Tanmeet Sethi, MD
Tanmeet Sethi, MD, clinical associate professor at the University of Washington in Seattle, senior faculty for the Center for Mind Body Medicine, and author of Joy Is My Justice. www.tanmeetsethimd.com
Bite into a Red Delicious apple and you’ve bitten into a juicy universe of health and healing. The apple is rich in pectin, a soluble, gel-like fiber that lowers cholesterol and balances blood sugar; vitamin C, which strengthens immunity, helps preserves the integrity of skin, and improves iron absorption; and potassium, an essential mineral that regulates blood pressure, nourishes muscles, and lowers the risk of colon cancer. But there’s another nutritional compound found in Red Delicious apples that you may not know about (or even heard of) that is equally effective in preventing and treating disease: procyanidins.
Procyanidins are one of the bioactive compounds in plants called flavonoids that endow plants with their bright, deep, vivid colors. Procyanidins are behind the blue in blueberries, the red in strawberries, the purple of plums, the red and green of grapes, and the deep brown of cocoa (the primary ingredient in chocolate). Along with apples, grapes, berries, plums (and prunes), and cocoa, you can also find procyanidins in legumes (beans and lentils) and nuts.
But procyanidins do a lot more than provide a palette for plants. They are powerful antioxidants, capable of containing the oxidative damage—a kind of cellular rust—that causes and complicates the chronic conditions that afflict millions of Americans, like heart disease, type 2 diabetes, and Alzheimer’s disease.
Here are the many ways that procyanidins can protect or restore your health, and how to get just the right amount in your daily diet.
About 45 percent of American adults have high blood pressure—systolic blood pressure (the top number) of 130 mmHg or higher or diastolic blood pressure (the bottom number) of 80 mmHg or higher. It’s the leading risk factor for heart disease and stroke. Procyanidins can help you bring high blood pressure under control.
In a recent study published in Pharmacological Research, scientists analyzed the results from six studies on procyanidins and high blood pressure, and found that high intake reduced diastolic blood pressure by an average of 4.6 points and reduced systolic blood pressure by an average of 2.8 points. Procyanidins, wrote the researchers, could be a “useful treatment of hypertensive patients as well as a preventive measure in prehypertensive and healthy” people.
Procyanidins improve circulation by strengthening the endothelium, the lining of blood vessels that controls whether these flexible tubes are relaxed or tight. They also help prevent the arterial plaque that clogs blood vessels. In addition, procyanidins stimulate the stem cells that renew and repair damaged blood vessels. And they help control an immune compound called NLRP3 that triggers the inflammasome, which generates numerous inflammatory (and cell-damaging) compounds called cytokines.
Cancer is the No. 2 cause of death in America, with nearly 2 million people diagnosed every year, and 610,000 dying. In a laboratory study from the Institute of Food Research, procyanidins in apples were used to starve a cancer by depriving it of blood. Here’s how: Tumors can’t grow to any substantial size without their own blood supply, which is dependent on the growth of new blood vessels (angiogenesis). Procyanidins block a compound that powers angiogenesis.
In a laboratory study from Georgetown University Medical Center, researchers combined a procyanidin in chocolate with breast cancer cells, and the breast cancer cells stopped dividing or proliferating, the core process in cancer. There was also far less activity in a gene that drives breast cancer.
Dozens of laboratory and animal studies suggest that extracts of black raspberries—rich in procyanidins—can inhibit many cancers in laboratory studies.
A scientific paper in the Journal of Berry Research, from researchers at the Ohio State University, presents five studies that show black raspberry extracts are effective in treating precancerous rectal polyps in patients with a high risk for colon cancer; colon cancer; oral dysplasia, a precancerous condition for oral cancer; and Barrett’s esophagus, a disease that increases the risk for esophageal cancer.
One out of every four adults ages 65 and older has type 2 diabetes (T2D), a disease of chronically high blood sugar. People with T2D have a higher risk for cardiovascular disease, kidney disease, and Alzheimer’s disease, and complications of T2D include nerve damage, problems with vision, and leg and foot ulcers that can lead to amputation. Another 88 million American adults—about one in every three of us—have prediabetes, blood sugar levels that put you at a much higher risk for developing T2D.
