Bioavailability of avocado‐derived mannoheptulose in dogs

Abstract

Mannoheptulose (MH) is a 7‐carbon sugar found in avocados and other natural sources that acts to reduce glycolysis via hexokinase inhibition. It has been proposed as a calorie restriction (CR) mimetic that delivers anti‐aging and health‐promoting benefits of CR without reducing food intake. Three studies were conducted to evaluate MH bioavailability when fed to dogs as an avocado extract (AvX) based on MH levels in urine (Study 1) and plasma (Study 2 & 3). In Study 1, Labrador Retrievers (LR; n=15) and Fox Terriers (n=15) were fed AvX‐containing diets formulated to deliver 0, 2 or 5 mg MH/kg BW. All dogs were subjected to 24‐hour quantitative urine collections. A dose‐dependent increase (p<0.05) in urinary MH occurred with increasing dietary MH. In Study 2, LR (n=6) were fed AvX‐containing diets once daily to deliver 0, 1 or 2 mg MH/kg BW. Sequential blood samples were collected before and after feeding through 12 hr and at 24‐hr post‐feeding. Plasma MH increased (P<0.05) with both MH diets compared to control. Peak MH occurred 6–8 hr post‐feeding and returned to non‐detectable levels by 24 hr. In Study 3, similar MH results were observed for LR (n=10) fed AvX‐containing diets twice daily to provide 0 or 2 mg MH/kg BW. Peak MH occurred within 2–4 hr of MH consumption and returned to non‐detectable levels by 24 hr. Mannoheptulose, fed as an avocado extract, is biologically available in dogs based on its appearance in plasma and urine.