Artificial sweeteners – are they better than sugar?

Artificial sweeteners are used as alternative to table sugar. I wrote a few months ago two articles about the detrimental effects of sugar on our health. But are artificial sweeteners any better? In this article, we will look at what science has been showing about the health effects of artificial sweeteners, with special focus on a very controversial one called aspartame.

Artificial sweeteners are many times sweeter than sugar and as they contain no calories, they were initially believed to be good for weight control and obesity. However, it is now known that artificial sweeteners are actually associated with an increased risk of developing chronic diseases, including obesity, type 2 diabetes, cardiovascular diseases and metabolic syndrome – as shown by many studies [1-4]. Interestingly, in 2014, a study in Nature (one of the most renowned scientific journals in the world) showed that artificial sweeteners induce glucose intolerance by altering our gut microbiome [5]. So instead of having the desired effect of preventing obesity and type 2 diabetes, artificial sweeteners might be doing exactly the opposite [6]. And according to the scientists, even tiny concentrations of a sweetener are sufficient to cause substantial changes in the our gut bacteria [7]. Besides, artificial sweeteners seem to increase appetite, leading to food overconsumption (especially unhealthy food) [4]. Also, because they are sweet, artificial sweeteners might continue stimulating our taste preferences for sweet foods, which might encourage sugar cravings and dependence [2, 8].

A recent study, just published last year in the scientific journal Stroke, showed that people who consumed 1 artificially sweetened beverage per day had a 3-fold increased risk of stroke and Alzheimer’s disease than people who did no consume this type of beverages [9]. 3 times increased risk is a lot!!!

So, now I would like to focus a bit more on the health effects of an artificial sweetener called aspartame.



This is one of the most controversial artificial sweetener. Why? Well, because 92% of the independently funded studies report that aspartame causes adverse health effects, but all the studies funded by the industry say they are safe [10] (conflict of interest, anyone?). According to the report in [10], the 8% of the independent studies that showed no problem with aspartame were all from the FDA (US Food and Drug Administration) except one which was a review article that considered only studies funded by the industry. And, as it is now well documented, the FDA had a huge conflict of interest in the approval of aspartame – just read this report [10] to get more information on this topic. Tip: when looking at a scientific study, check always their funding source.

So, as stated in [10], if we consider that actually neither the review article nor the FDA studies were that independent after all, basically all real independent studies showed a problem with aspartame. So, as you might imagine, I rather trust in the results from the independent studies. What have they been showing then? Why 100% of the really independent studies say aspartame has serious adverse health effects? And which adverse effects are these?

So let’s first look at the composition of aspartame.

Aspartame is composed of phenylalanine (50%), aspartic acid (40%) and methanol (10%).

Phenylalanine may cross the blood–brain barrier and cause severe changes in the production of very important neurotransmitters (chemicals necessary for communication between neurons) [11]. Aspartic acid is also thought to play a role as an excitatory neurotransmitter in the central nervous system. Glutamate is formed from aspartic acid and it happens to be one of the main excitatory neurotransmitters in our brain. Therefore, excess glutamate can be toxic for our neurons. It is now known that phenylalanine and aspartic acid (which are both amino acids) are toxic for our brain when the other amino acids present in protein are not present [11]. Methanol is metabolized into formaldehyde [11], which is classified as a known human carcinogen and it has no safe level of consumption [12].

In fact, several studies report a link between aspartame and certain types of cancer, especially leukemia and lymphomas (blood cancers) and brain cancers [13]. And this relationship was not always clear, because it seems that it is the long-term consumption of aspartame that leads to these cancers rather than a short-term consumption. In a study, people who consumed aspartame did not have more blood or brain cancers than people who had a low intake, however they were followed only for 5 years [14], and therefore it was a relatively short-term study. But a study that followed people during 18 years found that men who consumed aspartame had an increased risk of myeloma (brain cancer) and leukemia, and women had an increased risk of leukemia [15]. So, it seems that long-term consumption of aspartame can indeed lead to certain types of cancer. In men, aspartame is also associated with an increased risk of pancreatic cancer [16]. In these studies, men had a higher prevalence of these cancers with aspartame consumption than women. Why is that? So, as I explained above, aspartame is broken down into methanol, which is turned into formaldehyde, a known human carcinogen, by the enzyme alcohol dehydrogenase. This is the same enzyme that detoxifies regular ethanol. And men have higher levels of this enzyme than women [17], which is why women get higher blood alcohol levels when they drink the same amount of alcohol [18]. So this also means that because men have more of this enzyme, they have higher conversion rates from methanol to the carcinogenic formaldehyde, and therefore, higher rates of cancer due to the methanol from aspartame.

