Cruciferous vegetables have been proven to prevent Cancer
What are cruciferous vegetables?
Cruciferous vegetables are plants of Brassica genus. They include vegetables like:
- Bok Choy
- Brussel Sprouts
- Collard Greens
How do they prevent Cancer?
Cruciferous vegetables contain chemicals known as glucosinolates as well as vitamins, minerals, and other nutrients.
Glucosinolates are group of substances that break down into several biologically active compounds called nitriles, thiocyanates , indoles, and isothiocyanates. The last two mentioned here, are the most frequently examined for their anti-cancer effects.
These chemicals are responsible for the pungent aroma and bitter flavor of cruciferous vegetables.
The anti-cancer effects of glucosinolates have been shown in animal cells but the results of studies within humans are not so clear. The reason for it is that nutritional studies in humans are one of the hardest and difficult to perform, since they depend on many variables.
Is there a research backing up benefits of cruciferous vegetables?
Studies in animals and experiments with cells grown in the laboratory have identified several potential ways in which these compounds may help prevent cancer.
- 1. they help protect cells from DNA damage
- 2. They help inactivate carcinogens
- 3. They have antiviral and antibacterial effects
- 4. They have anti-inflammatory effects
- 5. They induce cell death (apoptosis)
- 6. They inhibit tumor blood vessel (angiogenesis) and tumor cell migration (needed for metastasis)
Studies in humans have shown mixed results.
Case control studies have found that people who ate greater amounts of cruciferous vegetables had a lower risk of prostate cancer (1,2)
Cohort studies in USA and Europe (Netherlands) found no association between cruciferous vegetable intake and colorectal cancer risk. One exception in a study in Netherlands in which women (but not men) who had high intake of cruciferous vegetables had a reduced risk of colon (but not rectal) cancer (3). Many factors might have made a gender difference, like ingestion of red meat. Red meat has been link with increase link of colorectal cancer.
Little association has been found. But Nurses’ Health Study and Health Professionals follow up study, showed women who ate more than 5 servings of cruciferous vegetables per week had a lower risk of lung cancer (4)
One case control study found that women who ate greater amounts of cruciferous vegetables had a lower risk of breast cancer (5)
The federal government’s Dietary Guidelines for Americans in 2010, recommend consuming variety of vegetables each day.
Higher consumption of vegetables in general will protect against other diseases including various types of cancer. However, trying to distinguish cruciferous vegetables for other form of foods in order to determine impact on cancer could be hard. Why? Because people who eat cruciferous vegetables may more likely develop healthy behaviors that reduce disease risk when compared to those who don’t eat vegetables at all.
There might also be a genetic background impact. Some people metabolize dietary isothiocyanates differently but this is just hypothesis and have not been proven.
In summary, cruciferous vegetables should be a part of daily nutrition in everyone life. Not only are they rich in anti-cancer chemicals, as mentioned above, but they also have nutrients like carotenoids (beta-carotene, lutein, xeaxanthin), vitamin C, E, K, and foliate, iron and many other minerals. They are excellent source of fiber.
Hope this information helped. Let us begin our journey to healthy life style!