Analysis of 10 randomized controlled trials including data from 688 participants revealed that lycopene supplementation was associated with significant reductions in systolic blood pressure (SBP) of an average of 2.6 mmHg, with greater effects observed in people with higher SBP at the start of the studies, higher lycopene doses, and longer duration supplementation.
Non-significant reductions in diastolic blood pressure (DBP) were recorded in the total pooled analysis, but statistical significance was achieved in people with higher overall blood pressure or DBP at baseline, wrote researchers in the Journal of Herbal Medicine.
“The results of this meta-analysis are consistent with recent systematic reviews that proposed the potential anti-hypertensive effects of tomato products supplementation,” wrote researchers from Iran and Canada.
Mechanisms of action
Commenting on the potential ways that lycopene may exert its blood pressure benefits, the researchers noted three possible mechanisms of action. One is via inhibiting the angiotensin converting enzyme (ACE), “thereby reducing angiotensin-II induced oxidative stress and indirectly enhancing nitric oxide (NO) production.
“Oxidative stress through the disruption of NO production leads to oxidative damage of the endothelial cells and ultimately to endothelial dysfunction. Lycopene enhances NO synthesis and bioavailability through reducing oxidative stress and thus improves endothelium-dependent vasodilation and reduces protein, lipids, DNA, and mitochondrial damage.”
Lycopene may also enhance the body’s own antioxidant defenses, including the antioxidant enzymes catalase and superoxide dismutase, said the researchers.
The carotenoid may also exert anti-inflammatory effects by inhibiting the NF-kB pathway.
“Lycopene has been shown to modulate adiponectin expression and secretion in animal cells and cell culture,” they added. “Evidence suggests that adiponectin has a potent role in regulating BP. Adiponectin reduces BP through anti-inflammatory, anti-atherogenic and insulin sensitivity effects and reversed salt-induced [hypertension].
“Overall, these findings indicate that lycopene supplementation could be regarded as a potential healthy supplement for regulating BP.”
The researchers called for additional studies with longer intervention periods and larger sample sizes to determine the optimal doses, are needed to determine the appropriate dosage of the supplement, and the useful effects of lycopene on SBP, DBP levels.
Source: Journal of Herbal Medicine
February 2022, Volume 31, 100521, doi: 10.1016/j.hermed.2021.100521
“Lycopene Supplementation and Blood Pressure: Systematic review and meta-analyses of randomized trials”
Authors: M. Rezaei kelishadi et al.