Broccoli, like most vegetables, is very low in calories. One cup chopped broccoli has about 31 calories. Not only that, but, this same amount will give you about a days worth of vitamins C and K, as well as a good amount of vitamin A and the other carotenoids, lutein and zeaxanthin, as well as a decent amount of folate and potassium.
Apart from broccoli’s basic nutrition goodness, much research has focused on some of the other health promoting phytochemicals in this vegetable. A study published in the April 2009 issue of Cancer Prevention Research suggest that daily intakes of at least 2 1/2 ounces of broccoli sprouts may confer protection against the Heliobacter pylori bacteria that wreaks havoc on some people’s gastric lining.
The study was done on 48 Japanese men and women diagnosed with H.pylori. One group was assigned to eat the 2 1/2 ounces of broccoli sprouts per day, and the control group was given and equal amount of alfalfa sprouts every day over the course of two months. Baseline severity of H.pylori was measured via breath, blood, and stool tests at the beginning of the study, at the four week point and at the study end. Levels of H.pylori were found to be significantly lower at the study end in those patients that had consumed the broccoli sprouts as compared to the alfalfa control group.
The active compounds thought to offer this protection are known as sulforaphanes. Sulforaphanes are present in cruciferous vegetables such as broccoli, brussel sprouts and cabbage. In this particular study, subjects were fed 3-day old broccoli sprouts, which are thought to have a much more concentrated amount of glucoraphanin (the precursor to the sulforaphanes), than mature broccoli plants.
There is a caveat to all of the sulforaphane potential benefit though, cooking method is very important in retaining the active compounds. This is from the Linus Pauling Institute:
Boiling cruciferous vegetables from 9-15 minutes resulted in 18-59% decreases in the total glucosinolate content of cruciferous vegetables. Cooking methods that use less water, such as steaming or microwaving, may reduce glucosinolate losses. However, some cooking practices, including boiling, steaming, and microwaving at high power (750-900 watts), may inactivate myrosinase, the enzyme that catalyzes glucosinolate hydrolysis. Even in the absence of plant myrosinase activity, the myrosinase activity of human intestinal bacteria results in some glucosinolate hydrolysis. However, several studies in humans have found that inactivation of myrosinase in cruciferous vegetables substantially decreases the bioavailability of isothiocyanates
Sulforaphanes have also been linked to improvements in vascular function in diabetics, prevention of certain genetic cancers, and protection against asthma (see the references for more detailed articles).
- Cruciferous vegetables, especially the broccoli, brussel sprouts, and cabbage, may offer powerful protection against several health issues, though further research on humans needs to be done
- Maximum sulforaphane benefits seem to be derived from the vegetables in their less cooked states
- Broccoli in its sprout form may have the most powerful amounts of the sulforaphanes
It may be relatively easy to consume raw broccoli and cabbage, but, I’d be hard pressed to eat a raw brussel sprout. The cooked versions of these vegetables still offer plenty of nutrition on their own, and consuming them in any manner is really the most important thing for your health.
Hu R, Khor TO, et al. Cancer chemoprevention of intestinal polyposis in ApcMin/+ mice by sulforaphane, a natural product derived from cruciferous vegetable. Carcinogenesis, 2006 Oct;27(10):2038-46