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Is Diet Soda Really That Bad?

May 23, 2014

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I’m Maria Marlowe, a Health Coach and author of Detox without the Deprivation. In my “Ask Health Coach Maria” series, I answer your health and wellness questions. Ask me your question here

Hi Maria,

I’m trying to get my dad to quit his diet soda habit. He thinks he’s doing himself a favor by drinking that instead of regular soda, but I’m not convinced. How bad is diet soda?

Sophia, KY

You’re right to question the healthiness of diet soda. A common misconception is that it’s healthier than regular. Not quite.

In fact, if you were going to drink any type of soda (which I don’t advise) then I’d rather you drink regular. While both have negative effects on our health, it appears that diet soda may do greater damage.

The high fructose corn syrup of regular cola may lead to weight gain, but cutting calories isn’t the same as staying healthy. The artificial sweeteners in diet soda can literally kill your brain cells, plus they can lead to weight gain themselves!

Here are the top 7 reasons I advise people to avoid diet soda: 

1. It kills your brain cells. Diet sodas use artificial sweeteners, like aspartame, to sweeten them without sugar. While this does lower the calorie count, it comes at a cost. Artificial sweeteners like aspartame are neurotoxins, which means they excite your neurons until the point of cell death. Independent research studies have also linked aspartame to memory loss and brain tumors

2. It weakens your bones. The phosphoric acid in both regular and diet soda leaches calcium from your bones, which can lead to fractures and osteoporosis down the line.

3. It induces weight gain. So much for “diet” soda. Studies show that diet drinkers tend to be heavier than regular soda drinkers or non-soda drinkers.

In one study, scientists at the University of Texas Health Science Center monitored 475 adults for 10 years, and found that those who drank diet soda experienced a 70% increase in waist circumference over the period, compared to those who abstained from the sugary drinks. For those who drank more than two diet sodas a day, they saw a 500% increase in waist expansion! They believe these results are due to the fact that aspartame raises blood glucose levels, and when there is excess glucose in the blood, it’s stored as fat.

Regular cola, on the other hand, contains high fructose corn syrup, which also leads to weight gain, not to mention an increased risk of diabetes and obesity.  

Additionally, many types of soda contain caffeine, an addictive stimulant that taxes the liver and adrenal glands. Caffeine can also cause the body to release more of the stress hormone cortisol, which can cause your body to hold onto and store weight more readily.

4. It increases your risk of obesity. Even though diet soda doesn’t contain sugar, it does induce an insulin response similar to the one caused by sugar. This effect can actually increase your risk of obesity far more than regular soda.

A University of Texas study found that drinking 1-2 cans of diet soda a day increases your risk of obesity by 54.5%, compared to 32.8% for those drinking the same amount of regular soda.

5. It can cause headaches and other symptoms. Sucralose, another artificial sweeter commonly used in diet sodas, can trigger migraines, intensify sugar cravings, increase appetite, and trigger insulin resistance (which can lead to diabetes down the line).

6. It ages your body. Soda is loaded with phosphoric acid, which gives it its flavor and increases its shelf life. However, it can actually decrease your shelf life: A study published in FASEB Journal in 2010 found that the high phosphate levels in sodas caused lab rats to die a full five weeks earlier that those rats who were fed diets with normal phosphate levels.

7. It increases risk of heart disease. A study by the University of Miami Miller School of Medicine found that regular consumption of diet cola increases your risk of a cardiac event by 61%. That’s a pretty scary figure.

So, there you have it, 7 very compelling reasons why diet soda is not, in fact, a healthy alternative to regular soda.

If you currently drink soda, either diet or regular, you can wean yourself off of it by replacing it with something similar, but healthier. If it’s the bubbles that you like, try club soda. There are also a number of new “natural” sodas on the market sweetened with stevia

If you use soda as a pick-me-up to boost your energy, try an herbal tea, whether hot or iced. Add a little raw honey if you like it sweeter.

Of course, the best liquid to drink is water, but if you find it boring (it’s not!), try jazzing it up with fresh cucumber or lemon slices, or another creative way to invigorate your water.

Have you quit a soda drinking habit? Share your experience in the comment section below!

Maria Marlowe is a Certified Health Coach and regular Wellness Today Contributor. Get your health question answered in her next column by sending her an email at