Research on the efficacy of garlic and aged garlic extract
in eliminating yeast infections has focused in recent years on
the potential therapeutic actions of their components, which
in team fashion are strengthened in acting as remedies and
providing health benefits.
Candida, the Infective Fungus
Candida albicans (C. albicans) is the most prevalent fungal
pathogen in humans, causing various forms of infection,
called Candidiasis that range from superficial infections of organ
linings to life-threatening systemic diseases, especially in
immuno-compromised patients with AIDS, cancer or organ
transplantation, indicating that the mammalian immune system
is a primary barrier to infectious agents.
Candida normally exists in small amounts in the human
body. Present in the oral and vaginal lining, the organism
can transform itself to a highly virulent form that can be lifethreatening,
particularly in patients with weakened immunity.
The virulence factors of C. albicans include changes to an invasive
form, adhesion to host cells and escaping host immune
A limited number of anti-fungal treatments are available,
but these remedies often have unpleasant side effects. In addition
Candida acquires resistance, requiring a switch in medication
or an increase in dose. In a move to find sources of
treatment other than the accepted medications fluconazole or
amphotericin women have sought natural, non-drug therapy
to eliminate the fungal infection.
The Nature of Candida
Candida albicans (C. albicans) is a form of yeast and a cause of
oral and genital infections in humans, mostly women. Invasion
of C. albicans into the blood is considered an important cause
of disease and death in immuno-compromised patients (e.g.,
patients with AIDS, those receiving cancer chemotherapy, or
those undergoing organ or bone marrow transplantation). C. albicans forms bio-films on surfaces of implanted medical devices,
increasing risk of infection. A major cause of concern in
hospitals are hospital-acquired Candida infections, in patients
who had not been considered at risk, for example, patients in
intensive care units.
C. albicans is one of many organisms that reside in the
human mouth and gastrointestinal tract. Under normal conditions,
C. albicans lives in 80 percent of the population, causing
no harm; but overgrowth results in candidiasis. To infect tissues,
the single cell form of C. albicans reacts to environmental
signals and switches into an invasive form that contains
many cells and has filaments (hyphae). These filaments are
an essential step for C. albicans to become virulent and cause
infections that can become systemic. The switch in form and
the addition of the hyphae is largely controlled by a gene called
Candidiasis and Women
Candidiasis affects around 75 percent of women, at some point
in life. Symptoms of this yeast infection may vary, depending
on the affected areas. Infection of the vagina or vulva causes
severe itching, burning, soreness and a discharge; using
douches for vaginal cleansing disturbs the normal vaginal flora
that includes lactic acid bacteria, such as Lactobacilli, causing
an overgrowth of Candida cells, promoting infection and local
inflammation. The risk of Candidiasis increases during pregnancy,
in the use of oral contraceptives, during hormone replacement
therapy, and infertility treatments. Antibiotic use is
also linked to an increased incidence of yeast infections, as is
wearing of a wet swimsuits for long periods of time, as moisture
increases Candida infection.
Medical treatment of vaginal Candidiasis by anti-fungal
drugs is effective to a large extent but C. albicans develops resistance
to medications, over time, and the infection returns.
For example, a popular oral medication, fluconazole, may be
partially effective in treating a vaginal yeast infection, but as resistance
develops over time the dose must be increased or one
must switch to another medication. Many women, concerned
by possible adverse effects of the medications prefer natural
cures over the use of drugs.
Garlic and Kyolic Aged Garlic Extract
Garlic contains compounds with antifungal activity but many
shun the fresh bulb, because of the pungent garlic odor that
lingers on the skin and breath, compromising social activities
and the potential of adverse gastric effects. The solution, as
many sufferers of C. albicans have found out, can be a daily
consumption of the odorless garlic preparation, Kyolic Aged Garlic Extract (AGE) that has antifungal compound and in addition
Kyolic AGE is made by the Wakunaga of America, by a slow
extraction and aging process, at room temperature; it contains
largely water soluble compounds, such as S-allyl cysteine and
S-allyl mercaptocysteine, as well as lipid soluble organosulfur
compounds, such as Diallyl disulfide (DADS) and other beneficial
AGE is the most popular garlic supplement; it is rich in antioxidants,
that help increase the power of the immune system;
it has high bioavailability and its manufacturing is regulated
by dependable quality control; AGE, standardized by the water
soluble organosulfur compound, S-allyl cysteine, has a wide
range of health effects that often surpass those of fresh garlic.
