Whether you love it, or love to hate it, sugar is a fun topic to look at because frankly, it's everywhere and that doesn't seem to be changing anytime soon. We tend to see two extremes with media presentations of sugar and sweeteners: there's the trend of immensely high concentrations of sugar and sweets (restaurants and eateries creating outlandish desserts like milkshakes covered in candy and topped with cake, doughnut or churro ice cream sandwiches covered in candy or sugary cereal, etc) and then there's the constant stream of advice from health naturalists aimed at reducing our sugar intake because 'it's the high rates of added sugar intake that are associated with health problems like obesity, diabetes, cancer, etc' (i.e. the claims that 'sugar is the root of all evil'). Add to this the contradictory advice for artificial sweeteners where on one hand they can offer a non-caloric way to sweeten foods but with the counter argument that they can cause health problems as well. Is there a happy medium?
But first, my sugar story...
I am not afraid to admit that I have a sweet tooth. When I was younger, sugary and sweetened foods were not only a staple in my diet, there was a borderline obsession. If candy or chocolate was present anywhere in the house (and there almost always was) I was sure to find it, and finish it before anyone else had the chance. There was a point in time however when the house candy inventory was not replenished, so I resorted to other foods as snacks. After a few months of this (and getting used to not eating candy or chocolate as a regular snack) I went to the fridge to grab an apple from the crisper drawer and THERE was all of the chocolate, just waiting in the crisper drawer! Low and behold, the house candy inventory was sitting there (with the apples) this whole time (months!) without my knowledge to where my family was absurdly proud of their clever hiding spot. I'm not sure what's worse: the fact that my family was actively HIDING chocolate from me, or the fact that it took me MONTHS to actually open the crisper drawer for an apple. Either way: not my proudest moment.
Flash forward through the years and experimenting with various diets, there were times (years) that I went without any type of sweetener (whether added, artificial, or naturally derived) out of an unrealistic fear that they were solely responsible for weight gain, health complications, etc. *I now (happily) have no shame in my sugar-eating game because I no longer obsess about it.
So why are so many people sugar-obsessed?
A popular theory that supports this notion of sugar being responsible for health problems like obesity is the theory that sugar is addictive ("as addictive as drugs") where reward signaling (a dopamine release) in response to sugar intake in animal studies could be associated with further addictive or sugar-seeking behaviors. (Westwater, et al. 2016) The premise behind food addiction is that highly palatable foods (the presence of sugar, and/or fat, and/or salt) seem to be associated with behaviors analogous to drug addiction like a loss of control, withdrawal, and cravings. (Westwater, et al. 2016) However, there are findings to suggest that it is NOT sugar specifically, but sweet flavors in general that may be responsible for this reward signaling (as well as fat and/or salt as these are the most notable flavors for the macronutrients; sweetness=carbohydrates, fatty and/or salty= proteins and dietary fats). (Westwater, et al. 2016) To this point, you could argue that you are biologically programmed to respond positively to foods with these flavors as they contain the macronutrients and can thus stave off hunger and starvation with their intake. Another issue with this argument that sugar is addictive is the fact that humans, for the most part, do not consume sugar alone but rather as a component in a food, and with the presence of other flavors. (Westwater, et al. 2016) Thus to quantify sugar-seeking behaviors based on foods that just happen to contain sugar would be misleading. As such, there is a lack of scientific evidence to support the claim that sugar itself is addictive in humans. (Westwater, et al. 2016)
But sugar IS bad for you, right?
