This study focused on how increasing the intake of fruits and vegetables, especially strawberries, blueberries, and spinach, can slow down , prevent, and even reverse the cognitive function and motor performance in rats.

The fruits and vegetables that are the most effective at preventing the effects of old age are those that are the highest in antioxidant capacity. In addition to anti-aging effects, the polyphenic compounds that are present in these fruits and vegetables also have antiinflammatory, antiallergic, antiviral, and antiproliferative effects. This suggests that their effects might be based on a combination of factors (Galli, Shukitt-Hale, Youdim, & Joseph, 2002).

In Fisher 344 (F344) rats, there are a few neuronal mechanisms and behavioral measures that have been shown to be affected by age. "Significant decrements occur in neuronal signal transduction, as measured by striatal dopamine release and GTPase activity as well as calcium clearance from striatal synaptosomes and measures of neuronal membrane fluidity, which appear to be age and oxidative stress dependent" (Galli, Shukitt-Hale, Youdim, & Joseph, 2002). The age-related changes in the F344 rats are also present in psychomotor and cognitive behaviors. Starting at 12 months, coordination, stamina, and strength decline. One specific test, the Morris water maze, which assesses spatial learning and memory, also characterizes deficits associated with neural aging.

"Dietary supplements, with strawberry extract (STB) or spinach extract (SPC) from 6 months to 15 months prevented the onset of age-related deficits in signal transduction as measured by oxotremorine-enhanced dopamine release and carbachol-stimulated GTPase coupling/uncoupling in isolated stiatial slices, as compared to animals fed a control diet" (Galli, Shukitt-Hale, Youdim, & Joseph, 2002). The blueberry extract (BB) diet actually reversed the age-related deficits in OX-enhanced DA release. In addition,  "fruit supplemented diets high in polyphenolics have an antiaging effect on striatial calcium recovery in the presence of peroxide" (Galli, Shukitt-Hale, Youdim, & Joseph, 2002). The BB diet also improved cerebellar membrane fluidity, and improved the performance of old animals no the rod walk, the accelerating roto-rod, and the inclined screen. Dietary supplementation with either STB, SPC, or BB for 8 weeks slowed down the age related impairments with the Morris water maze (MWM). The MWM is a well-accepted measure of hippocampal based learning and memory. It also measures acquisition, working memory, reference memory, the ability to shift set, and spatial learning strategies.

Initial studies have shown that the anthocyanins and hydroxycinnamic acids (HCA) that are isolated from BB helps to eliminate induced in vitro peroxide oxidative stress, a condition that F344 rates become increasingly susceptible to as they age.

The amounts of BB, STB, and SPC added to the diets of F344 rats is the equivalent to a daily one cup portion for humans.