The brain is by far our most precious organ–others are good, too, but they all pale in comparison to the mighty brain. Because the brain works so hard around the clock (even while we’re sleeping), it uses an extraordinary amount of energy, and requires a certain amount of nutritional support to keep it going. It’s high-maintenance, in other words. But there may be misconceptions about what keeps a brain healthy–for instance, there’s little evidence that omega-3 supplements or green smoothies would do anything above and beyond generally good nutrition. So what does science actually tell us can help our brains? Here’s what we know as of now.