In and around Acciaroli, Italy, a particularly pungent variety of locally grown rosemary — said to smell 10 times as strong as the norm — is a daily part of the diet. Residents raise and consume their own rabbits. Anchovies hauled in by the town’s fishermen feature prominently on dinner plates.

Abundant sunshine and clean air keep people outdoors, swimming at beaches or climbing the steep hills that ripple along the Cilento Coast, south of Naples.

Do these environmental factors and food choices — a hyperlocal twist on the Mediterranean diet, which also includes olive oil and fresh vegetables — explain why so many people here, both men and women, live past 90?