Cancer Prevention with garlic
Source:http://www.whfoods.com/genpage.php/genpage.php?tname=foodspice&dbid=60
While not as strong as the research evidence for cruciferous
vegetables, research on the allium vegetables—including garlic—shows
that these vegetables have important anti-cancer properties.
Interestingly, high intake of garlic (roughly translated as daily intake
of this food) has been found to lower risk of virtually all cancer
types except cancer of the prostate and breast cancer. However, moderate
intake of garlic (roughly translated as several times per week) has
been repeatedly found to lower risk of only two cancer types—colorectal
and renal cancer. This difference between "high" versus "moderate"
garlic intake may be a real difference that suggests we all need to eat
more garlic if we want to maximize its cancer-related benefits. Or it
may be a difference that is more related to research complications
involving the options given to research participants when reporting
their food intake. Still, garlic has a consistent track record with
respect to general anti-cancer benefits, and there are good research
reasons for classifying garlic as an "anti-cancer" food.
The allyl sulfides found in garlic may play a key role in its
cancer-prevention benefits. These garlic compounds are able to activate a
molecule called nuclear erythroid factor (Nrf2) in the main compartment
of cells. The Nrf2 molecule then moves from the main compartment of the
cell into the cell nucleus, where it triggers a wide variety of
metabolic activities. Under some circumstances, this set of events can
prepare a cell for engagement in a strong survival response, and in
particular, the kind of response that is needed under conditions of
oxidative stress. Under other circumstances, this same set of events can
prepare the cell to engage in programmed cell death (apoptosis). When a
cell recognizes that it has become too compromised to continue
functioning in a healthy manner with other cells, it stops proceeding
through its own life cycle and essentially starts to dismantle itself
and recycle its parts. It's critical for a cell to determine whether it
should continue on or shut itself down, because cells that continue on
without the ability to properly function or communicate effectively with
other cells are at risk of becoming cancerous. The ability of garlic's
allyl sulfides to activate Nrf2 suggests that garlic may be able to help
modify these all-critical cell responses and prevent potentially
cancerous cells from forming.
One especially interesting area of research on garlic and cancer
prevention involves meat cooked at high temperatures. Heterocyclic
amines (HCAs) are cancer-related substances that can form when meat
comes into contact with a high-temperature cooking surface (400°F/204°C
or higher). One such HCA is called PhIP (which stands for
2-amino-1-methyl-6-phenylimidazopyridine).
PhIP is thought to be one reason for the increased incidence of breast
cancer among women who eat large quantities of meat because it is
rapidly transformed into DNA-damaging compounds.
Diallyl sulfide (DAS), one of the many sulfur-containing
compounds in garlic, has been shown to inhibit the transformation of
PhIP into carcinogens. DAS blocks this transformation by decreasing the
production of the liver enzymes (the Phase I enzymes CYP1A1, CYP1A2 and
CYP1B1) that transform PhIP into activated DNA-damaging compounds. Of
course, your best way to prevent formation of PhIP is not to bring your
meat into contact with a 400°F/204°C cooking surface in the first place.
But this area of research still bolsters our view of garlic as an
allium vegetable with important cancer-preventive properties.
