In addition to Vitamin C, citrus fruits contain powerful cancer-fighting compounds called limonoids. Limonoids are chemicals found in the seeds, peel and pulp, and juice of citrus fruits, occurring more abundantly in the pulp and peel than in the juice; they are responsible for the bitter taste in the peel. Orange juice contains 300 mg of limonoids per liter of juice; grapefruit juice contains 200 mg/l, and lemon/lime juice 90 mg/l. The pulp/peel of citrus fruits contain 500 mg of limonoids per kilogram, so high-pulp juice would be much more beneficial than no-pulp juice. Using zest from the peels of oranges, lemons and limes is another good way to get those limonoids. I like to squeeze the juice from a fresh lime over my salad in lieu of salad dressing.
Research has shown that high levels of limonoids are capable of slowing the growth of cancer cells and causing cancer cell apoptosis (programmed cell death, or cell suicide) in lab studies. Limonoids help fight lung, breast, stomach, colon, skin and mouth cancers. Limonoids are natural aromatase inhibitors, depriving estrogen-positive breast cancer cells of estrogen. They are directly toxic to colon, pancreatic, liver, neuroblastoma, leukemia and other types of cancer cells. The most abundant and one of the most potent limonoids is limonin glucoside. Limonin glucoside is an easily digested limonoid which attaches to sugar molecules, neutralizing the harmful effects of the sugar. Limonin glucoside lasts up to 24 hours in the body; comparatively, the beneficial phenols in chocolate and green tea only last 4-6 hours in the body.
Essential oil of lemon has been studied quite a bit in relation to cancer and shows much promise. One review published in the Journal of Medicinal Plants Research in 2010, indicated its capability of stopping cervical cancer cells from spreading and of inhibiting free radicals from harming healthy cells. Researchers have learned that lemon as well as other essential oils use multiple pathways to fight cancer, including cell cycle arrest, apoptosis, anti-metastasis (stopping cancer cells from spreading), and anti-angiogenesis (stopping cancer cells from growing more blood vessels). Lemon and other essential oils can also provide relief for cancer patients from symptoms such as pain, anxiety, nausea and vomiting.
One fascinating aspect of the ability of citrus essential oils to combat cancer is that they can do this simply through being smelled! In early 2015, a study published in the Archives of Biochemistry and Biophysics revealed that citronella terpenes in lemon essential oil stop the growth of cancer. Terpenes activate certain olfactory (smell) receptors in the body to prevent the growth and spread of cancers. Olfactory receptors are not only located in the nose--they are also located in the skin and in some other organs. So, inhaling the scent of essential oils such as lemon and applying them to the skin as well as ingesting them can offer benefits. As always, please get advice from a knowledgeable practitioner before using essential oils.
Adding citrus fruits to your diet on a regular basis will help you fight a lot more than the common cold!
