True to our melting pot nature, Americans have a variety of names for this type of beverage. Most common are “soft drink,” “pop” or “soda.” But whatever you call them, they are bad for your health.

I know you know this. Sugary drinks are largely responsible for the obesity epidemic in this country. They rot your teeth and contribute to your risk of diabetes. I have seen patients who lost 20 to 30 pounds just by cutting out sodas. In 2012, New York City even made soda consumption into a public health issue by banning the sale of any soft drink larger than 16 ounces. Two years later, this ban was overturned, to public health officials’ disappointment and soda companies’ delight.

In the clinic, I have often heard the following: “I don’t drink soda. I drink diet, so that’s okay, right?” Many people believe that taking the sugar out of the sugary drinks makes them all good. Practically health food. Well, I hate to disappoint the diet lovers, but no, that’s not okay. Diet drinks are as bad or even worse than their sugary cousins. Here’s how.

Weight gain

That’s right. Gain. New studies are showing that people who drink artificially sweetened beverages actually gain more weight than those who don’t. In one study, drinking two cans a day increased waistlines by 500 percent. Yikes. This is thought to be because artificial sweeteners disrupt the body’s natural ability to regulate calorie intake based on the sweetness of foods. In other words, they mess with our metabolism and less becomes more.

Glucose intolerance

Another name for this is pre-diabetes, and pre-diabetes often turns into diabetes. You might think that a sugar free drink would have nothing to do with diabetes, a sugar problem, but it does. In one study, new diet soda drinkers’ blood sugar levels shot up to pre-diabetic level in just a few days. Recent research out of Israel suggests that this blood sugar effect may be related to the bacteria in our gut. We all have bacteria inside us, normal residents of our microbiome. Each person’s microbiome is unique. Usually these little guys work with us and enhance our health, or at least don’t harm us. Artificial sweeteners seem to alter the mix of bacteria inside us in a way that can lead to glucose intolerance.

Cardiovascular disease

Heart attacks are the number one killer in this country, and high blood pressure contributes. Diet drinks raise the risk of both. They also promote metabolic syndrome, which is the combination of increased blood pressure, a high blood sugar level, excess body fat around the waist and abnormal cholesterol levels. Metabolic syndrome is a setup for cardiovascular disease.

Kidney problems

An 11-year study out of Harvard looking at 3,000 women found that those who drank two or more diet colas a day had double the risk of kidney function decline. This did not happen with regular colas not that I’m suggesting you drink those either.


Not all of Lynette’s “cokes” have caffeine in them, but regular coke does, as do many others. Caffeine can irritate the stomach and bladder. Not only that, it is actually a diuretic, which means it makes your kidneys excrete more fluid. So if you’re drinking a caffeinated pop in order to hydrate yourself, you are shooting yourself in the foot. Or the kidney. It has the opposite of the desired effect.


Many diet drinks contain mold inhibitors, usually sodium benzoate or potassium benzoate. Potassium benzoate, when combined with vitamin C, can become benzene, a carcinogen. Lots of soft drinks have added vitamin C. Cancer in a can. Who needs it?

Bad teeth

Regular and diet sodas both are acidic. Diet colas have a pH of 3.2. Water, which is neutral, has a pH of 7 and battery acid has a pH of 1. Acid dissolves the enamel on your teeth. You may remember this from a grade school experiment where you put your tooth in a glass of coke.

Most cans are coated inside with BPA, bisphenol A, which is a chemical called an endocrine disruptor. Your endocrine system is your hormone system. BPA has been linked to reproductive problems as well as to obesity, diabetes and heart disease.

Are you grossed out yet? I hope so. It is my passionate and educated medical opinion that sodas, soft drinks, pop and “cokes” have absolutely zero redeeming value. There is no reason to drink them, and plenty of reasons not to. If you are thirsty, drink water.

Dr. Peggy Spencer is a physician at Student Health and Counseling. She is also co-author of the book “50 Ways to Leave Your 40s.” Email your questions directly to her at pspencer All questions will be considered, and all questioners will remain anonymous.