Breast Cancer Risk in Premenopausal Women Is Inversely Associated with Consumption of Broccoli, a Source of Isothiocyanates, but Is Not Modified by GST Genotype

Abstract

The role of vegetable consumption in relation to breast cancer risk is controversial. Anticarcinogenic compounds may be present only in specific vegetables, thereby attenuating findings for total vegetable intake. Cruciferous vegetables contain precursors of isothiocyanates (ITCs), which may be chemopreventive through potent inhibition of phase I, and induction of phase II enzymes, such as glutathione S-transferases (GSTs). We investigated associations between consumption of cruciferous vegetables, sources of ITCs, and breast cancer risk, and potential modification of relations by GSTM1 and GSTT1 genotypes. Cases (n = 740) were Caucasian women with incident breast cancer identified from all major hospitals in Erie and Niagara counties. Community controls (n = 810) were frequency matched to cases by age and county. An in-depth interview including a validated FFQ was administered in person. Odds ratios (ORs) and 95% CIs were used to estimate relative risks. Consumption of cruciferous vegetables, particularly broccoli, was marginally inversely associated with breast cancer risk in premenopausal women [4th quartile OR = 0.6, 95% CI (0.40-1.01), P = 0.058]. Associations were weaker or null among postmenopausal women. No significant effects of GST genotype on risk were observed in either menopausal group. These data indicate that cruciferous vegetables may play an important role in decreasing the risk of premenopausal breast cancer.

Dietary composition and nutrient content of the New Nordic Diet

“…In contrast, several studies indicate that cabbages may have specific health-promoting properties, e.g. as a prophylactic for cancer, above the general health benefits obtained from eating fruits and vegetables (22)(23)(24)(25)(26) . Cabbages have a high content of vitamin K, antioxidants, dietary fibre, folate, and of several carotenoids and glucosinolates that are not found in other foods.…”

Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults

“…In terms of the active chemical species, CVs are rich sources of glucosinolates, a class of sulfur-and nitrogen-containing glycosides that are hydrolyzed (by plant myrosinase or intestinal microflora) to form isothiocyanates. These isothiocyanates have been shown, in several in vitro and in vivo studies, to display anticarcinogenic properties as reviewed previously (9,17). Watercress (Rorippa nasturtium-aquaticum) in particular contains one of the highest concentrations of glucosinolates per gram weight of any vegetable (18,19) as well as containing high concentrations of carotenoids such as lutein and ␤-carotene (20).…”

“…Increased vegetable intake, particularly of cruciferous vegetables (CVs) such as cabbage, cauliflower, broccoli, Brussels sprouts, watercress, and mustard greens, is associated with a decreased risk of several cancers in human population studies (1)(2)(3)(4)(5)(6)(7)(8)(9). However, not all associations, which have mostly been obtained from epidemiologic studies, are necessarily causal, and thus, intervention studies with specific dietary factors of interest are crucial.…”

Sulforaphane is Superior to Glucoraphanin in Modulating Carcinogen-Metabolising Enzymes in Hep G2 Cells

“…Consumption of these vegetables has been repeatedly associated to lower cancer incidence in epidemiological studies, and it is believed that glucosinolates may be liable for this effect (Ambrosone et al, 2004;Lam et al, 2009). Once the vegetable is disrupted via either mastication or chewing, the enzyme so-called myrosinase (β-thioglucoside glucohydrolase) get in touch with the glucosinolate altering it to the isothiocyanate; the same thing happen in the human intestine by microflora myrosinase (Verkerk et al, 2009).…”