Broccoli sprouts help the body expel air pollutants such as benzene, say scientists

Cruciferous vegetables such as broccoli contain a compound named sulforaphane that is thought to boost the body's resistance to toxins

A daily drink of “broccoli sprout beverage” helps people remove certain air pollutants from their body according to a new report published in the journal Cancer Prevention Research

Scientists from John Hopkins in the US and China’s Qidong Liver Cancer Institute found that a tea made from broccoli sprouts contained compounds that helped the body expel the harmful chemicals benzene and acrolein in urine.

The research confirms previous studies of cruciferous vegetables (such as broccoli and kale) that suggest that their high concentration of sulforaphane accelerates our natural ability to adapt to toxins. Regular broccoli also contains the compound but in far smaller concentrations (3 grams of sprouts contains as much sulforaphane as 150g of broccoli).

This most recent study looked at 291 Chinese men and women living in a rural part of the Jiangsu Province over a period of 12 weeks.. One group of participants drank a beverage of water, pineapple, lime juice and broccoli sprout powder each day while the other drank the same mixture without the broccoli.

Scientists found that those that drank the broccoli mixture excreted on average 61 per cent more benzene and 23 per cent more acrolein. Both benzene and acrolein are found in car exhausts and cigarette smoke; the former is a known human carcinogen and the latter an irritant.

"This study points to a frugal, simple, and safe means that can be taken by individuals to possibly reduce some of the long-term health risks associated with air pollution,” said lead researcher Thomas Kensler of Johns Hopkins Bloomberg School of Public Health.

Although Kensler stressed that dealing with health problems caused by air pollution is ultimately the responsibility of public policy, this sort of measure – known as chemoprevention - may help strengthen resistance to pollution.

The World Health Organization estimates that air pollution kills roughly seven million people each year, with exposure associated with a number of ailments including lung cancer, cardiorespiratory mortality and pulmonary disease.

Kensler told the Wall Street Journal that “the more bitter your broccoli, perhaps the better,” adding that the daily drink administered in China was at the upper limits of consumable sulforaphane and that it caused “mild stomach discomfort”. The pineapple and lime juice, he said, were also necessary to mask the flavour of the broccoli sprouts.