Benefits
Less LDL oxidation in one small trial
In a 3-month randomized double-blind trial in 23 untreated adults with raised cholesterol, oxidized LDL fell from about 94 to 63 U/L on CitrOlive (two 500 mg capsules daily) and rose slightly on placebo, a significant difference between groups. The oxidized LDL to LDL ratio moved the same way. The trial was small and co-designed by a maker employee.
Cholesterol and triglycerides: no clear change versus placebo
In the same trial, total cholesterol fell within the CitrOlive group (236 to 228 mg/dL) but not significantly more than on placebo, and triglycerides, LDL and HDL cholesterol and apolipoproteins A1 and B did not differ between groups. Launch materials reported a triglyceride drop; the published trial did not find one.
Paraoxonase (PON1) activity rose within the CitrOlive group
PON1 is an HDL-linked enzyme that helps protect LDL from oxidation. In the 3-month trial it rose from 64.5 to 78.7 U/L on CitrOlive and was unchanged on placebo, but the paper reports this as a within-group change, not a significant difference between groups, and the placebo group started higher (81.6 U/L).
Vessel function and blood pressure with a related blend (Citroven)
In an 8-week randomized trial in 96 adults aged 40 to 75 with mildly raised cholesterol, Citroven, a sister IFF blend that adds grapefruit extract to bitter orange and olive leaf, improved flow-mediated dilation, diastolic pressure, total and LDL cholesterol and oxidized LDL (LDL-oxidase) versus placebo. Systolic pressure did not differ. It is not CitrOlive alone.
Olive leaf extract class evidence for blood pressure and lipids
In a 6-week crossover trial in 60 men with high-normal blood pressure, a different olive leaf extract supplying 136 mg oleuropein a day lowered daytime and 24-hour blood pressure by about 2 to 4 mmHg and reduced total and LDL cholesterol and triglycerides versus control. It was half-funded by its maker and did not test CitrOlive.
Mechanism of action
Protecting LDL from oxidation
Oxidized LDL is LDL whose fats and proteins have been damaged by oxidation, a change linked to fatty build-up in artery walls. Olive leaf and citrus polyphenols act as antioxidants in laboratory studies, which is the proposed reason oxidized LDL fell in the CitrOlive trial; this has not been measured directly in people.
Paraoxonase (PON1)
PON1 is an enzyme carried on HDL that breaks down oxidized lipids and helps protect LDL from oxidation. In the CitrOlive trial its activity rose only within the supplement group, so whether CitrOlive raises PON1 compared with placebo is not established.
Bitter orange flavonoids
The bitter orange extract supplies flavanones such as naringin, neohesperidin and hesperidin and flavones such as luteolin and diosmetin glycosides, as listed by the trial authors. These flavonoids are studied for effects on blood vessel lining cells and lipid handling, mostly in laboratory and animal work.
Olive leaf polyphenols
The olive leaf extract supplies oleuropein-family secoiridoids and hydroxytyrosol; IFF standardizes CitrOlive to more than 18 percent oleuropeosides. Separate trials of other olive leaf extracts have reported small blood pressure and lipid changes, but those products are not CitrOlive.
Vessel relaxation (animal tissue only)
In an ex vivo study, CitrOlive and separate citrus and olive leaf extracts relaxed aorta rings from spontaneously hypertensive rats in an endothelium-dependent way that relied on nitric oxide. This is animal tissue work; the CitrOlive human trial did not report blood pressure or vessel function results.
Clinical trials
3-month randomized, double-blind, placebo-controlled trial at the Catholic University of Murcia (UCAM), Spain (NCT04330937, registered after enrolment began). Two capsules daily, 2 x 500 mg CitrOlive per the methods (the abstract says 500 mg, two capsules a day; the registry lists one 500 mg capsule), or maltodextrin placebo. Outcomes: oxidized LDL, lipids, apolipoproteins, PON1. The paper reports no external funding; an IFF employee co-authored it and helped design the protocol. Blood pressure, one of the registered primary outcomes, is not reported. (Victoria-Montesinos et al. 2021, Antioxidants (Basel))
30 adults randomized, 23 completed (14 CitrOlive, 9 placebo); mean age 41.9, 70 percent men, total cholesterol above 200 mg/dL and LDL above 130 mg/dL, not on cholesterol, blood pressure or diabetes medicines.
Oxidized LDL fell from 93.8 to 62.8 U/L on CitrOlive and rose from 98.2 to 105.7 U/L on placebo, a significant difference between groups; the oxidized LDL to LDL and HDL to LDL ratios also differed. Total cholesterol fell significantly only within the CitrOlive group (236 to 228 mg/dL; placebo 246 to 241 mg/dL), and triglycerides, LDL and HDL cholesterol and apolipoproteins A1 and B did not differ between groups. PON1 rose from 64.5 to 78.7 U/L within the CitrOlive group, not reported as a between-group difference. Weight and body fat did not change. The authors call the small sample and 3-month length the main limitations.
Single-centre randomized, double-blind, placebo-controlled trial at UCAM, Spain (NCT04114916). Citroven, an IFF blend of grapefruit and bitter orange extracts plus olive leaf extract (the registry lists it as apigenin, luteolin, grapefruit extract and CitrOlive), 2 x 500 mg daily for 8 weeks, or maltodextrin placebo. Primary outcome: flow-mediated dilation (FMD). Two authors were affiliated with the maker, Nutrafur iff-Health, although the paper declares no conflict. (Sánchez Macarro et al. 2020, Nutrients)
110 healthy adults aged 40 to 75 with total cholesterol of at least 180 mg/dL and LDL of at least 110 mg/dL randomized; 96 analysed per protocol (51 active, 45 placebo).
FMD rose from 6.7 to 9.8 percent on the blend versus 6.9 to 7.4 percent on placebo (between-group p = 0.039). Diastolic pressure, total and LDL cholesterol, oxidized LDL, the glutathione ratio, protein carbonyls and IL-6 also improved versus placebo. Systolic pressure fell within the active group, but the between-group difference was not significant (p = 0.168), although the abstract groups it with the significant results; HDL, triglycerides, CRP and TNF-alpha did not differ. No adverse events were reported. This tested a different product and is not CitrOlive evidence.
Randomized, double-blind, controlled crossover trial at the University of Reading, UK: an olive leaf extract supplying 136 mg oleuropein and 6 mg hydroxytyrosol daily, or a polyphenol-free control, for 6 weeks each with a 4-week washout. Half the funding came from Comvita, maker of the extract. This is not CitrOlive. (Lockyer et al. 2017, European Journal of Nutrition)
60 men with high-normal blood pressure (systolic 121 to 140, diastolic 81 to 90 mmHg), mean age 45.
Compared with control, daytime and 24-hour systolic pressure were lower by about 4 and 3 mmHg and diastolic by about 3 and 2 mmHg, and total cholesterol, LDL and triglycerides were lower. Interleukin-8 fell, but other inflammation markers, vascular function and glucose measures did not change.