Imagine you had a remedy that was shown to help heal burns and achy joints, prevent bone loss, prevent premature aging in skin, muscles, bones, keep your nerves and your brain in top shape, protect your body from the effects of stress, and, while it’s at it, improve your digestion, heal ulcers, prevent cancer, protect you from heart disease and lower your cholesterol.
Would you throw it away?
This isn’t really a rhetorical question, because believe it or not, it’s very likely you have been throwing it away your whole life! Pretty much everyone has.
Many people know that there’s an abundance of goodness to be found in citrus fruits. What most people don’t know is that the greatest concentration of all the healing and life-enhancing agents in citrus fruits is found in the peel.
Traditional Chinese Medicine Has Used Citrus Peel for Two Thousand Years
True to form, traditional Chinese Medicine has known about the benefits of citrus peel for thousands of years. The first recorded use of Citrus Peel in Chinese Medicine was over 1800 years ago in the Divine Husbandman's Classic of the Materia Medica.
In TCM, citrus peel comes in two forms: the peel of an immature orange or a green tangerine (Qing Pi) and an aged peel (Chen Pi.) Their benefits are very similar. (The greatest difference is that Chen Pi is milder in its effects.)
According to TCM, Qing Pi and Chen Pi help stuck energy (Qi) to get moving again. Stuck energy will manifest in several ways:
- Digestive upsets of all kinds, including abdominal pain, bloating, acid reflux, diarrhea, nausea, and vomiting.
- Phlegm in your lungs, bronchioles, and nasal passages.
- Stiffness and pain in muscles and joints, usually from accumulated toxins in blood and lymph that haven’t been able to be eliminated yet.
Emotionally and mentally, stuck energy manifests in irritability and anxiety, with looping thoughts and recurring feelings of stress and anxiety.
So, is there anything to all this, or is citrus peel just a folk remedy with a nice placebo effect? Let’s take a look.
Is There Anything in Citrus Peel That Makes it Effective?
Chemists have identified a handful of compounds in citrus peel that have shown a wide array of benefits in animal and human studies. In this article, we’re going to limit ourselves to four of the most promising ones:
You’re going to see these names repeatedly throughout this article series, so get familiar with them now.
One of the things you might be been thinking when I listed all those benefits up there is this: how can one thing have so many different positive effects?
The answer to this can be found by exploring the answer to another question: do our thousands of maladies and diseases have some common causes? The answer to this question is, yes, absolutely. And if you have an ingredient that affects one or more of those common causes, you’ll see benefits spring up downstream all over the place.
So, in this series, we’re going to take a look at the effects of citrus peel on five specific areas that medical researchers know to be precursors to many forms of disease, and we’ll wrap it up by looking at the effects of citrus peel on specific conditions like cancer, heart disease, bronchitis, and more.
The five causal areas we’re going to look at are:
- Neural Degeneration
- Gut Health
In this post, we’ll cover the first two.
How Glycation Can Accelerate Aging
When there’s too much sugar in your system for too long, it alters your body’s proteins by forming what are called Advanced Glycation End-products (AGEs), which make them hard, brittle, and resistant to change and renewal. AGE’s can accumulate anywhere blood goes: skin, muscle, bone, organs, and especially the endothelial tissue that lines your circulatory system.
As more proteins become abnormally cross-linked, larger portions of tissue can’t do their job correctly or preserve themselves properly. The glycation of your circulatory tissue is part of what leads to some kinds of cardiovascular disease and is a major problem for diabetics.
Many diseases related to aging are associated with too many damaged proteins clogging up the plumbing.
I could go on, but here’s the take-away: anyone interested in preserving prime health should pay close attention to anything that can prevent glycation.
Obviously, controlling your sugar intake is a smart first step. But if you want to get all of the protection you can, you should consider adding citrus peel to your daily regimen. Researchers found that the Limonene in citrus peel is able to prevent glycation by a whopping 75%. It bound to proteins in a way that blocked the sugar from sticking to them, and the proteins stayed in their normal, healthy state.
