There is little to no evidence that grapefruit juice is good for high blood pressure.
For those with hypertension on prescribed medication, there is a dangerous correlation between grapefruit juice and high blood pressure. Patients prescribed certain drugs used to treat high blood pressure are cautioned never to drink grapefruit juice due to a dangerous interaction between the two.
Grapefruit Juice Blood Pressure Medication Interaction
Grapefruit juice binds with the enzyme in the liver and the intestinal tract, which inhibits the metabolism of calcium-blockers, the class of drugs most commonly used to manage high blood pressure. While the enzyme is busily metabolizing the grapefruit juice, the hypertension medication builds up in the system, so rather than lowering blood pressure effectively, the increased absorption may cause the blood pressure to drop dangerously.
Health Benefits of Grapefruit
Grapefruit may not be the answer to high blood pressure, but this citrus fruit packs a punch when considering health benefits. Here are a few recent studies.
Coronary Heart Disease: In a study published in the journal, Clinical Cardiology, researchers studies the effects of grapefruit pectin on plasma cholesterol and concluded that concluded that with no other changes in diet or lifestyle, grapefruit pectin supplementation alone was able to decrease plasma cholesterol 7.6%, low-density lipoprotein cholesterol 10.8%, and the low-density lipoprotein:high-density lipoprotein cholesterol ratio 9.8%. [Cerda, 589]
Stimulates Immune Cell Function: In a study published in the Journal of Nutritional Biochemistry, researchers studied the effects of grapefruit juice on bioavailability of polyphenols, markers of antioxidative and immune status, and reduction of DNA damage. The study concluded that consumption of grapefruit juice enhanced antioxidant status, reduced oxidative DNA damage and stimulated immune cell functions. [Bub, 2003]
Weight Loss: The weight loss claim is still under scrutiny. In a study published in the Journal of Medicinal Foods, researchers studied the effects of eating a half of a grapefruit daily on weight loss and insulin resistance. The study concluded that eating the fresh grapefruit prior to a meal was associated with significant weight loss and insulin resistance was also improved. [Fujioka, 46]
FSHN02-5/FS088: Using Medications Safely: Interactions Between Grapefruit Juice and Prescription Drugs .” EDIS – Electronic Data Information Source – UF/IFAS Extension. N.p., n.d. Web. 6 Apr. 2012. .
Cerda, JJ, and et al. “The effects of grapefruit pectin on patients at risk for coronary heart disease without altering diet or lifestyle..” Clinical Cardiology 11.9 (1988): 589-594. Print.
Bub, A, and et al. “Fruit juice consumption modulates antioxidative status, immune status and DNA damage. .” Journal of Nutritional Biochemistry 14.2 (2003): -. Print.
Fujioka, K, and et al. “The effects of grapefruit on weight and insulin resistance: relationship to the metabolic syndrome.” Journal of medicinal foods 9.1 (2006): 46-54. Print