THE RIGHT VITAMIN E (THE "E" COMPLEX)
by W. H. Leong
Vitamin E supplementation used to be
a simple proposition. There is a very
good chance that your cardiologist is
supplementing his or her diet with vitamin
E. A recent survey commissioned by the
Council for Responsible Nutrition (CRN)
has concluded that 75 percent of cardiologists
recommend vitamin E to their patients
and about half of the cardiologists surveyed
said they personally use vitamin E.
Scientists identified vitamin E about 80
years ago but only in the past few decades has
its power as an antioxidant been revealed and
fully appreciated. Vitamin E is a generic term
describing a group of compounds called
tocopherols and tocotrienols. Until recently
most vitamin E products contained only
tocopherols (alpha-, beta-, gamma- and
delta-tocopherol). But this is changing
as researchers have identified unique
health properties of tocotrienols (alpha-,
beta-, gamma- and delta-tocotrienol).¹
Tocotrienols may be the most powerful of
the vitamin E antioxidants.²
Tocotrienols are fat-soluble vitamins
related to the family of tocopherols. The
term vitamin E is now considered to be the
generic name describing both the tocopherols
and tocotrienols. However, both are
distinguished by their side chain. While
tocopherol has a saturated phytyl tail,
tocotrienol possesses an unsaturated isoprenoid
side chain. Tocopherols and
tocotrienols are further separated into individual
compounds assigned by the Greek
letter prefixes (á, â, ä, å) depending on the
number and position of methyl substitution
(-CH3) on the chromanol ring.
In nature, plants, fruits and vegetables
produce both forms of vitamin E—
tocopherols and tocotrienols. While tocopherols
are generally present in common
vegetable oils (i.e. soy, canola, wheat germ,
sunflower), tocotrienols, on the other hand,
are concentrated in cereal grains (i.e. oat,
barley, and rye, rice bran), with the richest
source found in palm (Elaeis guineensis).
Several studies have shown that vitamin E
improves the immune system, especially in
the elderly. With age, the immune system
becomes less efficient at fighting off
microbes and viruses. Part of this decline
may be due to low levels of vitamin E in the
bloodstream. Some studies have shown
improved immune responses in older people
who take vitamin E supplements.³ Vitamin E
may also slow the effects of aging by protecting
cells from free radical damage.
In a randomized, double-blind, placebocontrolled
intervention study at Tufts
University and published in the Journal of the
American Medical Association, daily supplementation
with vitamin E enhances immunity
in healthy elderly subjects.4 The
antioxidant vitamin E inhibits prostaglandin
E2 production and significantly improves
certain clinically relevant in vivo indexes of
cell-mediated immune response.
Subjects supplemented with vitamin E
antioxidant at 200 mg/day had a 65 percent
increase in delayed-type hypersensitivity skin
response (DTH) and a significant increase in
the amount of antibody made in response to
hepatitis B and tetanus vaccine compared
with placebo.
COX-2 is normally kept in check until it is
needed to play its part specifically in the
inflammation process. Hence COX-2, if well
regulated, plays an important role because
inflammation is sometimes needed for the
body's immune response. However, in
people with chronic inflammation such as
rheumatoid arthritis, uncontrolled COX-2
catalyzes the synthesis of prostaglandin E2
(PGE2), which increases inflammation and its
associated diseases such as cancer and vascular heart disease.
Researchers from the University of
California, Berkeley found that gammatocopherol
was a better form of vitamin E in
inhibiting COX-2 compared to alphatocopherol.
In addition, the metabolite of
gamma-tocopherol and gamma-tocotrienol:
LLU-alpha was also found to be a potent inhibitor
of COX-2 enzyme.5 Tocotrienols, through their
ability to reduce the synthesis of an eicosanoid,
namely thromboxane B2 in the cyclo-oxygenase
pathway, may have anti-inflammatory
effect. Moreover, tocotrienols are speculated to inhibit the
transcriptional activation of cyclo-oxygenase
gene.6
Almost all vitamin E supplements contain
tocopherol (mainly the alpha-tocopherol
form) but not tocotrienols. It doesn't matter
whether you take natural or synthetic
vitamin E, the form used is almost always
tocopherol. There is nothing wrong with
alpha-tocopherol but if a person expects to
obtain optimal and maximum antioxidant
protection, s/he should take the full spectrum
vitamin E that consists of both the
tocopherols and tocotrienols as produced in
nature.
All these forms of vitamin E work synergistically
as a team to confer the maximum
antioxidant and immune protection. Some
other examples are mixed carotenoids instead
of single betacarotene alone, B complex
instead of a single B6 or B12 vitamin alone.
The idea that one single form of vitamin E—
alpha-tocopherol out of eight fractions is the
"magic" vitamin E, and assuming that the
other forms are worthless, denies the very
fact that nature put these seven other tocopherols
and tocotrienols out there for a
reason.
In light of this new development, scientists
have begun to relook at their approach towards
supplementation. The best approach is to mimic nature
as nature knows best.
Elderly people can bolster their resistance
to infection by taking daily vitamin E supplements.
To realize vitamin E's full health
benefits in enhancing the immune system,
one really needs both tocopherols and
tocotrienols—"The E Complex"—as the
most complete and balanced vitamin E formula.
Web sites: www.carotech.net and
www.tocotrienol.org
References:
- Theriault, A., et al., "Tocotrienol: A review of its therapeutic potential." Clinical Biochemistry (1999). Vol. 32 pp. 309–19.
- Serbinova, E., Kagan, V., Packer, L. et al. "Free radical recycling and intramembrane mobility in the antioxidant properties of a-tocopherol and atocotrienol." Free Radical Biology & Medicine (1991). Vol. 10 pp. 263–75.
- Meydani, S. N., et al. "Vitamin E Supplementation and In Vivo Immune Response in Healthy Elderly Subjects: A Randomized Controlled Trial." JAMA Vol. 277 pp. 1380–6.
- Ibid.
- Ames, B. N., et al. "Gamma-tocopherol and its major metabolites, in contract to alpha-tocopherol, inhibit cyclooxygenase activity in macrophages and epithelial cells." Proceeding of the National Academic of Science (2000). Vol. 97(21) pp. 11494–9.
- Theriault, op.cit.
|
