Biological activity of avocado‐derived mannoheptulose in dogs

Abstract

Mannoheptulose (MH) is a 7‐carbon sugar found in avocados and other natural sources. It is proposed as a calorie restriction (CR) mimetic that delivers anti‐aging and health‐promoting benefits of CR without reducing food intake. Two studies were conducted to evaluate effects of MH on fasting insulin when fed as an avocado extract (AvX) to Labrador Retrievers (LR) and Fox Terriers (FT). Decreased fasting insulin is commonly associated with CR and longevity. In Study 1, 36 dogs, balanced by breed (18 LR; 18 FT) and age (18 young, 2.6 yr; 18 old, 11.8 yr), received control or test treatments during sequential 2‐week periods. Test dogs were fed one AvX‐containing gelatin capsule daily to deliver 1, 2, 10 or 20 mg MH/kg BW in a step‐up fashion. Control dogs were fed one placebo capsule daily. Fasting blood samples were collected weekly. Fasting insulin was lower (P<0.05) in dogs fed 2, 10 and 20 mg/kg. In Study 2, LR (15) and FT (15) were fed an AvX‐containing diet providing 0, 2 or 5 mg MH/kg BW. A glycemic meal challenge was induced on days 0 and 30 by feeding dogs one‐half their daily meal allotment after an overnight fast. Blood samples for insulin and glucose were collected at 0, 30, 60, 120 and 240 min post‐feeding. MH (2 mg/kg) reduced (P<0.05) insulin levels (mean, peak, area under curve) in old LR on day 30. Glucose was not affected by MH. Lower plasma insulin implies mannoheptulose is biologically active in dogs when fed as an avocado extract.