Caffeine: How much is too much?

Question: I love Diet Coke. Rather, I LOVE Diet Coke. But lately I've been reading about health risks associated with caffeine, so my question is this: How much Diet Coke can I drink without increasing my health risks?

Answer: There is still a lot of research going on in regards to caffeine consumption. Caffeine consumption has been linked to heart disease, osteoporosis and diabetes, to name a few. However, in all of these cases, the research has not been consistent, and therefore is still debatable. For example, while caffeine does increase the loss of calcium as measured in urine, the net loss of calcium is actually quite small. The amount of caffeine in a cup of coffee cancels out approximately the amount of calcium in 1 tablespoon of milk. Therefore, for people drinking moderate amounts of coffee in addition to moderate amounts of milk, it does not lead to increased risk of osteoporosis.

As for your Diet Coke, most caffeinated soft drinks contain 20-40mg of caffeine in 8 ounces (compared to 65-120mg in 8 oz of brewed coffee). "Moderate" caffeine consumption is generally considered to be ~300 mg/day. Therefore, having a couple of Diet Cokes a day is not likely to increase your health risk. However, caffeine sensitivity is very individual, so if you ever have side effects like jitteriness, stomach upset or insomnia, it's a good idea to cut back.