Polyphenols: Anthocyanins

This is part of our ongoing The Best Kept Secrets to Healthy Aging spotlight. Each day, we will be posting some of the great information that’s packed into our book, The Best Kept Secrets to Healthy Aging.

Today’s topic:

Berries, especially blueberries, are known to be a good source of the polyphenol subclass known as anthocyanins. New research shows that the health benefits of the anthocyanins extend throughout the body.

In one of the more recent studies, the blueberry anthocyanin, pterostilbene, showed an ability to support the health of colon cells by protecting against the early loss of cellular regulation.6 Because colon health and function is so absolutely dependent on tight and well-managed cellular regulation, this finding demonstrates just how powerful the anthocyanins are as promoters, supporters and managers of colon health.

The abilities of the anthocyanins to beneficially manage, direct and redirect the functions of the body’s physiologic systems are not limited to any one (or even few) of those systems. Cognitive functions, all-important to healthy aging, are sustained and boosted by anthocyanins.

In tests using laboratory animals, anthocyanin-rich blueberry extract has been effective in protecting against age-related deficits in neuron-to-neuron signaling in the brain, with accompanying improvements in learning abilities.7 In one study, in which aging rats were fed a standard diet supplemented with blueberry extract for 8 to 10 weeks, performance on an objective test of learning and memory depended on how much of the anthocyanin compounds were found in the rats’ brains.8 In other words, those rats that ate the largest amount of anthocyanin-containing blueberry extract accumulated the most anthocyanins in their brains. These animals had the best learning capacity and were found to perform the most accurately on this standardized assessment.

Exciting new research has shown that anthocyanins also promote the healthy function of non-neuron cells in the brain. These cells support neural activity by protecting neurons from the damage that can be caused by environmental toxins, oxidizing byproducts of the normal intense level of metabolic activity in neurons or aberrant electrical signals. In short, these cells help maintain the health of the neurons. However, if they become over-stimulated they can harm the very cells they are responsible for protecting by promoting free radical generation. Research published in the Journal of Neuroscience Research shows that blueberry anthocyanins help the supporting cells modulate their activity level and the intensity of their responses to various stimuli.9 What this means is that anthocyanins support brain defenses and stabilize the brain’s internal environment. Further evidence for the neuroprotective benefits of blueberry anthocyanins comes from a study in which rats were either fed a diet rich in blueberries or were placed in a control group. The rats were then injected with a chemical into their brains that led to a significant impairment of learning performance. Although all rats had significant decreases in their learning abilities, the group of animals receiving the blueberry extract performed significantly better at standardized learning tasks. Imaging results on the brains of rats fed blueberries also revealed significant protection of neurons versus rats in the control group.10 Because of their high anthocyanin content, blueberries are therefore protective against the damaging effects of free radicals on brain cells.

Together, these findings indicate that the anthocyanins in blueberries are able to enter the bloodstream, travel to the brain and act within the brain to foster an internal environment that supports learning ability and memory retention – both highly desirable results for promoting healthy aging.

Next Best Kept Secrets to Healthy Aging topic:

6. Suh N, Paul S, Hao X, Simi B, Xiao H, Rimando AM, Reddy BS. Pterostilbene, an active constituent of blueberries, suppresses aberrant crypt foci formation in the azoxymethane-induced colon carcinogenesis model in rats. Clin Cancer Res 2007;13:350-355.
7. Joseph JA, Shukitt-Hale B, Casadesus G. Reversing the deleterious effects of aging on neuronal communication and behavior: Beneficial properties of fruit polyphenolic compounds. Am J Clin Nutr 2005;81(Suppl.):313S-316S.
8. Andres-Lacueva C, Shukitt-Hale B, Galli RL, Jauregui O, Lamuela- Raventos RM, Joseph JA. Anthocyanins in aged blueberry-fed rats are found centrally and may enhance memory. Nutr Neurosci 2005;8:111- 120.
9. Lau FC, Bielinski DF, Joseph JA. Inhibitory effects of blueberry extract on the production of inflammatory mediators in lipopolysaccharideactivated BV2 microglia. J Neurosci Res 2007 Jan 30 (doi: 10.1002/ jnr.21205).
10. Duffy KB, Spangler EL, Devan BD, Guo Z, Bowker JL, Janas AM, Hagepanos A, Minor RK, DeCabo R, Mouton PR, Shukitt-Hale B, Joseph JA, Ingram DK. A blueberry-enriched diet provides cellular protection against oxidative stress and reduces a kainate-induced learning impairment in rats. Neurobiol Aging. 2008;29(11):1680-9.

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