Friday, April 10, 2015

Sweetener Update: Chronic Aspartame & Acesulfam-K Use Doesn't Mess W/ Your Microbiome | No Link Between Bad Lifestyle & Sweetener Use | No Good Advice from Dietitians

There's no scientific evidence that any of the various forms of "natural" sugar replacements like brown sugar & co would be better than artificial sweeteners.
Since artificial sweeteners their (non-existent) impact on insulin and, more recently, their effects of the gut microbiome are recurring topics in the Facebook messages I receive, I thought it may be nice to briefly summarize potentially relevant results of some of the more recent papers which put a questionmark behind some of the commonly heard "anti-sweetener" arguments, ... including the recently voiced objection that they would mess up your microbiome.

To this ends, I have conducted a brief database search, the results of which I will summarize briefly in only one to two paragraphs:
You can learn more about sweeteners at the SuppVersity

Unsatiating Truth About Artif. Sweeteners?

Will Artificial Sweeteners Spike Insulin?

Sweeteners & the Gut Microbiome Each is Diff.

Sweeter Than Your Tongue Allows!

Stevia, the Healthy Sweetener?

Sweeteners In- crease Sweet- ness Threshold
  • Recent intake of aspartame or Acesulfame-K is not associated with overall gut microbiome profile in adults (Frankenfeld. 2015).

    Unlike high-dose exposure to artificial sweeteners in rodents (Suez. 2015a,b), the chronic exposure to normal dietary amounts does not appear to induce significant changes in the gut microbiome. That's at least what the results of a recent study from the Global and Community Health George Mason University clearly indicate.

    In said study, Frankenfeld et al.  evaluated the gut microbiome in relation to recent aspartame and Acesulfame-K artificial sweetener consumption in thirty-one adults who completed a four-day food record and provided a fecal sample on the fifth day. The DNA analysis of the bacterial composition of the fecal samples showed that the bacterial composition of the participants (23%) who consumed aspartame and the participants (23%) who consumed Acesulfame-K did not differ significantly from the one of those subjects who did not use artificial sweeteners. As Frankenfeld et al. rightly point out, though, "[f]urther studies with more individuals are warranted to evaluate lower abundance microbial" (Frankenfeld. 2015).
  • No, sweeteners won't have you overeat. On the contrary: Epidemiological data suggests, people who consume more artificially sweetened foods and beverages have lower total energy, carbohydrate, and sugar intakes (Hunt. 2015).

    As the authors point out, "[t]he effectiveness of Low Calorie Sweeteners (LCS) for weight management is an area of debate", evidence on their use, however is lacking. To produce such evidence, Hunt et al. analysed the prevalence of LCS and macronutrient intake among US adults (19+y;n=9634, N=213,173,877) based on data from nonconsecutive 24 hr dietary recalls from NHANES 2007-2010. They categorized individuals into LCS usage groups as zero LCS use (56%; NO), LCS use 1-2x/2 day (23%; LO), or LCS use >3x/2 day (21%; HI) based on use of LCS in foods, beverages, and condiments. The classification shows that those in the highest LCS group, when compared to those who did not use LCS, were more likely to be: female, non-Hispanic white, age 51-70y, college educated, of higher income or BMI >30 kg/m² (all p<0.001).
    Figure 1: Data from NHANES 2007-2010 clearly indicates that people who use artificial sweeteners regularly can reduce their energy, sugar and carbohydrate intake significantly (Hunt. 2015).
    While this was more or less to be expected, the data in Figure 1, which reveals that "those who reported the higher LCS use evidenced mean total daily intake that was lower in total energy, carbohydrate, and sugar intake than those who did not use LCS" (Hunt. 2015), may be a bit surprising; and that despite the fact that these data are consistent with available published randomized controlled trials on the impact of use of LCS in weight management all of which show that they help to reduce the subjects energy intake and thus propel weight loss.

