Is there such a thing as a 'best' legal drinking age?

Some researchers think they have the answer.

You have to be 21 to legally buy alcohol in the United States.

That's higher than in some other countries, but a study in the journal, "Alcoholism" finds that it might be a good idea.

Researchers compared drinking habits before and after some states raised their legal drinking age to 21 or older.

The authors found that people who were able to buy alcohol legally at a younger age had a 15 percent increased risk of binge drinking more than once a month.

At the same time, access to alcohol before age 21 was associated with a reduced chance of engaging in any drinking that was not binge drinking. 

The authors say being able to buy alcohol under age 21 does not seem to increase overall drinking frequency.