A daily glass of orange juice might do more than deliver vitamin C. It may influence gene activity in ways that support heart health, according to new research.
In a small but detailed study, 20 healthy adults drank about two cups of 100% orange juice every day for two months.
Researchers from the University of São Paulo in Brazil, North Carolina State University and the University of California, Davis, tracked changes in more than 1,700 genes within participants’ immune cells, finding broad shifts in genetic activity tied to blood pressure, fat metabolism and inflammation — all key factors in cardiovascular health.
The findings highlight how citrus flavonoids — plant compounds also found in berries, tea and cocoa that act as antioxidants and anti-inflammatories — may influence the body at a molecular level. The research was published in the journal Molecular Nutrition & Food Research in late October.
Most of the changes among participants pointed toward lower inflammation and healthier blood vessel function, though responses differed by body weight. Normal-weight participants showed shifts in inflammation-related genes, while those who were overweight displayed changes tied to fat metabolism and energy use.
“These findings reinforce the therapeutic potential of orange juice by providing unprecedented insights into the molecular mechanisms behind its health effects,” the researchers wrote.
The findings also suggest that body weight “may influence molecular response to bioactive compounds in OJ and provide information for personalized recommendations on the consumption of flavonoid-rich foods,” they added.
The researchers cautioned that the study was small and lacked a control beverage, showing associations rather than proof of cause and effect.
They said more research is needed to determine whether these molecular shifts translate into clinical benefits.
Nicolette Pace, a registered dietitian nutritionist from New York, said the study supports using plant compounds to promote longevity and reduce future disease risk, but noted that while changes in gene expression and health are interconnected, they are not identical.
“Orange juice isn’t an elixir — it’s one deeply studied example,” Pace told Fox News Digital.
Nonetheless, she said, the new study “opens the door to incredible possibilities for how individualized nutrition can truly work.” (She was not involved with the study.)
Pace said she recommends low to moderate daily orange juice consumption.
“In normal amounts, the sugar content doesn’t cancel out the benefits,” she said.
Funding for the study came from the São Paulo Research Foundation, Brazil’s National Council for Scientific and Technological Development, the Food Research Center and the U.S. Department of Agriculture’s National Institute of Food and Agriculture.
Fox News Digital reached out to the study’s authors for comment.
Meanwhile, past research has found that adults who drank 100% orange juice before a meal ate fewer total calories and had lower blood sugar levels throughout the day compared to those who drank a sugar-sweetened “orange drink,” Fox News Digital previously reported.
Researchers at Toronto Metropolitan University determined that the difference likely comes from orange juice’s natural flavonoids, which may slow sugar absorption, showing that the body can differentiate between natural sugars and added sugars, according to the 2024 study.