The dolphin diet? Why certain saturated fats might help fight diabetes

Science Friday
A pair of dolphins leap in the wake of Royal Caribbean cruise line ship 'Grandeur of the Seas'

Doctors and health experts have long warned that a diet high in saturated fats can lead to multiple health issues including heart problems and increased risk of type 2 diabetes. A new study examining the eating habits of dolphins, however, seems to indicate that certain saturated fats may in fact reduce the risk of diabetes. 

Dolphins don’t join weight loss or exercise programs in the same way humans do. As it turns out, however, dolphins do seem to have health problems that resemble human health issues. Dolphins are known to develop a metabolic syndrome similar to a condition known as pre-diabetes in humans. Unlike humans, however, dolphins seem to be able to control their metabolic state, switching in and out of pre-diabetes, without ever developing the full-blown disease. 

Stephanie Venn-Watson, director of translational medicine and research at the National Marine Mammal Foundation in San Diego, wanted to know how dolphins were able to keep themselves from developing diabetes. She suspected it had something to do with the way dolphins controlled their diet. Together with a group of scientists, she began studying the eating habits of dolphins both in captivity and in the wild for clues. 

“Since we work and care for dolphins, we wanted to take a look at specific nutrients in fish that might unlock the secret of what it is in fish that might protect against this disease state,” Venn-Watson said. 

What she and her team of researchers found surprised them. 

Dolphins’ ability to protect themselves against diabetes, according to the study, comes from a certain type of fat the dolphins eat.

“Not only is it a fat, it's a saturated fat,” says Venn-Watson, who helped author a paper on the study that was recently published in the journal PLOS ONE. 

The fat is known as heptadecanoic acid or C17. Not much, however, is known about the mystery fatty acid, which can be found in dairy products, certain fish types and rye.

“If you go to Wikipedia today C17 has four humble lines. So it hasn't been well studied,” Venn-Watson said.

She wanted to find out more about the fatty acid, and what role it might play in human diets. So she and her fellow researchers went to the grocery store, and began pulling items from the shelves to test in their lab.  “We tested a bunch of different dairy products for C17,” Venn-Watson said, “Non-fat milk had no levels and then it increased until we got to glorious butter — clearly I'm biased — that had six times higher levels of C17 compared to even whole fat.”

The findings makes Venn-Watson wonder if recent trends in low-fat dairy products haven’t actually been doing some harm to people’s health.

“For us as we’ve moved more and more toward non-fat dairy products could that be lowering our C17?” she says. 

The researchers aren’t ready to recommend people begin spoon-feeding themselves butter, but they are planning to study the affects of lessened dairy fat on children’s diets. 

“We want to work with children's hospitals to see if children with metabolic syndrome, a disease called fatty liver disease, present in one in every 10 children, to see if maybe they're at increased risk because in fact kids have moved to non-fat milk as well,” Venn-Watson says.

The researchers may be far away from giving conclusive recommendations for humans’ diets. 

They are, however, using their research to improve the ways in which they take care of dolphins in captivity. 

“The research is early. We're hoping that by getting this research out that a broader research community will look at what foods have it [C17]. And for us, what’s wonderful is working in dolphin health that there's maybe a very easy way to be able to ensure that dolphins are getting the optimal diet,” Venn-Watson says.

This article is based on an interview that aired on PRI's Science Friday with Ira Flatow

Sign up for our daily newsletter

Sign up for The Top of the World, delivered to your inbox every weekday morning.