|Vegetable extracts may aid breast cancer prevention
August 9, 2005
By Keith T. Mead
Special to The Clarion-Ledger
It is well known that Asian women have lower rates of breast cancer compared with their Western counterparts, and one theory is they get ample amounts of protective phytochemicals from the vegetables in their diets.
Two of these phytonutrients are indole 3-carbinol (I3C) and sulforaphane, which are most abundant in vegetables such as kale, broccoli, cauliflower and cabbage.
They are gaining particular attention from scientists because of their relevance to breast cancer prevention. I3C, for example, has been shown to cause cancer cells to self-destruct without harming healthy cells. In one notable study, I3C inhibited human breast cancer cells from growing by as much as 90 percent in culture.
This natural chemical functions by changing the way estrogen is metabolized in the body. Specifically, it converts “strong” estrogen into “weak” estrogen.
Of the three forms of estrogen made by the human body, estradiol (E2) has the strongest ability to turn on the growth signals that can make breast cells cancerous. Estriol (E3), on the other hand, doesn’t and is considered by many doctors to be the more desirable form of estrogen. I3C has been shown to increase the conversion of strong E2 to weak E3 by 50 percent in women, and this has been shown to inhibit the growth of human cancer cells by 54-61 percent.
Another important metabolite of estrogen is 2-hydroxyestrone (2-HE), which has been shown to protective against cancer. I3C promotes the formation of this protective chemical from estrogen, while reducing the formation of other estrogen metabolites that have been linked to cancer.
Research conducted at the Strang Cancer Research Laboratory in New York showed that in every case studied, protection against breast cancer was directly linked to the amount of this beneficial 2-HE present.
In other studies, I3C also has demonstrated clinical benefits for cervical and prostate cancers, and has even been shown to inhibit tumor growth in the respiratory tract. Clearly, I3C is an all-around cancer preventive.
Another cancer-fighting chemical abundant in vegetables such as broccoli and broccoli sprouts is sulforaphane. Several universities are currently studying this natural substance for its ability to stop the growth of human cancer cells without disturbing healthy cells.
Prostate, breast and bladder cancer cells transplanted into mice all have been shown to stop growing in the presence of sulforaphane. Like I3C, it causes cancer cells to self-destruct. Unlike I3C, however, sulforaphane activates enzymes that detoxify cancer-causing chemicals from the body. In addition, it protects DNA from damage and promotes the body’s own DNA repair system.
Based on what I considered to be solid and convincing science, I recently introduced both I3C and sulforaphane to a friend who was experiencing problems with growths on her breasts.
She elected to take a daily dose of 200 mg of I3C plus 0.45 mg of sulforaphane in December. Less than five months later she had her annual mammogram. When you compare the last mammogram with one taken a year earlier, the three cysts circled by her doctor in the 2004 mammogram had disappeared. Also, the white mass at the front had significantly decreased.
Both I3C and sulforaphane are being investigated in large-scale breast cancer prevention clinical trials at the National Cancer Institute.
To those of us who have kept up with the published research on these nutrients, this comes as no surprise. Yet my guess is few people are aware of these natural agents.
There is little doubt in my mind prevention is the best weapon against cancer. The skyrocketing expense of cancer-fighting drugs is particularly worrisome. The New York Times reports some of the newer drugs becoming available could cost as much as $100,000 for just a few months supply.
All women over the age of 30 should be told about the benefits of protective phytochemicals.
If this isn’t reason enough to load up on your veggies, I don’t know what is.
Keith T. Mead is the head of the chemistry department at Mississippi State University, specializing in organic chemistry. His research program is funded by the National Cancer Institute.