Nutrition

Lipoic acid: The unique antioxidant

Pick up any health magazine and you’re bound to find an article about antioxidants such as vitamins E, C, and beta-carotene. But there’s a new antioxidant on the block that’s worth looking into. Why? Because this nutrient does more than some of the run-of-the-mill antioxidants. Lipoic acid can actually help treat certain medical conditions. And you don’t have to wait forever to find out if it’s working.

We’re still in the early stages of learning all of lipoic acid’s potential benefits. In the meantime, we have brought together the very latest scientific research about this nutrient. You should consider learning more about lipoic acid if you have any of the following:

Diabetes, or higher than normal blood sugar
Diabetic neuropathy
Cataracts, if still in the early stages
Brain or nerve degeneration
Cardiovascular problems such as atherosclerosis, hardening of the arteries, or cerebrovascular diseases
High cholesterol levels
Lipoic acid has also been examined in a variety of other medical conditions, including infections (such as HIV) and cancer.

Although LA is found in foods such as meats and spinach, full evaluations of food contents have not been done as thoroughly for LA as they have for other antioxidants. Our bodies are thought to be able to synthesize small amounts of LA, although there is no proof at this time. When LA is ingested as a supplement, about 80 percent is absorbed into the bloodstream.

What is lipoic acid?
Lipoic acid (LA) is a natural antioxidant. It is gradually becoming recognized for its unique abilities in the therapy andprevention of a broad range of diseases. In addition to antioxidant properties, LA helps the body use glucose; hence its potential for helping people with diabetes.

An antioxidant is any chemical, natural or synthetic, that neutralizes toxins or free radicals, thus protecting our cells from damage. A free radical is an unstable molecule with at least one unpaired electron. It reacts by trying to steal an electron from a neighboring molecule, causing damage in the process. Cigarette smoke, fried foods, ozone, excessive sun exposure, car exhaust, and air pollution are common causes of free radicals. It is believed that aging and many degenerative conditions are due to free-radical damage to cells. For instance, if a free radical damages our DNA, the eventual consequences could be a higher risk of cancer. If the damage occurs in arteries that supply blood to the heart, it could eventually lead to a heart attack. Thus, it has been proposed that the intake of antioxidants could potentially slow down this damage.

The chemical name of LA is 1,2-dithiolane-3-pentanoic acid. Usually you see it mentioned in the medical literature as alpha-lipoic acid or "thiotic acid." For the sake of simplicity, we will use the shorter version: lipoic acid or LA.

LA is easily absorbed from the diet or when taken as a supplement. It can enter the bloodstream and travel to many parts of the body. It can even cross the blood-brain barrier. Cells can absorb LA and transform it into a related antioxidant known as dihydrolipoate, which is exported to areas outside a cell. Therefore, LA can protect cells on both the inside and outside.

A brief history
In the fall of 1950, a team of scientists headed by Dr. Lester Reed, from the Department of Chemistry at the University of Texas in Austin, isolated a compound that affected the metabolism of glucose. They named this compound alpha-lipoic acid. The term lipoic refers to "lipid" or fat, since LA was not soluble in water.

Since 1950, hundreds of articles have been published on LA. Initially, scientists focused on the role of LA in sugar metabolism. However, in the late 1980s, LA’s powerful antioxidant capabilities were discovered. The research with this nutrient has accelerated over the past few years. Various patents have been taken, and researchers are testing LA for its potential in fighting infections and inflammation, protecting nerve cells, treating cardiovascular diseases, tumors, allergies, shielding against stomach ulcers, and so on. Naturally, there’s no guarantee that LA will turn out to be appropriate for all these conditions.

Let’s review some of the published research on LA and explore guidelines on how you can best take advantage of this unique nutrient.

The ideal antioxidant?
Our foods, especially fruits and vegetables, contain countless antioxidants. They are all important, and taking LA is certainly not a substitute for eating a diet loaded with refined sugars, desserts, and high-fat junk.

