Not long ago, ScienceDaily published an article entitled, “A
Ton of Bitter Melon Produces Sweet Results For Diabetes.” This
headline is but one of many recent announcements regarding
the benefits of an ancient vegetable that is a culinary treat
throughout much of the world. Unfortunately, bitter melon and
its many benefits remain unknown to most Americans.
Bitter melon grows in the tropical and subtropical areas of
the East Africa, Asia, India, South America and the Caribbean.
It is used traditionally as both food and medicine in all of these
areas. Momordica charantia goes by many names and is known
as bitter melon, bitter gourd, balsam pear, karela, and pare.
Most Westerners will identify bitter melon as looking like a pale
green or green cucumber with warts. Indian varieties may be
whitish to gray-green, as well. Commercial cultivars can range
up to a foot or more in length, whereas wild bitter melon varieties
may measure only an inch or so, more than making up for
their small size with greater bitterness and intense flavor. The
gourd becomes more bitter as it ripens. As a food, unripe bitter
melon is used fresh in salads, cooked into soups and curries,
employed as a flavoring for eggs, meat and so forth.
Long popular as part of the cuisine of South Asia and
China, bitter melon today is conquering new gastronomic territories.
Okinawans, renowned for longevity, are extremely
fond of a small local variety reputed to confer health benefits.
From Okinawa and other sources, bitter melon is becoming increasingly
widespread on the Japanese mainland. This reflects
an East Asian trend typical of Korea as well as Japan: Highly
flavored and colored nutrient-dense foods are being adopted
as everyday sources of health. Hence black and red rice, black
garlic, bitter melon and other such foods and condiments are
A Plethora of Benefits
Almost every part of the Momordica charantia plant has been
used in traditional medical practices, including not just the
fruit, but also the leaves/vines, seeds and roots. Folk and traditional
systems often suggest bitter melon for microbial infections,
sluggish digestion and intestinal gas, menstrual
stimulation, wound healing, inflammation, fever reduction, hypertension,
and as a laxative and emetic. All these benefits are
from a plant with fruit that has been proven safe by centuries
of oral consumption. The only concern generally of note is that
bitter melon seed consumption is not recommended for those
seeking to become pregnant.
In South Asia, bitter melon is recommended to support
immune health. Some of the effects are direct and some are
indirect. Benefits include the inhibition of the growth of a variety
of gram-negative and gram-positive bacteria, including
E. coli, Salmonella, Staphylococcus, Streptococcus and H. pylori.
Extracts, similarly, according to in vitro studies, appear to
have an impact on a number of viruses. For instance, bitter
melon constituents may prevent viral penetration of the cell
wall. Immune effects include support for healthy T-helper cell
ratios, natural killer cell populations and related mechanisms.
With current problems involving overweight and obesity,
some of the more attractive actions of bitter melon involve controlling
weight gain in the face of the consumption of excessive
calories. Animal studies have demonstrated that bitter melon
can reduce insulin resistance and visceral obesity caused by a
high-fat diet. Similarly, bitter melon may be protective against
many damaging results of high fructose diets, including diet-induced
hyperglycemia, hyperleptinemia, hyperinsulinemia, and
hypertriglyceridemia. The American Medical Association currently
is recommending that added sugars should not account
for more than five percent of the diet, yet added sugar, especially
fructose and “corn” sugars, are found everywhere in the
American food supply, although often hidden. Bitter melon may
offer some nutritional protection against these added sugars.
Traditional uses and preclinical research provide a very
positive picture of bitter melon. Human trials have confirmed
many of these findings. In clinical trials, the fresh fruit, its freshly
squeezed juice and the homogenized suspension of bitter
melon have led to significant reductions in both fasting and
postprandial blood glucose. The caveat is that the successful
trials in the literature as a rule have used almost exclusively
fresh preparations. For whatever reasons, dry extracts have
not fared well in clinical trials. Perhaps this is due to the fact
that dry extracts usually are concentrated for charantins even
though, according to some research, charantins, the saponins
commonly selected for “standardized” preparations, may be inactive
or only weakly active. Another possibility is that the most
active compounds in bitter melon rapidly deteriorate in most
dried powders and extracts.
