Coffee 'reduces' cancer risk
2006-01-09 09:09
Ottawa - Women with a particular gene mutation may reduce their risk of breast cancer by a startling amount simply by drinking coffee, according to new Canadian research.
The study, published in the January edition of the International Journal of Cancer, found that women with the so-called BRCA1 mutation, who have about an 80% risk of developing breast cancer before their 70th birthday, benefited from heavy coffee consumption.
"Those women who drank six or more cups of coffee a day on average had about a 75% reduction (sic) in the risk of breast cancer," University of Toronto professor and principal study author, Steven Narod, told broadcaster CTV.
Narod is a leading cancer researcher who helped isolate BRCA1 and BRCA2 mutations a decade ago in women primarily of Ashkenazi (Eastern European) Jewish heritage.
Caffeine cuts cancer risk
The results of the study indicate that women who drank one to three cups of coffee per day reduced their risk of breast cancer by 10%. The risk is further reduced, by 25%, if women drink four to five cups, and up to 69% beyond five cups.
Only women who drank caffeinated coffee derived any benefit, however.
"Estrogen is metabolised by different pathways, and one pathway yields to good oestrogen, the other to bad oestrogen ... Women who have more good oestrogen compared to bad have been shown to have a lower risk of cancer. It's like a marker of risk," said team researcher Joanne Kotsopoulo.
"Caffeine affects the enzyme that increases the good oestrogen production," she said.
Good news for coffee drinkers
Other foods such as broccoli, Brussels sprouts and soy, and supplements such as the broccoli extract DIM or Diindolylmethane, sold in pill form, may offer similar cancer protection.
But, Andre Nkondjoka, an epidemiologist at the University of Montreal hospital and study co-author, noted that coffee contains other elements, notably antioxidants.
"I'm personally convinced that the combination of all these ingredients play a role," he said.
Nkondjoka recalled a recent United States study which showed drinking coffee produced fewer side-effects than generally expected, while reducing hypertension.
"We have proposed doing a clinical study to look at the general effects of coffee on several thousand women, with or without the two BRCA genes," Nkondjoka added.
In 2005, 21 600 cases of breast cancer were diagnosed in Canadian women and 150 in men, according to the Canadian Cancer Society. An estimated 5 300 women and 45 men died of breast cancer last year.
About one thousand women in Canada carry the BRCA1 or 2 genes.
The study involved 1 690 women in Canada, the US, Israel and Poland.