Phytochemicals -- chemicals found in plant foods -- might have health benefits that explain why fruits and vegetables are good for you, just like your mom said. Potential benefits of one phytochemical, ellagic acid, include decreasing cancer risk and lowering cholesterol. Ellagitannins, which break down into ellagic acid when you consume them, are one of the compounds found in some berries and other fruits as well as some nuts.
Foods High in Ellagitannins
Raspberries lead the pack when it comes to raising ellagic acid levels. Pomegranates also appear to contain large amounts of ellagitannins, although raspberries have undergone more clinical studies. Strawberries, blackberries, cranberries, walnuts and grapes also contain ellagitannins. The ellagitannins in these foods break down into ellagic acid in the intestines. More of the ellagitannins are found in the seeds and leaves than in the pulp of fruits such as raspberries and strawberries; according to the United States Department of Agriculture, the pulp of green strawberries contains more than ripe strawberries.
Ellagic acid breaks down rapidly and isn't well absorbed. Because of these two limitations, taking pure ellagic acid supplements is not an effective way to get your dose of the compound, according to alternative medicine guru Jon Barron. Pure ellagic acid is both insoluble, meaning it won't dissolve in water, and biologically unavailable. USDA plant pathologist John Maas states that small amounts of dietary ellagitannins may be more beneficial than large doses of pure ellagic acid.
Since the seeds and leaves contain most of the ellagitannins, taking raspberry seed powder is one way to get more of the compounds that will break down into ellagic acid after consumption, Barron suggests. The highest levels of ellagic acid are found in the fruits that are freeze-dried, according to the American Cancer Society. There is no single accepted dose of foods containing this compound; in an Oklahoma State University study, women with metabolic syndrome who drank a preparation twice a day made using 25 grams of freeze-dried strawberry powder in water reduced their total cholesterol levels by 5 percent in four weeks.
Raspberry leaf can cause uterine contractions during pregnancy; don't take raspberry leaf supplements or drink raspberry tea if you are pregnant unless approved by your medical practitioner. Ellagic acid can inhibit a liver enzyme called cytochrome P450, which breaks down many medications. Taking ellagic acid supplements or consuming large amounts of the compound could affect the way you absorb certain medications. Ask your doctor before increasing your ellagic acid intake.
- American Cancer Society: Ellagic Acid
- Memorial Sloan-Kettering Cancer Center: Ellagic Acid
- JonBarron.org: The Truth About Ellagic Acid and Red Raspberries
- Nutrition Journal: Freeze-dried Strawberry Powder Improves Lipid Profile and Lipid Peroxidation in Women with Metabolic Syndrome: Baseline and Post Intervention Effects
- Agricultural Resource Service: Ellagic Acid in Strawberries
A registered nurse with more than 25 years of experience in oncology, labor/delivery, neonatal intensive care, infertility and ophthalmology, Sharon Perkins has also coauthored and edited numerous health books for the Wiley "Dummies" series. Perkins also has extensive experience working in home health with medically fragile pediatric patients.