Do dolphins get Alzheimer’s?

For the first time, a study has shown clear signs of Alzheimer’s disease in a wild animal: the dolphin. Both dolphins and humans have a long post-productive lifespan, and Alzheimer’s disease may be one of the costs of our longevity, the study suggests.

The research team – made up of scientists from the Universities of St. Andrews and Edinburgh in Scotland, the University of Florida in the US, and the University of Oxford in England – has detected signs of Alzheimer’s disease in the brains of dead dolphins found stranded along the coast of Spain. The team analyzed the accumulation of two proteins in dolphin brains: at the extracellular level, the accumulation of a protein called beta-amyloid, which causes senile plaques, and, at the intracellular level, the aggregation of a protein called tau, which triggers neurofibrillary degeneration. These senile plaques and neurofibrillary degeneration are the hallmarks of Alzheimer’s disease.

“It is very rare to find signs of full-blown Alzheimer’s disease in non-human brains,” says Simon Lovestone, a researcher at the Oxford University Department of Psychiatry

“It is very rare to find signs of full-blown Alzheimer’s disease in non-human brains,” says Simon Lovestone, a researcher at the Oxford University Department of Psychiatry and co-author of the study. This is the first time that the accumulation of these two proteins associated with Alzheimer’s have been observed in the brain of a wild animal.

Do dolphins with these signs of disease suffer from memory loss and confusion similar to what is observed in humans with Alzheimer’s? At this stage of research, scientists are unable to answer this question. This is difficult to verify in a wild species and the research team does not advocate testing dolphins in captivity.