Can reducing insulin levels help to lengthen our lives?

A new study in ants suggests that suppressing insulin may be a fountain of youth for ants – and may offer clues about life extension in other species.

The study by New York University researchers found that queen ants produce an anti-insulin protein that blocks part of the insulin pathway responsible for aging.

Insulin, a hormone that converts food into energy, is important to metabolism and aging. Normally, producing eggs would be an energy intensive activity that requires extra food, which raises insulin levels. The increased activity of the insulin pathway leads to a shorter lifespan in most animals, according to an NYU report.

Other research has found that insulin plays a central role in aging.

But the NYU study published in the journal “Science” shows ants are an exception to this trade-off between reproduction and longevity. It found that queens, which are responsible for the whole colony’s reproduction, live much longer than worker ants while sharing the same genome. For example, black garden ant queens can lay one million eggs and live for 30 years. Her worker sisters only live a year.

In “Harpegnathos saltator” ants, a species of ants native to India used in the NYU study, queens typically live for five years while workers live for only seven months.

Researchers found that, when old queens die, worker ants switch to become pseudoqueens and begin producing more insulin to produce eggs. This increased insulin activates of one of the two main branches of the insulin signaling pathway, MAPK, which controls metabolism and egg formation.

It also induces ovary development, which begins producing an insulin-suppressing protein called Imp-L2 that blocks signaling in the other main branch of the insulin signaling pathway, AKT, which controls aging. Reduced AKT leads to longer life span.

“The two main branches of the insulin signaling pathway appear to differentially regulate fertility and lifespan, with increased signaling in one aiding reproduction in pseudoqueens and decreased signaling in the other consistent with their extended longevity,” said the study’s co-senior author Danny Reinberg, professor of Biochemistry and Molecular Pharmacology at NYU Grossman School of Medicine and a Howard Hughes Medical Institute investigator.

The ant study is particularly interesting because research that manipulates longevity in animals like mice and flies tends to extend their lifespans by up to 20%. But ants can experience a 500% increase in their longevity.

We can’t wait to see further research to determine if the insulin connection also makes a difference in human life extension.