Soy May Not Protect Against Stomach Cancer
Posted by Unknown in Health Issues, Nutrition, Soybean on Saturday, 26 January 2013
Estrogen-like
compounds that come with a soy-rich diet are sometimes linked to a
reduced risk of cancer, but new research from Japan suggests that
protection doesn’t extend to stomach cancer.
Azusa
Hara and her colleagues from the National Cancer Center in Tokyo
examined data on about 85,000 people in an existing Japanese study.
The
researchers estimated how much isoflavone the study’s participants ate
from a list of questions they had answered in the 1990s, then followed
the subjects until the end of 2006 to see how many developed stomach
cancer.
During
the follow-up period, approximately 1,250 of the study’s participants
got stomach cancer, but the researchers saw no difference in risk
between those who ate the most isoflavone and those who ate the least.
According
to Dr. Richard Peek, director of Gastroenterology, Hepatology and
Nutrition at Vanderbilt University Medical Center in Nashville,
Tennessee, estrogen is thought to protect against stomach cancer because
the disease is much more common in men, at least until women are
post-menopausal — hinting that younger women’s higher estrogen levels
might be protecting them.
Peek told Reuters Health there are also studies on mice that suggest estrogen protects against stomach cancer.
The
Japanese team, however, found an increase in stomach cancer risk among
women taking hormone therapy who ate the most isoflavone-laden food,
compared to those who ate the least.
The
women in the study on hormone therapy were more likely to smoke, drink
and have a family history of stomach cancer, the researchers note, which
could explain the link.
Hara
and her colleagues wrote in the American Journal of Clinical Nutrition
that their results are limited by the use of their questionnaire and the
fact that they could not account for whether the subjects were also
infected with the bacterium Helicobacter pylori, which is also linked to
increased stomach cancer risk.
Still another well-known risk factor for gastric cancers is high salt intake.
According
to the American Cancer Society, a person in the United States has a one
in 114 chance of developing stomach cancer. An estimated 21,500
Americans were diagnosed with it in 2011 and an estimated 10,500 died
from it.
Stomach cancers were once the leading cause of cancer deaths in the U.S. until 1930.
“One
of the reasons for decline is that people have fridges now, and they
use less salt preservatives,” said Khaldoun Almhanna, a medical
oncologist at the Moffitt Cancer Center in Tampa, Florida.
