Atherosclerosis and its complications...heart attack
and stroke...are the major causes of death in the United States and have
reached epidemic proportions throughout the western world. This
degenerative condition of the arteries is characterized by accumulation
of lipids (mainly cholesterol) within the artery. Although any artery
may be affected, the aorta, coronary and cerebral vascular system are
most frequently involved.(2)
A number of dietary and lifestyle factors have been
associated with increased risk for atherosclerosis. Three commonly sited
risk factors may be modified with supplements of tocotrienols, a
recently researched form of vitamin E.(1)
Double-Blind Trial Shows Cholesterol Reduction in 75%
of Patients Given Tocotrienol Supplements
Numerous studies have indicated that lowering LDL and
total cholesterol levels decreases the risk of death from heart disease.
Elevated cholesterol, specifically LDL (low density lipoprotein), is a
clearly defined risk factor for the development of atherosclerosis. More
specifically, oxidized LDL cholesterol is clearly implicated as the
primary culprit. While vitamin E in the tocopherol form has been
associated with reduced risk of heart attack, it has shown no
significant effect on cholesterol levels.
In contrast, the tocotrienols have demonstrated
significant cholesterol-lowering effects in both animals and humans. In
clinical trials, approximately 75% of patients with high cholesterol
levels respond to the cholesterol-lowering effects of tocotrienols.
Researchers believe that, in those who do not respond, elevated
cholesterol levels are likely to be due to errors in cholesterol
transport or degradation.(1,4)
The most dramatic cholesterol reduction is seen when
tocotrienol supplements are combined with dietary changes (high fiber,
low fat diet). In a 12-week, double-blind trial, those who responded to
tocotrienol treatment, saw reductions of approximately 23% in total
cholesterol and 32% in LDL using dietary modification plus tocotrienol
supplements. Tocotrienols alone yielded a 16% decrease in total
cholesterol and a 21% decrease in LDL.(1,4)
In an 18-month study of 50 patients with
cerebrovascular disease, the authors reported apparent regression of the
disease in 7 patients in the tocotrienol group as demonstrated by
ultrasonography. The disease progressed in only 2 of the 25 tocotrienol
patients. None of the placebo group showed regression and 10 showed
progression.(1,5)
Dietary changes alone can reduce both cholesterol and
the incidence of atherosclerosis; however, the degree of reduction is
proportional to the degree of dietary change. Due to the difficulty of
changing eating habits, dietary changes alone are inadequate for most
people.
Tocotrienols vs. Cholesterol Drugs
HMG-CoA reductase is the rate-limiting enzyme
involved in cholesterol production. It exerts its action at the
corresponding receptor site. Tocotrienols appear to increase the natural
rate of HMG-CoA reductase degradation, which in turn decreases
cholesterol production. A 50% decrease in reductase can be seen within
two hours. No adverse side effects have been associated with
tocotrienols.(1,4)
The "statin" drugs and over-the-counter
yeast extracts decrease cholesterol production by competitive blocking
of the receptor sites. When receptor sites are blocked, the body
responds by producing more of the enzyme. This adaptive response
triggers a 200-fold increase in reductase levels within a few hours.
Significant adverse side effects may be associated with these
medications.(1)
Tocotrienols’ Unsaturated Side Chain Provides Higher
Antioxidant Activity than Tocopherols
Vitamin E as d-alpha-tocopherol, the form commonly
found in supplements, protects LDL from oxidation. In a study of more
than 1,000 people, vitamin E reduced the risk of nonfatal heart attack
by 77%. This protective effect is attributed primarily to its
antioxidant properties.(6) Non-esterified vitamin E has
higher antioxidant activity than esterified forms (tocopheryl acetate,
succinate, etc.)
There are eight different forms of vitamin E. The
four tocopherols (alpha-, beta-, gamma- and delta-tocopherol) share a
saturated phytyl side chain. The four analogous tocotrienols have a
triple-unsaturated side chain.
