You may believe it but broccoli (Brassica oleracea) is a member of the cabbage family. And what we are eating – those little green things at the end of the branches – are actually the flowers. Its closest relatives, judging from their looks, are the cauliflowers and romanesco. These vegetables are called cruciferous vegetables or brassicas.
Brassicas are rich in compounds known as glucosinolates which are metabolized to isothiocyanates, substances with cancer preventive properties. In this post, we review the latest news about the green wonder that is broccoli.
Broccoli and cancer
Researchers at University of California Berkeley reports that “an anti-cancer compound found in broccoli and cabbage works by lowering the activity of an enzyme associated with rapidly advancing breast cancer.” The compound has been identified as indole-3-carbinol (I3C) and it has been demonstrated to inhibit breast and prostate cancer cells in lab mice. Here’s how it works: I3C inhibits elastase, an enzyme which when present in high levels in breast cancer cells, indicates faster spread of the disease, reduced response to chemotherapy and other treatments, as well as low survival rates. Elastase shortens the cell cycle controller cyclin E. Short cyclin E results in accelerated cell cycle that makes cancer cells grow uncontrollably. By stopping elastase, I3C stops the proliferation of cancer cells.
“I3C is available as a supplement and is a preferred preventative treatment for recurrent respiratory papillomatosis, a condition involving non-malignant tumors of the larynx. Improved versions of the chemical could thus help treat cancers other than those of the breast and prostate.”
This study presented last month at the American Association for Cancer Research’s Seventh Annual International Conference on Frontiers in Cancer Prevention Research, evaluated the health effects of eating vegetables in smokers. Eating cruciferous vegetables such as broccoli on a regular basis afforded smokers 20 to 55% reduced risk of developing lung cancer. The variation is risk reduction depended on intensity of smoking habit and the type of vegetables consumed. Eating raw cruciferous vegetables proved especially beneficial, especially against with squamous or small-cell carcinoma, two lung cancer subtypes linked to heavy cigarette smoking. “These findings, along with others, indicate cruciferous vegetables may play a more important role in cancer prevention among people exposed to cigarette-smoking. ”
Yet another extract from broccoli and its relatives seems to have healing powers. The phytochemical called isothyiocyanates (ITCs) is present in broccoli, cabbage, kale, collard greens. Broccoli sprouts especially have it in large quantities – almost 30 times more than mature broccoli.
Oncology researchers at the Roswell Park Cancer Institute and their multinational collaborators demonstrated that ITCs prevent the development of cancer of the urinary bladder in lab mice. This anti-cancer property seems to be evident even in low dosage, meaning we don’t need to gorge ourselves with broccoli to be protected from bladder cancer.
Broccoli and the immune system
The efficiency of our immune system declines as we age. And with body’s immunity waning, we are more susceptible to many diseases – from cardiovascular diseases to neurodegenerative disorders, from diabetes to cancers – as we get older. But it seems that eating broccoli can actually give our immune system a boost and may just slow down the aging process.
Researchers at the University of California in Los Angeles (UCLA) identified the immunity booster as sulforaphane, a compound that is abundant in broccoli and other cruciferous vegetables.
Sulforaphane works by inducing the production of antioxidants, which provide protection against free radicals that can damage cells and lead to disease. Free radicals, which are normal by-products of metabolism, cause the wear and tear that our body experiences as we age. However, free radicals also exist as environmental pollutants that we are exposed to every day.
Although the anti-aging properties of sulforaphane have so far been only demonstrated in mice, the potential for human health is tremendous. After all, who needs anti-aging pills if you can have your antioxidants all-natural and fresh – everyday?
Broccoli cooking and preparation
So what is the best way of preparing broccoli? Well, research says boiling broccoli ruins its anti cancer properties!
University of Warwick researchers tested how food preparation and storage can affect the glucosinolate content of cruciferous vegetables. The following methods were evaluated:
- boiling for 5, 10 and 30 min
- steaming for 0-20 min
- microwave cooking for 0-3 min
- stir-fry cooking for 0-5 min
Boiling seems to result in a significant loss of glucosinate content. 20 to 30% are lost after 5 minutes of boiling, and 40 to 50% after 10 minutes. In broccoli, 70% is lost after 30 minutes. The other 3 food preparation methods did not result in significant losses.
Storing at room temperature and in the fridge does not seem to affect glucosinate content but thawing frozen vegetables does.
The UC Berkeley researchers provide us with recipes for yummy vegetable dishes such as brassica bites, caramelized brussel sprouts.
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