"WALL-E" is a 2008 animated movie about a garbage-collecting robot named WALL-E (Waste Allocation Load Lifter: Earth-Class) who — along with the alluring robot EVE — helps a polluted and deserted Earth flourish again.

Walnuts can do the same for you. And now, thanks to researchers from Harvard's T.H. Chan School of Public Health and their Spanish colleagues, we understand what's in these tasty morsels that make them so good for you.

The researchers tracked the health of 1,833 participants in the PREDIMED study for seven years and used artificial intelligence to identify what goes on in the body when you eat half an ounce — seven halves — of walnuts per day.

It turns out that that walnuts alter your metabolism by helping your body form 19 essential metabolites. The study focused on two especially important kinds: amino acids, the building blocks of proteins; and heart-friendly, polyunsaturated fatty-acids like omega-3 ALA. 

The result of boosting these metabolites? Participants saw a 17% lower risk of Type 2 diabetes and a 29% lower risk of cardiovascular disease than people who ate no walnuts.

Walnuts' fatty-acid composition plus their abundant phytosterols (they block cholesterol absorption) explain how they help lower bad LDL cholesterol.

Their ability to help you dodge diabetes may come from anti-inflammatory and metabolic benefits that improve glucose regulation.

To clean up your internal planet, snack on walnut halves and try the recipes for Carrot Top Pesto with walnuts or walnut-y Whole Grain and Dark Chocolate WTEW Bars in Dr. Mike's "What to Eat When Cookbook."