Alpha
Lipoic Acid
.
. . .Promotes healthy nerve function by preventing oxidative damage*
Features
& Benefits
-
Water and lipid-soluble
antioxidant*
-
Promotes normal nerve function*
-
Promotes healthy pancreatic
function*
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Helps maintain healthy eyes*
Facts About Alpha Lipoic Acid
Free Radicals: Alpha lipoic acid (ALA) is an antioxidant
co-enzyme found in foods and the body.1
It acts both as a water- and fat-soluble antioxidant, and therefore
benefiting different body tissues.*2
Part of how it accomplishes this task is by chelating metal ions,
such as copper, that tend to promote oxidation.1
Lipoic acid also regenerates other antioxidants, including vitamins
C and E 2,3 and coenzyme CoQ10.*4 It accomplishes this by donating
electrons to replace those given up by other antioxidants during
free-radical scavenging activity.2
Nerves: Protection of
neurons (nerve cells) appears to be a major role of lipoic acid.*
In humans, amounts of 400-800 mg of ALA daily have been shown to
promote healthy nerve function.*5,6 The
first study (known by its German initials DEKAN) involved 39 people given
800 mg lipoic acid orally and 34 people given placebo for four months.5
The people taking lipoic acid showed a significant improvement in heart
rate variability, an objective measure of the autonomic nerves serving the
heart. This improvement was significant compared to the control group.
There were no notable changes in adverse symptoms between the two groups.
Oral doses under 600 mg daily have not been effective for
nerve health in several studies.6
Eyes: Lipoic acid may
also help maintain normal pressure of the fluid in the eye, according to
one human study.*7 A group of 19 people given 150 mg of lipoic acid orally
for one month were shown to have a significant improvement in visual
function compared to a control group treated with placebo.7 A dose of 75
mg daily was not effective in this study. Oxidation within the lens of the
eye may contribute to declining clarity of vision with age.
Lipoic acid has been shown to protect animal lenses from such
damage.*8 Human studies have not yet been performed confirming this
benefit.
Glucose: Lipoic acid inhibits the enzyme aldose reductase.9 This enzyme produces sugars that can damage the lens and
nerves, particularly in patients with diabetes mellitus. The ability of lipoic acid to limit aldose reductase activity
may prove to offer protection for good eye health.* Lipoic acid promotes
normal insulin sensitivity and glucose metabolism in the body.*2,10
Actual insulin and glucose levels in the blood may not change while
taking lipoic acid.
Energy: Preliminary
evidence suggests lipoic acid promotes energy formation in the body.*11
Lipoic acid is a necessary cofactor in the enzyme complex central to the
function of the citric acid cycle.* This cycle starts the process of
energy production; one study suggests that oral lipoic acid therapy could
improve energy formation by improving function of the mitochondria.*11
Further studies are necessary to validate and determine the importance of
this possible lipoic acid benefit.
Safety and Toxicity
At a level of intake of 200-800 mg daily, no significant adverse
effects have been reported. Thiamin
deficiency may be aggravated by lipoic acid, so anyone at risk of this
condition (particularly alcoholics) should supplement the two nutrients
together. Diabetic patients
should only take lipoic acid above 200 mg daily if under the supervision
of a nutritionally-oriented practitioner to prevent possible episodes of
hypoglycemia.*2 There is no information regarding safety in pregnancy or
lactation.
Ingredient
Highlights
Lipoic
acid was first isolated from potatoes.
It is also found in other foods including animal products. It is well absorbed when taken orally.
References
-
Ou
P, Tritschler HJ, Wolff SP. Thioctic (lipoic) acid: A therapeutic
metal-chelating antioxidant? Biochem
Pharmacol 1995;50:123-6.
-
Nichols
TW Jr. Alpha-lipoic acid: Biological effects and clinical
implications. Alt Med Review
1997;2(3):177-82 [review].
-
Kagan
VE, Serbinova EA, Forte T, et al. Recycling of vitamin E in human low
density lipoproteins. J Lipid
Res 1992;33:385-97.
-
Kagan
V, Serbinova E, and Packer L. Antioxidant effects of ubiquinones in
microsomes and mitochondria are mediated by tocopherol recycling. Biochem
Biophys Res Comm 1990;169:851-7.
-
Ziegler
D, Schatz H, Conrad F, et al. Effects of treatment with the
antioxidant alpha-lipoic acid on cardiac autonomic neuropathy in NIDDM
patients. Diabetes Care
1997;20:369-73.
-
Ziegler
D, Gries FA. Alpha-lipoic acid in the treatment of diabetic peripheral
and cardiac autonomic neuropathy. Diabetes 1997;46(suppl 2):S62-6 [review].
-
Filina
AA, Davydova NG, Endrihovskii SN, et al. Lipoic acid as a
means of metabolic therapy of open-angle glaucoma. Vestnik
Oftalmol 1995;111:6-8 [in Russian].
-
Maitra
I, Serbinova E, Tritschler H, Packer L. Alpha-lipoic acid prevents
buthionine sulfoximine-induced cataract formation in
newborn rats. Free Rad Biol Med 1995;18:823-9.
-
Ou
P, Nourooz-Zadeh J, Tritschler HJ, Wolff SP. Activation of aldose
reductase in rat lens and metal-ion chelation by aldose reductase
inhibitors and lipoic acid. Free Rad Res 1996;25:337-46.
-
Jacob
S, Henriksen EJ, Schiemann AL, et al. Enhancement of glucose disposal
in patients with type 2 diabetes by alpha-lipoic acid. Arzneim
Forsch 1995;45:872-4.
-
Barbiroli
B, et al. Lipoic (thioctic) acid increases brain energy availability
and skeletal muscle performance as shown by in vivo 31P-MRS in a
patient with mitochondrial cytopathy. J
Neurol 1995;242:472-7.
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