Most of us think of orange juice as a simple breakfast habit, something you pour without much thought. However, scientists are discovering that this everyday drink can do much more in the body than quench thirst.
A recent study showed that regular consumption of orange juice can influence the activity of thousands of genes inside our immune cells. Many of these genes help control blood pressure, calm inflammation, and manage how the body processes sugar, all of which play important roles in long-term heart health.
The study followed adults who drank 500 ml of pure pasteurized orange juice every day for two months. After 60 days, many genes associated with inflammation and high blood pressure became less active.
These include NAMPT, IL6, IL1B and NLRP3, which are usually turned on when the body is stressed. Another gene known as SGK1, which affects the kidneys’ ability to retain sodium (salt), also became less active.
Such changes fit with previous findings that daily consumption of orange juice can lower blood pressure in young adults.
Previous findings have suggested that daily consumption of orange juice can lower blood pressure in young adults (Getty/iStock)
This is noteworthy because it provides a possible explanation for why orange juice has been associated with better heart health in several studies. The new paper shows that the drink doesn’t just raise blood sugar. Instead, it appears to trigger small changes in the body’s regulatory systems that reduce inflammation and help blood vessels relax.
Natural compounds in oranges, especially hesperidin, a citrus flavonoid known for its antioxidant and anti-inflammatory effects, appear to influence processes related to high blood pressure, cholesterol balance, and how the body handles sugar.
The answer also varies by body size. Heavier people tended to show greater changes in genes involved in fat metabolism, while leaner volunteers showed stronger effects on inflammation.
A systematic review of controlled trials involving 639 participants from 15 studies found that regular consumption of orange juice lowered insulin resistance and blood cholesterol levels. Insulin resistance is a key feature of pre-diabetes, and high cholesterol is an established risk factor for heart disease.
Another analysis focused on overweight and obese adults found small reductions in systolic blood pressure and increases in high-density lipoprotein (HDL), often called good cholesterol, after a few weeks of daily orange juice consumption. Although these changes are modest, even small improvements in blood pressure and cholesterol can make a significant difference when maintained over many years.
More clues come from studies examining metabolites, the tiny molecules produced as the body processes food. A recent review found that orange juice influences pathways related to energy use, cell communication and inflammation. It can also affect the gut microbiome, which is increasingly understood to play a role in heart health.
About the author
David C. Gaze is Senior Lecturer in Chemical Pathology at the University of Westminster.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
One study showed that drinking blood orange juice for a month increased the number of gut bacteria that produce short-chain fatty acids. These compounds help maintain healthy blood pressure and reduce inflammation. The volunteers also showed improved blood sugar control and lower levels of inflammatory markers.
People with metabolic syndrome, a group of risk factors that includes high blood pressure, high blood sugar, and excess body fat, may see particular benefits.
In one study, daily consumption of orange juice improved the function of the lining of blood vessels, known as endothelial function, in 68 obese participants. Endothelial function describes how well blood vessels relax and widen, and better function is associated with a lower risk of heart attacks.
Not all studies report the same results. A larger analysis of blood fat concentrations found that while levels of low-density lipoprotein (LDL), often called bad cholesterol, often decrease, other measurements of lipids, such as triglycerides and HDL, may not change much. Even so, people who regularly drink orange juice can still benefit.
A study of 129 workers at an orange juice factory in Brazil reported lower blood levels of apolipoprotein B, or apo-B, a marker that reflects the number of cholesterol-carrying particles associated with heart attack risk.
Overall, the evidence challenges the idea that drinking citrus juice is simply consuming sugar in a glass. Whole fruit remains the better choice because of its fiber, but a modest daily glass of pure orange juice appears to have effects that accumulate over time.
These include reducing inflammation, supporting healthier blood flow, and improving several blood markers related to long-term heart health. It’s a reminder that everyday foods can have more influence on the body than we might expect.