Top 9 Health Benefits of Pterostilbene Supplements
Pterostilbene Sources
Pterostilbene is a phytoalexin (plant chemical defense) similar to resveratrol, belonging to the stilbene class of molecules; it is named after the pterocarpus genus of plants.
Pterostilbene is contained in low quantities in a few plants, most notably blueberries and grapes. Despite being in low concentrations, it is likely bioactive following oral ingestion of these fruits and their products (such as wine).
Pterostilbene is a methoxylated resveratrol, essentially. It has a larger difference in structure from resveratrol than piceatannol (another common stilbene compound, which is more similar to resveratrol). These three structures form the common dietary stilbenes.
Pterostilbene Benefits
1. Absorption
Pterostilbene appears to be well absorbed, and better absorbed than resveratrol. While its absorption is somewhat respectable (for a polyphenolic) at lower oral doses, higher oral doses appear to actually be better absorbed than lower doses. Pterostilbene can be absorbed sublingually.
Chronic dosing of pterostilbene benefits to reduce the peak serum values while prolonging the time to reach peak levels. When looking at overall bodily exposure to pterostilbene, there isn't a predictable difference.
2. Neuroinflammation
10-30μM pterostilbene appears to reduce microglial nitric oxide production when stimulated by LPS without directly scavenging the nitric oxide radicals. It appears to work via inhibiting IκBα phosphorylation, and is slightly more potent than resveratrol.
3. Anxiety
Pterostilbene appears to exert anxiolytic effects in the 1-2mg/kg oral dosing range in mice subjected to an elevated maze test, although it appears ineffective at 5-10mg/kg; this is thought to be related to ERK phosphorylation in the hippocampus which is known to be related to anxiety and mood.
4. Memory and Learning
Isolated pterostilbene has been noted to improve cognition in aged rats when fed in the diet at 0.004-0.016% over 12-13 weeks, with the improvements correlating with hippocampal concentrations of pterostilbene.
5. Blood Pressure
Supplementation of pterostilbene at 125mg twice daily appeared to reduce blood pressure (diastolic and systolic) in hypercholesteromic adults, an effect not observed with 50mg taken twice daily but partially replicated (systolic only) when 50mg was paired with 100mg grape seed extract (GSE) also taken twice daily.
6. Cholesterol
Pterostilbene has been noted to increase the signalling of PPARα receptors at 100µM (8-fold) and 300µM (14-fold) concentrations, with 100µM of pterostilbene being 74.2% more effective than 100µM ciprofibrate as assessed by relative luciferase units. At concentrations of 1-10µM pterostilbene, the receptors were mostly inactive. Since pterostilbene is known to bind to PPARα it appeared to be an agonist of this receptor.
When supplemented to subjects with high cholesterol (200mg/dL) and high LDL-C, pterostilbene at both doses (50mg or 125mg, both taken twice daily) appeared to increase total cholesterol and LDL cholesterol relative to placebo, with the group given the low dose pterostilbene with grape seed extract (GSE; 100mg twice daily) not seeing this increase; the benefits to blood pressure seen with high dose pterostilbene were replicated with GSE.
HDL cholesterol was noted to be unchanged overall, but in people not on cholesterol medication taking the higher dose of pterostilbene there was a decrease relative to control.
High doses of pterostilbene supplementation (50-125mg twice daily) appear to increase, rather than decrease, cholesterol and LDL levels in subjects who already have high LDL concentrations; those not on cholesterol lowering medications also noted a decrease in HDL cholesterol.
7. Inflammation and Immunology
Pterostilbene may exert antiinflammatory effects at low concentrations with a potency greater than resveratrol; these effects may be relevant to oral supplementation of higher doses of pterostilbene.
Pterostilbene appears to reduce oxidation in neutrophils (the main mechanism of action of spirulina), although the effect seems to occur only at very high concentrations. It appears to be active following oral ingestion, but not to a large degree.
Neutrophils are known to produce oxidation when activated via the NADPH oxidase enzyme which may lead to injury in excessive levels (despite being protective against bacterial invaders at lower activity); resveratrol has previously been implicated as an NADPH oxidase inhibitor, and this activity appears to extend to pterostilbene as it can reduce chemiluminescence of neutrophils (an indication of antioxidant activity). And while pterostilbene doesn't inherently affect superoxide levels in neutrophils, 100µM is able to reduce superoxide production and subsequent myeloperoxidase (MPO) production to around 60% of control with lower concentrations ineffective.
