By Dr. Hilary Booth
Artificial sweeteners have been touted as a way to get that sweet taste without all the calories, but what are they really doing in your body? Research is showing that artificial sweeteners can cause diabetes, blood sugar dysregulation, obesity, and hormone imbalance – just to name a few.
Artificial Sweeteners and Your Brain
Food brings us pleasure. Feelings of happiness, joy, and reward are produced by the brain to encourage our desire to eat, and thus, to stay alive. This food-reward system has two parts: sensory and post-ingestive. Sensory means that we derive pleasure from the sight, smell and taste of food. Post-ingestive means that we derive pleasure from getting calories to our brain. Interestingly, the nutrient density of food plays no part in this. The brain strictly rewards us for eating something with sugar in it. This is why when we are upset, stressed, or nervous, we gain comfort from eating sugary foods.
Artificial sweeteners don’t activate this food-reward pathway in a normal way. When we eat artificial sweeteners, our taste buds detect “sweet” (often at 300 – 7,000x the sweetness of natural sugars!), but the ingested food lacks those expected calories. This uncoupling of the food-reward system leads to increased appetite because we seek more food to satisfy the second part of the equation: feeding the brain. We also eat more to try to obtain that pleasure and reward feeling that we’re not getting when our brain isn’t being fed. This cycle leads to obesity and blood sugar dysregulation.
In addition, these super-sweet sweeteners encourage sugar craving and sugar dependence, and studies show people tend to choose lower-nutrient food options when they have been exposed to artificial sweeteners.
Artificial Sweeteners and Your Hormones
Even after just seven days of artificial sweetener consumption, the body starts to show signs of impaired glucose tolerance and insulin sensitivity. When the body’s insulin/glucose regulation is impaired, it can lead to obesity and type 2 diabetes. It is important to note that insulin resistance also plays a causative role in many other conditions, including Altzheimer’s disease, infertility, breast cancer, autoimmune diseases, and heart disease. All hormones are connected, so when one hormone pathway is off balance, it can be detrimental to others.
Artificial Sweeteners and Weight Loss
Many people switch to “sugar free” or “diet” alternatives in order to lose weight. However, a multitude of large-scale studies have found that in both children and adults, artificial sweetener use is associated with obesity, and with weight increase over time. This is found to be true both in normal populations, and in groups of people who were actively trying to lose weight. Interestingly, substituting artificial sweeteners for their regular-calorie versions actually resulted in modest weight loss!
Artificial Sweeteners and Your Gut Bacteria
An interesting article published in the esteemed journal, Nature, showed that artificial sweeteners negatively alter the composition and function of bacteria in the gut. Significant differences were found between the gut bacteria present in people who ate artificial sweeteners and those who did not. Altered gut bacterial flora leads to compromised immune function, food intolerance, insulin resistance, autoimmune conditions, and altered serotonin function (the hormone that regulates mood and appetite). Science is just starting to understand the importance of the gut flora, but we know it plays a role in a multitude of normal body functions, and altered flora can cause illness. For these reasons, the article published in Nature calls for a reassessment of the widespread usage of artificial sweeteners, and I agree!
The Bottom Line
Artificial sweeteners are not a better alternative to the real thing. As with most things in life, there is no easy way around the calories that come with sugar intake. If you are going to include sugar as part of your diet, it’s best to go with the full calorie, non-diet version. The best advice would be to minimize sugar all together, sticking with all natural, unrefined versions when you do choose to indulge.
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Morgen K, Folich L. The Metabolism hypothesis of Altsheimer’s disease: from the concept of central insulin resistance and associated consequences to insulin therapy. J Neural Transm. 2015 Feb 12. [Epub ahead of print].
Suez J et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 2014. 514(7521): 181-6.
Yang Q. Gain weight by “going diet”? Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 2010. 82(2): 101-108.