Ingredients
Alpha-lipoic acid (ALA) is a sulfur-containing
fatty acid that performs vitamin-like roles in the body. Also
known as "lipoic acid" or "thioctic acid," ALA functions, in a
similar way to B complex vitamins, as a co-enzyme in the
metabolism of carbohydrates that produces energy inside cells
for the body’s metabolic needs. ALA is required for synthesis of
"acetyl CoA," a key metabolite in the cellular process that
turns glucose (blood sugar) into energy. Because the body
produces ALA on its own, it is not classified as a true vitamin.
As with other so-called "non-essential" nutrients, however,
internal ALA production may not always be optimal. Alpha-lipoic
acid functions as both a water-soluble and fat-soluble
antioxidant. (Antioxidants neutralize free-radicals, normal
by-products of metabolism that, while necessary at normal
levels, may damage tissues over time if not properly kept in
check by antioxidants.) ALA’s ability to act upon free radicals
in both a watery and fatty environment makes it a highly
versatile antioxidant. In the body, alpha-lipoic acid can be
converted (reduced) to DHLA, or dihydrolipoic acid. Together,
these two forms of ALA make up a "redox couple," which means
that each form can chemically change into the other and back
again. DHLA also functions as an antioxidant.
How “Sustained
Release” Works
Using a highly sophisticated process involving
mixing and compression, a specialized form of cellulose is
combined with ALA, which results in substantial lengthening of
the time required by the stomach to digest and release the
nutrient into the small intestine. This enables the ALA to be
slowly absorbed by the system, thereby maintaining and optimal
concentration of effective antioxidant in the bloodstream
throughout the day.
How “about R-Lipoic” Acid ?
Alpha
Lipoic Acid occurs in two forms, designated "R" and "S". Studies
suggest that R-alpha lipoic acid, the natural form, is more
biologically active than the S form. Like ALA, RLA recycles
antioxidant nutrients, such as vitamin C and E, and helps
maintain healthy blood sugar levels when used as part of the
diet.
Understanding R-Lipoic Acid
Benefits
Supports
the Body’s Defense Against Free Radicals*
Recycles Antioxidant
Nutrients such as Vitamin C and Vitamin E*
Helps Maintain a
Healthy Blood Sugar Level when used as part of the
diet*
Alpha-lipoic Acid––the "Ideal Antioxidant"
The
antioxidant potential of a substance is based on a number of
criteria, including:
1) Ability to quench specific
free-radicals.
2) Ability to bind or "chelate" metal ions that
can generate free radicals.
3) Supports function of other
antioxidants.
4) Absorption/bioavailability.
5) Concentration
in tissues, cells and extra cellular fluids.
6) Ability to
function as an antioxidant in fatty and watery
environments.
The "ideal antioxidant" would meet all the
above criteria. Very few antioxidants do, yet a particular
antioxidant with but a few of the characteristics is still
valuable and effective. Vitamin E, for example, is one of the
most important dietary antioxidants, yet it only works in fatty
environments such as cell membranes.
As a team, ALA and DHLA
come close to the ideal, for the following reasons:1,2,3
1) ALA
is easily absorbed when consumed orally.
2) ALA is readily
converted to DHLA in various tissues.
3) As a pair, ALA and
DHLA neutralize superoxide, hydroxyl, peroxyl, and hypochlorus
radicals.
4) ALA and DHLA form stable complexes with metal
ions such as iron, manganese, copper and zinc ions.
5) ALA and
DHLA scavenge free radicals in fatty environments and watery
environments.
6) DHLA recycles other important
antioxidants.
DHLA-regenerates vitamin C, vitamin E and
glutathione
Within the cell, antioxidants work as a team to
keep free radicals from damaging cell structures. In order to
neutralize a free radical, an antioxidant such as vitamin C must
give up an electron, which mean it becomes oxidized. Before it
can function as an antioxidant once again, it must be
regenerated back to its "reduced" form, by gaining an electron
to replace the donated electron. For this, it needs the help of
other antioxidants. Vitamin C, vitamin E and glutathione are key
antioxidants that can be generated by cycling between their
oxidized and reduce forms. This is necessary to maintain the
balance between oxidation and its reverse––the neutralization of
free radicals by antioxidants.