Being odorless, its consumption does not have the potential
anti-social drawbacks or gastrointestinal adverse effects that
accompany the eating of large amounts of fresh garlic.
Garlic Extract Compounds as Therapeutic as Anti-Candida Agents
Over the last few years preclinical experiments have supported
the action of garlic compounds as therapeutic agents against
Candida infections, as the ubiquitous opportunistic pathogen
C. albicans was found to be sensitive to garlic. AGE, contains
compounds called saponins, with a particular saponin Eruboside
B found by Matsuura et al, to be an antifungal agent that
is active against C. albicans. Another compound contained in
AGE, DADS, has also been shown in several studies to act
as antifungal agent and inhibit the growth of C. albicans. The
mechanism of action is complex; the organosulfur DADS kills
the Candida yeast by decreasing respiration and suppressing
the activity of protective enzymes and other molecules that are
critical for the viability of Candida albicans.
Inhibition of the Virulent, Invasive Form of Candida
In order to transform from a single infectious cell to the virulent
and invasive form, C. albicans must form filaments (hyphae),
a process that is largely controlled by a gene called SIR2. A
series of studies undertaken by Low et al, at the University of
Putra, Malaysia, investigated the effect of a garlic extract on
the transformation of C. albicans to its virulent invasive form.
The investigators found that growing Candida cells in the presence
of garlic extract prevented the transformation of the yeast
to its hyphal, invasive form. They also found that by increasing
concentration of the garlic extract there was a one and a
half to two and a half fold decrease in the expression of the
SIR2 gene that regulates the formation of the filaments. The
investigators concluded that it is unlikely that C. albicans would
develop a resistance to the garlic compounds; therefore, the
anti-Candida effects of the garlic extract, in preventing transformation
of Candida to its virulent pathogenic form may provide
an important alternative route to treatment with antifungal
Of all the kinds of infections caused by C. albicans, vaginitis is
considered one of the most disturbing to women. Vaginal yeast
infections occur when new yeast is introduced into the vaginal
area, or when there is an increased quantity of yeast already
present in the vagina, relative to the number of normally residing
protective bacteria. Such imbalance occurs, for example,
when beneficial, protective bacteria are destroyed by antibiotics
that are taken to treat infections of the urinary and respiratory
tracts, or some other types of infection. Other cases that
increase risk of vaginitis are in the use of immune-suppressive
drugs, as Candida cells can multiply, invade tissues, and cause
irritation of the lining of the vagina.
Women with suppressed immune systems, for example
after taking cortisone-related medications such as prednisone,
develop vaginal yeast infections more frequently than women
with normal immunity. Additional conditions that may predispose
women to developing vaginal yeast infections include
oral contraceptives, pregnancy and the use of douches or perfumed
vaginal hygiene sprays.
Treatment with antifungal medications can be effective but
Candida albicans develops resistance. One of the most promising
treatments that rely on natural ingredients is garlic and the
odor free Aged Garlic Extract (Kyolic AGE) that contain antifungal
components. In addition, AGE has been shown to increase
immunity, helping the body fight the Candida infections.
Though clinical trial will prove the efficacy of garlic in
eradicating Candida and curing vaginitis, experimental studies
show that exposing Candida cells to a variety of garlic compounds
present in AGE prevents Candida from developing
into the virulent invasive form that can lead to systemic infections,
strongly suggesting that AGE, the odorless form of
garlic may be a powerful remedy against infections by Candida albicans.
- Low CF, Chong PP, Yong PV, Lim CS, Ahmad Z, Othman F. Inhibition of hyphae formation and SIR2 expression in Candida albicans treated with fresh Allium sativum (garlic) extract. Appl Microbiol. 2008;105:2169–77.
- Lanzotti V, Barile E, Antignani V, Bonanomi G, Scala F. Antifungal saponins from bulbs of garlic, Allium sativum. Phytochemistry. 2012; 78:126–34.
- Kyo E, Uda N, Kasuga S, Itakura Y. Immunomodulatory effects of aged garlic extract. J. Nutr2001;131:1075S-9S. Review.
- Matsuura H, .Ushuroguchi T. Itakura Y., Hayashi Y and Fuwa T. Chem Pharm Bull. 1988; 36: 3659–63.
- Yousuf S, Ahmad A, Khan A, Manzoor N, Khan LA. Effect of garlic-derived allyl sulphides on morphogenesis and hydrolytic enzyme secretion in Candida albicans. Med Mycol. 2011;49:444–8.