In 1992, Johns Hopkins researcher Paul Talalay, M.D., and colleagues found that an antioxidant called sulforaphane, produced in the body from a compound in broccoli, triggered the production of enzymes that helped detoxify cancer-causing chemicals. The discovery, published in the Proceedings of the National Academy of Sciences, attracted worldwide attention and was hailed as a major breakthrough in our understanding of the link between increased fresh vegetable consumption and reduced cancer risk. Subsequent studies found that sulforaphane prevented the development of breast and colon cancer, as well as other tumors, in mice, exhibiting a powerful role in cancer prevention and protection.

"Chemoprotection is a deliberate effort to increase the body's defense systems against chemicals, including carcinogens, that can lead to disease," according to Dr. Talalay. "Chemoprotection may lower a person's risk of developing cancer by building up the body's own defenses, particularly through diet."

Talalay's team found that the key protective compound in broccoli (a chemical called glucoraphanin, which the body turns into sulforaphane) was 20 times more concentrated in young, three-day-old broccoli sprouts than it is in more mature broccoli plants.

To bring the exciting discovery to consumers, they formed Brassica Protection Products in cooperation with Johns Hopkins University. The company distributes the patented product called BroccoSprouts to grocery stores around the country. More recently, the team launched a line of teas enhanced with the antioxidant SGS (sulforaphane glucosinolate). Proceeds from the products will help support the Brassica Chemoprotection Laboratory, designed exclusively to study cancer-fighting properties of plants.

To learn more about the discovery and health benefits of broccoli in battling various forms of cancer, Helicobacter pylori, and other chronic conditions, the Post spoke with plant physiologist Jed Fahey, who is manager of the Brassica Chemoprotection Laboratory at Johns Hopkins.

Post: What are the unique health benefits of broccoli?


Fahey: Paul Talalay, M.D., professor of pharmacology at Johns Hopkins University School of Medicine, and colleagues discovered that broccoli contains disease-preventing components called phytochemicals, the most potent of which is sulforaphane. A natural compound, sulforaphane helps mobilize the body's natural cancer-fighting ability by inducing protective enzymes. It also has antibiotic activity against a number of fungi and bacteria.

The cancer-protective effects of some phytochemical compounds--those in broccoli sprouts, in particular--are very broad-based. They induce protective enzymes in various tissues, especially in the liver--one of the body's main detoxifying organs. The enzymes enhance an already-present capacity to detoxify carcinogens, which otherwise might create the mutations in individual cells that can lead to cancer.

We've investigated extensively the metabolism of these compounds in humans, and trials are in progress in China specifically looking at liver cancer and the potential of broccoli sprouts to delay or prevent its onset.

Post: What led the team at Johns Hopkins to focus on broccoli sprouts and not just broccoli?

Fahey: In looking for someone with plant expertise, Dr. Talalay hired me in 1993, and I began the search for a "better" broccoli. I started collaborating with organic farmers who grew plants throughout Maryland, and it quickly became apparent that there was a huge amount of variability in broccoli. Focusing on smaller and smaller plants, I started broccoli seeds in my lab, growing the seeds to a certain size under precise, controlled conditions--light and temperature. I soon discovered that the smaller the plant, the more potent in terms of its chemoprotective, or cancer-fighting, activity. The seed is the most concentrated source of sulforaphane; the compound becomes diluted as the plant matures. Genetics also plays a role, so we grew varieties with very high levels of sulforaphane.

Post: How does sulforaphane reduce the risk of cancer?

Fahey: A complex process, detoxification involves the coordinate stimulation of enzyme inducers with different functions. Some detoxify free radicals--highly reactive molecules linked to the cancer formation. Other enzymes reduce free-radical creation, and some conjugate carcinogens, allowing for more effective and rapid excretion in the urine. In other words, a carcinogen that would normally accumulate in the fat tissues of the body (when conjugated to a molecule whose production is triggered by a chemoprotective enzyme) may become more water-soluble--and thus more readily pass through the kidneys and be excreted.

Post: We recently featured an interview with Dr. Barry Marshall, who discovered the link between Helicobacter pylori and most ulcers. He mentioned your work and sulforaphane's effectiveness in killing H. pylori. What led to this discovery, and does sulforaphane also reduce the risk of stomach cancer?

