If you really need to concentrate on something, chew some gum. Why it helps...

The next time you really need to be focused and in the zone - find some chewing gum...

There's more evidence that says it can really help us concentrate on the task at hand. That's because the act of chewing gum increases blood flow to the brain by about 25%. It can also relieve tension in the jaw and face and improve cognitive function. 

Any flavor gum will do but researchers put several varieties to the test and found that peppermint or spearmint gum were the most effective. Don't have any gum handy? Chew some pretend gum. That was found to improve focus and memory a bit too.