If you like the taste of bitter melon, the success of freshly
prepared materials in clinical trials is great news because it
means that the vegetable may deliver not just a taste treat, but
also health benefits when consumed raw and cooked in salads,
soups, curries, egg and meat dishes, etc. There also remains
another option. Recent research suggests that a special form
of bitter melon, especially with proper handling, may deliver on
the promise of the fresh material even when dried and delivered
in capsules and tablets.
Sometimes Wild Is Better!
With many grains, fruits and vegetables, wild genotypes retain
healthful qualities that have been bred out of cultivated varieties.
For instance, Khorasan wheat (Kamut), a much older form
of wheat, provides more protein, minerals and more complex
carbohydrates with lower gluten levels than is true of modern
wheat. Similarly, carrots initially most often were purple rather
than orange because of the vastly greater amounts of phytonutrients
in the form of anthocyanidins. Lettuce was more bitter,
and so forth and so on.
With bitter melon, much the same is true. There are literally hundreds of different forms of bitter melon found in China and India. In many ways, the most interesting of these nutritionally are the “wild” forms found in India.
Recently, a comparative trial in animals looked specifically at
the differences among commercial herbal extracts of bitter
melon of Chinese, Indian and Indian wild genotype origin. The
goal was to establish benefits with regard to blood sugar and
insulin regulation and also parameters linked to blood pressure.
Very little work has been performed with wild genotypes
of bitter melon, even though there are a great many of these in
India alone. Most information available tends to cover topics
such as the effect of the wild forms on inflammatory responses.
Hints in the literature suggest that the blood sugar effects
of some of these wild genotypes could be more potent than
in the cultivars commonly used for extraction. For instance,
it has been found that extracts of bitter gourd activate cellular
machinery to regulate energy production (technically, Amp-activated
protein kinase) and the way that fats are handled by
the liver. These components can account for as much as 7.1 g/
kg of the dried wild material.
In a just published trial that did look at wild bitter melon,
over a period of 60 days the effect of an extract from the wild
genotype of bitter melon offered commercially under the name
Glycostat proved to be more efficacious than the varietals
typically used in Chinese and Indian preparations and certainly
more consistent in influencing all the health parameters
tested. Wild bitter melon was compared with
two commercially available Chinese and Indian preparations
in an animal model with a standard test called a Glucose Tolerance
Test (GTT). In this test, a fixed amount of glucose is
consumed and then the amount that accumulates in the blood
(Area Under the Curve/AUC) is measured and the change (delta)
is calculated. A smaller change is good because it means
that the body is rapidly taking the glucose into the tissues and
that there is good insulin sensitivity. All the bitter
melon extracts reduced the increase in blood sugar. However,
wild bitter melon was superior to both the Chinese and
Indian extracts and it was the only extract to deliver statistically
significant results. Of particular note, this greater benefit was
achieved without elevating insulin levels.
Other interesting findings included the wild extract’s significant
influence on the nitric oxide system (influencing whether
the blood vessels can dilate), a system that controls blood fluid
volume known as the renin-angiotensin system (RAS) and the
closely related angiotensin converting enzyme (ACE) activity.
These three systems and activities influence blood pressure
and cardiovascular health and in each of them, wild bitter melon
either was the only extract that exhibited significant activity
or it was more active compared to the Chinese and Indian
Bitter melon is yet another example of a traditional food and
health aid that has made good when tested against modern
Western standards. The benefits are real in areas such as blood
glucose and blood pressure support—with the caveat that until
now bitter melon needed to be eaten in large amounts or
the freshly prepared juice consumed regularly in order for the
benefits to be realized. Extracts and dried powders have been
less successful, perhaps because unstable or for other reasons.
A specially prepared wild bitter melon extract produced
with special processing appears to have solved this limitation.
Wild bitter melon extract supports both blood sugar and blood
pressure health, all without the bitter taste.