Eat your broccoli, boys: Compounds in the cruciferous vegetable may save your life, experts flag

21 Oct 2022 --- A UK-based study is uncovering how nutrients in the oft-avoided broccoli vegetable can reduce the risk, rate and severity of prostate cancer. The findings show that the compounds accumulate in the prostate gland and may have a protective influence on the gland’s cells.

The findings are published as part of a clinical trial at the Quadram Institute in Norwich, UK, in conjunction with the Norfolk and Norwich University Hospital.

“Human studies conducted at Quadram Institute of Bioscience have reported that these sulfur compounds not only accumulate within the prostate tissue, but also reduce the number of genes involved in the cancer progression,” Gemma Beasy, researcher at the Quadram Institute, tells NutritionInsight.

“The mechanisms by which these compounds affect prostate cancer are relatively unknown, and it is key for future research to understand the molecular mechanisms of how these compounds regulate cancer metabolism.”

The Quadram Institute will continue to investigate how the accumulation of broccoli-derived nutrient compounds in the prostate gland influences prostate cells. 

Open wide
Cruciferous vegetables like broccoli have long been correlated with a reduction in the risk of prostate cancer development. Moreover, they have been found to stop the cancer’s progression. This is accomplished by the breaking down of sulfurous compounds by plant enzymes and bacteria in the gut microbiome. Adding two or three servings of broccoli a week to diets may prevent or slow the progression of prostate cancer.

The compounds are then converted into other biologically active compounds that then accumulate in the gland. These compounds have been shown to protect against the aggressive cancer in previous studies. 

“Numerous epidemiological studies have reported that sulfur compounds found in cruciferous vegetables such as broccoli may prevent prostate cancer progression,” explains Beasy. “Much of this evidence has focused on the sulfur compounds, glucosinolates, which are broken down by myrosinase enzymes to the active compounds isothiocyanates.”

Probing the prostate
Dr. Tracey Livingstone, urologist and principal investigator of the study, further elaborates that until now the mechanism by which the prostate gland was exposed to the bioactive compounds was “largely unknown.” This is due to the fact that the compounds are barely detectable in the bloodstream after 24 hours. 

Therefore, the randomized and placebo-controlled clinical trial recruited 40 men who were scheduled to undergo prostate biopsies and were either known or suspected to have prostate cancer. The volunteers then took supplements containing glucoraphanin from broccoli, alliin from garlic or a placebo for a four-week period preceding their transperineal biopsies.The study found that the bioactive compounds in broccoli accumulate in the prostate and act as a protectant.

“The results demonstrate for the first time that the bioactive compounds attributed to this link, derived from broccoli, in particular, are indeed capable of accumulating within the prostate tissue to significantly higher levels than those consuming a placebo after only a short four-week intervention,” Livingstone underscores.

Down the hatch
According to the study published in Nutrients, this accumulation answers key questions about how dietary interventions, utilizing dietary nutrient compounds, can benefit patients suffering from prostate cancer. 

The results reveal that the broccoli-derived supplement significantly supported an increase in the concentration of sulforaphane in all zones of the prostate. The alliin from the garlic was also detected, but in much smaller quantities, and not much higher than those who did not take a garlic supplement. This is possibly due to the difference in the compounds.

Adding two or three portions of broccoli per week as part of a healthy balanced diet would be optimal,” Beasy advises. “Regarding cooking, the best way to preserve the sulfur compounds within broccoli is by steaming for a few minutes and avoiding boiling.”

By William Bradford Nichols