DHLA is an essential
component in the interaction between these antioxidants.4
Studies show that addition of alpha-lipoic acid to liver tissues
results in increased vitamin C levels. It has been found that
DHLA is responsible for regenerating vitamin C, which in turn
regenerates vitamin E.3 DHLA also converts glutathione from its
oxidized form back into its free radical scavenging reduced
form.3,5 The ALA/DHLA pair is thus vital for prevention of
"oxidative stress," which occurs which the balance is tipped in
favor of oxidation in cells.4 DHLA helps preserve antioxidants
in both the watery cell interior and the fatty structure of cell
membranes.6 Evidence from animal studies suggests that DHLA
protects the brain against free radical damage.7
Alpha-lipoic
Acid and Blood Sugar
Alpha-lipoic acid is a key factor in the
cellular process that metabolizes glucose to produce energy for
cellular functions. The importance of ALA’s role in blood sugar
metabolism is evidenced in studies on ALA and type-2 diabetes.
In a small pilot study, 13 people with type-2 diabetes showed
improved utilization of glucose in muscle tissue in response to
intravenous administration of ALA.8 In a four week controlled
multicenter trial, 74 people with type-2 diabetes took ALA in
oral doses of 600, 1200 or 1800 mg per day. After 4 weeks, the
normal lowering of blood sugar levels in response to insulin
improved.9 In vitro studies have shown that ALA has a positive
effect on insulin-stimulated uptake of glucose by muscle
cells.10
Safety
Alpha-lipoic acid is considered safe, and
no adverse effects have been seen with long-term
supplementation.1
Scientific References
1. Packer, L.. Witt,
E., Tritschler, H. Alpha-lipoic acid as a biological
antioxidant. Free Radical Biology and Medicine
1995;19(2):227-50.
2. Suzuki, Y., et al. Thioctic acid and
dihydrolipoic acid are novel antioxidants which interact with
reactive oxygen species. Free Rad. Res. Comms. 15(5):255-63.
3. Biewenga, G., Haenen, G., Bast, A. The pharmacology of lipoic
acid. Gen. Pharmac. 29(3):315-31.
4. Serbinova, E. Maitra, I.,
Packer, L. The synergy between vitamin E and alpha-lipoic
acid--–possible relationship against oxidative stress in vivo.
Life Chemistry Reports 1994;12:17-21.
5. Bast, A. Haenen, G.
Interplay between lipoic acid and glutathione in the protection
against microsomal lipid peroxidation. Biochimica et Biophysica
Acta 1988; 963:558-561.
6. Kagan, V. et al. Dihydrolipoic
acid––a universal antioxidant both in the membrane and in the
aqueous phase. Reduction of peroxyl, ascorbyl and chromanoxyl
radicals. Biochem Pharmacol 1992;44(8):1637.
7. Prehn, J. et
al. Dihydrolipoate reduces neuronal injury after cerebral
ischemia. J Cereb Blood Flow Metab 1992;12(1):78-87.
8. Jacob,
S. et al. Enhancement of glucose disposal in patients with
type-2 diabetes by alpha-lipoic acid. Arzneimittelforschung
1995;45(8):872-4.
9. Jacob, S et al. Oral administration of
RAC-alpha-lipoic acid modulates insulin sensitivity in patients
with type-2 diabetes mellitus: a placebo-controlled pilot trial.
Free Radical Biology & Medicine 1999;27(3/4):309-14.
10.
Estrada, D. et al. Stimulation of glucose uptake by the natural
coenzyme alpha-lipoic acid/thioctic acid: participation of
elements of the insulin signaling pathway. Diabetes
1996;45(12):1798-804.
© 2002 Doctor's Best, Inc. Revised
5/21/03
*This statement has not been evaluated by the Food
and Drug Administration. This product is not intended to
diagnose, treat, cure or prevent any disease.
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