The Role of Circulating Lycopene in Low-Grade Chronic Inflammation: A Systematic Review of the Literature

Abstract

Background and aims: In recent years, it has become clear that low-grade chronic inflammation is involved in the onset and progression of many non-communicable diseases. Many studies have investigated the association between inflammation and lycopene, however, results have been inconsistent. This systematic review aims to determine the impact of circulating lycopene on inflammation and to investigate the effect of consuming tomato products and/or lycopene supplements on markers of inflammation. Methods: Eligible studies, published before March 2020, were identified from PubMed, EBSCOhost and ScienceDirect. Human studies published in English, that evaluated the effect of circulating lycopene in relation to inflammation biomarkers were screened and included. Studies assessing lycopene intake or general intake of carotenoids/antioxidants without measuring circulating lycopene, as well as those not reporting inflammation biomarkers as outcomes, were excluded. Results: Out of 80 publications identified and screened, 35 met the inclusion criteria. Results from 18 cross-sectional studies suggest that lycopene levels are adversely affected during inflammation and homeostatic imbalance. Most of the 17 included intervention studies reported increased circulating lycopene levels after tomato/lycopene supplementation, but almost no changes in inflammation biomarkers were observed. Conclusions: There is little evidence that increasing tomato intake or lycopene supplementation diminuates this inflammation. However, depletion of lycopene may be one of the first signs of low-grade inflammation. The available data thereby imply that it is beneficial to consume lycopene-rich foods occasionally to stay healthy and keep circulating lycopene at a basal level.

Lycopene Inhibits Oxidative Stress-Mediated Inflammatory Responses in Ethanol/Palmitoleic Acid-Stimulated Pancreatic Acinar AR42J Cells

“…Patients with chronic pancreatitis had significantly lower plasma concentrations of antioxidants (selenium, vitamin A, vitamin E, beta-carotene, xanthine, beta-cryptoxanthine, and lycopene) compared with both control subjects and patients with recurrent acute pancreatitis [ 34 ]. Steenwijk et al [ 35 ] screened the publications which were published before March 2020. They suggested that there is little evidence that increasing tomato intake or lycopene supplementation decreases inflammation.…”

Sustainable Valorization of Tomato By-Products to Obtain Bioactive Compounds: Their Potential in Inflammation and Cancer Management

“…However, in a double blind, randomized, placebo-controlled crossover trial, in participants who had ingested a supplement containing a tomato extract (lycopene, phytoene, and phytofluene), no effect was observed on inflammation and oxidative stress despite the observed attenuation of the post-exercise increase in the muscle damage biomarker myoglobin [ 77 ]. Indeed, a recent systematic review [ 78 ] evaluated the effect of lycopene on the inflammation and the consumption of lycopene supplements and tomato products on the biomarkers of inflammation in humans. It was indicated that the lycopene levels were negatively affected during the inflammation.…”

“…Although an increase of lycopene levels (serum or plasma) was observed after intake of tomato /lycopene supplementation, there was no change in the inflammatory biomarkers. The authors of this study pointed that there is little evidence that the increase of consumption of tomato or lycopene supplements reduces the inflammation, but the depletion of lycopene could be one of the first indicators of low-grade inflammation [ 78 ].…”

Valorized Food Processing By-Products in the EU: Finding the Balance between Safety, Nutrition, and Sustainability

“…As a result, the extraction of phenolic compounds, dietary fibers, and other bioactive compounds from these by-streams has been widely studied [61]. Compounds such as lycopene from tomato pomace [62,63] and various phenolic compounds from grape seed extract, apple peels, and orange peels [36,[64][65][66] are examples of compounds that can be valuable for the food industry for their health effects.…”