Resveratrol was the discovery of the decade a few years back noted for its powerful antioxidant capabilities and anti-aging properties as a natural supplement. The finding of these molecules commonly found in red grapes caught scientists attention to seek out other naturally occurring molecules in the foods we eat. Researchers found another powerful antioxidant in a cousin of the grape, blueberries. The molecule is known as Pterostilbene and it has a similar structure to Resveratrol. It turns out that Pterostilbene surpasses the health benefits of Resveratrol in that it has greater bioavailability and is more stable as a molecule allowing it to remain longer in your system. Pterostilbene is reported to have similar antioxidant properties as Resveratrol but also has other functions as well.
Pterostilbene contains phytoalexins which are molecules produced by plants that fight disease. Basic research on animals suggest that this group of molecules anti-cancer agents, lower cholesterol levels, lower triglyceride levels, stabilize blood sugar levels, and restore loss of memory function. Much of this is accomplished by altering genetic expression and activation of specific enzymatic pathways. Pterostilbene differs from Resveratrol in that Pterostilbene has two terminal methyl groups (CH3) that Resveratrol doesn't have. This difference in structure makes Pterostilbene more lipid soluble which means it can pass through and/or remain in the plasma membrane of all cells in the body. While in the membrane, it is an excellent scavenger of free radicals. This makes it a powerful protector of omega-3 fatty acids and their double bonds found in the hydrophobic region of the bilipid layer. This means it is rapidly absorbed by the intestinal wall and is readily available to every cell in the body once it is absorbed hence its high bioavailability.
The two extra methyl groups also make Pterostilbene more stable than Resveratrol which means Pterostilbene has a longer life time in the body. So, a much lower dose of Pterostilbene is required to see the similar benefits of Resveratrol.Researchers have reported that animals that were fed a blueberry diet demonstrated lower blood lipid and cholesterol levels. High blood levels of lipids and cholesterol are associated with heart disease and stroke. Pterostilbene's ability to lower bad fats in the blood is attributed to its ability to bind to what is called a peroxisome proliferator-activated receptor alpha (PPAR-alpha). This receptor is also known as NR1C1 (nuclear receptor subfamily 1, group C, member 1). What this means is that PPAR is a protein receptor found in the nucleus that is coded by the PPAR-alpha gene. Peroxisomes are actually organelles that are found inside all animal cells that are bilipid bags that contain enzymes that break down fatty acids and certain amino acids. These lipid fat bags are also involved with the biosynthesis of plasmogens, some phospholipids and energy production.
Back to the PPAR-alpha gene. This gene codes for a transcription factor. A transcription factor is a protein that is encoded by the genome that binds to specific DNA sequences and by do so controls whether that gene is transcribed or not. In other words, a transcription factor can bind to an upstream sequence of a gene and turn a gene off or on. So, transcription factors can promote/activate or repress the expression of a given gene. This transcription factor is particularly important to the liver. The PPAR-alpha gene coding for the transcription factor is activated by improper diet such as starvation or long fasting that brings you into ketosis. The transcription factor binds to the genes involved with fatty acid transport into peroxisomes and also mitochondria. In other words, fatty acids in blood such as triacylglycerides and cholesterol will be taken inside cells and broken down in their peroxisomes thereby lowering blood levels of bad lipids and cholesterol.
Further animal studies on rat mammary glands have provided some insight to the anti-cancer properties of Pterostilbene. The proposed mechanism involves a group of enzymes known as cytochrome P450. Cytochrome P450 is found in the second plasma membrane of mitochondria and is known as a chromophore because of the color you see when looking at it in the light microscope. This is due to the double bonds found in this very large molecule. This enzyme is involved in the electron transport system within the mitochondria that makes the energy molecule ATP. This group of enzymes can activate a number of components such as procarcinogens that can turn smoke, pesticides and other toxic molecules into carcinogens. The presence of Pterostilbene can inhibit particular P450 activity generating anti-cancer activity.
Clinical trials are underway to determine the effects of Pterostilbene but results won't be available until early 2013. For the moment, animal studies are all we have to determine what Pterostilbene can do and how safe it is to take. It is known that dosages similar to Resveratrol or lower are safe and effective.