Barbara
J. Scott, MPH, RD responds:
Garlic has been shown to have
antibacterial, antiviral and antifungal properties. Benefits on
digestive disturbances and cardiovascular system, and a possible
protective effect against the development of stomach cancer have
also been shown. Specific research with either treatment or
prevention of candidiasis especially in HIV infected individuals is
still needed. Current clinical applications (supported by clinical
studies) include arteriosclerosis, common cold, cough/bronchitis,
fevers, inflammation of the mouth and pharynx (not clear whether
this applies to candidiasis). In folk medicine (use supported by
practice over time), garlic has been used internally for
arteriosclerosis, high blood pressure, colds, coughs, bronchitis,
and gastrointestinal ailments. It has been used externally for
corns, warts, calluses, muscle pain, arthritis.
Because garlic may have both systemic and local (by direct
contact) effects, its potential effectiveness against candidiasis
might depend on the mode of administration: "External" -
held in the mouth to be effective against oral candidiasis or
perhaps as a suppository for vaginal candidiasis has not been
documented in the literature to my knowledge. This type of use might
be tried, but as these tissues are extremely sensitive, care should
be taken to start with small amounts as some allergic reactions
(contact dematitis and burn-like skin lesions on skin exposed to
garlic) have been documented. The effectiveness of internal
(swallowed) garlic against a bacterial that causes ulcers has been
shown. Therefore, it is possible that it may also have an effect on
candidias of the GI tract.
The chemical properties of garlic have been researched
extensively, and many active compounds have been identified in the
bulb (fresh or dried) and oil. The primary compounds, allinins, are
transformed into the active forms when the bulbs are minced or
ground. At present, it appears that the best way to get the most
benefit is to consume fresh raw garlic (cut up to release enzymes
that in turn activate the beneficial compounds) in relatively large
amounts each day to get the best source of the active compounds.
However, consumption of enteric coated capsules or tablets of garlic
that have been dried at relatively low temperatures and labeled with
the amount of allicin may also be effective.
Since many of the active ingredients are at least partially
destroyed by the acid in the stomach, the most effective means of
getting the greatest effects include:
a. Fresh garlic (cut up first to release enzymes to activiate
allicin): Chew or hold in your mouth as long as you can. Inclusion
of garlic in cooking may also be effective as the other foods
consumed may have some protective effect against the stomach acid
and allow the garlic to pass into the small intestine.
b. Buy enteric coated capsules or tablets (the protective coating
allows them to pass intact through the acid stomach and into the
small intestine where enzymes can act under the alkaline conditions
present there.)
Usual dosages recommended are:
Fresh Garlic: 1 to 4 cloves daily Capsules or tablets (dried form):
4 to 12 mg of allicin daily (this information should be included on
the label of any quality garlic product).
Intake at these levels should pose no risk for a healthy person.
However, some side effects that have been observed include allergic
reaction, heartburn, flatulence, and other GI upset. In addition,
since consumption of garlic can reduce blood clotting time, persons
taking anticoagulant medications or aspirin, should avoid eating
large amounts of garlic. Large doses of garlic can affect the
menstrual cycle and are not recommended for either pregnant or
lactating women. Other foods in the same family include leeks,
shallots, and onions. Increasing these in your diet may also be
beneficial.