BARTOW – A study examining the effects of 100% grapefruit juice consumption on vascular function in women reported that consumption led to lower vascular stiffness when compared to a control drink. Increased arterial stiffness is primarily a consequence of aging and has been associated with an increased risk of cardiovascular disease, including heart attack and stroke.

Originally published in the American Journal of Clinical Nutrition1, this randomized controlled cross-over study included 48 postmenopausal women aged 50 to 65 years old. The women consumed 340 mL/day (approximately 11.3 oz) of 100% grapefruit juice or a control drink that was matched to grapefruit juice for sugars, calories, and most vitamins and minerals, but contained no naringin, the primary polyphenol in grapefruit juice. Beverages were consumed for six months, followed by a two-month rest period before participants consumed the opposite beverage for another six months. The women ate their normal diet throughout the study but limited their intake of other citrus and foods high in polyphenols, such as tea, cocoa, and wine.

Following consumption of 100% grapefruit juice, measurements of the arteries found they were less stiff compared to the control drink, linking 100% grapefruit juice to positive effects on vessel health. Consumption of 100% grapefruit juice was not found to adversely affect total energy (calorie) intake, body weight, glucose metabolism, or insulin resistance.

A recent follow-up analysis2 on blood samples from a subset of women in the study found that the consumption of 100% grapefruit juice affected the expression of certain genes and proteins associated with beneficial effects on inflammation, immunity, cell interaction, and vascular function. These positive effects were likely due to naringin since the control drink was nutritionally similar to 100% grapefruit juice but lacked naringin. These data help explain how polyphenols might work in the body to positively affect health outcomes. 

“These results add to the growing body of evidence supporting the beneficial health effects of citrus juice polyphenols, like naringin in grapefruit juice and hesperidin in orange juice,” said Dr. Rosa Walsh, Director of Scientific Research for the Florida Department of Citrus. “100% citrus juices deliver vitamins, minerals, and bioactive compounds that help contribute to good health and are a great addition to a well-balanced diet.”

An 8-ounce serving of 100% grapefruit juice is an excellent source of vitamin C and also counts toward total fruit intake. Research supports a positive role for 100% grapefruit juice and fresh grapefruit toward various health benefits, including immune support, weight management, and fighting inflammation and oxidative stress.    

About the Florida Department of Citrus The Florida Department of Citrus is an executive agency of Florida government charged with the marketing, research, and regulation of the Florida citrus industry. Its activities are funded by a tax paid by growers on each box of citrus that moves through commercial channels. The industry employs more than 33,000 people, provides an annual economic impact of $6.762 billion to the state, and contributes hundreds of millions of dollars in tax revenues that help support Florida’s schools, roads, and health care services. For more information about the Florida Department of Citrus, visit FloridaCitrus.org/newsroom.