Small pancreatic cells actually lead to a longer lifespan in mammals, a study published this week found.

The study, led by Hebrew University Biology Professor Yuval Dor, was published on Monday in the Developmental Cell journal, and discovered larger pancreatic cells foster organ growth, but can also speed up the aging process.

“A correlation between two things that are so remote was shockingly beautiful and unexpected,” Dor said in an emailed statement.

Although many scientists subscribed to Greek philosopher Aristotle’s theory that larger animals live longer than their smaller counterparts, the paper found that lifespan was directly correlated with cell size rather than body size.

To come to this conclusion, researchers from Israel, Canada and Germany tested pancreatic cells from 24 different species ranging in size, according to the statement.

Through observations of cells in mice, spanning from infants to adults, the researchers found a link between the size of individual pancreatic cells and increased organ growth.

When the team compared the same cell types in humans, they found that it was cell replication – rather than individual cell growth – that promoted organ growth.

After analyzing the cells in various other mammals, the scientists found conclusive evidence that those with larger pancreatic cells aged faster, and species with smaller cells lived longer.

The protein that advances this process, called mTOR, allows mammals to grow quickly in the early phases of life, but can also lead to weakening and aging later in life.

This theory of aging is called antagonistic pleiotropy, said Dor, and suggests there are unintended consequences that come along with the benefits of these cellular processes that foster growth and reproduction.

“This might explain why some mammal species sacrifice longevity for the rapid early organ growth associated with cell growth instead of replication: you get the selective advantage in early life but you pay the price later on,” Dor said.