Paul Brennan of the International Agency for Cancer Research and other scientists have just completed a lung-cancer study that appears to back up this theory. In particular, the team studied the diets and genes of more than 4,000 people in Eastern and Central Europe.
According to the results published today in the journal The Lancet, the researchers found that people with an inactive form of the GSTM1 gene were 33-per-cent less likely to get lung cancer if they ate cruciferous vegetables on a weekly basis.
Furthermore, "in people who had an inactive GSTT1, there was a 37-per-cent protective effect, while those with both genes inactivated had a 72-per-cent protective effect."
They found no protective effect in people with active forms of the genes.
Think about that last sentence. If you could get tested and discovered that you have active forms of both genes then you'd have no health reason to eat Brussels sprouts and broccoli. That strikes me as something I'd really like to know.
On the other hand, this result might also provide support for the idea of developing drugs to deactivate the glutathione-S-transferase enzymes so that isothiocyanates will hang around the body for longer periods of time. Or maybe high dose isothiocyanate pills could overwhelm the enzymes that break them down so that the isothiocyanates can still provide protection.
For this study, the researchers looked at 2,141 people with lung cancer, comparing them with 2,168 healthy individuals in the Czech Republic, Hungary, Poland, Slovakia, Romania and Russia, where consumption of these vegetables has traditionally been high.
Participants filled out a food questionnaire, and also gave a blood sample so researchers could detect GSTM1 and GSTT1.
The questionnaire listed 23 foods, including three cruciferous vegetables: cabbage and a combination of Brussels sprouts with broccoli.
When the results were stratified by smoking status, a protective effect was seen in smokers with both genes inactive (OR 0.31; 95% CI 0.12-0.82) but not in people with both genes active. In non-smokers, there seemed to be a protective effect regardless of genotype, however the results did not reach statistical significance.
|Share |||Randall Parker, 2005 October 28 02:00 PM Aging Diet Cancer Studies|