Fact Check

Do Lemons Cure Cancer?

Claims that lemons "kill cancer cells" and are "10,000 times stronger than chemotherapy" are unsupported by credible medical evidence.

Published April 17, 2011

Claim:
Lemons have been proved to "kill cancer cells" and are "10,000 times stronger than chemotherapy."

Although an item about the supposed cancer-curing properties of lemons was originally circulated with a tag line suggesting that it had been issued by Baltimore's Health Sciences Institute (a subsidiary of Newmarket Health, which is located at 819 N. Charles Street in Baltimore), that agency has denied any connection to this piece:

Lemon (Citrus) is a miraculous product that kills cancer cells. It is 10,000 times stronger than chemotherapy.

Why do we not know about that? Because there are laboratories interested in making a synthetic version that will bring them huge profits. You can now help a friend in need by letting him/her know that lemon juice is beneficial in preventing the disease. Its taste is pleasant and it does not produce the horrific effects of chemotherapy. How many people will die while this closely guarded secret is kept, so as not to jeopardize the beneficial multimillionaires large corporations? As you know, the lemon tree is known for its varieties of lemons and limes. You can eat the fruit in different ways: you can eat the pulp, juice press, prepare drinks, sorbets, pastries, etc... It is credited with many virtues, but the most interesting is the effect it produces on cysts and tumors. This plant is a proven remedy against cancers of all types. Some say it is very useful in all variants of cancer. It is considered also as an anti microbial spectrum against bacterial infections and fungi, effective against internal parasites and worms, it regulates blood pressure which is too high and an antidepressant, combats stress and nervous disorders.

The source of this information is fascinating: it comes from one of the largest drug manufacturers in the world, says that after more than 20 laboratory tests since 1970, the extracts revealed that: It destroys the malignant cells in 12 cancers, including colon, breast, prostate, lung and pancreas ... The compounds of this tree showed 10,000 times better than the product Adriamycin, a drug normally used chemotherapeutic in the world, slowing the growth of cancer cells. And what is even more astonishing: this type of therapy with lemon extract only destroys malignant cancer cells and it does not affect healthy cells.

Institute of Health Sciences, 819 N. L.L.C. Cause Street, Baltimore, MD1201

It is true in a general sense that lemons (and citrus fruits in general) provide a number of useful nutritional and health benefits, as described in the Encyclopedia of Healing Foods:

The fruit juice contains mainly sugars and fruit acids, which are made mainly of citric acid. Lemon peel consists of two layers: the outermost layer ("zest"), which contains essential oils (6 percent) that are composed mostly of limonene (90 percent) and citral (5 percent), plus a small amount of cintronellal, alphaterpineol, linayl, and geranyl acetate. The inner layer contains no essential oil but instead houses a variety of bitter flavone glycosides and coumarin derivatives.

Lemons are an excellent source of vitamin C. In addition, they are a good source of vitamin B6, potassium, folic acid, flavonoids, and the important phytochemical limonene. A 3½-ounce (100 gram) serving is about 2 medium lemons and provides 29 calories, 1.1 grams of protein, 0.3 grams of fat, and 9.3 grams of carbohydrate, with 2.8 grams of fiber and 2.5 grams of natural sugars.

The phytochemical limonene, which is extracted from lemons, is currently being used in clinical trials to dissolve gallstones and is showing extremely promising anticancer activities.

Several academic papers published in the last decade have also suggested that lemons, as well as other citrus fruits, might possess some substantial anti-cancer properties. For example, a 2002 report on the medicinal use of citrus issued by the University of Florida's Institute of Food and Agricultural Sciences noted that:

Recent research has focused on the biological activity of compounds found in citrus species, including compounds called flavanoids, carotenoids and limonoids, especially in terms of their effects on citrus palatability and anti-cancer activity. Citrus flavonoids have potential antioxidant (prevents aging), anti-cancer, antiviral, anti-inflammatory activities, effects on capillarity, and cholesterol-lowering ability. The principal carotenoids in pink grapefruit are lycopene and beta-carotene. Lycopene-containing fruits and vegetables have been shown to contribute to a significant reduction in prostate and mammary cancer risk.

