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Aspartame... the good, the bad and the confusing!

STUDENT CONTRIBUTOR: Dorothy Perelman | School of Nutrition, Ryerson University

September 29, 2020

Everyone has a different opinion about sugar. Some feel sugar is just an inevitable part of every day life and doesn't really present much of a threat to health and wellness. Some feel sugar is solely to blame for the noticeable jump in the amount of people challenged by obesity, cancer and chronic diseases - like diabetes - over the last decade. There has been research done that supports the idea that sugar might even have addictive qualities. Current evidence suggests a chemical reaction happens in the brain when we have sugar that knocks the usual balance in our bodies out of whack.

There are different strategies used to reduce sugar intake. You can go the 'clean eating' route and cut out all sugars - natural and otherwise. You can make the switch to natural sugar substitutes like honey, maple syrup or stevia. Or you can use one of many artificial sweeteners available at your local grocery store. Seems easy, right? Wouldn't that be nice! The hard truth is that sugar is sugar is sugar!! Adriana Valencia, RD, CDE of TCOYD says that 'some types of sugar may be less processed, but they will not give you the same calorie and carb reduction that a low calorie sweetener will'.

There's a lot of confusion around whether sugar substitutes and sweeteners are causing more health problems than sugar, itself. The amount of health and nutrition-related information flooding the internet and social media platforms doesn't make easy to get to the bottom of whether sweeteners are 'good' for you or not.

You hear it all the time...

“Sugar is soooo bad for you!”

"Splenda gives you cancer!"

“Sugar makes you fat!”

"Sweeteners are poison... you're drinking chemicals!"

If aspartame was killing us, we’d know by now because there would be a bunch of deaths reported to be being linked back to aspartame. That data simply doesn't exist. According to the National Library of Medicine's Aspartame: Review of Safety publication, "the aspartame safety data have been evaluated and found satisfactory by regulatory scientists in all major regulatory agencies and expert committees" and "consumption by hundreds of millions of people over the past 20 years represents billions of man-years of safe exposure."

So, what's the real deal?

Sweeteners can be found in the ingredients list on packaging for many common food and beverage products. They usually appear in foods that are labeled 'diet' or 'sugar-free'. There has been a lot of research done to try to get to the bottom of the actual impact of sweeteners. Quite a few studies have linked sweeteners to various cancers, but most are based on rats - not humans - and have since been found inconclusive. According to an article posted by Klara Knezevic RD, LD, CLT, 'the National Cancer Institute and other health agencies say there is no sound evidence pointing to any serious health problems with the use of these sweeteners'.

It's no surprise that sweeteners have increased in popularity to replace sugar; as has the debate whether they are safe for us to consume or not. Instead of sacrificing the sweet taste of sugar in our morning coffee, we use sweetener brands like Splenda, Stevia, Equal or Sweet’N'Low. These sugar substitutes give us all the sweetness without the sugar and calories. Win-win, right? Or... does that seem a little too good to be true? Sweeteners and their potential health consequences have long been a bone of contention in nutrition. Are they a healthy substitute? Or the root of all evil?

This blog is going to focus on the most popular sweetener; aspartame. Aspartame - found in most diet food and beverage products - seems to be the prime suspect when it comes to people's misgivings about sugar substitutes.

What Is Aspartame And Where Can you Find It?

Researchers at the Medical College of Wisconsin and Marquette University discovered that sugar substitutes such as stevia, xylitol and aspartame can have multiple negative health consequences.

Aspartame, specifically, is an artificial sugar substitute. Scientifically speaking, it is a methyl ester of 2 amino acids: aspartic acid and phenylalanine. Since aspartame is composed of amino acids, it provides 4 kcal/gram - the same amount as sugar.

What you may not realize is that aspartame is 200x sweeter than sugar, so you only need to use a small amount to get the same sweetness as you would with sugar. As a result, aspartame is labelled as “sugar-free” or “calorie-free” and is found in products like pop and other carbonated drinks, gum, instant coffee, puddings, yogurts and frozen desserts. It's sold under brand names you might recognize, like Equal, Splenda, NutraSweet, and Natra Taste.

The GOOD news is...

A study conducted at The Centre Hospitalo-Universitaire (CHU) de Rennes in France analyzed the effects of aspartame and acesulfame K (another artificial sweetener) on insulin release in 50 healthy adults. Each individual was assigned to a random group. One group consumed a drink containing aspartame and acesulfame K while the other group - the control group - was given an unsweetened drink. Each group consumed their beverage twice a day for 12 weeks. The results? Drum roll please...

