What is Pterostilbene?
This potent polyphenol is promising in health and aging research because of its molecular structure and bioavailability. But it might be able to do more than we even know.
In 2003, researchers gave red wine drinkers everywhere reason to raise a glass when they announced that resveratrol — a natural chemical found in, among other things, grape skins — might be linked to long life.
Resveratrol, they found, extended the life span of yeast cells by as much as 70 percent. Plus, it seemed to induce gene expression changes that gave them reason to believe the compound might prevent and treat a wide-range of health issues.
Researchers have pinned their hopes on a new rising star called pterostilbene (pronounced tear-oh-STILL-bean).
But 15 years and thousands of scientific studies later, and resveratrol hasn’t lived up to its initial promise. The trouble is, it disappears from the body in roughly 15 minutes — meaning, in scientific terms, it isn’t very bioavailable.
So researchers have pinned their hopes on a new rising star called pterostilbene (pronounced tear-oh-STILL-bean), which is very similar to resveratrol but with one tiny but crucial structural difference: It has just one hydroxyl group, compared to resveratrol's three. Hydroxyl groups facilitate metabolization (the way to get rid of the molecule) by the body. Fewer hydroxyl groups make it harder for the body to eliminate the molecule — no bad thing when the molecule has benefits. The upshot is that pterostilbene's slightly different molecular structure allows it to cross cell membranes more easily and hang out in the body longer than resveratrol.
“Resveratrol was like the poster child for polyphenols,” says Ryan Dellinger, Elysium’s director of scientific affairs whose doctoral research involved pterostilbene. There is no great reason for this: Dellinger thinks it’s likely because, with limited money and time for scientific research (and more than 500 “promising” polyphenols to study), companies and scientists focused on the one that —at the time— seemed the most promising.
One good thing: Pretty much everything you know about resveratrol is true for pterostilbene, Dellinger says. Only it’s more potent.
How Pterostilbene Works
Pterostilbene is a polyphenol, a type of molecule that occurs in plants, particularly small berries and nuts. Blueberries are a particularly rich source of pterostilbene; although it is found in grapes, pterostilbene (unlike its cousin resveratrol) doesn’t survive the wine-making process.
What’s a polyphenol? “Phenol” refers to a certain chemical structure (in this case, a hydroxyl group linked to a benzene ring); “poly” just means the molecules have more than one of the structure. One of polyphenols’ main jobs is to help the plant fight off pathogens. When eaten by humans, polyphenols may serve as powerful antioxidants, which can stop or delay damage to cells.
Scientists have been aware of phenols since the early 19th century — Joseph Lister, the pioneer of antiseptic surgery, reported on one phenol’s disinfectant properties in 1867 — though the term “polyphenol” didn’t have its first recorded use until 1894.
As with the rest of polyphenols, researchers don’t fully understand how pterostilbene works. Dr. Jose M. Estrela, a professor of physiology at the University of Valencia (Spain) who has studied pterostilbene says "the good thing is that pterostilbene works, but the bad thing is that we cannot fully explain its potential health benefits with the information that we have.”
“The good thing is that pterostilbene works,” Estrela says. “The bad thing is that we cannot fully explain its potential health benefits with the information that we have.”
Pterostilbene for Health and Aging
Pterostilbene’s connection to sirtuins is just one of the reasons longevity scientists are so excited by the compound.
Pterostilbene may also have wide-ranging applications for skin disorders — but first and foremost, it could be be a powerful protector against skin cancer in humans and animals. Applied topically, Pterostilbene isn’t a sunscreen, like zinc, which actually shields the skin from UVA and UVB rays. Instead, pterostilbene acts indirectly by increasing the antioxidant defenses of the skin. Don’t confuse “indirectly” with “sort of, kind of,” by the way. Quite the opposite: In Estrela’s lab, when mice were irradiated two times a week for six months, their entire backs were covered with carcinomas. But those who received the pterostilbene treatment had zero tumors.
Because pterostilbene also has anti-inflammatory effects, scientists have had success in mice models using it to treat psoriasis, atopic dermatitis, and contact/allergic dermatitis.
Pterostilbene could also help researchers studying colon cancer, the third-highest cause of cancer death – and one whose incidence is increasing among people younger than age 50. In human genes, the compound has been shown to inhibit growth in colon cancer cells (specifically more so than resveratrol).
In the liver, a 2005 study in mice found that pterostilbene (along with quercetin, a polyphenol found in apple skins and cherries) inhibited liver tumor growth up to 56 percent — and extended life, “the first time that in vivo administration of natural polyphenols shows inhibition of metastatic growth of a highly malignant tumor and extension of host survival.” Scientists aren’t sure why this works: One theory is that the polyphenols interfere with cell division. Cancer is unchecked cell division, but if something stops those cells from dividing, they die.
And more benefits of pterostilbene are likely to be uncovered. Consider this: There are about 11,000 published scientific papers about resveratrol, versus barely 400 on pterostilbene. But research on pterostilbene is at least 10 years behind resveratrol. Give it time.