A morning glass of orange juice may offer more than a refreshing start to the day, with research pointing to potential health benefits beyond helping the immune system.
Orange juice is rich in vitamin C and antioxidants, nutrients often associated with immune support and protection against common winter viruses.
However, a growing body of evidence suggests that drinking one or two glasses daily could also support long-term heart and metabolic health.
In a recent study, people who consumed two cups of 100 percent orange juice each day experienced notable changes in genes linked to metabolism, blood vessel function and inflammation.
Participants carrying more weight also showed greater improvements in the way their bodies processed fat after drinking orange juice, a change that could potentially contribute to weight loss.
Other research has reported similar findings, including lower blood pressure, suggesting that regular orange juice consumption may be associated with a reduced risk of heart disease.
Scientists believe flavonoids—antioxidant compounds found in orange juice—may influence genes involved in inflammation and cardiovascular function.
The type of juice matters, though. Orange juice blends containing added sugar have been consistently associated with a higher risk of heart disease because they can cause blood sugar spikes and promote inflammation in the heart and blood vessels.
Recent studies suggest that drinking orange juice once or twice a day may help lower cholesterol, blood pressure and excess weight
By contrast, 100 percent orange juice contains only naturally occurring sugar and does not include added additives or preservatives.
In a study published last year in Molecular Nutrition & Food Research, researchers split 20 participants into two equal groups: 10 adults with a normal weight and 10 who were overweight.
Before the trial began, each participant provided a fasting blood sample. Researchers then isolated peripheral blood mononuclear cells, or PBMCs—a group of white blood cells that includes immune cells such as lymphocytes and monocytes.
All participants drank 17 ounces, equivalent to two cups, of pasteurized 100 percent orange juice every day for 60 days.
After the two-month period, participants gave a second fasting blood sample. This allowed researchers to examine whether daily orange juice consumption had altered the activity of specific genes.
The researchers identified significant changes in the activity of 1,705 genes: 1,673 became less active, while 32 became more active.
Several genes associated with inflammation were less active after the daily orange juice intake, including one involved in producing the inflammatory protein IL-1β.
The study also detected changes in genes involved in blood pressure regulation. Activity decreased in NAMPT, NLRP3, NR4A2 and SGK1, genes that have previously been linked to high blood pressure.
Orange juice also influenced genes related to fat storage. Several genes involved in the development of fat cells—including KLF4, RIPK1, PLIN2 and CXCL8, some of which have previously been associated with obesity—became less active.
Earlier research has likewise pointed to potential benefits for cardiovascular health.
A 2020 review found that regular orange juice consumption was associated with lower blood sugar and insulin levels, factors that may reduce the risk of type 2 diabetes.
Similarly, a 2021 meta-analysis looking at 639 participants found that orange juice consumption lowered cholesterol, which is directly linked to heart disease risk, and insulin resistance, a precursor to type 2 diabetes.
And a meta-analysis in the journal Food & Function found that overweight and obese adults had reductions in blood pressure and increases in HDL (good) cholesterol after several weeks of drinking orange juice regularly.
These benefits may be due to structural changes in blood vessels. One recent study of 68 obese participants found that daily orange juice consumption improved endothelial function, or function of the lining of the blood vessels.
Better endothelial function means the blood vessels are able to more easily relax and widen, lowering the risk of heart attacks.
Researchers caution that before adding orange juice to your breakfast rotation, make sure you’re only picking up 100 percent fruit juice, as other varieties can include more added sugar than a Krispy Kreme donut or a chocolate chip cookie.