There was no significant difference in participants' insulin sensitivity, no significant changes in insulin secretion and no changes in body weight, BMI or wrist measurements during the two 12 week periods.

Another study decided to take it a step further and examined the effects of stevia, aspartame, and sucrose on food intake, satiety, as well as insulin levels in healthy individuals. What did they find?

Participants who consumed stevia and aspartame ate less food over the entire day compared to those who consumed sucrose. In terms of satiety, people did not feel any different when consuming the sweeteners vs sucrose. Better yet, both blood sugar and insulin levels tested 20 minutes after eating proved to be significantly lower in those who consumed aspartame, as compared to those who had sucrose.

Before you go and stack up on sweeteners, though, be sure you consider all the facts!

The dark side of aspartame...

After aspartame is ingested, it's broken down into phenylalanine, aspartic acid, and methanol. Although this may not matter to most people, it is a major concern for people who have phenylketonuria and need to be careful because they cannot break down phenylalanine into tyrosine. As a result, phenylalanine builds up in the body and can lead to brain damage2... no bueno!

Several studies have shown that aspartame may also contribute to headaches thanks to those same increased amounts of phenylalanine in the brain. This side-effect is more of a concern when aspartame is consumed with carbohydrate rich foods. Why? Because carbs trigger the pancreas to release insulin - a hormone that is used up to allow glucose to enter our cells, thus lowering glucose levels in the blood. This makes it easier for phenylalanine to cross the blood-brain barrier, which - among other things - may interfere with the production of serotonin - the 'happy' hormone. 2

There is also evidence to suggest that individuals with mood disorders are particularly sensitive to aspartame. If you find you are prone to mood swings or symptoms of depression, you should probably try to limit your intake of aspartame.

BUT... aspartic acid and phenylalanine are already in most sources of dietary protein, like meats and poultry, and methanol naturally exists in fruits and vegetables - all components of a healthy, balanced meal as recommended by the Canada Food Guide. What you need to keep in mind when it comes to figuring out the risk to your health is the amount you're actually consuming. The amount of aspartic acid and phenylalanine found in food-based sources of protein far exceeds the amount found in aspartame. The amount of methane - a known carcinogen that is converted to formaldehyde in the body - is only 'poisonous' if consumed in large doses. The amount of methane found is aspartame is considered safe.

Here's where it gets confusing...

The effects of aspartame are still being researched today. There is controversy about its risks, and a lot of conflicting information to sort out. It seems for every research study that determines its safety, another follows confirming its risks. A recent journal published by Critical Reviews in Food Science and Nutrition states that "taken as a whole, the evidences for the effect of aspartame on metabolic variables associated to diabetes and obesity, are limited and do not support or refute a beneficial or harm related to consumption of this sweetener".

Overall, both artificial, non-nutritive sweeteners and intense sweeteners from natural sources are controlled under the Food and Drugs Act and Regulations in Canada. Sugar substitutes approved for use in Canada include: acesulfame-potassium, polydextrose, sucralose, thaumatin and sugar alcohols (polyols) like sorbitol, isomalt, lactitol, maltitol, mannitol and xylitol. Details about the permissions and limits applied to each, can be found on Health Canada's website.

According to the FDA, the acceptable daily intake is 50mg/kg of body weight. Trust me, that is more than enough for your daily cup-o-joe. It works out to be the equivalent of 21 cans of Diet Coke per day. To be clear: this is NOT us encouraging anyone to drink 21 cans of Diet Coke every day. Health Canada recommends controlling your sugar intake by:

  • Reading the labels on foods and beverages to identify those that contain sugar substitutes.

  • If you experience stomach discomfort or diarrhea from consuming sugar substitutes, cut back on your intake.

  • If you are diabetic, consider how sugar substitutes can play a role in a healthy, balanced diet.

  • If you are pregnant, make sure that your consumption of sugar substitutes is not replacing foods needed for a healthy pregnancy.

Here's a quick, visual guide to give you an idea about recommended servings:

If you take one thing from this blog post, let it be that aspartame - much like many other 'guilty pleasure' foods - is OKAY to have in moderation... but, you should always be sure to consider your own unique physiology, health needs and wellness goals. Consult with your doctor or a registered dietitian if you have any concerns and/or unanswered questions you'd like addressed.

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