Effect of Lycopene Intake on the Fasting Blood Glucose Level: A Systematic Review with Meta-Analysis

Abstract

Lycopene is a lipophilic unsaturated carotenoid exhibiting a strong singlet oxygen-quenching ability. Herein, we investigated the effect of lycopene intake on the fasting blood glucose (FBG) level by conducting a systematic review and meta-analyses. We searched 15 databases (from the earliest date to June 2022 for PubMed or to August or September 2018 for the other databases) and included human interventional studies that assessed the effects of oral lycopene intake on FBG levels of participants ≥ 18 years of age. Three authors independently selected applicable studies and then assessed the study quality. Data were pooled as standardized mean difference (SMD) and analyzed by the random-effects model. Heterogeneity was assessed by I2 statistics. A meta-analysis including 11 trial arms (n = 750) revealed a tendency towards a significant decrease in FBG level with not-important heterogeneity [SMD = −0.15 (95% CI: −0.31, 0.00), p = 0.05, I2 = 9%]. Subgroup meta-analysis including two studies (n = 152) in type 2 diabetes patients revealed significantly decreased FBG levels with not-important heterogeneity [SMD = −0.37 (95% CI: −0.69, −0.05), p = 0.02, I2 = 0%]. Most studies meeting the eligibility criteria had a moderate risk of bias. The funnel plot for FBG suggested an absence of publication bias. In conclusion, this systematic review and meta-analyses suggested that lycopene intake exerted an FBG-decreasing effect.

Overview of the Potential Beneficial Effects of Carotenoids on Consumer Health and Well-Being

“…The global diabetes prevalence and health expenditure are currently rising and are expected to reach 700 million people and USD 776 billion by 2045. A healthy lifestyle, primarily including the adoption of a healthy diet rich in fruit and vegetables, is the cornerstone for the glycemic control and prevention of TD2 [90]. Recent meta-analysis studies have examined the associations of dietary intakes and circulating concentrations of carotenoids with the risk of T2D.…”

“…Furthermore, lycopene intake has exerted a fasting blood glucose (FBG) decreasing effect. However, despite the promising results, the same authors warn about the need to carry out more studies in order to confirm the causality and explore the role of foods rich in carotenoids in the prevention of T2D [90,91].…”

Photochemical and Photophysical Properties of Carotenoids and Reactive Oxygen Species: Contradictions Relating to Skin and Vision

“…Indeed, this work compared six solvents including the complex mixture used by Di Mascio and could not replicate their results, thus showing that there is not a substantially increased quenching efficiency of singlet oxygen by lycopene compared to other carotenoids. While both these sets of older data refer to environments far removed from those of biological interest, the DiMascio result is still frequently quoted in the recent biological literature, for example [6][7][8]. There is no clear reason for these different results; certainly lyc is a particularly insoluble carotenoid in polar solvents, and this could lead to experimental difficulties.…”