ScienceDaily (May 23, 2007) — According to new research presented
at Digestive Disease Week® 2007 a vegetarian diet may have a significant
impact on the gastrointestinal (GI) system, affecting the risk for certain diseases.
The average person's lifetime risk of developing colorectal cancer (CRC) is
about seven percent and the role of diet in preventing this type of cancer remains
under debate. Most of all, previous studies enrolled middle-aged subjects, raising
the possibility that CRC development may start before common interventions.
Researchers from Tata Memorial Hospital (TMH) in Mumbai, India, set out to determine
whether a vegetarian diet is associated with reduced risk of CRC if started
very early in life.
In this study, researchers used a prospectively created database of 8,877 Indian
patients managed in a clinical nutrition service from January 1, 2000 through
December 31, 2005, to examine the association of life-long vegetarianism with
incidence of CRC. During the evaluation for nutrition support, a history of
life-long vegetarianism (due to religious reasons) was obtained from all patients
to plan an appropriate diet. Twenty-seven percent of subjects (2,092 patients)
from the control cohort were life-long vegetarians and 22.4 percent (178 patients)
of subjects with colon cancer were vegetarians.
Patients with colorectal cancer (n=796) comprised the primary patient cohort
for this study. Three groups of controls were generated from the same database
for separate comparison with the CRC cohort. These included all patients with
non-CRC cancers (control group one: n=7,273), patients with non-CRC and tobacco-related
cancers (control group two: n=1,844), and patients with benign disorders (control
group three: n=74). Multivariate analysis of 7,641 patients was performed by
adjusting for age, gender, body mass index and economic status.
Vegetarianism was significantly associated with patients over 65 years, male
gender, body mass index (BMI) of less than 20 Kg/m2 and economic deprivation.
Colorectal cancer was positively associated with old age and male gender, and
inversely associated with vegetarian diet, low BMI and economic deprivation.
The inverse association of CRC and lifelong vegetarianism was observed with
all the three control groups.
"A well-planned vegetarian diet is a healthy way to meet your nutritional
needs," said Yogesh M. Shastri, M.D., of Johann Wolfgang Goethe University
Hospital, Frankfurt, Germany and previously a co-author of this study at TMH,
Mumbai, India. "The exact mechanism by which life long vegetarianism may
reduce the risk of sporadic CRC needs further investigation. Prolonged vegetarianism
starting in early life may be a viable lifestyle option for those at risk of
developing the disease."
Adapted from materials provided by American Gastroenterological Association,
via EurekAlert!, a service of AAAS.