3/15/2005
An a-peel-ing discovery
The next time you sink your teeth into a succulent tangerine, you may want to think twice about throwing away the peel. According to Heart and Stroke Foundation researcher, Dr. Stewart Whitman, tangerine peel contains a powerful flavonoid that may lower your risk of heart disease.
When it comes to cholesterol, our white blood cells have two different protein receptors that regulate cholesterol intake. The first is the LDL receptor that lets in LDL (bad) cholesterol and the second is the Class A Scavenger receptor that lets in an oxidized form of LDL cholesterol, which is also a very bad type of cholesterol.
Fruit has always been considered a heart-healthy food. But Dr. Whitman and his team are contributing to a growing body of research that is uncovering its substantial disease-fighting potential. The researchers already knew flavonoids found in citrus fruits – hesperetin (oranges), narigenin (grapefruit*), tangeretin (tangerines) and nobiletin (tangerine peel) – had the ability to block intake of LDL through the LDL receptor.
Sweet success
But it was through Dr. Whitman’s research with the unique compound found in tangerine peel that they uncovered something much more exciting – nobiletin was the only flavonoid that successfully blocked uptake of oxidized LDL through the Class A Scavenger receptor.
“LDL cholesterol accumulation is never a good thing,” says Dr. Whitman. “This was an incredibly significant discovery for us and it provides great hope for preventing one of the key processes in the early stages of heart disease.”
Atherosclerosis - the buildup of plaque on artery walls -- is one of the major risk factors for heart disease and stroke. When plaque ruptures, it can form blood clots capable of blocking the arteries to the heart and brain causing a heart attack or stroke. As a leading risk factor for these life-threatening conditions, the ability to prevent and/or treat cholesterol buildup is vital.
Finding appeal in the peel
Dr. Whitman has proven that the flavonoid nobiletin packs a heart-healthy punch. Of course, the source of nobiletin poses some challenges – not many people enjoy the taste of tangerine peel. But with a little bit of clever thinking, there are many tasty ways to get your daily dose of nobiletin. Dr. Whitman suggests a citrus smoothie with shredded tangerine peel. Or how about throwing a dash of peel into your salad dressing? For those who like their tea, infuse it with some peel. You’ll be doing your heart a favor!
* The use of grapefruit and grapefruit juice is cautioned with certain cholesterol, blood pressure, angina and arrhythmia medications. If you have a concern, you can substitute oranges or orange juice or double check with your physician or pharmacist to see if this issue applies to you.