When older adults eat a specific amount of cocoa flavanols, blood flow in certain parts of their brain goes up—but only in those areas, and not because they just think it should work or because their body is reacting to anything else.

Eating a lot of cocoa flavanols (almost half a gram) might boost blood flow to certain parts of the brain in older adults, but eating just a tiny bit (23 mg) doesn’t do anything — so more seems to make a difference.

Eating a chocolate drink with a lot of cocoa flavanols can make more blood flow to certain parts of the brain in people aged 50 to 65, and this effect shows up about two hours later—compared to a drink with very little cocoa.

Eating a specific amount of cocoa flavanols doesn’t change blood flow in the brain unless you’re also consuming other flavanol-rich foods — even if the chocolate tastes and looks the same and has the same calories and stimulants.

Eating a specific amount of dark chocolate compounds can make more blood flow to your brain—even when you're just sitting still and not thinking hard—suggesting it might naturally help your blood vessels work better.

Eating cocoa with flavanols might boost blood flow to a part of your brain that helps you form memories, like when you're trying to remember names or facts.