No single food or food substances can protect you against cancer.
But scientists believe that the right combination of foods in
a predominantly plant-based diet may. Evidence is mounting that
the minerals, vitamins and phytochemicals in plant foods interact
to provide extra cancer protection. This concept is called synergy.
In addition, vegetables, fruits, whole grains and beans are
low-energy-dense, low calorie foods and probably protect against
weight gain. According to the Second Expert Report, experts
believe that weight gain – particularly obesity and overweight
– are implicated in the development of cancer. Eating a predominantly
plant based diet can help prevent weight gain and therefore
protect against those cancers whose risk is convincingly increased
by higher body fat (namely cancers of the colorectum, esophagus,
endometrium, pancreas, kidney, and breast in postmenopausal
women). That is why AICR recommends that at least 2/3 of your
plate should be filled with vegetables, fruit, whole grains
Garlic belongs to the family of vegetables called Allium,
which also includes onions, scallions, leeks and chives. According
to AICR's second expert report, Food, Nutrition, Physical Activity,
and the Prevention of Cancer: A Global Perspective, foods belonging
to the allium family of vegetables probably protect against stomach
cancer. Moreover, the evidence in the report shows that garlic, in
particular, probably decreases one’s chances of developing colorectal
The protective effect of garlic was shown to have a dose response
relationship. In other words, highest exposure to the food showed
the greatest decrease in risk. For cancer protection, AICR experts
suggest including garlic as part of a well-balanced predominantly
These allium vegetables contain many substances now being studied
for their anti-cancer effects, including: allicin,
allixin, allyl sulfides, quercetin
and a large group of organosulfur compounds. In laboratory
studies, components of garlic have shown the ability to slow
or stop the growth of tumors in prostate, bladder, colon and stomach
Laboratory research has also shown that one garlic component, called
diallyl disulfide, exerts potent preventive effects against cancers
of the skin, colon and lung. Recently, this compound proved able to
kill leukemia cells in the laboratory. A compound derived from garlic
called ajoene has displayed similar activity.
In animal studies, components in Allium vegetables have
slowed the development of cancer in several stages and at various
body sites: stomach, breast, esophagus, colon and lung.
AICR has funded research on the following topics relating to garlic
and the cancer-fighting components it contains. Click each topic
to search for relevant AICR-funded research studies performed to date.
the full list of AICR’s Recommendations for Cancer Prevention.