STAY SHARP ALL DAY

If you’re feeling drowsy at work, don’t reach for a soda. British researchers discovered that people who downed a sugary drink containing 42 milligrams (mg) of sugar and 30 mg caffeine—the amount in a 12-ounce cola—exhibited slower reaction times and a greater number of lapses in attention for the next 70 minutes compared with those who sipped a sugarfree beverage. Although a sugar rush has been shown to boost cognitive performance, the effect is short-lived, lasting just 10 to 15 minutes. Your best option for a brain boost: a sugarfree drink that delivers at least 80 mg caffeine, says lead investigator Clare Anderson, Ph.D. A classic example: 8 ounces of black, unsweetened coffee.