Nutritional Content Of Half A Red Grapefruit

Half a red grapefruit contains 52 calories, making it a low-calorie breakfast or snack food. While half a red grapefruit provides a good source of vitamins and fiber, it also contains properties that interact adversely with some medications. If you take any prescription drugs or dietary supplements, talk to your doctor before including grapefruit -- in any quantity -- in your diet.

Fiber

Half a red grapefruit contains 2 g of dietary fiber. Men should get between 28 g and 34 g of fiber daily, while women should get between 22 g and 28 g of fiber each day. Eating fiber-rich foods, such as grapefruit, may help reduce your risk of developing cardiovascular disease. Fiber consumption can reduce low-density lipoprotein -- otherwise known as "bad" cholesterol -- and can lower your blood pressure and blood glucose levels.

Vitamin C

Half a red grapefruit contains 38.4 mg of vitamin C. Men should get 90 mg of vitamin C daily and women should get 75 mg. Vitamin C possesses strong antioxidant abilities capable of neutralizing free radicals that can harm your health. Although vitamin C remains unproven as a way to prevent colds, it can play a role in fighting off infections, notes Harvard School of Public Health.

Fructose

The American Heart Association recommends grapefruit among its triglyceride-friendly fruits. Half a red grapefruit contains 2.18 g of fructose. To control your triglycerides, a type of artery clogging fat, the AHA recommends you limit fructose intake to 50 g to 100 g a day. This means you could eat nearly 25 whole red grapefruits daily, without exceeding the guidelines. If you need to lower your triglycerides, other good fruit choices include cantaloupes and raspberries.

Drug Interactions

Grapefruit interacts adversely with several medications, including calcium channel blockers, statins, birth control pills, antidepressants and other psychiatric drugs. Even half a red grapefruit could lead to side effects, as grapefruit prohibits your body's CYP34A enzyme from being able to metabolize some drugs. If medications aren't properly broken down, they end up elevated in your bloodstream, which can raise their effectiveness and the likelihood of side effects, some of them fatal.