Blackmores Institute

The systematic review and meta-analysis examined the evidence of 19 randomised controlled trials for the effects of phytosterol supplementation on blood pressure in an adult population and found that phytosterol supplementation led to significant reductions in both systolic blood pressure (WMD: 1.55 mmHg, 95% CI: 2.67 to 0.42, p 1⁄4 0.007) and diastolic blood pressure (WMD: 0.84 mmHg, 95% CI: 1.60 to 0.08, p 1⁄4 0.03).
 
 Principally found in nuts, fruit and seeds, phytosterols are cholesterol homologues and are present in the diet in quantities similar to cholesterol. Numerous studies have indicated positive effects of phytosterols on blood pressure. Some studies on the beneficial effects of a high intake of vegetables and fruits in cardiovascular disease suggest that these effects may be due to the presence of phytochemicals, including phytosterols. 
 
 “Previous studies have investigated the effects of phytosterols on cardiovascular outcomes; however, contradictory reports from these studies were shown in endothelial function and blood pressure. Several reports have indicated a positive effect of phytosterol intake on blood pressure while some studies have shown an increase in patients' blood pressure with consumption of phytosterols,” the authors explained.
 
 “The results of our meta-analysis indicate that supplementation with phytosterols reduces systolic and diastolic blood pressure. Although the magnitude of the observed reduction appears small, it seems to be both statistically and clinically significant and based on recent studies, even a minor decrease in blood pressure is beneficial for cardiovascular risk management and can effectively reduce cardiovascular events,” the authors stated.
 
 While the exact mechanism by which phytosterols lower BP is not yet fully understood, the authors proposed three possible mechanisms:
 • Phytosterols significantly increase the release of prostacyclin, a potent vasodilator, from vascular smooth muscle cells, which decreases peripheral vascular resistance and arterial stiffness to reduce BP 
 • Indirectly phytosterols contribute to decreased body weight and body mass index - studies have found that each kilogram of body weight loss brings about a ~1 mmHg reduction in both SBP and DBP
 • Through their cholesterol-lowering properties, phytosterols have the potential to lower blood pressure. A few mechanisms have been suggested in this case, including reducing large arterial stiffness, as well as improving endothelial function 
 
 The review found that in analyses of subgroups, short-term supplementation with phytosterols of less than 12 weeks was more effective in reducing blood pressure than long term supplementation, prompting researchers to state further investigation is required.
 
 “Phytosterols seem to reduce both SBP and DBP in a dose- and duration-dependent manner. Therefore, supplementation with these plant-derived compounds may be a beneficial adjuvant therapy in hypertensive patients as well as a complementary preventive option in prehypertensive and normotensive individuals,” the authors concluded.
 
 Source:
 Clin Nutr. 2019. DOI: <a href="https://doi.org/10.1016/j.clnu.2019.12.020">10.1016/j.clnu.2019.12.020</a>

People with hypertension may benefit from introducing phytosterols into their treatment plan according to a systematic review published in the journal, Clinical Nutrition.

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