Much of the media coverage regarding sugar is focused on the associations between high intake of added sugars (particularly sugar-sweetened beverages) with obesity, diabetes, poor dental health, metabolic syndrome and heart disease. (Kaartinen, et al. 2017) We have all heard the advice to reduce our intake of added sugars and for the most part, much of the population has obliged. Yet there have been NO noted decreases in the prevalence of obesity over the last decade, despite intakes of added sugar being reduced closer to intakes from the 1970's. (Erickson and Slavin, 2015)
The basis behind this advice (to reduce added sugar) is primarily due to the fact that added sugar contains calories but is low in nutrients (i.e. 'empty calories') and therefore can increase total caloric intake (if calories are not otherwise controlled for) while also NOT providing necessary nutrients for adequate metabolic functioning. (Erickson and Slavin, 2015) To this point, reducing added sugar could be a valid argument. There have been study results to show for example that adults who ordered sugar-sweetened beverages (soda, juice, lemonade, sweet tea, etc) over water while out at restaurants ended up taking in an average of 440 calories and 58g of sugar MORE than those who did not order those beverages. (An, 2016) In this study, individuals who ordered sugar-sweetened beverages (i.e. 'added sugar') took in more total calories, sugar, saturated fat and sodium than those who ordered water. (An, 2016) [It doesn't take much calculation to see that those extra calories could certainly add up to a caloric excess.] There should be a big red flag waving right now: these individuals ALSO took in higher amounts of saturated fat and sodium (in addition to total calories and sugar) than those who did not order sugar-sweetened beverages, which could indicate that it is NOT the beverages specifically but rather ALL of the meal choices made that contributed to higher caloric intake (sugar-sweetened beverages are not a source of saturated fat or sodium, but other menu options would be). Going back to the population-wide decrease in added sugar intake, the fact that LOWERING intake of added sugar (particularly sugar-sweetened beverages) among the population has NOT decreased obesity rates in the last decade, wouldn't it be viable to say that added sugar ALONE is not the problem? Perhaps we need to look beyond added sugar...
So how should we quantify sugar intake?
When discussing sugar, it is important to note differences like 'added sugar' (sugar added to foods that would not otherwise contain it) compared to 'naturally occurring' (sugar naturally present in fruits, vegetables, and dairy). 'Free sugars' can consist of BOTH added or naturally occurring sugars, but where the sugar is removed from intact foods, and therefore has an absence of fiber. (Kaartinen, et al. 2017) For example, fructose is a naturally occurring sugar in fruits and vegetables, but when removed from the intact food source, i.e. an absence of fiber (like in fruit juices, high fructose corn syrup, honey, etc) these 'unbound sugars' are therefore considered 'free sugars'. This distinction is important to understand where for example a food product can be labeled as having 'no added sugar' but yet it still contains free sugar (lack of fiber) as seen in products like fruit juices. It should go without saying that free sugars can provide a higher concentration of sugars as there is a lack of fiber. Translation: take away the fiber, and now you can get more sugar packed into the same size package=increased concentration.
What it really comes down to is the concentration...
There are some recent study findings that looked at consumption of fruits, vegetables and fruit juices with risk for thyroid cancer where the whole fruit and vegetable consumption had an inverse relationship with risk for thyroid cancer while the consumption of fruit juices had a positive relationship (i.e. the more fruit juice consumed, the higher the risk for cancer). (Zamora-Ros, et al. 2017) This study proposes that the absence of dietary fiber, and therefore HIGH CONCENTRATION of sugar in these dietary trends, despite the fact that it is naturally occurring sugar and not 'added sugar', could likely be associated with this increased risk. (Zamora-Ros, et al. 2017)
According to another study of sugar intake in an adult population, intakes of naturally occurring sugars from intact whole foods (with fiber) were inversely associated with BMI and waist circumference, physical inactivity level, and smoking behaviors (i.e. the MORE fruits and vegetables eaten, the LOWER BMI and waist circumference, more physically active, and less likely to smoke). (Kaartinen, et al. 2017) In this study, the individuals who were leaner and living more healthy, active lives, were actually eating MORE sugar (i.e. higher carbohydrate diets) than those who were overweight or obese, physically inactive and engaging in unhealthful behaviors; HOWEVER this sugar was in the form of naturally occurring bound sugars from intact whole foods, (foods WITH fiber). (Kaartinen, et al. 2017) **This study implies benefits from a 'high carbohydrate diet', albeit these benefits were dependent on the FORM of the carbohydrates (i.e. the concentration of sugars in the presence of fiber).
So why the push to reduce or eliminate sugars?
There are actually contradictory arguments stating a lack of clear and convincing evidence to show that added sugar is uniquely associated with obesity or diabetes, relative to any other caloric source. (Erickson and Slavin, 2015) These counter-arguments suggest that added sugar is no different from any other digestible carbohydrate to where it is NOT uniquely linked to negative health outcomes. (Erickson and Slavin, 2015) However, due to negative associations prevalent in the media regarding the role of sugar in health, there has been in turn a push to eliminate sugar from the diet (from added sugars as well as naturally occurring sugars) to where there is ultimately confusion as to what sugar actually is. **Some people preach to avoid many carbohydrate foods because "fruits and grains are too 'high in sugar' or 'turn into sugar in the body"...