Many studies have also shown aspartame might be involved in the pathogenesis of certain mental disorders and in an impaired learning [11]. It may namely cause depression, insomnia, headaches, seizures, memory loss, multiple sclerosis, Alzheimer’s disease, Parkinson’s disease and brain cancer [11]. The detrimental effects of aspartame on the brain are thought to be due to an altered neurotransmitter functioning [11]. Even at low doses (well below the maximum acceptable daily intake) a diet containing aspartame given during only 8 days to people induced irritable mood, more depression and worse performance in cognitive tests than when the same people were given a diet with very low aspartame [19]. Also, certain individuals seem to be more susceptible to the effects of aspartame in their brain, namely people with mood disorders [20].

Aspartame consumption during pregnancy or at the time of conception can cause serious adverse effects to the fetus [21]. If you are interested in this topic and how aspartame has so detrimental effects on the brain I really encourage you to read this report [21].

Besides all these effects, aspartame also affects the metabolism of glucose, as I reported above for several artificial sweeteners including aspartame.

Aspartame is nowadays added to more than 6,000 products worldwide [22], especially to so-called “diet” beverages and foods. So watch closely the ingredient list of everything that claims to be “diet”. I find this is really mean. Some people go for this “diet” products because they think they are consuming something healthier, when they are actually consuming probably even more harmful ingredients. Over 500 pharmaceuticals also contain aspartame [22], especially vitamin and drug pills for children, so watch carefully for those as well. As I stated before in my previous articles, I really believe we should be aware of what we are eating and it is crucial to always check the ingredient list of everything we put in our mouths.

All these associations between aspartame and cancer and brain disorders have led scientists to call for a urgent re-evaluation of the safety of aspartame by the regulatory entities [13, 22]. The scientists in this study [22] state:

On the basis of the evidence of the potential carcinogenic effects of aspartame herein reported, a re-evaluation of the current position of international regulatory agencies must be considered an urgent matter of public health.”

However, we have to be aware that there is a lot of money involved, and that the companies that produce and use aspartame are powerful, and therefore it might take some years for the entities to finally do something. So right now it is up to us consumers to be aware of the situation and simply say no to these type of products, and to spread the word about it.


Be aware that aspartame, although undoubtedly the most controversial artificial sweetener, is not the only one used by the food industry. Other common artificial sweeteners include sucralose, saccharin, and acesulfame, which are all also of concern. For example, sucralose has been shown to trigger migraines in susceptible individuals [23].  Furthermore, in spite of its non caloric content, sucralose still affects the metabolism of glucose and can contribute to the metabolic risk factors of type 2 diabetes [24]. And where can you find them? In basically the majority of processed and packaged foods.

For optimal health, eat real food, meaning vegetables, fruits, legumes, nuts and seeds, healthy fats, etc – basically foods which come from Nature and which don’t need an ingredient list, and avoid both sugar and artificial sweeteners. Your health will thank you! In my honest opinion Nature provides us with so many tasty real foods, including sweet foods such as fruits, dried fruits (dates, raisins, figs, etc) and raw unprocessed honey, so why consuming something that is so controversial?

I hope you liked this article and if so, please help us spread awareness on this topic by sharing this article in your social networks! Thank you 🙂

PS: If you haven’t yet, you can subscribe to our free weekly newsletter here.



