Including cranberries and grapefruit as part of a healthy diet can lead to improvements in your health. Each 1-cup serving of fresh cranberries contains only 46 calories and provides 18 percent of the daily value for fiber and 22 percent of the DV for vitamin C. Eat half a medium grapefruit and you will have consumed 74 percent of the DV for vitamin C. If you choose a pink or red grapefruit, you'll also get 24 percent of your vitamin A, all for only 41 calories. Both of these fruits are also filled with beneficial phytochemicals that may help lower your risk for certain medical conditions.
Heart Disease
Consuming grapefruit or grapefruit juice may help you increase your high-density lipoprotein, or good cholesterol, according to a study published in "Nutrition and Metabolism" in 2011. Study participants consumed half a grapefruit or 127 grams of unsweetened white grapefruit juice 20 minutes before each meal for 12 weeks to achieve this benefit. Cranberries contain a variety of phytochemicals that act as antioxidants and stop free radicals from damaging your cells, thus lowering your risk for heart disease, according to an article published in "Critical Reviews in Food Science and Nutrition" in 2010.
Cancer
Grapefruit contains phytochemicals, including naringenin and limonoids, that may help prevent the spread of cancer. Cranberries also contain beneficial compounds that help kill cancer cells and keep them from spreading, according to an article published in "The Journal of Food Science and Agriculture" in October 2011. However, research in these areas is still in the preliminary stages.
Other Health Benefits
Eating cranberries may help you avoid getting cavities by creating a more acidic environment in your mouth and keeping plaque from attaching to the teeth, according to an article published in "Critical Reviews in Food Science and Nutrition" in 2008. Drinking cranberry juice regularly may help limit the number of urinary tract infections that women develop, especially those who frequently get these infections, according to an article published in "The Cochrane Database of Systematic Reviews" in 2012.
Considerations
Grapefruit and grapefruit juice can interfere with medications, causing them to be either more or less effective, so check with your doctor before consuming these foods, especially if you take antibiotics, blood pressure medications and cholesterol drugs. Drinking large amounts of cranberry juice can cause upset stomach or diarrhea and may not be safe for people who take blood thinners. Don't rely on grapefruit or cranberries to treat any health problem, including urinary tract infections, since neither has been proven effective for this purpose.