Summary of Pterostilbene Benefits
Pterostilbene is a naturally abundant antioxidant that benefits the cardiovascular system (blood vessels) and improves the regulation of sugar in the body. Improved sugar regulation protects against diabetes. Pterostilbene also benefits the nervous system by supporting natural antioxidant defense. For this reason, a diet enriched with pterostilbene may protect against dementia.
Pterosilbene is the primary antioxidant in blueberries, and is also found in pterocarpus marsupium heartwood. The pterostilbene content of blueberries varies from 99ng to 520 ng/gram.
Pterostilbene is more bioavailable than resveratrol. Thus, some researchers think that pterostilbene is an improved version of resveratrol. But so far, much less research has been conducted on pterostilbene than resveratrol.
Evidence suggests that pterostilbene has antioxidant, anti-inflammatory, anticarcinogenic, anti-diabetic, and neuroprotective properties. The majority of this evidence was conducted in animal models or in vitro (in cells isolated from an organism). For this reason, we should temper our enthusiasm for pterostilbene with healthy skepticism.
Pterostilbene and Red Wine
It has higher bioavailability than other stilbene compounds. This enhanced bioavailability may contribute to its therapeutic effects.
Pterostilbene is structurally related to resveratrol, a compound in red wine. Resveratrol has comparable beneficial effects to pterostilbene. But pterostilbene has superior bioavailability due to its two methoxy groups. Pterostilbene is reported to have 80% bioavailability vs 20% for resveratrol.
In animal models and in vitro studies, pterostilbene:
- Reduces oxidative stress and production of reactive-oxygen species
- May increase the expression of antioxidant defense enzymes like superoxide dismutase (SOD).
Chemical structure of pterostilbene vs resveratrol vs piceatannol (courtesy of examine.com).
Benefits of Pterostilbene on the Brain
Several studies show that berries may thwart aging-associated cognitive decline.
- Blueberry extract decreased markers of dopamine-induced oxidative stress, indicating an antioxidant effect
- Blueberry fed rodents had increased glutathione (GSH) and Purkinje cell function, and performed better on rod-running motor tasks
- Old rats fed a blueberry enriched diet displayed better object memory recognition
Joseph and colleagues investigated whether the beneficial effects of blueberries on the brain can be attributed to pterostilbene. They found that pterostilbene-fed rats performed better on cognitive measures in a dose-dependent manner. Rats receiving low and high dose pterostilbene had serum levels of 3.951 and 25.576 respectively. Pterostilbene was also detected in the brain’s of mice fed high but not low dose pterostilbene.
Cardiovascular benefits of pterostilbene
Lifestyle factors like smoking and sedentary lifestyle stress the vasculature (blood vessels).
Regular consumption of dietary antioxidants may protect the cardiovascular system from injury.
Blueberries and pterostilbene have a protective effect against cardiovascular disease. Many mechanisms have are proposed, like the induction of antioxidant enzymes.
- Rodents fed a blueberry enriched diet had 22% smaller average myocardial infarction size
- Heart cells (cardiomyocytes) in rodents fed blueberry were 24% more resilient to reactive oxygen species (ROS)
- Blueberry supplementation reduces hardening and narrowing of the blood vessels. This effect is due to increased expression of antioxidant enzymes (SOD1, SOD2, GSR, thioredoxin reductase)
- Blueberries reduced hydrogen peroxide-induced injury to endothelial cells
- Pterostilbene reduced the expression of the cell-cycle mediators CDK-2, CKD-4, cyclin E, cyclin D1, Rb, and PCNA. These mediators contribute to the development of plaque in the blood vessels.
- Pterostilbene inhibits programmed cell death (apoptosis) in endothelial cells in blood vessels. Pterostilbene suppreses both Bax and p53, which are pro-apoptotic proteins.
- Pterostilbene decreases NF-kB activation, a protein which mediates the immune response and inflammation
- Future studies will look at the benefits of blueberries and pterostilbene in high-risk groups. Smokers are a particularly high risk of atherosclerotic injury.
Benefits of Pterostilbene on Glucose Regulation
In diabetes, the regulation of insulin, fats and sugar is impaired. Sedentary lifestyle has increased the risk of diabetes worldwide.
The heartwood plant Pterocarpus marsupium tends to lower blood sugar (it has hypoglycemic effects). Recall that pterostilbene is one of the primary antioxidants in pterocarpus marsupium. The antiglycemic effects of PM are attributed to the presence of pterostilbene.
- Hyperglycemic mice treated with Pterocarpus marsupium (PM) showed improved glycemic control and insulin resistance. PM also normalized lipid levels.
- A 20mg/kg dose of pterostilbene decreased plasma glucose by 42% and body weight by 20% in a mouse model of diabetes.
- Sugar-coated hemoglobin is a marker of diabetes. Chronically elevated glucose tends to sugar-coat the hemoglobin protein, which carries oxygen in the bloodstream. Pterostilbene treatment was reported to decrease plasma glucose by 54% and while also reducing glycosylated hemoglobin.
Researchers have argued that the effects of pterostilbene in animal models are comparable to metformin.
Many of these studies are conducted in animal models like rodents, or *in vitro *(isolated cells outside of an organism). Therefore, the reported benefits of pterostilbene should be viewed with a skeptical eye.
Many of the benefits of pterostilbene are attributed to its antioxidant effects. But most scientists are unconvinced that purported antioxidants really prevent disease as advertised. There are a lot factors that influence how data and which data is reported in the scientific community. Publication bias, commercial interests, and simple wishful thinking may influence our thinking about supplements.
Many people choose to supplement their diet with pterostilbene because it won’t cause any harm. So even if their is a small chance that it will help, it may be worth it. This is kind of like Pascal’s wager.
Mccormack D, Mcfadden D. A review of pterostilbene antioxidant activity and disease modification. Oxid Med Cell Longev. 2013;2013:575482.