  1.         Pepino, M.Y., Metabolic effects of non-nutritive sweeteners. Physiol Behav, 2015. 152(Pt B): p. 450-5.
  2.         Swithers, S.E., Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements. Trends Endocrinol Metab, 2013. 24(9): p. 431-41.
  3.         Azad, M.B., et al., Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. CMAJ, 2017. 189(28): p. E929-E939.
  4.         Pearlman, M., J. Obert, and L. Casey, The Association Between Artificial Sweeteners and Obesity. Curr Gastroenterol Rep, 2017. 19(12): p. 64.
  5.         Suez, J., et al., Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature, 2014. 514(7521): p. 181-6.
  6.         Bokulich, N.A. and M.J. Blaser, A bitter aftertaste: unintended effects of artificial sweeteners on the gut microbiome. Cell Metab, 2014. 20(5): p. 701-3.
  7.         Gophna, U., Microbiology. The guts of dietary habits. Science, 2011. 334(6052): p. 45-6.
  8.         Yang, Q., Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience 2010. Yale J Biol Med, 2010. 83(2): p. 101-8.
  9.         Pase, M.P., et al., Sugar- and Artificially Sweetened Beverages and the Risks of Incident Stroke and Dementia: A Prospective Cohort Study. Stroke, 2017. 48(5): p. 1139-1146.
  10.       Walton, R.G., Survey of aspartame studies: correlation of outcome and funding sources.
  11.       Humphries, P., E. Pretorius, and H. Naude, Direct and indirect cellular effects of aspartame on the brain. Eur J Clin Nutr, 2008. 62(4): p. 451-62.
  12.       Pretorius, E., GUT bacteria and aspartame: why are we surprised? Eur J Clin Nutr, 2012. 66(8): p. 972.
  13.       Huff, J. and J. LaDou, Aspartame bioassay findings portend human cancer hazards. Int J Occup Environ Health, 2007. 13(4): p. 446-8.
  14.       Lim, U., et al., Consumption of aspartame-containing beverages and incidence of hematopoietic and brain malignancies. Cancer Epidemiol Biomarkers Prev, 2006. 15(9): p. 1654-9.
  15.       Schernhammer, E.S., et al., Consumption of artificial sweetener- and sugar-containing soda and risk of lymphoma and leukemia in men and women. Am J Clin Nutr, 2012. 96(6): p. 1419-28.
  16.       Chan, J.M., F. Wang, and E.A. Holly, Sweets, sweetened beverages, and risk of pancreatic cancer in a large population-based case-control study. Cancer Causes Control, 2009. 20(6): p. 835-46.
  17.       Chrostek, L., et al., Gender-related differences in hepatic activity of alcohol dehydrogenase isoenzymes and aldehyde dehydrogenase in humans. J Clin Lab Anal, 2003. 17(3): p. 93-6.
  18.       Frezza, M., et al., High blood alcohol levels in women. The role of decreased gastric alcohol dehydrogenase activity and first-pass metabolism. N Engl J Med, 1990. 322(2): p. 95-9.
  19.       Lindseth, G.N., et al., Neurobehavioral effects of aspartame consumption. Res Nurs Health, 2014. 37(3): p. 185-93.
  20.       Walton, R.G., R. Hudak, and R.J. Green-Waite, Adverse reactions to aspartame: double-blind challenge in patients from a vulnerable population. Biol Psychiatry, 1993. 34(1-2): p. 13-7.
  21.       Bowen, J. and M.A. Evangelista, Brain cell damage from amino acid isolates:  a primary concern from aspartame-based products and artificial sweetening agents., 2002.
  22.       Soffritti, M., et al., The carcinogenic effects of aspartame: The urgent need for regulatory re-evaluation. Am J Ind Med, 2014. 57(4): p. 383-97.
  23.       Patel, R.M., R. Sarma, and E. Grimsley, Popular sweetner sucralose as a migraine trigger. Headache, 2006. 46(8): p. 1303-4.
  24.       Pepino, M.Y., et al., Sucralose affects glycemic and hormonal responses to an oral glucose load. Diabetes Care, 2013. 36(9): p. 2530-5.


Leave a Reply

Your email address will not be published. Required fields are marked *