Feasting with Cruciferous for Cancer Prevention
From the AICR Research Conference
There’s a good chance that one of the vegetables on your Thanksgiving table is part of the Cruciferous family, a large group of vegetables packed with nutrients and other healthful compounds. Research has long linked cruciferous vegetables with overall good health, along with cancer prevention. Now, new evidence presented at AICR’s Research Conference last month helps explain why cruciferous vegetables may play a role in preventing cancer.
A Healthy, Eclectic Family
Cruciferous vegetables are all part of the Cruciferae or cabbage family, and it’s a large family. Vegetables categorized as cruciferous include: broccoli, Brussels sprouts, cabbage, cauliflower and kale, along with rutabaga, watercress, and bok choy. Although population studies are inconsistent, several studies have linked high cruciferous vegetable consumption to lower risk of several cancers, including lung, prostate and colorectal.
One major breakthrough in diet and cancer research occurred in 1992 when a Johns Hopkins University professor isolated sulforaphane from broccoli with funding from AICR. Sulforaphane belongs to a well-studied group of anti-cancer compounds called isothiocyanates (ITCs), and cruciferous vegetables are packed with ITCs. In laboratory research, sulforaphane, along with other ITCs and phytochemicals in cruciferous vegetables, leads to slower cancer cell growth and cell death in many types of cancer cells. And over the years, researchers have identified numerous substances in cruciferous vegetables that have shown anti-cancer potential (see chart).
Cruciferous Cell Workings
Scientists at the Research Conference revealed several ways in which cruciferous vegetables may prevent cancer. Here are a few highlights:
- Researchers knew that sulforaphane and other ITCs were attaching to cell proteins and altering them but they did not know the targeted protein. After months of analysis, a team of researchers has identified it: tubulin, a common protein that provides the supporting structure, the skeleton, of the cell. When the scientists looked at the effect of the ITCs binding to tubulin in cancer cells, they saw slower cell growth and cell death.
- ITCs and other cruciferous compounds can reduce oxidative stress and inflammation, both of which play a role in cancer. New lab studies suggest that ITCs can act along with several other dietary compounds to trigger a protein that can turn "on" genes related to antioxidant activity. The protein, Nrf2 for short, is known to regulate hundreds of genes and many of them protect against carcinogens, inhibit inflammation and help antioxidant activity.
- Other cell studies suggest that sulforaphane, along with other dietary compounds, may prevent cancer by turning "on" or "off" a gene connected to both aging and cancer. The affected gene relates to the production of telomeres, the DNA tips of our chromosome. Shorter telomeres are linked to both aging and cancer. In order to multiply, most cancer cells need the protein that produces telomeres but normal cell do not. Giving breast cancer cells sulforaphane reduced the amount of the telomere-producing protein, leading to slower growth and cell death.
Variety of Health
As the research continues, stay tuned for more findings as to how cruciferous veggies affect our cells and health. But as scientists point out, there are multiple ways these vegetables, and their compounds working individually and together, play a role in preventing cancer.
That’s why, for cancer prevention, AICR recommends eating a variety of vegetables along with fruits, whole grains and legumes. Aside from their cancer-protective substances, cruciferous vegetables also may help fight cancer indirectly by helping with weight control. Like other vegetables, cruciferous veggies are relatively low calorie and can help fill you up. And with so many to choose from, there’s plenty you would probably enjoy.
- BMC Cancer. 2010 Apr 27;10:162. Cruciferous vegetable intake is inversely associated with lung cancer risk among smokers: a case-control study.
- Cancer Epidemiol Biomarkers Prev. 2010 Oct;19(10):2534-40. Epub 2010 Sep 14. Cruciferous vegetable intake and lung cancer risk: a nested case-control study matched on cigarette smoking.
- Nutrient in Cruciferous Vegetables Protects Against Lung Cancer in Study of 18,244 Chinese; Benefit Depends on Genetic Factor.
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