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According to the most recent statistics from the American Heart Association,
105 million Americans have an average total blood cholesterol of 200 mg/dL
or less, a classification considered desirable until recently. In July
2004, new recommendations for intensive lipid (or fat) modifying treatment
for highrisk patients were endorsed by the National Heart, Lung, and Blood
Institute, the American College of Cardiology, and the American Heart
Association. These recommendations update the 2001 National Cholesterol
Education Program’s (NCEP) Adult Treatment Panel III (ATP III) report,
setting lower treatment goals for LDL cholesterol, as well as supporting
the use of lipid-lowering treatment and lifestyle modifications including
nutrition, physical activity, and weight control. Although an LDL cholesterol
of less than 100 mg/dL is still considered an optimal goal, these updated
recommendations advocate 70 mg/dL for individuals considered to be at
very high risk.
Since dietary and exercise modifications are often unable to achieve these
reductions, many patients increasingly turn to drug therapy. The use of
statins (a class of fat-lowering drugs that inhibit HMGCoA, a key enzyme
in cholesterol synthesis) has risen dramatically. While statins can be
effective in significantly reducing cholesterol, concern over potential
side effects, such as exercise intolerance, muscle weakness, and pain,
has been growing. As a result, finding natural, scientifically supported
products that are effective, and without significant side effects, is
always welcome.
The
natural products receiving increased attention in the dietary supplement
marketplace for effectively targeting heart health are plant sterols,
polymethoxylated flavones, tocotrienols, and pomegranate.
PHYTOSTEROLS
For over 50 years, plant sterols (or phytosterols) and their esters have
been studied for their effects on blood cholesterol in humans. Extensive
clinical data on animals and humans indicate that these naturally occurring,
fat-soluble compounds can play important roles in maintaining healthy
cholesterol levels. Chemically similar to cholesterol in structure, plant
sterols cannot be manufactured in the body and must be obtained from diet.
And the typical Western diet does not supply enough sterols or stanols,
which are found in vegetables, fruits, legumes, grains, and oils, to result
in significant alterations in blood lipids.
Cholesterol, however, can be derived from the diet or synthesized in the
liver itself, playing numerous critical roles in the body, from hormone
synthesis to maintaining proper cell function. Plant sterols appear to
block cholesterol from reaching the blood steam. Due to the aforementioned
similarity in molecular structure to cholesterol, phytosterols coat the
gastrointestinal tract, preventing cholesterol from being absorbed into
the blood. Plant sterols may also lower cholesterol by interfering with
the liver’s ability to synthesize cholesterol.
RESULTS
OF PHYTOSTEROL CONSUMPTION
Clinical studies have demonstrated that supplemental phytosterols can
lower total cholesterol an average of 6 to 10 percent, and LDL cholesterol
8 to 15 percent. Studies also show that using supplemental phytosterols,
in combination with statins, may further reduce blood cholesterol. For
example, the combined use of statins and phytosterols lowered blood cholesterol
by 39 percent, with sterols contributing 7 percent of the overall reduction.
Importantly, phytosterols do not appear to significantly decrease HDL
cholesterol.
Phytosterols achieved GRAS (Generally Recognized as Safe, an FDA approval
rating applied to food and nutrients) status in the late 1990s, thus confirming
their safety. In 2000, the FDA approved the use of claims that foods containing
plant sterols and stanols reduce risk of cardiovascular disease. Recently,
the FDA has extended these health claims to include a wider variety of
foods including dietary supplements. The result: an increase in the number
of dietary supplements that now contain phytosterols.
POLYMETHOXYLATED
FLAVONES
Flavonoids are a large class of plant chemicals that have powerful antioxidant
properties and play important roles supporting both circulatory and immune
health. While the benefits of flavonoids have been known for years, a
specific class called polymethoxylated flavones (PMFs) are receiving attention
for their cholesterol-lowering abilities in both animal and human studies.
