Effect of long-term feeding of the Obudu natural honey and table sugar-sweetened diets on obesity and pro-inflammatory biomarkers in rats

BACKGROUND: This study investigated long-term effect of the Obudu honey on selected biomarkers of energy storage regulation, compared to table sugar. METHODS: Fifty Wistar rats assigned to 5 groups of 10 rats each, were fed rat chow only (NC), 8% table sugar (S8%), 16% table sugar (S16%), 10% honey (H10%) and 20% honey (H20%) diets respectively, for 29 weeks. On dry weight basis, the percentages of table sugar and honey for each level of incorporation were equivalent. Diet intake, body weights and fasting blood glucose (FBG) were measured fortnightly. At the end of the study, serum glucose, insulin, leptin and tissue necrosis factor – α (TNF-α), wet weight of white adipose tissues (WAT) were measured. RESULTS: After an initial adjustment to the diets, there was no significant difference in diet consumed by female and male subgroups, except the female group fed H20% which was consistently lower than the NC and the corresponding S16% fed group (P < 0.05). Both honey and sugar incorporated diets caused significant body weight gain in the female animals compared to NC; an effect which was higher with the honey than sugar, and depended on the level of each sweetener used as well as feeding duration (P < 0.05). Furthermore, S8% and S16% diets increased leptin concentration in the female rats, by 35.8 and 45.3% respectively compared with NC and by 63.8 and 40.5% compared to H10% and H20% respectively (P < 0.05). Also, the S8% and S16% diets significantly increased serum insulin in the female subgroups compared to the corresponding honey-sweetened diets; and in both male and female rats when compared to NC (P < 0.05). Lastly, the S8% and S16% diets also caused a dose-dependent increase of TNF-α in both female and male rats compared to the H10% and H20% diets and the control (P < 0.05). CONCLUSION: Data obtained from the study associated table sugar with obesigenic and inflammatory mechanisms more than the Obudu honey, particularly in the females. However, the data did not exempt the honey from obesigenic effect. The effects were subtle and may require a longer time to precipitate obesity.