Dogs are like humans in yet another way. Elderly dogs demonstrate better cognitive performance if given higher antioxidant diets and more stimulating environments.
During the two-year longitudinal study, William Milgram, Ph.D., of the University of Toronto, Elizabeth Head, Ph.D., and Carl Cotman, Ph.D., of the University of California, Irvine and their colleagues found older beagles performed better on cognitive tests and were more likely to learn new tasks when they were fed a diet fortified with plenty of fruits, vegetables and vitamins, were exercised at least twice weekly, and were given the opportunity to play with other dogs and a variety of stimulating toys. The study is reported in the January 2005 Neurobiology of Aging.
Citrus pulp mixed in with dog food? I wonder if they had problems getting the dogs to eat it.
For the study, the researchers divided 48 older beagles (ages 7 to 11) into four groups. One group was fed a regular diet and received standard care; a second group received standard care but was fed an antioxidant fortified diet, consisting of standard dog food supplemented with tomatoes, carrot granules, citrus pulp, spinach flakes, the equivalent of 800 IUs of vitamin E, 20 milligrams per kilogram of vitamin C, and two mitochondrial co-factors--lipoic acid and carnitine; the third was fed a regular diet, but their environment was enriched (regular exercise, socialization with other dogs, and access to novel toys); the fourth group received a combination of the antioxidant diet as well as environmental enrichment. In addition, a set of 17 young dogs (ages 1 to 3) were divided into two groups, one fed a regular diet and the other fed the antioxidant fortified diet.
I am skeptical that the vitamin E was a big benefit. Too much of a single antioxidant can actually dampen down metabolism by quenching too many free radicals. Not all free radicals are purely detrimental. The body uses free radical molecules for intracellular and intercellular signalling. Dampen down those signals too much and the net result can be harmful. I'd like to see this experiment repeated with more fruits and vegetables and no vitamins. I bet well chosen fruits and vegetables such as blueberry, spinach, kale, and perhaps even some nuts could provide as antioxidant punch as this study's mixture that included vitamins.
The fruits and vegetables added to the antioxidant fortified diet was the equivalent of increasing intake from 3 servings to 5 or 6 servings daily. Previous research suggests that antioxidants might reduce free radical damage to neurons in the brain, which scientists believe is involved in age-associated learning and memory problems. Mitochondrial co-factors may help neurons function more efficiently, slash free radical production and lead to improvements in brain function. Other studies suggest that stimulating environments improve learning ability, induce beneficial changes in cellular structure, may help the brain grow new neurons, and increase the resistance of neurons to injury.
I've had Australian Shepherds turn up their noses at me when I offered them various fruits - and this in spite of their begging when they saw me eating out of a human food bowl. But perhaps mixed in with much tastier foods (like some blood poured out of a red meat package) dogs could be persuaded to eat their fruits. Though getting them to eat tomato sauce is not hard when it is mixed with pasta and some oil. the right
The combination of better environment and better diet had the most powerful effect.
Overall, older dogs in the combined intervention group did the best on these learning tasks, outperforming dogs in the control group (standard diet, standard care) as well as those that received either the antioxidant diet or environmental enrichment. However, older beagles that received at least one of these interventions also did better than the control group. For instance, all 12 of the older beagles in the combined intervention group were able to solve the reversal learning problem. In comparison, 8 of the 12 dogs that ate the antioxidant diet without environmental enrichment and 8 of the 10 that received environmental enrichment without the antioxidant diet solved the problem. Only two of the eight older dogs in the control group were able to do this task. Dietary intervention in the younger canines had no effect.
Similar dietary changes for older humans would probably provide a similar cognitive benefit.
Also see my previous posts "Concord Grape Juice Improves Memory Of Aged Rats" and "Choline May Restore Middle Aged Memory Formation".
|Share |||Randall Parker, 2005 January 19 02:47 AM Brain Enhancement|