Grapefruit can be a nutritious addition to one’s diet, providing a source of vitamin C, potassium, carotenoids, fiber, and various other health-promoting vitamins, minerals, and phytochemicals.
Only a few clinical trials have examined grapefruit's health effects in humans. Some preliminary studies have pointed to potential benefits on cardiovascular health and metabolic health, including reduced blood pressure, weight loss, and improved lipid profiles and endothelial function.[1][2][3][4] However, these effects aren’t found consistently, and more research is needed.
In observational studies, higher intakes of flavonoid-rich foods tend to be associated with a reduced risk of all-cause mortality, cardiovascular disease, and cerebrovascular disease (e.g., stroke).[5][6] However, the relationship is less robust when looking specifically at grapefruit or its main types of flavonoids (flavanones). Some studies have even reported an increased risk of all-cause mortality with higher levels of consumption.[7][8] It’s unclear why this is, but the researchers suggested it could relate to the risk of drug interactions with grapefruit or to the disproportionate consumption of fruit juice rather than whole fruit.