
- Protect your cells from damage
Allysian Genesis™ – how to prepare?
Allysian Genesis™ contains cruciferous vegetables, including the following:
- Brussels sprouts
Similar to preparing cruciferous vegetables at home, using cool to room temperature water, rather than hot, will help retain the beneficial nutrients of the GLSs in Allysian Genesis™. Try Allysian Genesis™ in a smoothie, with protein powder, or with fresh fruit/vegetable juice for an extra boost of flavour and energy! Click here to find out more!
Rajan, T.S., De Nicola, G.R., Iori, R., Rollin, P., Bramanti, P., & Mazzon, E. (2016). Anticancer activity of glucomoringin isothiocyanate in human malignant astrocytoma cells. Filoterapia, 110:1-7.
Rajendran, P., Dashwood, W., Li, L., Kang, Y., Kim, E., Johnson, G., Fischer, K.A., Lohr, C.V., Williams, D.E., Ho, E., Yamamoto, M., Lieberman, D.A., & Dashwood, R.H. (2015). Nrf2 status affects tumor growth, HDAC3 gene promoter associations, and the response to sulforaphane in the colon. Clinical Epigenetics. 7:102.
Royston, K.J., & Tollefsbol, T.O. (2015). The epigenetic impact of cruciferous vegetables on cancer prevention. Curr Pharmacol Rep. 1(1): 46-51.
Verkerk, R., Schreiner, M., Krumbein, A., Ciska, E., Holst, B., Rowland, I., De Schrijver, R., Hansen, M., Gerhauser, C., Mithen, R., & Dekker, M. (2009). Glucosinates in Brassica vegetables: the influence of the food supply chain on intake, bioavailability and human health. Mol. Nutr. Food Res., 53, S219-S265.