Why is this? Refer to my post on carbohydrates for a refresher, but carbohydrates are broken down into saccharides, also called 'sugars' (like glucose which is the primary fuel source of the body). However, it could be argued that when these carbohydrates come in the form of intact whole foods (containing fiber, water, and micronutrients) they are essentially the perfect package providing bioavailable nutrients in a manner that supports digestive and metabolic function. The addition of added sugar (for example: sucrose/table sugar) would still provide calories (as a carbohydrate source) but now without the fiber (or micronutrients or water) that would be present from an intact whole food. Given the fact that most people do not consume added sugar by itself (we are not typically snacking on sugar cubes) most of the added sugar that would be present in a diet is a component of a food, of which COULD also offer other nutrients (fat, protein, salt, etc). This could allude to the notion that as long as calories, fiber content, and nutrient content of the diet are controlled for, then added sugar would not seem to pose a threat by itself. [THIS is why there is likely to be health problems associated with a high intake of sugar, where if calories are NOT controlled for, or there is a LACK of nutrient-dense foods, then there is a risk for caloric surplus and/or nutrient deficiency.]
The big takeaway: Yes, you need carbohydrates to live a healthy, active lifestyle. Yes, carbohydrates turn into 'sugar' in the body (NOT the same as the sugar found in sweets) but whole food forms of carbohydrates (with fiber, water, and micronutrients) benefit a healthy body and lifestyle. No, you do not need to avoid fruits or other carbohydrates because 'they are high in sugar', but rather mind the total concentration of sugars you eat in regards to your calorie and nutrient requirements. **In my opinion, focus on whole foods and ensure that you are meeting your nutrient requirements (fiber, protein, water, micronutrients, etc) but know that the occasional sweet treat is merely adding to your total calories for the day (like increasing total carbohydrates). In this sense, if you are highly active but unable to meet your calorie needs with whole foods alone, then having a sweet treat could potentially benefit you by getting you closer to your calorie goals.
But what about sugar and risk for diabetes?
There are certainly studies that show an association with sugar or high fructose corn syrup/HFCS-sweetened beverages (sodas, fruit drinks and juices, lemonade, iced tea, energy drinks, vitamin water) increasing risk for obesity and diabetes. (McArdle, et al. 2013) Most of these studies however look at trends in the population and compare for example regular drinkers (one or two sugar-sweetened beverages DAILY) compared to non-regular drinkers (less than one drink per month) to where there was an observed increased risk for diabetes, obesity, hypertension, abnormal cholesterol, and physical inactivity in the regular drinkers compared to the non-regular. (McArdle, et al. 2013) However it should be noted that when calories are controlled for, there was STILL an increased risk for diabetes and insulin resistance with regular intake of these drinks, despite calories not contributing to weight gain; which alludes to the total concentration of free sugars as being a key factor. (McArdle, et al. 2013) How can this be? If calories are controlled for, this means that the individual is in caloric balance (eating enough calories to balance with their energy expenditure). However if these calories are coming from sources that provide high concentrations of free sugars (and thus supplying most of the calories in the form of free sugars), then they are also likely NOT getting calories from other foods that would provide adequate fiber, water, micronutrients, etc. **In this sense, despite being in caloric balance, the calories they ARE getting in are from nutritionally poor foods (lack of fiber, water, micronutrients, etc) and could therefore lead to nutrient deficiencies and further health complications.
While talking about high concentrations of free sugars...
