Alpha-lipoic acid (ALA; also known as ‘thioctic acid’) is a substance made by cells of many kinds — bacterial, plant, and
animal. There are two forms of ALA: R-ALA and S-ALA — the R-form is the one found in nature; the S-form results from synthetic
production of ALA in which both forms are made in equal amounts. Supplements are available containing either the R-form alone
or a 50:50 mixture of R- and S-.
ALA’s role in the body
ALA serves as a cofactor in several biochemical processes in the body, including the process by which energy is extracted
from carbohydrates (sugars).
ALA is also an antioxidant that neutralizes several kinds of oxygen radicals and related reactive molecules, including hydroxyl,
peroxyl and superoxide radicals, singlet oxygen, hydrogen peroxide, hypochlorous acid, peroxynitrite, and nitric oxide. Several
of the body’s other antioxidants can be regenerated by ALA: vitamins C and E and glutathione. These antioxidant properties make ALA nature’s most powerful defense against the ravages of ‘reactive oxygen species’ (ROS).
Many good review articles about ALA are available, but most of them are under the control of unscrupulous scientific journals
which charge outrageous fees to read them. Of the reviews freely accessible on the Internet, we recommend the Wikipedia article, the review on ALA and cardiovascular disease by Wollin and Jones, the review on ALA and exercise by Sen and Packer, all of which are somewhat technical but contain many passages useful and interesting to non-technical readers. The review
on ALA and peripheral neuropathy by Head and the excellent review by Kidd on neurodegeneration, dementia, and aging are considerably less technical.
What we can’t tell you
In the U.S. and some other industrialized countries, government agencies like the U.S. Food and Drug Administration
have adopted censorship as a method for intensifying their control over the supplement industry and its customers.
Thus, FDA regulations prohibit us from telling you that any of our products are effective as medical treatments,
even if they are, in fact, effective.
Accordingly, we will limit our discussion of Alpha-Lipoic Acid to a brief summary of relevant research,
and let you draw your own conclusions about what medical conditions it may be effective in treating.
ALA has been of great interest to medical biologists since it was discovered in the 1950s. Nearly 2500 scientific articles
that deal in some way with this substance have appeared since then, and numerous clinical trials have been conducted to test
its effects on various medical conditions. As a result of this attention, the list of conditions for which ALA has been successfully
applied is a long one, and includes:
- Insulin resistance
- Metabolic syndrome
- Diabetic neuropathy
- Diabetic retinopathy
- Peripheral neuropathy
- DNA damage
- Neurological disorders: memory, learning, dementia, Alzheimer’s, Parkinson’s, Huntington’s, ALS
- Burning mouth syndrome
- Cardiovascular disease
- Vascular flexibility and function
- Multiple sclerosis
- Chronic fatigue syndrome
- Copper toxicity
- Lead toxicity
- Iron depletion
- Altered taste perception
- Pigmentation, skin bleaching
- Cell signalling
- Down’s Syndrome
Let us look at several of these applications in a bit more detail.
Aging may be slowed by ALA
Evidence that ALA interferes with the aging process comes from lab experiments of several kinds:
- ALA decreases intracellular build-up of lipofuscin (a granular debris that is considered to be a fundamental cause or symptom
- It prevents oxidative damage to cells’ mitochondria (energy extractors) and other structures.
- ALA improves brain function in aging rats by improving the levels of neurotransmitters.
- ALA extends the lifespan in roundworms (a favorite test animal for aging research).
- It restores vascular function in aged rats to conditions usually seen in younger animals.
Neuropathy and retinopathy reduction by ALA
Many studies have been conducted to test ALA on diabetes-related neurological conditions, such as neuropathy and retinopathy. These studies have utilized tissue culture, lab animals, and humans. Many of the older clinical studies used intravenous injections of ALA solutions; while these experiments have generally shown
significant benefits, they are essentially useless as clinical trials since daily intravenous treatments are impractical in
most cases. The research money would have been better spent on studying oral ALA treatments.
Fortunately, more recent studies have tended to use orally dosed ALA — and have also shown significant benefits.
- Oral treatment for 4-7 months tends to reduce neuropathic deficits.
- Oral treatment with ALA improved neuropathic symptoms and deficits in a study of 181 diabetic patients who received once-daily
oral doses of 600 mg, 1,200 mg, or 1,800 mg of ALA or placebo for 5 weeks.
ALA for other neurological disorders
Dysregulation of energy production, and inadequate suppression of free radical damage (‘oxidative stress’), have been implicated
as promoters of conditions such as Alzheimer’s, Parkinson’s, Huntington’s, cognitive aging, and various other neurological and neuromuscular diseases. Experiments in tissue culture, lab animals, and in humans have provided evidence that ALA can counteract the promoters of
these ailments and reverse their symptoms:
- In mice with a genetic predisposition to develop extreme Alzheimer’s symptoms, treatment with ALA reversed oxidative stress
and improved cognition.
- ALA and its derivatives “improve the age-associated decline of memory”.
- ALA produced significant increases in survival in transgenic mouse models of Huntington’s Disease.
- ALA protects brain tissue from lipid peroxidation — a process that contributes to neuron destruction in Alzheimer's disease.
- In mice with ALS (amyotrophic lateral sclerosis), “administration of lipoic acid in the diet produced a significant improvement
ALA for cardiovascular conditions
Oxidative stress is increasingly implicated as a major causative factor in atherosclerosis. It triggers inflammatory events
that generate peroxides, superperoxides and hydroxyl radicals within the endothelial tissue of blood vessels. These processes
damage the vasculature. ALA has been shown to improve endothelial function in the heart arteries of old rats, and to “possess a lipid lowering effect… ”and it “reduced the athero-lesion formation in rabbits fed a high cholesterol diet.”
Oxidative stress is also highly correlated to hypertension (high blood pressure). In experiments with mice, “the development
of hypertension could be either totally prevented or markedly attenuated by chronic treatment with potent antioxidative therapies
such as alpha lipoic acid.”
Use with biotin
Since ALA competes with vitamin B7 (biotin) for access to certain enzymes and molecular transporters, it would be sensible
to take a biotin supplement if one is supplementing with ALA. A dose of a few milligrams of biotin per day should be adequate. The biotin should be taken at a different time than the
ALA supplement, since they compete for absorption.
Are Alpha-Lipoic Acid supplements useful for the conditions and purposes mentioned above?
We aren’t allowed to tell you, so you should take a look at some of the references cited here,
and then decide for yourself.