Artificial sweeteners increase your weight, spike your blood sugar, and make you crave sweets.
The irony is that they appear to be doing exactly what people consuming them hope to avoid.
What’s going on, and what can we do instead?
A recent study, published in Nature magazine, caught some media attention. In this study, the researchers spiked drinking water of young mice with one of three artificial sweeteners: saccharine, (think the pink Sweet’N Low packets), sucralose (think Splenda, the yellow packets), or aspartame (think blue packets). Mice were split into groups. Each group was fed one of the artificially sweetened water, plain water or ordinary sugar water. After a week, the mice receiving artificial sweeteners developed noteworthy glucose intolerance. The mice drinking plain or sugar water displayed no significant changes.
Research has been hinting at this problem since the 1990’s, but it’s been difficult to reach consensus on whether artificial sweeteners are a magic solution, or if they produce more harm than good.
How sugar addiction works
When your body tastes sweet flavors, your tongue tells your brain, “Whoah baby, I LOVE this stuff!!” Your pleasure centers light up like a mini-fireworks display. Then it fires off lots of signals, one of them being, “Hey Mr. Insulin! We’ve got the sweet stuff on the conveyor belt. It’s currently at the back of the tongue and comin’ through. Stand by!” Insulin emerges from pancreatic cells quickly to meet the sugar molecules racing from your mouth into digestion.
This is part of why sugar is so dang hard to give up. I share helpful tips for how to cut back on your sugar consumption here.
Now, if you’re consuming a non-caloric sweetener, your insulin stands by like a stood-up date. It’s waiting and waiting, but the anticipated glucose load fails to arrive.
Insulin doesn’t like being stood up. It knows the sugar is out there, somewhere. So, it stalks the sugar. Long biochemistry story short, insulin pairs up with partner in crime, grehlin (a powerful hunger hormone) to rev up your appetite. It’s gonna get that sugar, somehow, someway. Shortly, you’ll soon be hungry again. And insulin stores many of your calories away in fat cells, causing them to grow – as if to get even with you for the stand-up date thing. Oh, and just to make it worse – those fat cells don’t shrink, even when you lose weight.
People who eat artificial sweeteners are more likely to be overweight.
In fact, one review article found that people consuming non-caloric sweeteners are influenced psychologically that, over time, may actually increase calorie intake.
Huh? You’re probably asking what the heck that means. Think about the last time you saw someone order the super-sized burger and fries, with a side of diet soda. This is a common line of reasoning, where the diet soda drinker says well, I’m saving calories with the diet soda, so I can have the extra cookie.
Just like sugar, artificial sweeteners are addictive.
Studies with rats receiving cocaine and saccharine gave rats the choice between either drug. Rats chose saccharine. By the way, rats also choose real sugar over cocaine.
Until now, the arguments were basically summed up like this.
Argument #1: Scientists theorized that overweight people consuming artificial sweeteners were naturally predisposed to weight problems, and that consuming artificial sweeteners have nothing to do with it. After all, they have no calories or sugar, so how could one stand to reason they promote weight gain or glucose intolerance? Scientists concluded that the benefits of artificial sweeteners on weight and blood sugar are worth risks.
Argument #2: Scientists concluded, based on evidence, that artificial sweeteners are high jacking your metabolic pathways and driving hunger and blood sugar upward. They conclude that they aren’t worth the risks.
What scientists and clinicians tend to agree upon is that artificial sweeteners hang a hat on another thorn.
Artificial sugars are much sweeter than real sugar, which raises your threshold for sweetness.
This hijacks your normal sense of taste for sweet.
Over time, normal-tasting foods, like fruit, become less tasty. Vegetables may become unpalatable. Your taste buds become minted for artificial sweetness, and now need much more sugar in order to light up your brain’s pleasure centers. So you will consume more of the fattening sugar. (Remember, insulin stores any excess sugar in fat cells, and this converts to fat.)
The most recent mouse study’s findings that non-caloric sweeteners spike blood sugar isn’t actually huge news in the research world. But where it gets fascinating is that the study found a new mechanism for why it happens.
Artificial sweeteners change our gut bacteria (aka “microbiota” or “microbiome”).
Thanks to developments in research on the human microbiota, we now have a much better appreciation for the trillions of organisms that we host. I mean that literally. You and me, we host trillions of yeast, bacteria, and maybe even some parasites. In general, this is a very good thing. We would die, or suffer disease without these good friends.
In fact, our shocking rise in autoimmune diseases is starting to suggest that a less-than optimal microbiota is at least playing an important role.
There is a connection between the microbiota and weight gain.
Your microbiota is a dynamic “metabolic organism”.
Studies are showing that even subtle shifts in gut bacteria can set up problems. This may be subtle enough that you, the host, may not even notice. Certain nasty bacteria can take up residence in our pretty little guts and extract more calories from our food.
This is no “light” matter. Researchers are now exploring whether disturbances in microbiota are responsible for obesity. (And you thought that people who are overweight simply ate too much.)
Lesson: Respect thy microbiome.
I can’t tell you just how many people I’ve met who have nearly “perfect” diet and lifestyle practices, but can’t shed the weight. The microbiota theory holds a lot of promise for these folks.
In the coming decades, I believe we will be surprised as science unpacks the incredible stories of our micro-organism communities. And that the conversation in medicine will shift toward not just keeping our cells well, but toward keeping our microbiota well.
At the end of the day, I think scientists, clinicians, and public health practices are finally starting to scratch out the old “calories in, calories out” mantra. It’s fascinating – and sometimes overwhelming – that there is so much more impacting our health than we ever realized.
Count chemicals, not calories.
Everything that harms your microbiota, can potentially impact your weight. It may also impact your physical and emotional well-being in ways you never would expect.
To quote Clinical Nutrition Specialist, JJ Virgin, “Our bodies are not bank accounts. They are biochemistry labs.”
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1. “Artificial sweeteners induce glucose intolerance by altering the gut microbiota.” Jotham Suez, et. al. Nature, 2014. Published online Sept 17, 2014.
- “Artificial Sweeteners: A systematic review of metabolic effects in youth.” Rebecca Brown, et. al. Int J Pediatr Obes. Oct 8, 2010. Found: http://www.ncbi.nlm.nih.gov/
- Appetite. 2014 Aug 13;83C:82-88. doi: 10.1016/j.appet.2014.08.003. [Epub ahead of print]
3. “Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies”1,2,3 Paige E Miller and Vanessa Perez Am J Clin Nutr. Sep 2014. Found http://www.ncbi.nlm.nih.gov/
The effect of non-caloric sweeteners on cognition, choice, and post-consumption satisfaction.
PLoS One. 2007 Aug 1;2(8):e698.
Intense sweetness surpasses cocaine reward.