Not only is it the Vitamin C that is beneficial, but ...
Limonoids
Lemons and limes contain disease-fighting compounds known as limonoids. The human body is able to readily absorb a specific, long-acting limonoid known as limonin, according to the US Agricultural Research Service. Both lemons and limes contain nearly as much limonin as they do vitamin C. The results of a 2001 culture study summarized in "Nutrition and Cancer," revealed that this compound, at a concentration of 100 mcg/mL, was effective at partially inhibiting the growth of human ovarian cancer cells and inducing the death of breast cancer cells.
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