Washington, July 23 (IANS): A unique saturated fat found in fish and whole fat daily products can reverse diabetes, researchers have reported after discovering that dolphins suffering from prediabetes were cured when fed with a modified diet rich in the saturated fat.

The researchers are hopeful that controlled doses of this saturated fat called heptadecanoic acid may help reverse prediabetes in humans soon.

Because of the popularity of fish-based omega-3 fatty acids as a human health supplement, the team from the US National Marine Mammal Foundation (NMMF) assessed fatty acid blood levels in 49 dolphins as well as in their dietary fish.

"We were surprised to find that among the 55 fatty acids studied, the saturated fat heptadecanoic acid appeared to have had the most beneficial impact on dolphin metabolism," said Stephanie Venn-Watson, director of NMMF's translational medicine and research programme.

Dolphins with higher levels of heptadecanoic acid in their blood had lower insulin and triglycerides, he said.

The study also showed that while some fish have high levels of heptadecanoic acid other fish types had none.

Six dolphins with low heptadecanoic acid were then fed fish high in this fatty acid.

Within six months on the new diet, indicators of metabolic syndrome in dolphins, including elevated insulin, glucose, and triglycerides normalised.

Key to this surprising outcome was reversal of high ferritin, an underlying precursor to metabolic syndrome.

"We saw blood ferritin levels decrease in all six dolphins within three weeks on the new diet," Venn-Watson said.

Heptadecanoic acid, also called margaric acid, is found in dairy fat, rye and some fish.

The fish with the highest heptadecanoic acid content was mullet.

"We hypothesise that widespread movement away from whole fat dairy products in human populations may have created unanticipated heptadecanoic acid deficiencies," Venn-Watson contended.

"This dietary deficiency may be playing a role in the global diabetes pandemic," he warned in a paper that appeared in the journal PLOS ONE.

Does this mean that we can now eat butter without guilt?

"Butter may have both good and bad saturated fats but it is always best to check with your physician before making changes to your diet," the authors concluded.