They also found that the hesperidin in citrus peel lowers blood sugar, which can help to lessen the impact of glycation.
The challenge with trying to get limonene from eating high volumes of citrus fruit is that, for all their benefits, citrus fruits come with high sugar content (especially modern conventionally farmed fruits, which have been genetically selected for their sweetness.) You’d be fueling the fires of glycation by eating that much sugar in order to try and get at the limonene content.
But all of the sugar is in the juice. The only carbohydrate content in the peel is dietary fiber, and the peel has the highest concentration of limonene. Two wins for the peel.
How Oxidative Stress Leads to Breakdown and Disease
Every day, you are bombarded by free radicals, which are a form of unstable oxygen that destroys whatever cells they touch. Natural processes produce some free radicals, so your body has a built in antioxidant defense system to deactivate them.
But modern life bombards you with far more free radicals through polluted air, toxins in your water and food, and the failure of the modern diet to provide you with enough antioxidants. When there’s more free radicals than what your body can handle, whatever tissues they touch start to break down--organs, arteries and veins, muscle and bone, everything is susceptible.
Heart disease, cancer, and autoimmune disorders can all be brought on by excessive oxidative stress.
Citrus Peel Contains a Potent Antioxidant Network
Free radicals come in different forms and require different kinds of antioxidants to deactivate them. (For example, some are water soluble, and others are fat soluble.)
Citrus fruits are known to be excellent sources of many of these antioxidants (polyphenols, flavonoids, Vitamin C, and more.) When scientists studied 31 different fruits, they found that citrus peels had higher concentrations than the rest of the fruit, and that tangerine peel (Qing Pi and Chen Pi) had the highest concentrations, able to attack free radicals of multiple types. ,
What’s more, your liver is particularly sensitive to oxidative damage because of everything it has to process. It’s a major clearinghouse for a lot of good things and a lot of bad things--kind of like customs at a major international airport. But the hesperidin in citrus peel has been shown to reduce oxidative stress directly in the liver. 
Why should an athlete care about oxidative stress?
Oxidative stress isn’t just something to worry about if you have a disease. Somewhat ironically, exercise is a significant source of oxidative stress. The more oxygen your physical activity and recovery requires, the stronger the antioxidant network you’re going to need.
All the tissues you’re trying to build -- stronger muscle, denser bone, thicker skin, faster nerves, heart and lungs that give you more endurance -- all of them need antioxidant protection.
In the next article, we’re going to look at all of the ways citrus peel helps fight inflammation.
 Contemporary Pharmacology of Chinese Herbs, 1997; 643-643
 Joglekar MM, Panaskar SN, Chougale AD, Kulkarni MJ, Arvindekar AU. A novel mechanism for antiglycative action of limonene through stabilization of protein conformation. Mol Biosyst 2013 July
 Jung UJ, Lee MK, Jeong KS, Choi MS. The hypoglycemic effects of hesperidin and naringin are partly mediated by hepatic glucose-regulating enzymes in C57BL/KsJ-db/db mice. J Nutr. 2004 Oct;134(10):2499-503
 Murakami, A., Nakamura, Y., Ohto, Y., Yano, M., Koshiba, T., Koshimizu, K., Tokuda, H., Nishino, H., and Ohigashi, H. Suppressive effects of citrus fruits on free radical generation and nobiletin, an anti-inflammatory polymethoxyflavonoid. Biofactors 2000;12(1-4):187-192.
 Rincon, A. M., Vasquez, A. M., and Padilla, F. C. [Chemical composition and bioactive compounds of flour of orange (Citrus sinensis), tangerine (Citrus reticulata) and grapefruit (Citrus paradisi) peels cultivated in Venezuela]. Arch Latinoam Nutr 2005;55(3):305-310.
 Tirkey N, Pilkhwal S, Kuhad A, Chopra K. Hesperidin, a citrus bioflavonoid, decreases the oxidative stress produced by carbon tetrachloride in rat liver and kidney. BMC Pharmacol. 2005 Jan 31;5:2.