A series of new scientific studies is shedding light on how daily orange juice consumption may shape key biological processes linked to cardiovascular health. Researchers say that the drink, a common part of breakfast for millions, appears to trigger changes in the activity of thousands of genes inside immune cells — many of which regulate blood pressure, inflammation and sugar metabolism.

The findings were highlighted by David C. Gaze, Senior Lecturer in Chemical Pathology at the University of Westminster, who reviewed the research in The Conversation. He noted that the latest results point to subtle but meaningful effects on systems that influence long-term heart function.

In one study, adults consumed 500 millilitres of pure pasteurised orange juice every day for two months. By the end of the trial, several genes associated with inflammation — including NAMPT, IL6, IL1B and NLRP3 — showed reduced activity. These genes are typically activated during physiological stress. Researchers also reported lower activity in SGK1, a gene that helps determine how efficiently the kidneys retain sodium, a factor tied to blood pressure regulation.

Scientists involved in the work say these changes suggest that regular orange juice intake may encourage relaxation of blood vessels while curbing inflammatory responses. These effects align with earlier findings showing that young adults who drink orange juice regularly tend to record lower blood pressure readings.

The research also supports long-standing interest in hesperidin, a natural flavonoid found in oranges. Hesperidin is known for its antioxidant and anti-inflammatory properties, and the latest results suggest it may play a role in balancing cholesterol levels, supporting healthy blood pressure, and influencing sugar metabolism.

Responses also varied depending on body type. Genes linked to fat metabolism appeared more responsive in overweight participants, while inflammation-related genes shifted more noticeably in leaner individuals.

Broader analyses have also pointed to benefits linked to insulin resistance and cholesterol management. A review of 15 controlled studies involving 639 people found that consistent orange juice consumption reduced insulin resistance and levels of LDL, the so-called “bad” cholesterol. Another study involving overweight adults recorded slight reductions in systolic blood pressure and a rise in HDL, considered “good” cholesterol.

In metabolite-focused research, orange juice consumption was associated with favourable changes in energy use, cellular communication and inflammation pathways. Volunteers who drank blood orange juice for a month showed an increase in gut bacteria that produce short-chain fatty acids, compounds tied to healthier blood pressure and reduced inflammation.

Among people with metabolic syndrome, orange juice intake improved endothelial function — the ability of blood vessels to relax and widen. Better endothelial function is linked to lower risks of heart attack and other cardiovascular events.

Researchers say not all studies report large shifts in cholesterol or triglycerides, but the overall evidence points to a consistent trend: regular orange juice consumption may help reduce inflammation, support healthier blood flow and improve several markers linked to heart disease risk.