Share on PinterestIn a recent paper, researchers reviewed studies linking three key lifestyle factors to brain health. Mint Images RF/Getty Images In a recent paper, researchers reviewed studies linking exercise, relationships, and passion to brain health. They found reasonable evidence that all three factors offer protection against cognitive decline. Their review noted that randomized controlled trials are needed to confirm their findings. Changes to cognitive function during the aging process are related to the brain’s white and gray matter volume. Gray matter consists of biological structures, including neuronal cell bodies, synapses, and capillaries, whereas white matter consists of myelinated axons, through which signals are carried between neurons. Gray matter volume…