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Grapefruit contains nutrients that may decrease or prevent varicose veins. According to the University of Maryland Medical Center, varicose veins -- those dark, bluish veins on your feet and legs -- are the most common vein disorder, affecting 60 percent of American women. Varicose veins are mostly a cosmetic issue, but in some instances, their presence may lead to serious conditions such as blood clots. Several components in grapefruit, as well as other citrus fruits, are thought to affect varicose veins. However, insufficient scientific evidence exits to support the use of grapefruit for the treatment of varicose veins, so discuss use of grapefruit as a medicinal therapy with a health care provider before beginning a treatment regimen.
Bioflavonoids
Bioflavonoids are a group of plant pigments that produce colors in flowers and fruits, and may help reduce varicose veins. Citrus bioflavonoids are found in the peels of citrus fruits such as oranges, lemons and grapefruits. These bioflavonoids have antioxidant and inflammatory effects that may strengthen collagen --- the main protein in connective tissue --- to keep your vein walls strong, according to GreatVistaChemicals.com. When a vein's one-way valve malfunctions, blood may flow backward and build up in the vein, causing it to enlarge and become a varicose vein, according to the University of Maryland Medical Center.

Grapefruit, as well as other citrus fruits and some vegetables, contains the bioflavonoid rutin. Rutin is suggested as a possible treatment for varicose veins by the University of Maryland Medical Center. Oxerutins --- flavonoids from rutin --- are thought to relieve the pain and swelling that occurs with severe varicose veins, according to the UMMC. Rutin and other bioflavonoids--- found in citrus fruits such as grapefruit --- are believed to prevent the hemorrhages and ruptures in capillary and connective tissues that are associated with varicose veins, according to GreatVistaChemicals.com.