You Ask, I Answer: Diet Soda

I was debating [with a colleague] about whether diet soda is bad for you.

I mentioned some folks believe the artificial sweeteners in them may be cancer-causing, but that it's a step up from guzzling sugary sodas every day.

She said something about the acid in the soda not being that bad for you, because our stomachs are already acidic.

But I always thought the acid in the soda wasn't so good for the tum tum.

What's your verdict?

-- Judith (last name withheld)
(location withheld)

The problem with all soda -- diet or not -- is the phosphoric acid in it.

Not so much because it's bad for your stomach (it isn't), but because of its effect on our calcium levels.

Our bodies like to stay in balance (you might remember the term "homeostasis" from your high school biology class). Calcium and phosphate, in particular, are two minerals that are actually good buddies. In fact, they're inseparable.

If one's level in our blood goes up, the other one wants to go up as well. So when you drink that can of diet soda, your body's phosphate levels rise. Calcium sees this, and says, "Wait a second, I want to go up, too!"

If you are like most people in the United States, your calcium intake isn't as high as it needs to be, meaning you don't have much available calcium floating around. So in order to up its levels, calcium, eager to join phosphate, starts leeching extra calcium from the first place where it can find it – our bones.

Let me be very clear here – if your calcium intake is adequate, the occasional diet soda is not going to harm you or make you develop osteoporosis.

But, in looking at teenagers, for instance (many of whom are already calcium deficient and on top of that are guzzling down two or three sodas a day) this is a problem.

Phosphoric acid is also responsible for wearing away enamel (a protective layer) on our teeth, leading to an increased risk of tooth decay.

I don't see anything wrong with having a soda here or there as a treat (i.e.: at the movie theater, at a barbeque, etc.), but definitely take issue with soda being someone's sole source of liquid day in, day out.