Have you had your broccoli today? If not, then you have missed out on a healthy dose of a long list of nutrients such as vitamins C, K, A, B and D, folate, manganese, calcium, magnesium and fibre. Although the health benefits of all the cruciferous vegetables such as broccoli, cauliflower, cabbage and kale are well documented, it is broccoli that is receiving the most attention in research circles these days. It is now undisputed that broccoli contains anti-oxidant, anti-inflammatory and pro-detoxification components making it a unique food in terms of cancer prevention.
Antioxidants and anticancer agents are continually being isolated from broccoli and its sprouts, making it the most researched vegetable in the past 20 years. The antioxidant benefits of broccoli can be attributed mainly to the high vitamin C content enhanced by significant amounts of flavonoids and carotenoids. The anti-inflammatory components are its omega-3 content in the form of alpha linolenic acid and a flavonol called kaempferol.
The ability of broccoli to enhance detoxification in our bodies thus ridding us of harmful substances that threaten our cells is due to a family of potent phytochemicals called isothiocyanates (ITCs) made from the glucosinolates in broccoli. Two of these ITCs, namely sulforaphane and Indole-3-Carbinol, also called I3C, are at the centre of most of the research being done pointing towards broccoli or broccoli sprouts being protective against most cancers in humans. Researchers believe that ITCs in broccoli spark hundreds of genetic changes, activating some genes that fight cancer and switching off others that fuel tumours.
A research group at the Institute of Food Research led by Professor Richard Mithen has provided an explanation of how eating broccoli might reduce prostate cancer risk. For the study1, men who were at risk of developing prostate cancer ate either 400g of broccoli or 400g of peas per week in addition to their normal diet over 12 months. Tissue samples were taken from their prostate gland before the start of the trial and after 6 and 12 months, and the expression of every gene measured using Affymetrix microarray technology. It was found that there were more changes in gene expression in men who were on the broccoli-rich diet than on the pea diet, and these changes may be associated with the reduction in the risk of developing cancer, that has been reported in epidemiological studies. 400g a week equates to a very manageable 10 spears of broccoli. More benefit and protection could be derived in men by eating two cups of broccoli a day.
And in women
There’s good news for women too: In research conducted at the University of Michigan, sulforaphane was demonstrated to target cancer stem cells in cell cultures and in mice. Cancer stem cells, which are not destroyed by chemotherapy, are believed to be the reason breast cancer can recur, grow and spread. Researchers injected varying concentrations of sulforaphane derived from broccoli extract into mice implanted with breast tumours. This resulted in a substantial reduction in cancer stem cells in these tumours. Additionally, cancer cells derived from animals that received sulforaphane that were reimplanted into other mice failed to form tumours. Tests in cultured human breast cancer cells showed a similar reduction in cancer stem cells. This shows the potential of sulforaphane to prevent or treat cancer by targeting the critical cancer stem cells.2
Research using broccoli extracts against cervical cancer has been extremely promising as well. In one double-blind placebo controlled trial using a daily dose of I3C, one-half of women with biopsy-proven early stage cervical cancer had complete regression of their cancer where none in the control group did3. In addition, a study done on mice suggests that adding the chemo protective agents to the maternal diet during pregnancy and nursing may just reduce the incidence of cancers in their offspring 4.
But warding off cancer is not all that broccoli is good for. Researchers from Johns Hopkins University have found that eating just a few ounces of broccoli each day may significantly reduce a person’s risk of stomach ulcers. The risk of stomach ulcers as well as stomach cancer is significantly increased by the presence of the Helicobacter pylori bacterium which causes chronic inflammation of the stomach lining. A reliable marker of infection is a chemical called HpSA found in the stool. In this study5, 50 people in Japan were assigned to eat either 2.5 ounces of broccoli sprouts or 2.5 ounces of alfalfa sprouts each day for two months. Alfalfa is not a cruciferous vegetable and contains no sulforaphane. Consumption of alfalfa sprouts had no effect on HpSA levels; however among those who ate broccoli sprouts, HpSA levels decreased 40 percent by the end of the experiment. Participants were then told to stop eating broccoli sprouts. After another two months, HpSA levels had returned to pre-study levels. This implies we need to eat broccoli and keep on eating it! The researchers also found that inflammation levels of the stomach were reduced in those eating broccoli and hence broccoli raw and cooked can be included in the diet of ulcer and gastritis sufferers to prevent inflammation of the stomach lining progressing into serious illness.
Although much of the research has been done using extracts from broccoli sprouts, normal broccoli also contains these protective phytochemicals, just in lesser quantities, so you need to eat more of it.
The best ways to eat broccoli:
If you have only experienced overcooked, soggy, khaki-green broccoli then this is probably not your favourite vegetable. However your whole perception of this natural wonder may change with a better method of preparation. Start with fresh broccoli and wash it well to remove traces of pesticides. Steam the spears in unsalted water for just 3-4 minutes so that they’re bright green and still crisp. Shake the water out of each spear. Eat plain or sprinkle with a little olive oil and lemon juice. Then there are also all delicious broccoli soups one could make. See recipe below. Of course juiced and raw broccoli (shredded in a coleslaw is good) would ensure that none of the nutrients are lost but be sure to chew raw broccoli very well to derive all the benefits.
So have you had your broccoli today?
Broccoli and Blue Cheese Soup
1 Tbsp Olive Oil
1 Onion, peeled and chopped
2 cloves Garlic, crushed
2 heads Broccoli, trimmed and cut into florets
4 cups Vegetable or Chicken stock
½ cup Cream
50g Blue Cheese, crumbled
salt and pepper to taste
freshly grated nutmeg
25g Blue Cheese, extra
Heat the olive oil in a large saucepan over a medium heat. Add the onion and garlic and cook for 4-5 minutes, or until golden.
Add the broccoli and stock to the pan. Cover and bring the soup to the boil. Turn down the heat and simmer for 10-15 minutes, or until the broccoli is tender.
Pour the soup into your blender and whizz until it is smooth. Stir in the cream and blue cheese. Season to taste with the salt and pepper.Ladle the soup into bowls, crumble over the extra blue cheese and sprinkle grated nutmeg.
- Traka M, Gasper AV, Melchini A, Bacon JR, Needs PW, et al. Broccoli Consumption Interacts with GSTM1 to Perturb Oncogenic Signalling Pathways in the Prostate. PLoS One, 3(7): e2568 DOI:
- Li Y, Zhang T, et al. Sulforaphane, a dietary component of broccoli/broccoli sprouts, inhibits breast cancer stem cells. Clin Cancer Res. 2010 May 1;16(9):2580-90. Epub 2010 Apr 13.
- Bell MC, Crowley-Nowick P, et al Placebo-Controlled Trial of Indole-3-Carbinol in the Treatment of CIN. Gynecologic Oncology Volume 78, Issue 2, August 2000, Pages 123–129
- Yu Z, Mahadevan B, et al. Indole-3-carbinol in the maternal diet provides chemoprotection for the fetus against transplacental carcinogenesis by the polycyclic aromatic hydrocarbon dibenzo[a,l]pyrene. Carcinogenesis. 2006 Oct;27(10):2116-23. Epub 2006 May 16.
- Yanaka A, Fahey JW, et al. Dietary Sulforaphane-Rich Broccoli Sprouts Reduce Colonization and Attenuate Gastritis in Helicobacter pylori-Infected Mice and Humans. Cancer Prevention Research, 2009; 2 (4): 353