Dr. John Day, Cardiologist

Podcast: Play in new window | Download

Subscribe: RSS

Are Artificial Sweeteners Dangerous?

For years I suffered from daily headaches.  I was convinced this was because of my stressful job as a cardiologist.

One day, after giving up Diet Coke for quite some time, I realized that I had not had a headache in months. Could the aspartame have been the cause of my daily headaches?

The use of artificial sweeteners in the U.S. has gone up five-fold in the last 40 years.  This is mostly in the form of diet drinks.  In this article, I will share the latest scientific data on artificial sweeteners and answer the question: Are artificial sweeteners dangerous?

Is Your Sweet Tooth Genetic?

From a historical standpoint, craving sweets probably served us well.  Sweet plants are less likely to be poisonous in the wild and the natural sweet tooth that children have helps them to get enough calories to survive to adulthood.

However, these days a sweet tooth often leads to troubling conditions.  “I have always had a sweet tooth,” Becky told me at her last cardiology clinic visit.  In addition to her cardiac issues she also suffered from obesity and diabetes.

This past week at the Obesity Society Annual Meeting in Los Angeles, researchers presented a study that hit the worldwide press.  They found that if people had the FTO variant gene (also known as the “fat gene” or in reference to this study, “the sweet tooth gene”) or the DRD2 gene (the addiction gene), their brains light up like a Christmas tree at the slightest sight of sweets as seen by real time MRI brain imaging.

While I don’t have the DRD2 addiction gene, I do have two copies of the FTO “sweet tooth” gene.  This double dose of the FTO variant gene explains my lifelong sweet tooth cravings.  As I have gotten older, and have struggled with weight gain in the past, I have looked to artificial sweeteners to satisfy my FTO variant genes without paying an apparent caloric price.

If you want to find out if you have the FTO variant gene or the DRD2 gene, you can easily do so through a simple home saliva DNA test kit from 23andMe for $199.  To find out the details on this process, please see an article I wrote on the subject called, How to Test Your Genes.

What Artificial Sweeteners Do You Need to Know About?

If you use artificial sweeteners, you need to know the four main players.  As everyone reacts differently, it is possible that one or more of these artificial sweeteners may be causing problems for you.

That was certainly the case for me with aspartame.  I discovered that it was indeed the aspartame after systematically removing and then reintroducing each of the chemicals listed on the ingredient label of Diet Coke.

1. Aspartame (NutraSweet or Equal)

This is one of the first generation of artificial sweeteners having been FDA approved in 1981.  Aspartame is a combination of aspartic acid and phenylalanine.  For people with a genetic disease, called phenylketonuria or PKU, aspartame is highly poisonous.  The main way Americans currently get aspartame is through diet drinks from the Coca-Cola company.

2. Sucralose (Splenda)

Sucralose is part of the second generation of artificial sweeteners.  Sucralose was FDA approved in 1998 and is made from adding chlorine atoms to natural sugar.  This chlorinated sugar compound cannot be broken down by your body and thus is mostly calorie free.  As you might imagine, the addition of chlorine atoms to sugar has generated a lot of possible health conspiracy theories on the Internet.

Interestingly, in 2015, Pepsi switched all of their
diet sodas from aspartame to sucralose.  Their motives for doing so are unclear.  It is certainly possible that this was done to create a market for people who do not tolerate aspartame well or it could have been done as a marketing ploy to boost sales given their lagging market line of diet drinks.

3. Sugar Alcohols (chemicals that end in “tol”)

In contrast to aspartame or sucralose, which don’t raise blood glucose levels, the sugar alcohols do raise sugar levels in the blood but not to the extent of regular sugar.  Most people get sugar alcohols from sugarless gums, sugar free candies, and even in other food products like sugar free jams and ice cream.

In addition to aspartame, I also struggle with sugar alcohols.  If I eat more than a stick or two of sugarless gum I often suffer from bloating, gas, and abdominal pain.  Other people may have diarrhea.

If you suffer from any of these symptoms, carefully check the labels of everything you put in your mouth.  If you see any chemical ending in the letters “tol,” there is a good chance that the processed food companies have slipped in sugar alcohols without you even being aware of them.

4. Stevia

While not technically an “artificial sweetener,” given that the South Americans have been chewing on stevia leaves for millennia, one could argue that modern day processing techniques of stevia render it “artificial.”

Indeed, the Coca-Cola Company now markets Truvia under the health food halo of stevia when in reality the main ingredient listed is just a sugar alcohol.  If you want to consume a more natural, non-sugar and calorie free sweetener, try to get your stevia organic and as close to the natural leaf as possible.  This may require you to visit your local health food store.

My Top 7 Artificial Sweetener Questions

Nearly everyday patients ask me about my opinion on artificial sweeteners.  Here are the top 7 artificial sweetener questions I get.

1. Do artificial sweeteners cause cancer?

Since the 1970s, reports emerged about saccharin causing bladder cancer in rats.  What scientists did not understand at that time was that this bladder cancer risk was unique to rats and not to other animals or humans.

The second big cancer scare from artificial sweeteners was in 1996 with the publication of a report suggesting that aspartame caused brain tumors.  While this study was widely circulated in the press, it has now been dismissed by modern scientists due to shoddy science.  Subsequent studies have not clearly linked aspartame to cancer.

Newer artificial sweeteners have also undergone intense scrutiny and, fortunately, none seem to cause cancer.  Of course, it is certainly possible that at some future date we might discover that one or more artificial sweeteners causes cancer.  Thus, my opinion is that studies do not currently show a clear risk of cancer from artificial sweeteners. 

2. Do artificial sweeteners cause weight gain?

While most people consume artificial sweeteners to lose weight, could these substances actually cause weight gain?  Surprisingly, when artificial sweeteners are fed to rats they will consistently gain weight.  This is even true with stevia.