When comparing potencies, pterostilbene appears to be less effective than resveratrol (assessed by IC50 values of reducing extracellular chemiluminescence) with pterostilbene also being less potent than piceatannol, and the potency of curcumin lying between resveratrol and piceatannol. When looking at intracellular chemiluminescence, curcumin seems most potent (IC50 3.57µM to pterostilbene's 21.58µM) and resveratrol is intermediate to the two.
8. Interactions with Cancer Metabolism
Resveratrol has previously been noted to increase apoptosis via the Notch signalling pathway(which induces Cyclin D1 and survivin as it is prosurvival which appears to extend to pterostilbene in lung cancer cells (A549) with an IC50 value on cell growth of 3.476µM. Pterostilbene appears to reduce the Notch1-dependent survial while induces production of reactive oxygen species, leading to apoptosis.
9. Longevity and Life Extension
Pterostilbene (70μM) has been noted to upregulate a variety of mitochondrial genes in a yeast assay (148 up and 13 downregulated) involved in respiration, electron transport, mitochondrial protein targeting, and mitochondrial protein synthesis.
The oxidative stress seen during the aging process in neurons appears to be attenuated with low dietary levels of pterostilbene (0.004-0.016% of the diet), with a potency greater than resveratrol.
Safety and Toxicology
In mice, doses of pterostilbene up to 3,000mg/kg daily (500-fold the estimated human intake) have failed to exert any significant clinical or biochemical toxicity.
Pterostilbene up to 250mg daily (125mg twice daily) in humans over the course of 6-8 weeks has failed to cause any biochemical or clinical signs of toxicity, with side effects not significantly different than placebo aside from one dropout due to worsening cholesterol which may be related to an increase in LDL-C seen with this dose when tested elsewhere in hypercholesterolemic adults.
Health Benefits of Pterostilbene
Pterostilbene is a compound found naturally in blueberries. It is a chemical similar to resveratrol and is available in dietary supplement form. Preliminary research suggests that pterostilbene may reduce inflammation and offer antioxidant benefits.
Due to a lack of research, little is known about the safety of long-term or regular use of dietary supplements containing pterostilbene. Keep in mind that supplements haven't been tested for safety, and dietary supplements are largely unregulated. In some cases, the product may deliver doses that differ from the specified amount for each herb. In other cases, the product may be contaminated with other substances such as metals. Also, the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.
Supplements containing pterostilbene are sold in many natural-foods stores and in stores specializing in dietary supplements. They can also be found online.
Using Pterostilbene for Health
It's too soon to recommend the use of pterostilbene supplements as a standard treatment for any condition, however, increasing your intake of pterostilbene by consuming blueberries on a regular basis may help enhance your health. Research suggests that a diet high in berries may help fight cognitive decline and protect cardiovascular health.
It's also important to note that self-treating a chronic condition such as diabetes with pterostilbene and avoiding or delaying standard care may have serious consequences. If you're considering the use of pterostilbene in the treatment of a chronic condition, make sure to consult your physician.
References
Qureshi AA, et al. Suppression of Nitric Oxide Production and Cardiovascular Risk Factors in Healthy Seniors and Hypercholesterolemic Subjects by a Combination of Polyphenols and Vitamins. J Clin Exp Cardiolog. (2012)
McCormack D, McFadden D. A review of pterostilbene antioxidant activity and disease modification. Oxid Med Cell Longev. (2013)
Rimando AM, et al. Resveratrol, pterostilbene, and piceatannol in vaccinium berries. J Agric Food Chem. (2004)
Hougee S, et al. Selective COX-2 inhibition by a Pterocarpus marsupium extract characterized by pterostilbene, and its activity in healthy human volunteers. Planta Med. (2005)
Langcake P. Disease resistance of Vitis spp. and the production of the stress metabolites resveratrol, epsiton-viniferin, alpha-viniferin and pterostilbene. Physiol Plant Pathol. (1981)