Recent studies have further shown that limonoids inhibit the development of cancer in laboratory animals and in human breast cancer cells as well as reducing cholesterol. Researchers have also suggested that, if ingested, limonoids may not be absorbed in the large intestine, and therefore could be distributed throughout the body, with beneficial effects.

Likewise, a 2000 paper from University of California Davis on "The Potential of Citrus Limonoids as Anticancer Agents" observed that:

Vitamin C and flavonoids are antioxidants, substances that neutralize active oxygen species which can damage body cells and contribute to chronic diseases including cancer. Carotenoids, colored pigments in fruits and vegetables such as beta-carotene, lycopene, and lutein, also provide some antioxidant protection, but have other beneficial actions involving cell growth and vision. Folate is a B vitamin that is needed for the synthesis of DNA, and therefore is important for the integrity of genetic material in cells and the healthy growth of tissues. Recent information indicates that mild folate deficiency alters the structure of DNA in a way that may decrease the expression of tumor suppressor proteins. A survey of food folate sources showed that orange juice is the largest contributor to the food folate intake in the U.S. population. Recent research suggests that U.S. consumers may be getting another health benefit from orange juice and other citrus products — phytochemicals called limonoids — which appear to possess substantial anticancer activity.

And a 2004 ScienceDaily article reported on similar research from Texas A&M University's Kingsville Citrus Center:

Research by Texas Agriculture Experiment Station scientists has shown that citrus compounds called limonoids targeted and stopped neuroblastoma cells in the lab. They now hope to learn the reasons for the stop-action behavior and eventually try the citrus concoction in humans.

Neuroblastomas account for about 10 percent of all cancer in children, Harris said, and is usually a solid tumor in the neck, chest, spinal cord or adrenal gland. The finding in citrus is promising not only for its potential to arrest cancer, but because limonoids induce no side affects, according to Dr. Ed Harris, Experiment Station biochemist who collaborated on the study with Dr. Bhimu Patil, a plant physiologist at the Texas A&M University-Kingsville Citrus Center in Weslaco.

"Limonoids are naturally occurring compounds," Harris said. "Unlike other anti-cancer drugs that are toxic, limonoids apparently do not hurt a person. That's the beautiful potential."

Patil calls citrus fruit "a vast reservoir of anti-carcinogens." As a plant physiologist, he has succeeded in isolating and purifying a number of limonoids from citrus so that the biochemists could evaluate and compare their anti-cancer abilities at the molecular level.

"Limonoids are unique to citrus," Patil said. "They are not present in any other fruits or vegetables. My goal is to find the direct benefits of citrus on human health."

However, the best that can be said at this point is that citrus fruits may potentially harbor anti-cancer properties that could help ward off cancer. No reputable scientific or medical studies have reported that lemons have definitively been found to be a "proven remedy against cancers of all types," nor has any of the (conveniently unnamed) "world's largest drug manufacturers" reported discovering that lemons are "10,000 times stronger than chemotherapy" and that their ingestion can "destroy malignant [cancer] cells." All of those claims are hyperbole and exaggeration not supported by facts.

Sources

Carper, Jean.   The Food Pharmacy.     New York: Bantam Books, 1988.   ISBN 0-5533-4524-9   (p. 222-223).

Ferguson, J.J. and Timothy M. Spann.   "Medicinal Use of Citrus."     University of Florida.   October 2002.

Jacob, Robert, et al.   "The Potential of Citrus Limonoids as Anticancer Agents."     Perishables Handling Quarterly.   May 2000.

Murray, Michael.   The Encyclopedia of Healing Foods.     New York: Atria Books, 2005.   ISBN 0-7434-8052-X   (pp. 286-287).

ScienceDaily.   "Citrus Shows Promise for Certain Childhood Cancer."     1 December 2004.

David Mikkelson founded the site now known as snopes.com back in 1994.

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