Manipulating mitochondria: playing in the fountain of youth

Nutrition Action Healthletter, Dec, 2008 by David Schardt

* Is it safe? "There are no concerns about quercetin's toxicity, but it's early in the whole story," says researcher Mark Davis.

CARNITINE & LIPOIC ACID

University of California biochemist Bruce Ames got plenty of media attention in 2002 when he announced that old, sedentary rats given two compounds that occur naturally in mitochondria "got up and did the Macarena."

Ames and his colleague Tory Hagen found that rats fed carnitine and lipoic acid during the last months of their lives--roughly equal to humans aged 70 to 100--spontaneously doubled their physical activity compared with similar rats fed a placebo. (10)

Carnitine shuttles fat into the mitochondria, where the fat is burned for energy. Lipoic acid is an antioxidant.

Ames and Hagen patented the combination, which is sold as "Juvenon" in partnership with alternative medicine guru Andrew Weil.

Weil calls Juvenon "a remarkable health supplement," and has said that he takes it every day.

In the "Macarena" study, lipoic acid and carnitine boosted the activity of the rats' mitochondria. "That would explain their increased physical activity," notes Hagen.

In a second study, old rats fed the two nutrients had less mitochondrial damage in their brains and better spatial and temporal memory than rats given a placebo. (11)

In both studies, the rats got the equivalent of 14 to 100 times more carnitine and 5 to 25 times more lipoic acid than you'd get in a daily dose of Juvenon (500 mg of carnitine and 200 mg of lipoic acid).

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In a third study, carnitine and lipoic acid improved short-term memory and learning in beagles. (12)

"That was eye-opening to us," says Hagen, "because it's quite relevant to what might happen in humans." The dogs got the human equivalent of a double dose of Juvenon.

Still, no research has looked at the impact of carnitine and lipoic acid on mitochondria in humans, concedes Hagen.

"I keep admonishing people that I can tell them what happens in rats, but I can't tell them what would happen in people just yet. There's a huge amount of work that we're just starting."

The Bottom Line

* Do they work? There are no human studies, but high doses of carnitine plus lipoic acid made laboratory rats more physically active and improved the memory of dogs.

* Are they safe? In 14 studies, people with nerve damage caused by diabetes who were taking 600 to 1,800 mg a day of lipoic acid reported no more side effects than people taking a placebo. Carnitine also appears to be safe.

Mitochondria Magic

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Mitochondria are the furnaces within cells that help convert fat, protein (amino acids), or carbohydrate (glucose) into ATP (adenosine triphosphate). ATP is the "currency" that transports the energy that the cell uses to fuel the chemical reactions that sustain life.

Mitochondria have their own genetic material. But unlike the DNA in the cell's nucleus, which comes from both parents, mitochondrial DNA is passed down from mother to child.

(1) J. Appl. Physiol. 90: 1137, 2001.

(2) J. Gerontol. A Biol. Sci. Med. Sci. 61: 534, 2006.