The December 2013 issue of Real Simple magazine (page 148) cites a study published in June 2013 in "Social Cognitive and Affective Neuroscience" - which, according to the Real Simple article, "reported that the practice [of meditation] can reduce anxiety levels by up to 22 percent. Research has also suggested that meditating can actually form new and permanent neural connections in the brain." "The amazing thing? All you need is five minutes a day."
While it is not clear whether the participants in the study meditated only 5 minutes a day, practicing for 5 minutes would certainly be a great start. And I know from personal experience that that little bit of time can really make a difference.
Here is a link to a shorter version of the article, along with tips for your 5 minute meditation practice: