Small quantities of fresh broccoli sprouts contain as much cancer protection as larger amounts of the mature vegetable sold in food markets, according to researchers at Johns Hopkins University. Just 5 grams (0.17 ounces) of sprouts contain concentrations of the compound glucoraphanin equal to that found in 150 grams (5.2 ounces) of mature broccoli. The compound is a precursor to sulforaphane, proven in animal studies to boost cell enzymes that protect against molecular damage from cancer-causing chemicals.
Sulforaphane has been shown to mobilize, or induce, the body's natural cancer protection resources and help reduce the risk of malignancy. Broccoli is the best source of the chemical precursor to sulforaphane -- glucoraphanin. Now, broccoli sprouts are an "exceptionally rich source" of inducers of cellular enzymes for "detoxifying" chemical carcinogens -- cancer causing compounds. Some of these compounds are potent enhancers of phase 2 enzymes, which speed the detoxication of electrophiles and reactive oxygen metabolites. Therefore, they say, induction of phase 2 enzymes by these compounds can "...protect cells against mutagenesis and neoplasia."
The researchers attempted to calculate how much broccoli one would have to eat in order to produce a significant degree of protection against cancer, based on epidemiologic evidence. They found that one would have to eat about two pounds of an average broccoli a week in order to reduce, say, one's risk of colon cancer by about 50%.
An additional complication is that it is impossible to determine by the looks of this cruciferous vegetable alone or even with knowledge of how and where it was grown whether you are buying the 'high-inducer' or 'low-inducer' broccoli. The enzyme-inducing abilities of samples taken from 22 varieties of fresh and 7 brands of frozen mature broccoli vary greatly. Only sophisticated scientific measurements can determine the concentrations.
But fresh broccoli sprouts offer an alternative. One can get away with eating 10 to 100 times lower quantities. Three day old sprouts have the additional advantage that they're far more uniform in their potency. Broccoli sprouts look and taste something like alfalfa sprouts, according to the researchers. The report also notes that small quantities of broccoli sprout extracts markedly reduced the size of rat mammary tumors that were induced by chemical carcinogens.
The researchers refer to the concept of "chemoprotection" -- deliberate efforts to increase the body's own defense mechanisms to reduce susceptibility to carcinogens by administration of substances that can be precisely identified, and ideally, delivered in the diet. The interesting aspect of chemoprotection strategies is that they're almost never organ-specific. Chemoprotection produces a general cancer protective effect which blocks multiple steps -- a cascade of steps -- that are common to cancer formation.
INSIGHT: At the present time, broccoli sprouts are not being grown commercially. However you can grow them yourself quite easily. You can purchase organic broccoli seeds from Johnny's at 207-437-4301. Item number 148, four ounces are $9.00 or a pound for $12.00. Non-organic seeds can probably be purchased through farm supply stores or other seed catalogs. You can also call Jaffe Brothers at 619-749-1133 for instructions on how to sprout. They also sell sprouting lids to apply to Ball jars which make the entire process quite convenient. The library or health food store may also have some instructions on sprouting seeds.
A small amount of spouts go a long way. A pound of sprouts will probably make over ten pounds of sprouts which from the researchers calculations translates up to as much cancer protecting phytochemicals as 1000 pounds (half a ton) of broccoli! The other major benefit is that the sprouts don't smell as you don't have to cook them. They are eaten raw, usually as an addition to salad. I have already ordered my sprouts. I suspect that there are similar benefits for many of the other vegetables when eaten as sprouts. From the Proceedings of the National Academy of Sciences (1997;94:10367-10372)
Sprouting Time 5-7 days Temperatures 60-80
Yield 1 Tbs seed=1-1 1/2 cups sprouts
Place seeds in the jar and cover with cheesecloth or other porous material. Secure the cloth with a rubber band. Fill the jar full with filtered water and let soak overnight. I have had some patients tell me that distilled water actually works much better than filtered or bottled water as it seems to increase the percentage of seeds that sprout successfully.
In the morning drain off the water. The cloth will keep the seeds in the jar. Rinse seeds with water again and let drain. You can also use reusable plastic sprouting lids (available from Jaffe Brothers at 619-749-1133) which attach to Ball jars. This avoids having to use new cheesecloth each time. Put the container on its side in a dark location that stays about 70 degrees. Rinse twice each day with water and drain. Continue the rinse cycle until harvested. When sprouts are 1-2 inches long you can put them in the light to green them up. You can rinse out the hulls or skim them of the top of the water with a spoon. They are not harmful to eat but removing them minimizes spoilage when sprouts are stored. Sprouts are best stored in an airtight container in the refrigerator and keep for about one week.