    Against that background it's not exactly surprising that Drewnowski et al. (2015a) found that US adults who consume low calorie sweeteners and thus care about their sugar intake and health, have higher Healthy Eating Index (HEI 2005) scores and are more physically active. Similarly, "LCS use [is]more common among populations with a lower burden of obesity and related chronic disease, specifically, non-Hispanic whites and those with more education/higher incomes" (my emphasis in Drewnowski. 2015b).
Artificial Sweetened Foods Promote, Not Hinder Fat(!) Loss | more
Yes, yes and yes! Sweeteners will help you lose weight! Latest meta-analysis leaves no doubt: "Findings from observational studies showed no association between LCS intake and body weight or fat mass and a small positive association with BMI; however, data from RCTs, which provide the highest quality of evidence for examining the potentially causal effects of LCS intake, indicate that substituting LCS options for their regular-calorie versions results in a modest weight loss and may be a useful dietary tool to improve compliance with weight loss or weight maintenance plans" (Miller. 2014)
  • Dietitians' perceptions about sweeteners are uncertain, ambivalent and divergent, sometimes explicitly being linked to fears about adverse health effects (Harricharan. 2014).

    I must say that I am hardly surprised that artificial sweeteners are another thing dietitians should, but don't really know about. Data from France, Germany, Hungary, Portugal and the United Kingdom shows that whether "sweeteners are good" or "bad" depends on the dietitian you pick. While some argue (not totally unwarrantedly) that "they feel it is important for consumers to reduce their attachment to sweet tastes", the highly diverging "expert advise" makes it quite obvious why consumers are confused and that Harricharan et al. are right, when they demand "clear and authoritative guidance" (Harricharan. 2014) and evidence, not bro-science based recommendations from health-professionals.
Learn more about artificial sweeteners and more specifically about their non-existent effects on insulin in my previous article "Science Round-Up Seconds: The Pro-Insulinogenic Effect of Artificial Sweeteners + Mechanisms & Consequences" | more
Overall, there is no doubt that the deliberate and strategical use of artificial sweeteners, when you're dieting is useful. What remains to be seen is whether the results of the Frankenfeld study can be confirmed for other artificial sweeteners. If that's the case, the long-term consequences of artificial sweetener use on the gut microbiome and thus potential on health in general are probably irrelevant.

Assuming that there are unwanted consequences, the latter may explain the partly paradoxical results in epidemiological studies and would warrant investigations into the use of pre- and probiotics, i.e. substances that promote the growth of or replace those bacteria the count of which is reduced by artificial sweeteners | Comment on Facebook!
References:
  • Drewnowski, Adam, and Colin D. Rehm. "Consumption of Low-Calorie Sweeteners among US Adults Is Associated with Higher Healthy Eating Index (HEI 2005) Scores and More Physical Activity." Nutrients 6.10 (2014a): 4389-4403.
  • Drewnowski, A., and C. D. Rehm. "Socio-demographic correlates and trends in low-calorie sweetener use among adults in the United States from 1999 to 2008." European journal of clinical nutrition (2015b).
  • Frankenfeld, Cara, et al. "Artificial Sweetener Consumption and Microbiome Profiles in 31 Adults Living in the United States." The FASEB Journal 29.1 Supplement (2015): 262-5. 
  • Harricharan, Michelle, et al. "Dietitian perceptions of low-calorie sweeteners." The European Journal of Public Health (2014): cku171.
  • Hunt, Kelly, et al. "Low calorie sweetener and macronutrient intake in the US adult population: NHANES 2007-2010." The FASEB Journal 29.1 Supplement (2015): 254-6.
  • Miller, Paige E., and Vanessa Perez. "Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies." The American journal of clinical nutrition 100.3 (2014): 765-777.
  • Suez, Jotham, et al. "Non-caloric artificial sweeteners and the microbiome: findings and challenges." Gut microbes ahead-of-print (2015a): 1-7.
  • Suez, Jotham, et al. "Artificial Sweeteners Induce Glucose Intolerance by Altering the Gut Microbiota." Obstetrical & Gynecological Survey 70.1 (2015b): 31-32.