The unsaturated bonds on the side chain give the
tocotrienols greater antioxidant activity and a different biologic
action. When those bonds become saturated, the molecule becomes a
tocopherol. Reports from laboratory studies indicate a 40-60 times
higher antioxidant activity against lipid peroxidation in rat liver
microsmal membranes with d-alpha-tocotrienol than with d-alpha-tocopherol
and 6.5 times more protection of cytochrome P-450 against oxidative
damage.(1) Cytochrome P-450 is present in most tissues and
serves as an oxygenating catalyst in a variety of reactions.
Alpha-tocopherol is most often used in supplements
and is the standard for measurement of vitamin E. Tocopherols are the
dominant form of vitamin E in corn (86%) and wheat germ (72%). Rice
bran, on the other hand, contains 66% of its vitamin E as tocotrienols.(1)
Natural Anti-Thrombin Properties
Abnormal coagulation of platelets is also an
important factor in the development of atherosclerosis. When platelets
aggregate they release compounds that cause migration and proliferation
of smooth muscle cells into the innermost layer of the artery.(2)
Aspirin has been recommended to atherosclerosis patients because of its
ability to inhibit production of thromboxane A2, a potent
factor in coagulation and clot formation. However, aspirin is associated
with a number of negative side effects including gastrointestinal
bleeding and it has not been shown to positively influence any of the
other risk factors for atherosclerosis.
Both tocopherols and tocotrienols, as well as other
natural substances such as sesame seed oil, inhibit platelet aggregation
without the negative side effects associated with aspirin. Vitamin E
provides antioxidant protection and tocotrienols may lower cholesterol
as well.
As anti-thrombic agents tocotrienols have been shown
to decrease platelet aggregation by 15% to 30%. Thromboxane A2
is difficult to measure because of its extremely short half-life. Its
metabolite, thromboxane B2, is generally accepted as an
indicator of thromboxane A2 production. Tocotrienols are
reported to cause a 31% decrease in thromboxane B2.(1,4)
Multiple studies report a significant relationship
between tocotrienols and cancer. In laboratory studies, tocotrienols
significantly inhibited the growth of cancer in cultures. Although it
has not been shown to cure or kill cancer cells, it may halt or slow the
progression of cancer.(1,3)
Symptoms of Atherosclerosis
Atherosclerosis is usually associated with high blood
pressure, weak pulse and wide pulse pressure. Symptoms, depending upon
the arteries involved and degree of obstruction, may include angina, leg
cramps, gradual mental deterioration, weakness or dizziness...or there
may be no symptoms.(2) For many a heart attack or stroke is
the first symptom...or at least the first symptom they notice. Symptoms
may appear so gradually that they go unnoticed or they may be attributed
to the normal aging process.
1. Wilkinson, R., Tocotrienols and the Modification of Coronary Heart
Disease Risk Factors, Yakim WA.
2. Murray, M and Pizzorno, J, Encyclopedia of Natural Medicine,
Prima Publishing, Rocklin, CA, 1991.
3. Wilkinson, R., Recently-Available Tocotrienol Form of Vitamin E,
Nutrition & Healing, January 1998.
4. Qureshi, A, Qureshi, N, "Tocotrienols: Novel
Hypocholesterolemic Agents with Antioxidant Properties", In: Vitamin
E in Health and Disease; 247-67, Marcel Dekker: New York, 1993.
5. Tomeo, A, Geller, M, et al, "Antioxidant effects of
tocotrienols in patients with hyperlipidemia and carotid stenosis",
Lipids; 30:1179-83, 1995.
6. Stephens, N, Parsons, A, Schofield, P, Kelly, F, Cheeseman, K,
Mitchinson, M, "Randomized controlled trial of vitamin E in
patients with coronary disease: Cambridge Heart Antioxidant Study
(CHAOS)", Lancet; 347(9004):781-786, 1996.
