Apart from being legit addictive (and bad for you in about a billion other ways), sugar's also sabotaging your skin by causing wrinkles, and damaging collagen and elastin -- the stuff that keeps your skin looking youthful.
There's more! Nothing serves quite so well as the tried-and-true eye test, and people with high blood sugar levels just look older than people with low blood sugar levels. And there's more bummer news, particularly for soda lovers: sipping on sugar-sweetened sodas may make your white blood cells age faster, compromising your immunity.
You ditch your crew on the regular
To paraphrase The Beatles, you look younger with a little help from your friends -- people in their 70s with the most good friendships outlive those with the fewest. So going through those awkward stages of making adult friends is worth it, especially considering that friendships are as important as diet and exercise.
Plus, generally being social can delay cognitive decline, and it may help fight the major ager mentioned above: stress. "Social interactions affect rate of aging in that they change your perceived or actual stress levels," says Dr. Roizen. So if you haven't, get out there at lunch, introduce yourself, smile a lot -- remember, you attract more flies with honey, not vinegar, just like your mother said! -- and reap the benefits of new friends who, thanks to YOUR friendship, will die within hours of you, thus sparing you the loneliness of later life.