Share this content

For decades, we have known that consuming sugar increases your risk for heart disease, diabetes, memory loss, cancer, and weight gain.

A recent study published in Circulation showed that women who had sugary beverages less than once per month, compared to those who had more than two servings a day — defined as a standard glass, bottle, or can — had a 63% increased risk of premature death. And those who only had 1 serving per day showed less risk than those with 2 or more servings per day, but much more than those who had none.

This risk has led many people and even many doctors to use diet drinks with artificial sweeteners and other food products instead of products with sugar.

Have diet products helped with weight loss? The reality is not much, and many would say long term that there is no sustained weight loss from choosing artificially sweetened products.

Now the latest study assessing the safety of artificially sweetened drinks was published in October 2020 in the Journal of the American College of Cardiology.

French researchers published their initial results after following 105,000 people over the last 6.6 years in a prospective observational study that is still ongoing. Study subjects completed dietary records every six months. The results were assessed sugar intake with non-calorie sweetener intake. Their aim was to assess how sugar intake and sweetener intake affect the risk for cardiovascular events, such as heart attack, stroke, or sudden cardiac death.

In this study, sugary drinks consisted of all beverages containing at least 5% sugar (i.e., soft drinks, syrups, 100% juice, fruit drinks).

For sugar, they compared:

  • Non-consumers (less than 1 serving per month)
  • Occasional users (less than 2 servings per day)
  • High consumers (2 or more servings per day)

For non-caloric sweeteners, they compared:

  • Non-consumers (less than 1 serving per month)
  • Occasional users (less than 2 servings per day)
  • High consumers (2 or more servings per day)

For sugar, the results showed that occasional sugar users showed a 5% increased risk for cardiovascular events and high consumers had a 20% increased risk.

For sweetener use, the results showed that occasional sweetener users showed a 15% increased risk for cardiovascular events and high consumers had a 32% increased risk. The most common sweeteners used in this study appear to be the artificial sweeteners, aspartame (sold as Equal and NutraSweet) and Sucralose (sold as Splenda).

This initial data from an ongoing study shows that drinking beverages with artificial sweeteners are equally harmful to drinking beverages with sugar, and artificial sweeteners may be even worse for you.

It was not a surprise to anyone that drinking beverages with sugar increased the risk for serious cardiovascular events. Yet, the results showing harm from diet drinks should be eye-opening and a major wake-up call for people who use artificial sweeteners regularly.

The most likely mechanism for the harm caused by artificial sweeteners is that they have been shown to kill good bacteria in the gut and promote the growth of bad microbes, causing gut microbiome chaos and disorder.

We know that healthy gut microbes help us in many important ways:

  • They help us lose weight
  • Improve blood pressure levels
  • Reduce LDL and total cholesterol levels to normal
  • Improve blood sugar control
  • Decrease inflammation
  • Reduce levels of TMAO, a compound produced by gut bacteria that is associated with increasing cardiovascular events by 62%.

The bad gut microbes show the opposite harmful effects.

The reality is that artificial sweeteners kill the healthy gut microbes that protect us from nearly all the risk factors for cardiovascular events. With this in mind, we should not be surprised that consuming artificial sweeteners increase our risk for heart disease.

A previous study was published in Nature, showing that the most commonly used artificial sweeteners saccharin, sucralose, or aspartame all adversely impacted the gut microbiome and worsened blood sugar control.

One limitation of this ongoing French study is that researchers combined natural sweeteners, such as stevia, with artificial sweeteners such as Aspartame (sold as NutraSweet and Equal) and Sucralose (sold as Splenda). It would be far better if they were looking at them separately.

To date, there is no evidence that natural sweeteners (Stevia) harm the gut microbiome, or cause any other significant harm, yet this will require further observation over time. There is some limited information that stevia and other natural sweeteners (like Xylitol) may block the growth of some beneficial bacterial species, limiting their proliferation. Even though they do not appear to kill large numbers of good bacteria, they may inhibit some good bacteria from growing.

For now, I strongly recommend that all of us avoid the use of sugar and artificial sweeteners—including aspartame (blue packs), saccharin (pink packs), and sucralose (yellow packs). It is ironic that these artificial sweeteners were initially created to help prevent diabetes and weight gain, but that they may actually cause the same problem that they were intended to prevent.

Our best choice is to enjoy food that is unsweetened, natural, and unprocessed! Food can still taste delicious without overwhelming our taste buds with sweetness.

For an occasional treat when you want to celebrate a special occasion, stick with a natural ingredient, such as a small quantity of honey. If you use natural sweeteners, do so only occasionally.

Although not as sweet as sugar or artificial sweeteners, fresh fruit offers our palate some sweetness, without a jump in blood sugar levels and it nourishes our healthy gut microbes. Fresh fruit is good for us, and we should eat 2-3 servings daily.

I wish you the best of health!

Steven Masley, MD, FAHA, FACN, CNS


  1. Jotham Suez et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. NATURE 9 October 2014;514:181-86. doi:10.1038/nature13793
  2. Affect of stevia on Lactobacillus reuteri. Letters in Applied Microbiology, 2014;58.3: 278-284.

Please share these blogs with your friends and family!

Send them this link to sign-up to receive my blog posts: www.drmasley.com/