Most of the compounds we read about — lycopene, lutein, beta-carotene, quercetin, etc. — act as “direct” antioxidants. When we consume fruits and vegetables that contain these compounds, they possibly work to affect free radicals, rendering them harmless.
There is another category of nutrients that may act “indirectly” to activate the body’s detoxification systems. These are known as glucosinolates and are found in broccoli, brussels sprouts, cabbage, cauliflower. Such foods may work to affect the body’s own antioxidant systems. This cascade of antioxidant activity may cycle over and over, continuing to circulate in your system as many as 3 to 4 days after the glucosinolate-containing food has been consumed. Certain natural enzymes in the liver help eliminate toxic molecules from the body. These toxins come from many sources: cigarette smoke, pollution, drugs, even free radicals generated by our own bodies in response to illness.
Among all of the cruciferous vegetables, broccoli sprouts have the highest level of the glucosinolates relevant to this enzymatic process. Just two or three tablespoons of broccoli sprouts a day provide a powerful dose of glucosinolates. After broccoli sprouts, cauliflower sprouts are second highest in terms of containing the relevant glucosinolates. Other sprouts outside the cruciferous family, such as alfalfa sprouts, aren’t high in these compounds. Researchers speculate that these compounds are most concentrated in the budding plant because the organism needs a high concentration of protective phytochemicals to shield them from predators, pollution, the elements, etc. As plants grow, they are somewhat diluted though still present, which is why they retain their health benefits when consumed.
Speaking of consumption, chewing breaks down the glucosinolates to their active form, known as sulforaphane, which is then what triggers the enzymatic process. Glucosinolates are a hot topic in phytochemical research right now. For example, some research suggest glucosinolates may help lower blood pressure. Other studies have focused on potential benefits including lower risk of various cancers, such as stomach, colon, esophageal, lung and breast cancers. Now scientists are exploring how the glucosinolates found in cruciferous vegetables interact with a natural antioxidant found in all cells called glutathione. Essentially, glutathione helps to trap the free radicals that can damage our DNA and cause cancer.
So, add broccoli, broccoli sprouts, cauliflower, Brussels sprouts and other cruciferous veggies to your diet — aiming for at least 2 servings (1 cup) of these a day.
Published June 7, 2004