There are many dietary supplement strategies that
can be used to support and promote your weight
loss efforts in the gym and while you're dieting.
Some of these strategies are old, and some are
more recent; but rarely can you find a dietary
supplement ingredient that approaches the issue of weight
loss from an entirely new angle. Consequently, it's been very
interesting for me to research and write about blueberry leaf
extract.
Glucose And Fat Storage
To understand the contribution that Blueberry leaf can make
to weight loss, we must first discuss the role of glucose
(blood sugar) in relation to weight gain. First of all, glucose
is obtained from sugars and other carbohydrates in our diet.
All carbohydrates (except for fiber) are generally converted
into glucose in our livers.1 The glucose is then used as a fuel
in energy metabolism to help power our bodies. But what
happens if our energy needs are already met; what does our
body do with the glucose? Basically, a healthy body has two
choices: it can convert a limited amount of it into glycogen
(muscle sugar), and it can convert unlimited amounts of it
into body fat which can be stored for an extended period of
time.2 As a matter of fact, a small protein in liver cells is largely
dedicated to helping convert excess dietary carbohydrates
into fat stores.3
So, besides the obvious avoidance of excessive carbohydrates
and sugar-laden foods, what can be done to inhibit this
process of converting carbs into fat? There are three
strategies, which can be used:
- Reduce glucose absorption from the diet,
- Reduce glucose synthesis in the liver,
- Accelerate glucose metabolism.
Ideally, the most effective strategy would be to achieve all
three at the same time.
Chlorogenic and Hydroxycinnamic Acids
Recent research has identified two unique natural
compounds that appear to do just that. The two compounds
are: chlorogenic and hydroxycinnamic acids. New studies
suggest that taken together these two unique compounds:
- May help to reduce dietary glucose absorption in the intestines,
- Help reduce glucose synthesis in the liver, and
- Speed up the metabolism of glucose—simultaneously.
Here's how it works: The enzyme glucose-6-phosphatase
(G6P) plays a major role in the formation of glucose in our
body. Chlorogenic acid was recently discovered to specifically
inhibit the activity of this key enzyme. Inhibition of G6P
activity in the liver results in a reduction of liver glucose
production—which in turn may help reduce high rates of
glucose output by the liver.4,5
In fact, both chlorogenic acid and hydroxycinnamic acid
(aka, caffeic acid) are involved in the glucose reduction in
our body. Research of Dr. Welsch and his colleges at Rutgers
University reveals that glucose absorption in the intestines
was reduced to 80 percent in the presence of chlorogenic
acid and 30–40 percent in the presence of caffeic acid.
These results suggest that both chlorogenic and caffeic acids are involved in the regulation of glucose level
including the unique ability to inhibit dietary glucose
absorption in intestines.6 Other recent research also
indicates that the presence of caffeic acid accelerated
the metabolism of glucose, which can reduce the total
glucose concentration in circulating blood.7 Results of
other studies provide further evidence that caffeic acid
is involved in the reduction of blood glucose in diabetic
animals.8
Pharmaceutical companies also actively interested in
this important area of research have already synthesized
several synthetic analogs of chlorogenic acid. These
compounds are potent inhibitors of the glucose-6-
phosphatase activity in the human liver.9 Other evidence
has also confirmed that chlorogenic acid derivatives
reduce blood glucose in animals, which also confirms
the blood glucose lowering properties of chlorogenic
acid.10,11
Therefore, it is strongly suggested from all the above that
the effectiveness of chlorogenic and caffeic in glucose
reduction will depend on whether these compounds are
taken simultaneously and in sufficient amounts.
Blueberry Leaves
So, what does all this have to do with Blueberry leaves?
Surprisingly enough, concentrations of chlorogenic
and caffeic acids have recently been discovered in the
Blueberry leaves (Vaccinium arctostaphylos L) found
in the Caucasian Mountains of the northern region in
the Republic of Georgia (in the previous Soviet Union).
Interestingly, Caucasians have been using medicinal
teas infused with leaves of the blueberry for the self-treatment
of diabetes for literally centuries. In light of
the previous information about chlorogenic and caffeic
acids and their effect on blood glucose levels, this folk
use of Blueberry leaves for diabetes makes sense.
Caucasian blueberry has a legendary reputation as
aid to diabetics. Decoctions and infusions of the leaves
are used in folk medicine as hypoglycemic agents and
are usual major component of "anti-diabetes teas." Even
more impressive, in Russia, a standardized blueberry leaf
extract, known as "Diabetic Chai Cherniki" was effectively
used for the treatment of diabetes, gastric colitis and high
cholesterol, and has been repeatedly shown to contain
pharmaceutically significant levels of both chlorogenic and
caffeic acids.12
Now back to the concept of using Blueberry leaves
extract as a strategy for weight loss. The logic is fairly
simple: if you can reduce the amount of glucose that
is absorbed, reduce the amount that is manufactured
in the liver, and increase the rate at which glucose is
metabolized, the result is that you'll likely be able
to reduce the conversion of glucose into body fat. Of
course, this does not mean that Blueberry leaves extract
is a license to eat as much sugary and carbohydrate-rich
foods as you'd like, but rather that if you're making
an effort to eat a healthy, balanced diet, that Blueberry
leaves extract can help prevent the carbohydrates that
you are consuming into being converted to body fat. A
good dose of blueberry extract is 200 mg.
References:
- Whitney E, Cataldo C, Rolfes S. Understanding Normal and Clinical Nutrition, Fifth Edition (1998) West/Wadsworth, Belmont, California. pp. 114.
- Whitney E, Cataldo C, Rolfes S. Understanding Normal and Clinical Nutrition, Fifth Edition (1998) West/Wadsworth, Belmont, California. pp. 116–8.
- Yamashita H, et al. Proceedings of the National Academy of Sciences USA 2001;98:9116.
- Arion WJ, et al. Arch Biochem Biophys (1997) 15; 339(2):315–22.
- Hemmele H, et al. J Med Chem (1997) 17; 40(2):137–45.
- Welsch, et al. J Nutr (1989) 119(11):1698–704.
- Cheng JT, Liu IM. Naunyn Schmiedebergs Arch Pharmacol (2000) 362 (2):122–7.
- Hsu FL, Chen YC, Cheng JT. Planta Med (2000) 66(3): 228–30.
- Simon, et al. Arch Biochem Biophys (2000) 15; 373(2):410–28.
- Herling, et al. Eur J Pharmacol (1999) 386(1):75–82.
- Mshavanadze VV. Bulletin of the Georgian Academy of Science (1971a) 62:189–92.
- Mshavanadze VV. Bulletin of the Georgian Academy of Science (1971b) 62:446–7.
