A study led by Shela Gorinstein of the Hebrew University of Jerusalem suggests that consuming grapefruit, particularly red grapefruit, can lower your triglyceride levels. If you reduce your triglycerides, an artery-clogging fat, blood flows more easily to and from your vital organs, naturally lowering your blood pressure. But if you take blood pressure medications, combining them with grapefruit could prove dangerous.
Blood Pressure Drugs
Combining blood pressure medication with grapefruit juice can lower your blood pressure too drastically because having grapefruit in your body stops your body's CYP34A enzyme from being able to metabolize medication. This means that medications stay in your system longer than intended and, if you keep taking the medication, the drug will build up in your system. If blood pressure medications build up in your system, your blood pressure could drop to dangerously low levels. Your heart could stop beating.
Calcium Channel Blockers
If you take calcium channel blockers, a type of blood pressure medication, do not mix them with grapefruit. Channel blockers known to cause serious side effects when mixed with grapefruit include felodipine and nifedipine. Calcium channel blockers work by preventing calcium from getting into your blood vessels and heart. This lowers your blood pressure. If you take any type of blood pressure medication, ask your doctor if you can safely combine it with grapefruit juice.
If you have high blood pressure, you may also have high cholesterol. High blood pressure makes it easier for cholesterol to collect in your arteries, and the cholesterol buildup in your arteries puts added pressure on your heart. Since the two conditions are linked, your doctor may prescribe drugs to lower your cholesterol as well as your blood pressure. If you take statins, a class of cholesterol-lowering drugs, do not combine them with grapefruit juice.
Red Grapefruit Juice
Gorinstein's grapefruit study, published in the "Journal of Agricultural and Food Chemistry" in 2006, showed that consuming grapefruit may help naturally lower your cholesterol and, in turn, blood pressure. The participants of Gorinstein's study – 57 men and women with high blood pressure – consumed grapefruit for a month. At the end of the month, those who consumed grapefruit enjoyed a reduction in their triglycerides, a type of lipid that contributes to your total cholesterol levels. Red grapefruit proved more helpful than white grapefruit in lowering triglycerides. While drinking red grapefruit juice may prove effective in naturally lowering your blood pressure, if you take any kind of medication -- not just blood pressure or cholesterol-lowering drugs -- consult a medical professional before adding grapefruit juice to your diet.
- "Journal of Agricultural and Food Chemistry"; Red Grapefruit Positively Influences Serum Triglyceride Level in Patients Suffering from Coronary Atherosclerosis: Studies in Vitro and in Humans; Shela Gorinstein, et al.; 2006
- American Heart Association: About High Blood Pressure
- “The New York Times”; Experts Reveal the Secret Powers of Grapefruit Juice; Nicholas Bakalar; March 2006