Scientists reported in the journal Antioxidants that the procyanidins in cocoa can help control diabetes in many ways. They boost the secretion of insulin, the hormone that ushers blood sugar out of the bloodstream and into muscle, fat, and other cells. They improve insulin sensitivity, the ability of cells to make use of insulin. They lower cholesterol and triglycerides, heart-hurting blood fats. And, of course, they decrease oxidation and inflammation. “Cocoa or dark chocolate,” write the researchers, “might be a potential preventive tool useful for the nutritional management of TD2.”
Procyanidins also directly stimulate the sympathetic nervous system, activating the burning of excess fat and improving metabolism—lowering the risk for TD2 and helping manage the disease if you have it.
More than 6 million older Americans have Alzheimer’s disease. And an estimated one in five older adults have mild cognitive impairment (MCI), the mental decline that is characterized by poor memory, judgment, focus, and trouble finding the right words when speaking or writing.
In a study titled Procyanidins and Alzheimer’s Disease, scientists write that procyanidins are a “potentially effective” way to prevent and treat Alzheimer’s disease. They point out the compounds can prevent or reduce the amyloid-beta plaques and tau tangles in the brain, the cellular pathologies that are a feature of the disease; improve the “plasticity” of neurons in the brain, or their ability to change and adapt; and improve cognitive function itself. Procyanidins also work to improve cognitive function by improving blood flow to and decreasing inflammation in the brain.
In a recent study, researchers from the USDA Human Nutrition Research Center on Aging at Tufts University gave either freeze-dried strawberry powder (the equivalent of 2 cups a day of strawberries) or a placebo to 37 people aged 60 to 75. After 12 weeks, the strawberry group had significantly improved memory and learning ability compared with the placebo group.
And in a study in the journal Hypertension, researchers looked at 90 people with MCI, giving them a daily cocoa drink with either high, intermediate, or low levels of procyanidins and other flavonoids. After eight weeks, those getting the high-procyanidin drink performed better on several tests that measure cognitive impairment, including the Mini Mental State Examination. They also had lower blood pressure, less insulin resistance, and lower levels of oxidized cholesterol. “Regular consumption” of procyanidin-rich cocoa “might be effective in improving cognitive function” in people with mild cognitive improvement, write the researchers.
The key to getting a healthful daily dose of procyanidins from the diet is to eat a wide variety of colorful foods every day: one or more servings of berries, grapes, apples, chocolate, legumes, nuts, and tea (black and green). The more diverse the menu, the more likely you’ll be to get all the procyanidins you need.
Cooking at home rather than eating out is another good strategy for maximizing your intake of procyanidins—simply because you have more control over the menu. And don’t forget spices! Cinnamon, for example, is a particularly rich source of procyanidins, and also excellent for balancing blood sugar.
A social network and friends is also a good way to meet your goals for healthy eating—perhaps having a dinner with friends once or twice a week where everyone brings a procyanidin-rich dish. Even if you can’t have dinner together, you can network with people who want to eat healthier and encourage each other in your goals—sending pictures of your favorite procyanidin-rich snacks or meals or sharing a checklist of the procyanidin-rich foods you ate that day.
Getting procyanidins from supplements—like green tea extract, pycnogenol (pine bark), or resveratrol (grape extract)—is not the best way to guarantee a steady, healthful level of procyanidins. Supplements are potentially a good addition to any diet, but shouldn’t be used to meet your nutritional goals.
Red wine has lots of procyanidins, but that doesn’t mean it’s good for you That’s because it also delivers ethanol, which is toxic to the body. For women, even small amounts of alcohol are linked to an increased risk of breast cancer. Just one drink a day (six ounces of wine) increases risk by up to 50 percent. Feel free to enjoy red wine in the context of occasional social gatherings and enjoyment, but don’t look to red wine as a steady, daily source of a healthful bioactive like procyanidins.