However, LA offers some benefits you won’t find in other antioxidants. In a 1995 review article published in the journal Free Radical Biology and Medicine, one of the leading scientists in the area of antioxidant chemistry, Lester Packer, Ph.D., from the University of California at Berkeley, reports on the uniqueness of LA. He even comes close to calling LA the "ideal" antioxidant, for the following reasons:

LA is readily absorbed from the diet or as a supplement.
It can regenerate vitamin C from dehydroascorbic acid, its oxidized form.
It can potentially regenerate other antioxidants.
LA increases the levels of glutathione, a very important antioxidant normally found in our cells.
It can be used therapeutically in a variety of medical diseases.

LA can enhance the synthesis of glutathione, the main antioxidant within our cells. Glutathione effectively mops up all types of toxins and free radicals. However, we cannot take supplements of this antioxidant since it is unable to cross cell membranes. Fortunately, both laboratory and animal studies have shown that LA can stimulate the production of glutathione. This is particularly important during periods of excessive stress or exposure to toxic substances, or even exposure to radiation.

It seems that LA can even pitch in and help when the body is lacking vitamin E. When laboratory animals were depleted of their vitamin E stores because their diet lacked this nutrient, they displayed obvious symptoms of vitamin E deficiency. However, when their diet was supplemented with LA, the animals were completely protected.

What about side effects?
Low doses of LA, such as 10 to 50 mg, do not cause side effects of any significance. However, higher doses could cause gastrointestinal symptoms of nausea or stomach upset. Extremely high doses could potentially lead to very low blood sugar.

For long-term use, we do not recommend that you take more than 100 mg a day until extensive human studies are completed. People don’t always realize that even a good thing can turn bad. Some antioxidants are thought to turn into pro-oxidants (oxidation-causing) in excessive dosages. Also, the body needs some oxidation-type chemicals in order to fight off certain germs. It may be unwise to mop up all oxidants in the body, since some may play certain key roles. It would certainly be wise to make your healthcare practitioner aware of the supplements you are taking.

LA and aging
Glucose (sugar) has been implicated in the aging process because of its ability to react with some proteins, such as collagen, to produce glycation. That is, the glucose molecule attaches to some amino acids of a protein and makes the protein less functional, leading to malfunction. The initial phase of this attachment is called glycation.

As we age, the amount of glycation of the proteins in our bodies tends to increase. We should also note that blood sugar generally increases as we age. The glycation of the collagen in our tendons and arteries increases with age, in proportion to the increase in blood glucose that occurs with aging.

However, restricting calories can help prevent this age-related increase in glyca-tion. In other words, avoiding excess sugar and excess calorie consumption could theoretically, over the years and decades, help our proteins stay healthier. Practical ways to use this information include:

Eat small, frequent meals throughout the day instead of one or two excessively large ones. Eating these small meals, or snacks, will help maintain your blood sugar at a relatively steady state, instead of wide fluctuations.
Make sure to get some protein with each meal. Avoid a purely carbohydrate meal, except when you want to induce sleep at night. Carbohydrates, eaten an hour or two before bed, will help you feel sleepy.
Even relatively "healthy" drinks, such as fruit juices, can increase blood sugar significantly when consumed in large amounts, such as six ounces or more. Many people quickly gulp down eight ounces of orange juice in the morning, in addition to a cup of coffee laced with a teaspoon or two of sugar.
Lipoic acid could also help lower the rate of glycation. According to a study published in 1997, LA was found to reduce glycation of proteins in human tissues. This is an important finding not only for diabetics, but for all of us.

For prevention and anti-aging
Because of its effectiveness as an antioxidant, it would seem logical for anyone who takes supplemental antioxi-dants to consider adding LA to his or her regimen. The ideal dose of LA as an antioxidant has not been determined. However, 50 mg a day, or every other day, would certainly be reasonable. If you prefer to be more cautious, you may consider as low a dose as 10 mg a day. If your capsules contain 100 mg, you could open the capsule and take a small portion of it. You may also need LA in times of stress, infection, or other types of illness.

As with many nutrients and medicines, our philosophy is to take occasional breaks and not use them for a few days.

How will LA make you feel?
We, the authors, have noted that the ingestion of LA can often lead to a mild, relaxed feeling of well-being. Interestingly, there’s also a slight visual enhancement that occurs.