Artificial Sweeteners and Your Brain

Submitted by Amy Sercel MS RD CD

Edited by Marcia Bristow MS RDN CSSD CD

From sugar-free candy to diet soda, artificial sweeteners are everywhere.  Whether you’re trying to limit your sugar intake to lose weight, you have diabetes, or are working to promote your overall health, you might choose foods made with artificial sweeteners because they contain fewer calories than foods made with sugar.  Unfortunately, recent studies have shown that consuming artificial sweeteners may not actually be as health promoting as you might think.

When you eat sugar, a pathway in your brain is activated that ultimately causes the release of dopamine, a neurotransmitter that signals pleasure.  Dopamine is considered an essential part of the reward pathway in the brain, and it’s part of the reason that sugary foods taste so good to people.  Your brain releases dopamine when you take the first bite of something sweet, but as you continue eating it your body releases other hormones to signal that you aren’t hungry anymore.^1,2

Recently, researchers have investigated how artificial sweeteners, which taste sweet but do not provide your body with any calories, might impact this reward pathway.  It appears that the reward pathway is only fully activated when a sweet taste is accompanied by calories.^2–4 Researchers found that hungry mice consistently chose food that contained real sugar, and therefore also contained calories, instead of the artificially sweetened food.  They believe this is because the hormones signaling that you are no longer hungry are only released when the sugar in the sweet food you eat is converted into glucose for your cells to use as fuel.²

If you regularly consume artificial sweeteners, it appears that the reward pathway in your brain could be thrown off so food that contains real sugar will become even more rewarding, making you want to eat more in general.^5,6 This may explain why people who consume more artificial sweeteners tend to have a higher body mass index, and people do not tend to lose much weight by switching from caloric to artificial sweeteners.  The pleasant taste of the artificial sweeteners activates the dopamine reward pathway, but because that taste is not accompanied by calories the pathway is not turned off.  As a result, you will continue to look for food until you’ve satisfied your body’s need for calories.⁷

Research in this area is still evolving, so it will be important to continue learning about new findings related to the influence of artificial sweeteners’ on the brain’s reward pathway.  In the meantime, limit the amount of artificial sweeteners you consume.  Choose whole, unprocessed foods whenever possible.  If you’re a diet soda-drinker, consider switching to unsweetened iced tea or sparkling water flavored with a splash of fruit juice or infused with some fresh fruit.  This will help you stay hydrated and you might find that you have more energy as a result.  If you’re craving a sweet snack, try some fresh fruit with nut butter, a handful of trail mix that contains raisins or other dried fruit, or some yogurt with a little granola.  These foods will satisfy your craving while providing other important nutrients, making them great options for anyone looking to manage their weight and promote overall health.

References:

1.         Murray S, Tulloch A, Criscitelli K, Avena NM. Recent studies of the effects of sugars on brain systems involved in energy balance and reward: Relevance to low calorie sweeteners. Physiol Behav. 2016;164:504-508. doi:10.1016/j.physbeh.2016.04.004

2.         Kirkwood C, Kirkwood C. Tricking Taste Buds but Not the Brain: Artificial Sweeteners Change Brain’s Pleasure Response to Sweet. Scientific American Blog Network. https://blogs.scientificamerican.com/mind-guest-blog/tricking-taste-buds-but-not-the-brain-artificial-sweeteners-change-braine28099s-pleasure-response-to-sweet/. Accessed February 26, 2018.

3.         Brain cannot be fooled by artificial sweeteners; higher likelihood of sugar consumption later -- ScienceDaily. https://www.sciencedaily.com/releases/2013/09/130922205933.htm. Accessed February 27, 2018.

4.         Tellez LA, Ren X, Han W, et al. Glucose utilization rates regulate intake levels of artificial sweeteners. J Physiol. 2013;591(22):5727-5744. doi:10.1113/jphysiol.2013.263103

5.         Green E, Murphy C. Altered processing of sweet taste in the brain of diet soda drinkers. Physiol Behav. 2012;107(4):560-567. doi:10.1016/j.physbeh.2012.05.006

6.         Why artificial sweeteners can increase appetite -- ScienceDaily. https://www.sciencedaily.com/releases/2016/07/160712130107.htm. Accessed February 27, 2018.

7.         Yang Q. Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 2010;83:101-108.