Humans, sadly, aren't starfish. Once we're adults, if you lop off our limbs, they don't grow back. You can heal, sure, but you can't grow or regrow. But your mind is different. Your brain never stops growing.

If that comes as a shock to you, don't feel bad. In her TED talk on the subject, neuroscientist Sandrine Thuret explains that even many medical experts are still in the dark about the human brain's remarkable ability to keep growing new cells throughout our lives.

Which is fascinating. But is it useful? Short of avoiding actively re-aggravating the injury, you can't control how fast a cut heals or a broken bone knits itself back together. Can you do anything to influence how many brain cells you grow, or is this process, known as 'neurogenesis,' simply something that goes steadily on inside our skulls whatever we do?

Here's where Thuret's talk gets really interesting. There definitely are ways to grow more brain cells -- and they're not at all difficult (or unpleasant) to do. Here are Thuret's top three suggestions:

  • Learning
  • Sex
  • Running

Happily, you'll notice these are all activities you'd probably be pleased to engage in even if they weren't growing your brain (OK, running might not be as universally beloved as the other two, but still...). The fact that doing these things can help boost your memory, improve your mood and even lower your chances of becoming depressed will just be an added bonus for many.

Thuret also notes that your diet can impact how fast your brain manufactures new cells as well, recommending not-at-all-unpleasant foods such as fatty fish like salmon, dark chocolate, blueberries and red wine (assumedly in moderation). A high fat diet will slow neurogenesis, though the picture is complicated with the timing and amount of food you eat also playing a role.

But of course, as with everything within our control, we have to admit that if we can influence things for the better, we can also influence them for the worse. Thuret outlines some equally common factors that can slow neurogenesis, including stress and sleep deprivation.

Curious to learn more? Check out the complete eleven minute talk below.