In humans it is much more difficult to interpret these studies.  The primary unanswered question is: Do overweight people use artificial sweeteners or do artificial sweeteners make people overweight?  It is the classic chicken and the egg conundrum.

Theoretically, artificial sweeteners could cause weight gain by confusing the body.  This is certainly true with rats.  Once rats are fed artificial sweeteners they lose their ability to regulate how many calories they eat.  Also, animals fed artificial sweeteners don’t secrete the same hormones that tell them they are full so they continue to eat.

In humans, MRI brain studies show that the more artificial sweeteners you consume, the more your brain “lights up” at the sight of real sugar.  In other words, diet sodas may intensify your sugar addiction.

Lastly, while you don’t get any nutrition from artificial sweeteners, the wrong kind of gut bacteria thrive on artificial sweeteners.  Thus, any possible weight gain may be from changes to your gut flora.

Before you are completely convinced that artificial sweeteners cause weight gain, I should point out that in studies of overweight people when they substituted artificial sweeteners, in place of sugar, they lost weight.

Probably the best line of evidence comes from a seminal Harvard study which looked at the causes of weight gain over time.  In this study of 168,215 people, diet sodas actually caused a 0.12 pound annual weight loss.

However, after reviewing countless studies on artificial sweeteners, my take is that artificial sweeteners probably do not cause any significant weight gain or weight loss in most people.

3. Do artificial sweeteners cause diabetes?

While artificial sweeteners have been touted as a safe alternative for diabetics, some medical studies suggest that artificial sweeteners may actually cause diabetes.  For example, one large study of 6,039 people showed that artificial sweeteners actually increased your risk of diabetes by 25%.

Reports like these sounded the alarm for more research from the medial community.  This, in turn, led to studies like the Health Professionals Follow Up Study of 40,389 people from Harvard University.  Fortunately, this study did not show any increased risk of diabetes from diet drinks.

Contrary to what you might see somewhere on the Internet, four carefully performed scientific studies also showed no significant increase in the glycemic response to artificial sweeteners.  Likewise, position papers from the American Heart Association and the American Diabetes Association, which included the top scientists in the world, could find no clear link between artificial sweeteners and diabetes.

Based on my review of the science, artificial sweeteners probably do not cause diabetes.

4. Do artificial sweeteners cause heart disease?

As with a possible diabetes risk, some studies report an increased risk of heart disease from artificial sweeteners.  Indeed, one study reported up to a 50% increased risk with just 1 daily diet soda.  In this study, not only was their risk of heart disease increased but their cholesterol, waist line, and blood pressure all went up from just one diet soda each day.

Fortunately, for every study that suggests a possible cardiac risk from artificial sweeteners, there are just as many, if not more, studies showing no increased risk.  As a cardiologist, I tell my patients that, based on the most recent science, artificial sweeteners probably do not cause heart disease.

5.Is Agave Safer?

I am often asked if agave is a safe natural alternative to sugar. While agave is a low glycemic sweetener, due to its high fructose content, in contrast to all of the artificial sweeteners we have discussed thus far in this article, agave is highly caloric.

While there are not much scientific data specifically on agave, I classify agave as something akin to high fructose corn syrup.  As with high fructose corn syrup, agave is a highly processed plant extract that is very high in fructose.

6. Is Stevia Safer?

Real stevia has been used for millennia by South Americans with no apparent health consequences.  While rats gain weight on stevia, fortunately, the scientific data do not suggest any increased risk of weight gain or diabetes in humans.  In my opinion, stevia is probably the safest non-caloric sweetener.

7. Is Regular Soda Pop Safer than Diet Soda?

Whenever the subject of artificial sweeteners comes up, typically one person will say with pride, “at least I don’t drink anything diet.”

“What do you drink?” I’ll often ask.

“I only drink the regular soda,” is the reply I generally get.

Which is less bad for you?  If you had to choose, should you do the sugary Coke or the Diet Coke?

For those of you who regularly follow my blog, you already know the answer.  Neither.  However, if you look at the scientific data, artificial sweeteners may be “less bad” for you than high fructose corn syrup.  Let me explain.

Medical studies consistently show significant weight gain with sugary drinks.  These include soda pop, sports drinks, and even fruit juice.

For example, in a seminal Harvard study, just having a little more than one sugary drink a week caused people to gain 0.25 pounds a year.  In that same Harvard study, substituting a diet drink actually caused a 0.12 pound annual weight loss.

When it comes to diabetes and heart disease, the findings are the same.  Sugary drinks put you at increased risk whereas the data are not clear for diet drinks.

My personal view is that while neither sugar or diet drinks are “healthy,” sugary drinks consistently increase health risks whereas it is not so clear with diet drinks.

My Take on Artificial Sweeteners

At the beginning of this article I shared with you that I suffered from daily headaches for years, and that, remarkably, after quitting my daily Diet Coke habit, all of these headaches mysteriously disappeared.  I, like many other people, suffer from aspartame headaches.  Perhaps this is one reason why Pepsi recently switched from aspartame to sucralose.

I also suffered with abdominal issues from sugarless gums.  I share this because many people may have sensitivities to certain artificial sweeteners or other food additives.  The less of these chemicals you put in your body the better.

I realize that with all of the conflicting medical studies, navigating the waters of artificial sweeteners can be challenging.  Here are my three tips to navigating the waters of artificial sweeteners.

1. While artificial sweeteners do have many side effects, studies indicate that they may not be as dangerous as some Internet sites suggest.

2. Artificial sweeteners are best consumed as an occasional treat, if at all.

3. If you use artificial sweeteners, stevia may be a better option.

What has been your experience with artificial sweeteners?  Do you use stevia?  Please share your experiences below for our community.