The Sarasota Bay Dolphin Diet May Provide Important Clues to Prevent Diabetes

Just like people, some dolphins are susceptible to prediabetes, also called metabolic syndrome. This syndrome includes elevated insulin, glucose, triglycerides, fatty liver disease and associated iron overload. While metabolic syndrome is not a direct cause of death in dolphins, it is a chronic condition that – when removed – may help dolphins live longer, healthier lives. Thanks to funding from the Office of Naval Research, the National Marine Mammal Foundation worked with the Sarasota Dolphin Research Program for several years to find out why some dolphins get this disease, while others do not.
Through a series of publications featured in a special Frontiers in Endocrinology issue, ‘Marine mammals as outside the box models for insulin resistance and type 2 diabetes,’ some important clues have been discovered. First, Sarasota Bay dolphins had lower insulin, glucose, triglycerides, and iron in their blood compared to dolphins with metabolic syndrome. Second, Sarasota Bay dolphins and the fish they eat had different types of nutrients compared to dolphins with metabolic syndrome (and the fish they eat). Third, metabolic syndrome in dolphins was not associated with either higher stress (indicated by a stress-related hormone, cortisol) or higher body mass index (i.e. body weight).
Current studies are focusing on nutrients in dietary fish that may protect dolphins against developing prediabetes. If we can find the right combination of nutrients that prevent or treat prediabetes in dolphins, this may provide critical clues on how to prevent and treat diabetes in people.
— Dr. Stephanie Venn-Watson, National Marine Mammal Foundation
Citations
Venn-Watson, S., Smith, C., Stevenson, S., Parry, C., Daniels, R., Jensen, E., Cendejas, V., Balmer, B., Janech, M., Neely, B.A., and R.S. Wells. 2013. Blood-based indicators of insulin resistance and metabolic syndrome in bottlenose dolphins (Tursiops truncatus). Frontiers in Endocrinology doi: 10.3389/fendo.2013.00136.
Wells, R.S., McHugh, K.A., Douglas, D.C., Shippee, S., McCabe. E.B., Barros, N.B., and Phillips, G.T. 2013. Evaluation of protective factors against metabolic syndrome in bottlenose dolphins: feeding and activity patterns of dolphins in Sarasota Bay, Florida. Frontiers in Endocrinology doi: 10.3389/fendo.2013.00139.