Typical PMFs are compounds found in concentrated amounts in the peel of
citrus fruits, including oranges and tangerines. These studies demonstrated
that PMFs possess potent cholesterol-lowering properties. In a recent
study, hamsters fed a high-cholesterol diet, adding one percent of PMFs,
significantly reduced total cholesterol levels 27 percent, LDL cholesterol
by 40 percent, and triglycerides by 44 percent. There appears to be at
least two actions by which PMFs can function to lower cholesterol: by
reducing liver production of LDL and triglycerides.
TOCOTRIENOLS
Tocotrienols comprise one-half of the vitamin E family, which include
the better-known tocopherols, found in foods like rice or palm oil. Like
tocopherols, tocotrienols function as antioxidants, but are thought to
be more potent than tocopherols. In addition, tocotrienols have demonstrated
an ability to inhibit an enzyme required for cholesterol production in
the liver, thus reducing cholesterol levels. Studies showed that subjects
with carotid atherosclerosis who consumed tocotrienols for two years had
a reduction in the amount of cholesterol-laden atherosclerotic plaque
compared with those who received a placebo.
PMFS + TOCOTRIENOLS
= SYTRINOL™
Three human clinical studies investigating the effect of a new patented
blend of PMFs and tocotrienols called Sytrinol™ on cholesterol levels
have yielded impressive results. In the first study, 10 people having
an average total cholesterol greater than 230 mg/dl, LDL cholesterol greater
than 155 mg/dl, and total triglycerides of between 100 and 307 mg/dl received
300 mg of Sytrinol for four weeks. Total cholesterol decreased by 24 percent,
LDL cholesterol decreased by 19 percent, and triglycerides dropped by
24 percent. These results were confirmed in a second study also involving
10 high-cholesterol people in whom similar reductions in cholesterol levels
were observed. Given the success of the first two studies, a larger, more
controlled study involving 120 high-cholesterol people was initiated.
In the first 12 weeks, people received either 300 mg/day of Sytrinol or
a placebo for 12 weeks. In the next four weeks, everyone stopped taking
Sytrinol or placebo. Then people switched groups, so that those that received
the placebo in the beginning then received the Sytrinol. After 12 weeks,
those receiving Sytrinol experienced 27 percent reductions in total cholesterol,
25 percent reductions in LDL cholesterol, and 30 percent reductions in
triglycerides. No significant changes were reported in the placebo group.
HDL cholesterol did not increase or decrease. Sytrinol did not cause any
side effects or toxicity. These results may be attributable to the unique
combination of Sytrinol’s mechanisms to inhibit triglyceride synthesis,
and cholesterol production in the liver.
POMEGRANATE
Aside from its delicious taste, pomegranates contain a wide array of beneficial
polyphenolic compounds. Supplementation with pomegranate juice in animal
studies showed a reduction of cholesterol and atherosclerosis. A 2004
human study out of Israel showed that after one year of pomegranate juice
consumption, subjects with severe atherosclerosis experienced up to a
30 percent reduction in blood-vessel thickness indicating a reduction
in atherosclerosis, compared with a nine percent increase in blood vessel
thickness in the placebo group, indicating an increase in atherosclerosis.
There was also an increase in the beneficial enzyme shown to be connected
with lower risk of cardiovascular disease and diabetes. While the mechanisms
of action and specific compounds responsible for them are not well understood,
the combination of potent antioxidants present in pomegranates may in
part be responsible for health benefits.
For those looking for alternatives to statin drugs, natural products that help to lower cholesterol and help maintain cardiovascular health are quickly becoming a reality. Coupled with other nutrients well-known for their cardioprotective properties, such as CoQ10, B vitamins, and omega-3 fatty acids; pomegranate, polymethoxylated flavones, and plant sterols offer strong new weapons to help maintain optimal heart health.
ABOUT
THE AUTHOR
Article submitted by Douglas Laboratories with editorial contributions
by Natalie Shamitko, Assistant Editor and Technical Specialist at Douglas
Laboratories, and Andrew Halpner, Ph.D. (Nutrition), Editor in Chief and
Director of Product Development and Technical Services for Douglas Laboratories.
