Overview
Brassica oleracea, a species encompassing broccoli, cabbage, Brussels sprouts, kale, and cauliflower, is a rich source of bioactive compounds with chemopreventive and neuroprotective properties. The primary beneficial compounds are glucosinolates, which are hydrolyzed to isothiocyanates (ITCs) such as sulforaphane. Sulforaphane has been extensively studied for its ability to activate the Nrf2/ARE pathway, a key regulator of antioxidant and detoxifying enzymes, thereby offering protection against oxidative stress, inflammation, and carcinogenesis [1][3][4]. Research shows that the concentration of these compounds varies with plant variety, growth stage, and processing methods, with higher levels typically found in sprouts and young plants [3]. Additionally, Brassica oleracea contains lipid-soluble antioxidants including carotenoids, chlorophylls, and tocopherols (vitamin E), contributing to its overall health-promoting profile [5]. These compounds collectively support cellular defense mechanisms and may reduce the risk of chronic diseases, including cancer and neurodegenerative disorders.
Dosage Guide
Recommended Daily Allowance
For generally healthy individuals
Therapeutic Doses
For treatment of specific conditions
Upper Intake Limit
Maximum safe daily intake
200 g— No established UL for whole food; high intake may affect thyroid function in susceptible individuals, especially with iodine deficiency
Special Forms
Alternative forms for specific needs
Standardized sulforaphane delivery for research and supplementation
Enhance conversion of glucoraphanin to active sulforaphane
Clinical Notes
- High intake of raw Brassica vegetables may interfere with thyroid function due to goitrogenic glucosinolate breakdown products; cooking reduces this effect
- Individuals with iodine deficiency or hypothyroidism should moderate raw Brassica consumption
- Supplemental sulforaphane extracts should be used cautiously in those with thyroid disorders or on antithyroid medications
- Ensure product quality and myrosinase activity in supplements for optimal sulforaphane release
Research
Sulforaphane purified from Brassica oleracea seed meal shows tumor-inhibiting potential; broccoli seeds contain high levels of precursor compounds.
Highlights challenges in standardizing botanical supplements, including quality and safety concerns relevant to Brassica-derived products.
Isothiocyanate content, especially sulforaphane, varies with growth stage and extraction method; sprouts and young plants yield higher bioactive levels.
Isothiocyanates from Brassica vegetables exhibit neuroprotective effects via activation of the Nrf2/ARE pathway.
Brassica oleracea vegetables contain variable levels of carotenoids, chlorophylls, and tocopherols, which contribute to antioxidant activity.
Assesses safety of plants used in food supplements; Brassica species are generally recognized as safe when consumed appropriately.
Sulphur-containing biostimulants like thiosulphate influence growth and cadmium accumulation in Brassica oleracea, relevant for food safety in contaminated soils.
Related Brassica rapa contains phenolic glycosides with alpha-glucosidase inhibitory activity, suggesting potential metabolic benefits
