If you're taking a conventional lipoic acid pill, then you need to know that the health-promoting, anti-aging benefits associated with this nutrient are only being delivered by half of your supplement. The other half is worse than useless: it actually antagonizes the effects of the good half of the supplement. To put it bluntly: the lipoic acid you're taking harbors both a hero ... and an "evil twin." Many molecules used by the body have a specific "handedness" (chirality). For example, alpha-tocopherol, or essential fatty acids. In some cases, synthetic versions of these molecules have a different "handedness" than the natural molecule.
You're probably familiar with some examples of this phenomenon, such as natural d- vs. synthetic dl-alpha-tocopherolor natural cis- vs. unnatural trans-fatty acids. Some of these artificial molecules are merely less potent than the natural forms, such as in the case of dl-alpha-tocopherol. But others are actually harmful - for example, trans-fatty acids.
Unless they specify otherwise, "lipoic acid" supplements are a 50/50 mixture of the natural R (+) lipoic acid, and the synthetic S (-) lipoic acid. These mixtures are called "racemates." In some cases, S (-) lipoic acid - or the racemate - is simply less effective than R (+) lipoic acid. But in other cases, the S (-) form actually acts in opposition to the activity of R (+) lipoic acid.
Insulin resistance, in which the cells of the body stop responding properly to the hormone insulin, happens to some degree in almost all of us as we age. Insulin resistance causes higher levels of insulin, blood sugar, and free fatty acids, all of which are threats to your health.
- Lipoic acid has been used to support healthy blood sugar metabolism. Scientists have compared the effects of the two "lipoic acid" molecules seperately.
- R (+) lipoic acid has emerged as the active ingredient in the racemate. R (+) lipoic acid fights all of the major effects of insulin resistance. The S(-)-form does not help in some of these areas, and even makes things worse in others.
Lipoic acid is known as a powerful and versatile antioxidant.
- R (+) lipoic acid is more easily absorbed and taken into the cells than S (-) lipoic acid.
- Both forms of lipoic acid can be made more powerful by "charging" them up into their DHLA form. R (+) -lipoic acid is "upgraded" much more rapidly than S(-)-lipoic acid.
- Many studies have found that R (+) lipoic acid provides much more effective protection than S (-) lipoic acid or the racemate. In some cases, the S (-) lipoic acid actually counteracts the effects of R (+) lipoic acid.
Lipoic acid is known for its ability to protect brain and nerve cells from free radicals and toxins. Excessive levels of "transition metals" such as iron, copper, and cadmium are believed to play an important role in many neurological disorders. Having too much free iron in a key part of the brain has been implicated as a cause of Parkinson's disease, for example.
- R (+) lipoic acid supplements partially reverse the age-associated loss of spatial and temporal memory seen in old animals.
- An animal study using R (+) lipoic acid found that it was able to significantly reduce age-related buildup of iron in the brain. Other studies suggest that S (-) lipoic acid will not work as well.
The biggest source of free radicals in your body are your cellular "power plants," the mitochondria. They are both the origin, and the target, of most of the free radical damage in the body. As we age, our mitochondria become less and less efficient, generating less and less energy while creating more and more free radicals.
- R (+) lipoic acid, in animal experiments and in test-tube studies, makes mitochondria more efficient, so that they produce more energy and create fewer free radicals. Age-associated damage to mitochondrial structure is significantly reduced. S (-) lipoic acid does not have these effects, and may antagonize the action of R (+) lipoic acid.
- These benefits have a real impact on the organism. Animals undergoing a simulated heart attack recover heart function more rapidly when infused with R (+) lipoic acid; S (-) lipoic acid has no such effect.
- Animals who receive R (+) lipoic acid supplements look better and are more active.
Nearly all researchers into the biology of aging agree that the decay of mitochondrial function is a major engine of the aging process. Caloric restriction, with adequate nutrition, is the only proven way to slow down the fundamental aging process in mammals.
- Many of the benefits of R( +) lipoic acid closely mimic those of caloric restriction. R (+) lipoic acid's effects on mitochondrial function are the most striking and unique parallel.
- A study in a short-lived strain of mouse demonstrated that R (+) lipoic acid can dramatically increase its lifespan. Neither S (-) lipoic acid, nor the racemate, had any significant effect.
- The National Institutes on Aging are currently funding studies to see if R (+) lipoic acid can truly slow down the aging process.
The Bottom Line
Common "lipoic acid" supplements are thus like a house at war with itself. The S (-) form should be removed from supplements in favor of pure R (+) lipoic acid.
"We're finding - and others are, too - that the R (+) form - the natural form - is much more powerful than the racemic mixture ... Hopefully ... companies are going to be producing on more of a clinical scale the R (+) form of lipoic acid, because we're finding very significant effects using this, as opposed to the racemic mixture." - Dr. Tory Hagen, in Mitochondrial Decay in Aging.
"We have presented in this study new information indicating that this enhancement of glucose metabolism is sterospecific, with the R (+) enantiomer being much more effective than the S (-) enantiomer." - Dr. Ryan Streeper and colleagues, in The American Journal of Physiology.
"Lipoic acid sold in a health food store is a synthetic mixture, a racemic mixture. And R(+) is the natural form and S (-) is an unnatural one ... And in our hands R(+) works and S (-) doesn't." - Dr. Bruce Ames, in Strategies for Engineered Negligible Senescence.
"R (+) LA [that is, R (+) lipoic acid], and not a racemic mixture of R (+) and S (-) LA, should be considered a choice for therapeutic applications." - Dr. Lester Packer and colleagues, in Free Radical Biology and Medicine.
"The S (-) enantiomer ... part of the racemate, which is present as about a 50% impurity, needs to be eliminated." - Dr. Guido Zimmer and colleagues, in Methods in Enzymology.
150 mgR(?) lipoic acid (sodium salt)*
*Contains 15 mg sodium per capsule.
Non-medicinal ingredients: microcrystalline cellulose, sodium stearyl fumarate, silicon dioxide, dicalcium phosphate. Capsule: hypromellose, gellan gum.