By Benjamin V. Treadwell, Ph.D.

If you're middle-aged or older, you may have found learning to use your computer challenging, even frustrating at times. In contrast, your children or grandchildren plop down in front of any device, turn it on and use every feature as if born with this ability.

Humans are not the only mammals whose mental quickness declines as we get older. Age-associated mental decline has been demonstrated in virtually all animals, including mice, rats and, more recently, dogs. So why the enormous difference, between young and old, in the ability to learn new things?

Less Energy with Age
Remember all the energy you had as a child, then less after the teen years, and even less as you approached thirty and beyond? This gradual decline not only affects the musculoskeletal system, but all organs of the body, including the central nervous system. 

Many involved in research on aging attribute this decline in energy production to a gradual deterioration of the mitochondria. These tiny cellular structures (several hundred per cell) contain the machinery to convert food (carbohydrates, fats, amino acids) into a specific form of chemical energy, ATP.

The cell uses ATP for a variety of tasks including removing cellular debris (cleaning house, so to speak), and maintaining and repairing/replacing damaged cellular constituents such as DNA and proteins. These activities help prevent potentially lethal mutations as well as the accumulation of damaged tissue molecules (such as those present in wrinkled, aged skin) due to exposure to chemicals and/or UV irradiation from the sun.

As the mitochondria deteriorate, they are not able to produce as much ATP. The earliest noticeable effects seem to be less physical and mental energy. In other words, we move and think/learn more slowly as our mitochondria age.

More for the Mitochondria
Recent animal studies at the laboratories of Bruce Ames (University of California, Berkeley) and Tory Hagen (Linus Pauling Institute, Oregon State University) support the theory that age-impaired mitochondria are at least partly responsible for slower learning.

Working with older and younger rats, researchers isolated mitochondria and found a significant decrease in energy production for the older subjects. However, after the older rats were fed acetyl-L-carnitine (ALC) and alpha lipoic acid (LA) for a two- to three-week period, their mitochondria produced energy almost as efficiently as the mitochondria from the young animals. The older rats with the ALC and LA-enriched diet also demonstrated improved learning ability.

Quicker-Thinking Canines
The outcome with rats prompted extending the investigation to dogs who, as mentioned earlier, also show a decline in learning ability, especially after age seven to eight. The results will be published in the September 2007 FASEB Journal. (See this month's "Research Update" for a preview.)

In this study, two groups of dogs, 7.6 to 8.8 years old, were fed twice a day. One group ate food containing 5 mg of LA and 12.5 mg of ALC per pound (based on the dog's weight). For the second group, these two ingredients were replaced with methylcellulose, a placebo. After five days on this diet, a two-month testing period began.

The dogs were presented with a tray containing two coasters, one with a yellow peg attached to the center and an identical coaster without the marker. A treat/reward was hidden under the coaster with the peg. After each test, the positions of the coasters were switched. The dogs were scored as to the percentage of times they identified the coaster with the peg.

In a variation of this test, the peg was moved from the center of the coaster to a position one centimeter away, but attached to the coaster by a piece of Velcro. Again the subjects were scored as to their choice of coasters. In both tests, the dogs on the diet containing LA and ALC made significantly fewer errors than the placebo group. (See graph below.)

Studies for Dog's Best Friend
The results of this study seem to show a reversal of at least some of the age-associated learning impairments for the dogs receiving the LA and ALC-enriched diet. This data, in conjunction with the research on rats, also seems to support the theory that improving mitochondrial health produces more of the energy required by the brain cells involved in learning and memory. 

Although these results are encouraging, whether a similar effect is produced in humans has yet to be determined. Studies are underway and should yield results in the not too distant future.      

A group of investigators from several universities and research institutions recently designed experiments to test the effectiveness of two compounds — acetyl-L-carnitine (ALC) and alpha lipoic acid (LA) — on cognitive decline in middle-aged dogs. Specifically, these researchers intended to demonstrate whether/how two months of ALC and LA supplementation of middle-aged beagles affected their mental acuity/ability to learn new tasks.

As compared to the control group (beagles of similar age and health who were fed a diet with a placebo), the supplemented group scored significantly higher in two different tests designed to measure learning quickness. The results indicate that feeding the animals a combination of ALC and LA can offset the normal cognitive decline in middle-aged dogs.   

Details and methodology will be published in the September, 2007 FASEB Journal, the research communication forum for the Federation of American Societies for Experimental Biology.

To read the abstract, click here .
"Acetyl-L-carnitine and alpha-lipoic acid supplementation of aged beagle dogs improves learning in two landmark discrimination tests"
The FASEB Journal: Published online before print July 10, 2007 as doi: 10.1096/fj.07-8531com

This Research Update column highlights articles related to recent scientific inquiry into the process of human aging. It is not intended to promote any specific ingredient, regimen, or use and should not be construed as evidence of the safety, effectiveness, or intended uses of the Juvenon product. The Juvenon label should be consulted for intended uses and appropriate directions for use of the product.

QUESTION:   I have purchased Vigorate for my eight-year-old Bichon Friese and I have two questions. First, is it too early to give my dog this supplement? (Is he too young?) Second, what changes should I expect to see and in what time frame? — L. P.

ANSWER: An eight-year-old dog is considered middle-aged. This an ideal time to start your Bichon on Vigorate, although you can start two to three years earlier and still see some effect from the supplement. Typically, at your dog's age, he may have more pep and seem a little sharper after about a month. Another change that is often exhibited by white dogs taking Vigorate is a disappearance of the common brown-reddish discoloration of the fur, especially around the mouth and eyes. This effect usually takes two to three months.

Send your questions to AskBen@juvenon.com.
For more questions and answers, go to juvenon.com/product/qa.htm.

Benjamin V. Treadwell, Ph.D., is a former Harvard Medical School associate professor and member of Juvenon's Scientific Advisory Board.