This week in the journal Cancer Prevention Research, scientists from Johns Hopkins and China's Qidong Liver Cancer Institute report that daily consumption of a half-cup of "broccoli-sprout beverage"—a tea made with broccoli sprouts—produced rapid, sustained, high-level excretion of benzene in research subjects' urine. Their conclusion, building on prior research, is that broccoli helps the human body break down benzene and excrete its byproducts. As benzene is a known human carcinogen commonly found in polluted air in both urban and rural areas, voiding it is an unmitigated virtue.
The broccoli-sprout beverage also increased the levels of the lung irritant acrolein, another common air pollutant, in the subjects' urine.
So every alt-juice shop that sells a $14 broccoli-sprout smoothie on its "cleansing" merits is technically not entirely lying.
The broccoli-sprout beverage is understood to be a vehicle for the compound sulforaphane, which has been shown to have cancer-preventive qualities in animal studies, apparently by activating a molecule called NRF2 that enhances cells' abilities to adapt to environmental toxins. In another study earlier this year, sulforaphane-rich broccoli sprout preparations decreased people's nasal allergic responses to diesel exhaust particles.