By Stephen Daniells, Nutra Ingredients USA
Supplementation with resveratrol at doses achievable in the diet may boost mental function, but pterostilbene may be even more potent for brain boosting benefits, suggests new studies in mice.
Two new studies show that resveratrol was capable of enhancing cognitive function in lab animals, while one such study reported that the results were even more noteworthy with pterostilbene supplementation.
The studies – one by a team in the US and the other in Japan – add to an ever growing body of science supporting the potential benefits of both compounds.
Pterostilbene and resveratrol
Resveratrol is often touted as the bioactive compound in grapes and red wine, and has particularly been associated with the so-called 'French Paradox'.
The potential health benefits of the compound include anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.
Interest in the molecule is increasing. At the recent SupplySide East show in New Jersey Datamonitor’s Tom Verhile told attendees: “New food and beverage product launches containing resveratrol tripled in 2009-2010. This is an ingredient to watch…”
However, the science supported the reported benefits. Pterostilbene, chemically similar to resveratrol, is emerging as a nutrient to watch. Studies have already reported that pterostilbene is superior to resveratrol for certain health conditions, and it has shown promise for improving cardiovascular health, glucose levels, and cognitive function.
Pterostilbene vs resveratrol
The first study, published in Neurobiology of Aging, was performed in mice that have been genetically developed as a model of accelerated aging and age-related cognitive decline. Identical doses of pterostilbene and resveratrol were used, and equivalent to about two glasses of wine, said the researchers (120 mg per kg of diet).
Results indicated that both compounds boosted cognitive function in the pterostilbene modulated markers of cellular stress and inflammation, whereas no such effects were observed for resveratrol.
“One potential explanation that can account for our findings is related to the chemical structure differences between these 2 compounds,” report researchers from Case Western Reserve University, Tufts University, and the USDA.
“In this regard, the substitution of the hydroxy group of resveratrol with a methoxy group in pterostilbene makes this molecule more lipophilic. This change may lead to better bioavailability of pterostilbene and consequently a more potent neuroprotective effect in the brain.
“This is supported by the fact that while diet consumption and weights did not vary in our studies, pterostilbene was found at higher doses both in serum and brain tissue compared with resveratrol, which was found at low levels in the serum and undetectable in the brain tissue.
“While it is yet to be determined whether the cognitive improvements induced by pterostilbene in [this mouse] model can be applied to humans, recent reports demonstrate that fruits containing pterostilbene such as blueberries ameliorate cognitive function in aged humans,” they added.
In a second study by researchers from Nagoya City University Graduate School of Medical Sciences in Japan, resveratrol was associated with improved cognitive function in mice.
Results published in The Journal of Nutritional Biochemistry indicated that consumption of red wine containing 20 milligrams of resveratrol per liter improved cognitive function in mice, but wine containing 3.1 mg/L of resveratrol had no effect.
According to the Japanese researchers, the average concentration of resveratrol in red wine is 4.7 mg/L
“It is thus possible that drinking red wines with regular concentrations of resveratrol for long periods lowers the risk of age-associated cognitive decline,” they wrote.
The potential benefits of resveratrol were linked to an increase in the production of a peptide called of insulin-like growth factor-I (IGF-I), which is reported to promote the growth of blood vessels (angiogenesis) and neurons (neurogenesis) in the hippocampus.
“This may explain at least in part the beneficial effects of moderate consumption of red wine on cognitive function in humans,” wrote the researchers.
Of mice and men
The findings from these studies need to be repeated in humans before any firm conclusions can be drawn.
Data from humans is few and far between, and findings from a study by scientists at the Brain, Performance and Nutrition Research Centre at Northumbria University in the UK reported that a single dose of 250 or 500 milligrams of resveratrol may boost blood flow in the brain but does not affect cognitive performance (American Journal of Clinical Nutrition, Vol. 91, pp. 1590-1597).
Source: Neurobiology of Aging
Published online ahead of print, doi: 10.1016/j.neurobiolaging.2011.08.015
“Low-dose pterostilbene, but not resveratrol, is a potent neuromodulator in aging and Alzheimer's disease”
Authors: J. Chang, A. Rimando, M. Pallas, A. Camins, D. Porquet, J. Reeves, B. Shukitt-Hale, M.A. Smith, J.A. Joseph, G. Casadesus
The Journal of Nutritional Biochemistry
Volume 22, Issue 12, Pages 1150-1159
“Resveratrol improves cognitive function in mice by increasing production of insulin-like growth factor-I in the hippocampus”
Authors: N. Harada, J. Zhao, H. Kurihara, N. Nakagata, K. Okajima