Lemons were first cultivated in Asia about 4,000 years ago for use in cooking, with other cultures later prizing lemons for their medicinal properties. By the 1600s, physicians knew that daily intake of lemon juice could prevent scurvy outbreaks in sailors who were at sea for long periods. More recent research is investigating lemons to treat various diseases, including cancer of the prostate, although human trials are needed to determine the effectiveness of lemons for prostate conditions.
Lemon Compounds
Like other citrus fruits, lemons contain a variety of nutrients, including vitamin C and potassium, but lemons also contain compounds called flavonoids. Flavonoids are antioxidants that can protect your body's cells against the damaging effects of free radicals and other reactive oxygen species. However, cheaper powdered lemon peel supplements tend to have far fewer flavonoids than standardized versions. Lemons also contain pectin, which a study published in the June 2001 issue of the "Journal of Agriculture and Food Chemistry" found inhibited the growth of cancer cells.
Scientific Evidence
Lemons contain a flavonoid called hesperidin, and researchers at the University of California-Santa Barbara published a study in "Phytotherapy Research" in 2010 showing hesperidin suppressed the growth of certain types of prostate cancer cells. A study at the University of California-Los Angeles, published in 2006 in the "Journal of Nutritional Biochemistry," found that another flavonoid, naringenin, stimulated the repair of DNA in prostate cancer cells. A review of the diets of men with prostate cancer in India, reported in 2010 in the "Asian Pacific Journal of Cancer Prevention," linked higher consumption of tea, melon and citrus fruits with a reduced risk for prostate cancer.
Contradictory Research
A 2006 systematic review in the "Journal of Preventive Medicine and Public Health" looked at 11 different studies and was unable to find any association between the risk of prostate cancer and the intake of citrus fruits. The journal "Cancer Causes and Control" also published a review in February 2010 that looked at studies involving a variety of cancer patients, including 1,294 with prostate cancer. Although the researchers found a possible preventive effect of citrus against cancers of the digestive and upper respiratory tract, none was found for cancers of the prostate.
Considerations
Lemons and supplements with lemon extracts are generally considered safe, with few side effects. Higher amounts could worsen acid reflux disease in some patients and also could increase iron absorption that would be harmful if you have hemochromatosis, a disease in which the body absorbs too much iron from the diet. Lemon peels also contain oxalates that may exacerbate kidney or gallbladder conditions.
References
- “Journal of Agricultural and Food Chemistry”; Citrus Pectin: Characterization and Inhibitory Effect on Fibroblast Growth Factor−Receptor Interaction; Yan Liu, et al.; June 2001
- Drugs.com; Lemons; 2009
- "Phytotherapy Research"; Hesperidin Suppressed Proliferations of Both Human Breast Cancer and Androgen-Dependent Prostate Cancer Cells; C.J. Lee, et al.; January 2010
- "Journal of Nutritional Biochemistry"; The Citrus Flavonoid Naringenin Stimulates DNA Repair in Prostate Cancer Cells; K. Gao, et al.; February 2006
- "Journal of Preventive Medicine and Public Health"; Citrus Fruits Intake and Prostate Cancer Risk: A Quantitative Systematic Review; Jong-Myon Bae, et al.; May 2008
- "Cancer Causes & Control"; Citrus Fruit and Cancer Risk in a Network of Case-Control Studies; R. Roschi, et al.; February 2010