Fahey: When I began this research, I had visited broccoli sprout plants and heard anecdotal reports of people being cured of stomach problems--gastritis and ulcers--after eating broccoli sprouts. I made the connection that perhaps the sulforaphane in the sprouts was involved in the response and began investigating the action of sulforaphane against Helicobacter pylori. In laboratory tests, we discovered that sulforaphane killed Helicobacter pylori, which is linked causally to most ulcers and often-fatal stomach cancers. The discovery was a pleasant surprise. If clinical trials continue to support sulforaphane's bactericidal activity against H. pylori, the finding could have broad public-health impact, especially in underserved areas of the world. Since about 80 percent of certain populations living in poverty and terrible sanitary conditions around the world are infected with Helicobacter pylori, curing this infection with a natural, inexpensive plant would have great potential to reduce the diseases caused by this infection.

Post: Should we also include more mature broccoli and other vegetables in the diet?

Fahey: Optimally, yes. People should simply add sprouts, in particular broccoli sprouts, to a diet already rich in a variety of fruits and vegetables. If someone is not fond of fruits or vegetables, broccoli sprouts might be a good way to expand their dietary horizons. We know for a fact that the fiber in vegetables is an important dietary ingredient that you will not get from a supplement--or tea, for that matter. To get sulforaphane in your diet, eat broccoli sprouts but don't overlook other vegetables. A small amount of broccoli sprouts lacks the fiber contained in a large serving of broccoli. In a balanced diet, you need five to nine servings of fruits and vegetables a day. You still need fiber, vitamin C, and so forth that you will not get very much of from either vitamin pills or broccoli sprouts.

Post: Do other vegetables such as cauliflower contain sulforaphane?

Fahey: Cauliflower--the vegetable that Americans are familiar with--does not. Cauliflower sprouts do. Cauliflower sprouts are exceedingly expensive to produce, however, because good seed are very hard to get and very expensive.

Post: What led you and the team at Johns Hopkins to develop broccoli sprout teas? Does the tea taste good?

Fahey: The tea is delicious. The company— Brassica Protection Products (which I actually helped to found)--added sulforaphane (they use the term "SGS" for "sulforaphane glucosinolate") into teas— black, green, and red. Many studies in the scientific literature suggest that tea has a cancer-protective effect. Given the fact that tea is healthy and many Americans drink tea, it seemed like a good beverage into which to add SGS, as opposed to soft drinks or juices that are high in sugar. These teas thus contain the same naturally occurring antioxidant compound found in broccoli and broccoli sprouts, and it is extracted directly from them.

Post: How do the 15 milligrams of SGS found in one of these teas compare with broccoli sprouts?

Fahey: The 15 milligrams in a tea bag represent about one fifth of the amount in one serving (30 grams) of sprouts, which has about 75 milligrams of SGS. And that amount is equivalent to what is present in over one pound--about 20 ounces--of fresh broccoli.

The range of SGS in broccoli available at a supermarket varies tremendously--it can vary ten-fold. But if you take a rough average of the amount that you'd find sampling ten heads in ten different grocery stores, the amount would be ten- to 20-fold less than the amount found in an ounce of sprouts.

Post: Are recipes available for broccoli sprouts?

Fahey: Many recipes are available. I sprinkle sprouts on salad or add them to soups and casseroles. I know that Brassica Protection Products does have recipe cards available for consumers.

Post: Does cooking lessen SGS content?

Fahey: No, although SGS is highly water soluble, like vitamin C. If you boil sprouts in water and throw away the water, you're losing essential SGS. If microwaving, do it briefly and use minimal water.

I lean toward a Mediterranean diet, consuming a lot of nuts, salads, vegetables (cooked or not), strawberries, and blueberries. We don't have anything but olive oil in our house, so I cook with it and use it on salads and in cooking. I won't touch butter or margarine.

Post: Are you involved in other research studies?

Fahey: Yes. For example, we've been looking at the chemoprotective potential of honey and various lesser-known plants such as Thai ginger. It appears that honey is also effective against Helicobacter pylori in studies from other labs, as well as in wound and burn healing.