EFFECTS OF HAWAIIAN-GROWN COFFEE ON SERUM LEPTIN LEVELS AMONG HEALTHY INDIVIDUALS

Abstract

Coffee is one of the most widely consumed beverages in the world. New studies indicate that coffee consumption does provide some health benefits including protecting against cardiovascular disease, type II diabetes, Alzheimer’s disease, and obesity [1, 2]. Coffee also appears to improve cognitive function and decrease the risk of depression [2]. The mechanisms of how coffee provides these health benefits, however, are still unclear. Reductions in of oxidative stress and subclinical inflammation are thought to be possible mechanisms associated with the beneficial effects of coffee [3].In this study, we focused on leptin, an adipocytokine that plays an important role in metabolic regulation. Elevated levels of leptin have been associated with an increased risk of inflammation-related diseases like type 2 diabetes, hypertension, cardiovascular disease, and obesity [4]. In previous studies, consumption of coffee (Coffea arabica) has been shown to decrease serum levels of leptin [5]. The aim of this study is to determine if consumption of Hawaiian-grown coffee has any specific biological effects on serum leptin concentrations. Based on literature review, we hypothesize that short term consumption of Hawaii-grown coffee will reduce plasma leptin levels among healthy individuals. A randomized, blinded, crossover intervention study was conducted which included all ethnicities. Participants consumed 24oz. of Hawaiian-grown coffee per day for four weeks, preceded by one-week washout periods in which participants abstained from coffee or tea consumption. Blood samples were collected and analyzed for leptin concentrations. The results of the coffee interventions showed no significant changes to serum levels of leptin after 4 weeks of Hawaiian-grown coffee consumption for both varieties of coffee used in this study.