Contents lists available at ScienceDirect Journal of Functional Foods journal homepage: www.elsevier.com/locate/jff Moderate but not high daily intake of chili pepper sauce improves serum glucose and cholesterol levels Saša Kenig a , Alenka Baruca-Arbeiter b , Nina Mohorko a , Mojca Stubelj a , Maša Černelič-Bizjak a , Dunja Bandelj b , Zala Jenko-Pražnikar a , Ana Petelin a, ⁎ a University of Primorska, Faculty of Health Sciences, Polje 42, SI-6310 Izola, Slovenia b University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies, Glagoljaška 8, SI-6000 Koper, Slovenia ARTICLE INFO Keywords: Capsaicinoids Inflammation Lipid profile Genetic profiling Clinical study ABSTRACT Chili and its main active ingredient capsaicin have been shown to induce several favorable biological activities. In the present study we have tested the effect of three chili sauces mimicking popular commercially available chili sauces with an increasing amount of capsaicinoids on a broad range of serum biochemical markers in thirty healthy subjects. We show that in the region where daily use of chili is traditionally low, moderate consumption of 4.4 mg of capsaicinoids per day has beneficial health effects, such as decrease in glucose level, LDL cholesterol and C-reactive protein. However, when a product with higher daily dose of capsaicinoids (16.7 mg/day) was consumed, those effects were lost. Considering that biochemical marker levels returned to the initial levels after a week-long wash-out period, we suggest that regular intake of moderate amounts of chili product would be most profitable. 1. Introduction Chili peppers (Capsicum sp.), although originally South American, are used in culinary cultures worldwide and their production has in the last decade been increasing (Faostat, 2017; www.fao.org/faostat/). Chilies contain non-caloric bioactive ingredients, which have lately gained considerable interest as a potential anti-obesity dietary inter- vention. Studies investigating how chili peppers affect energy balance, metabolism and other health related parameters are focused mainly on the activation of transient receptor potential vanilloid-1 (TRPV) re- ceptors by capsaicin, their most abundant bioactive compound, also responsible for its pungency. In animal models, several benefits of either single capsaicin con- taining meal or regular capsaicin intake were described. These include accelerated thermogenesis, an increase in lipid oxidation (Kawabata et al., 2009), inhibited adipogenesis and therefore reduced deposition of lipids in liver and as visceral fat (Li et al., 2012). Improved glucose tolerance was also found consistently (Lee et al., 2013; Song et al., 2017). Moreover, some studies found that capsaicin has anti-in- flammatory effects. Mice fed a high-fat diet supplemented with cap- saicin exhibited lower levels of metabolic endotoxemia and chronic low grade inflammation with lower body weight gain (Kang et al., 2010). In addition, injection of capsaicin in obese mice exerted an anti- inflammatory effect on adiposse tissue and decreased macrophage in- filtration (Kang et al., 2010). Capsaicin could also induce vasodilatation by stimulating NO production, which makes it useful to reduce hy- pertension and delay the onset of a stroke (Yang et al., 2010). Studies in humans gave less conclusive results. While capsaicin was able to increase thermogenesis and energy expenditure and change substrate oxidation according to most studies, there are also reports where the same parameters were not affected. This may be due to different concentrations of capsaicin used, length of intervention, body composition or previous habits of subjects’ chili consumption (reviewed in Fattori, Hohmann, Rossaneis, Pinho-Ribeiro, & Verri, 2016). More- over, many studies evaluating influence of capsaicin or its analogs on concrete serum markers are limited to particular subject groups. In women with gestational diabetes (Yuan et al., 2016) capsaicin de- creased postprandial hyperglycemia, reduced insulin resistance and the ratio between insulin and glucagon, reduced fasting triglyceride and total cholesterol levels. Further, an increase in fasting serum HDL cholesterol was reported for subject whose initial HDL cholesterol level was too low (Qin et al., 2017). Capsaicin could also reduce blood pressure in hypertensive, but not in normotensive subjects (Harada and Okajima, 2009). In addition to studies focusing on capsaicin, several population-based studies confirmed the association between self-re- ported intake of spicy food with lower serum LDL, an inverse https://doi.org/10.1016/j.jff.2018.03.014 Received 9 January 2018; Received in revised form 26 February 2018; Accepted 8 March 2018 ⁎ Corresponding author. E-mail addresses: sasa.kenig@fvz.upr.si (S. Kenig), alenka.arbeiter@upr.si (A. Baruca-Arbeiter), nina.mohorko@fvz.upr.si (N. Mohorko), mojca.stubelj@fvz.upr.si (M. Stubelj), masa.cernelic@fvz.upr.si (M. Černelič-Bizjak), dunja.bandelj@upr.si (D. Bandelj), zala.praznikar@fvz.upr.si (Z. Jenko-Pražnikar), ana.petelin@fvz.upr.si (A. Petelin). Journal of Functional Foods 44 (2018) 209–217 1756-4646/ © 2018 Elsevier Ltd. All rights reserved. T