Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/16/2001
Publication Date: N/A
Interpretive Summary: We have previously reported that selenium from selenium-enriched broccoli reduces chemically-induced colon cancer more than other chemical forms of Se. This study demonstrates that high-selenium broccoli also reduces breast cancer and that high-Se broccoli sprouts have the same colon cancer inhibiting qualities as high-Se broccoli florets. Rats injected with a carcinogen known to cause colon cancer and breast cancer were fed diets that used broccoli sprouts or broccoli florets as sources of selenium. After many weeks on the diet, the animals were killed and examined for cancerous lesions in the gut or tumors in mammary tissue. Both cancers were significantly reduced in animals fed Se from high-selenium broccoli products. These results are further evidence that broccoli may be an especially good source of selenium, and nutrition professionals may be wise to take this into account when giving nutritional advice.
Technical Abstract: Selenium (Se) from high-Se garlic reduces the incidence of chemically- induced mammary tumors and Se from high-Se broccoli reduces colon cancer. However, the ability of Se from high-Se broccoli to protect against mammary cancer has not been tested. Also, the sprout form of broccoli contains many secondary plant compounds that are known to reduce cancer risk, but the anti-carcinogenic activity of broccoli sprouts has not been investigated. The present studies examined the ability of high-Se broccoli or high-Se broccoli sprouts to protect against chemically-induced mammary or colon cancer. In one experiment, Sprague Dawley rats that consumed diets containing 3.0 ug Se/g supplied as high-Se broccoli had significantly fewer mammary tumors than rats fed 0.1 ug Se as selenite with or without the addition of regular broccoli. In the second experiment, Fisher F-344 rats fed 2.0 ug Se/g supplied as either high-Se broccoli florets or high-Se broccoli sprouts had significantly fewer aberrant colon crypts than rats fed 0.1 or 2 ug Se/g diet supplied as selenite with or without the addition of low-Se broccoli. These data demonstrate that the cancer-protective effect of Se in high-Se broccoli extends to mammary cancer and the protective forms of broccoli against colon cancer include high-Se broccoli sprouts.