There's long been good reason to think that some form of calorie restriction could slow aging. But it's always been really hard to know whether that strategy would work for humans. However, a new study published this week helps clear up some long-standing confusion about whether restricting calories helps rhesus monkeys live longer - and the researchers write that they think their work shows it's "highly likely" humans could experience the same benefits for a longer life. Previously, scientists have shown that in animals like mice, fruit flies, rats, certain worms, and yeast, cutting calories a significant amount (around 30% in one recent mouse study) could extend life and health, including brain health, for a significant span - sometimes doubling or tripling it.