Glycemic index (GI) refers to a value placed on different carbohydrate foods regarding how quickly or slowly they increase blood glucose concentrations. (Nix, 2013) The GI of a food is acquired by comparing the increase in blood glucose concentrations after ingesting the equivalent of 50g of that carbohydrate compared to 50g of pure glucose (or white bread used as a standard for pure glucose). (Nix, 2013) According to this index, carbohydrates that are quickly absorbed would boast a higher GI. However, glycemic index alone does not take into account serving sizes or the amount of carbohydrate present in a serving size, but where glycemic load (GL) does. Glycemic load would take into account the amount of carbohydrates present in a typical serving to where the presence of fiber, and the other macronutrients (protein and fat) could also play a role in how quickly or slowly the food increases blood glucose concentrations. (Nix, 2013) In this case, a carrot would actually boast a relatively high glycemic index (it can increase the blood glucose quickly) but only when this amount is in a high enough concentration to equal 50g of carbohydrates (imagine trying to eat about 1-2lbs of carrots to equal 50g of carbohydrates). Conversely, a normal serving size of carrots has a significantly decreased glycemic load because of the presence of fiber and the actual serving size typically eaten (unless of course you are juicing and drinking a few lbs of carrots in one sitting, then yes you would have a quick increase in blood glucose concentrations).
Free sugars actually range from being high glycemic to low glycemic but where context and concentration becomes even more important. For example, fructose has a notably low GI, HFCS (high fructose corn syrup) and sucrose/table sugar have a moderate GI, but where candies like jelly beans and skittles have a high glycemic load (artificial sweeteners and sugar alcohols have low or no glycemic index). This change in blood glucose response between glycemic index and glycemic load is due to the concentration of sugars present in a serving size. (There is a high concentration of sugars in a serving of those candies compared to the small amount of sugar required to equal 50g of carbohydrate for the glycemic index measurement). As such, it could be argued that glycemic load is a more beneficial marker for assessing blood glucose response to foods and where lower glycemic load foods (whole grains, legumes, nuts, fruit and vegetables) are emphasized as a part of a healthy diet for preventing and managing diabetes. (Nix, 2013) **It should be noted that GI and GL measurements do NOT dictate foods as being 'good' or 'bad' across the board, but where understanding the blood glucose response to these foods can be beneficial. When it comes to athletes and sports, competition days can often consist of long endurance events, or multiple events in a day, or multiple hours of activity between warm-up and the competition or game itself. This all equates to a need to utilize fuel quickly and efficiently without sacrificing performance due to digestive needs. In these instances, the use of low residue (low fiber) foods (high GI/GL foods like white bread) could be beneficial in providing quickly absorbed carbohydrates for energy without the characteristically slower digestion for fiber content.
For the most part, the glycemic response in the body should respond adequately to foods, regardless of whether they are high or low glycemic. However, in cases of hyperglycemia (high blood glucose) and/or insulin resistance (or type II diabetes), understanding these differences can notably be associated with preventing or improving outcomes. (Jung and Choi, 2017) Reports suggest that in type II diabetics, the intake of high glycemic and low fiber foods was positively associated with metabolic syndrome. (Silva, et al. 2013) This means that in individual's who are already diabetic or insulin resistant, the continued intake of high glycemic and low fiber foods increased their rates of obesity, waist circumference, and decreased their 'good' HDL cholesterol, all of which increases their risk for cardiovascular disease. (Silva, et al. 2013)
As well, studies suggest that the carbohydrate amount in a diet is less relevant than the glycemic response to carbohydrates where both high carbohydrate and low carbohydrate diets can be useful for managing type II diabetes (or high blood glucose), but with an emphasis placed on low glycemic and high fiber carbohydrates for these benefits. (Jung and Choi, 2017) (According to this study review, low carbohydrate diets are defined as <50% of calories coming from carbohydrates and high carbohydrate diets defined as >50%). **Once again, I am saying that a very low carbohydrate diet is no more effective for improving health (weight, diabetes, etc) than a diet containing moderate or high amounts of carbohydrates, but rather it comes down to the FORM with which they come in (free sugars vs intact foods, or high concentration vs low). Lower glycemic carbohydrates (carbohydrates that have more fiber, and which tend to be lower in total sugar concentration) seem to present as more beneficial for blood glucose concentrations than high glycemic load carbohydrates in cases of diabetes.
...and what about the low or no glycemic index for artificial sweeteners and sugar alcohols?
Artificial sweeteners, or non-nutritive sweeteners, provide sweetness to foods without the added calories. Some commonly seen non-nutritive sweeteners include sucralose (Splenda), aspartame (NutraSweet, Equal), acesulfame-K (Sweet One), and saccharin (Sweet n' Low) to name a few. The fact that these sweeteners can taste similar to, or stronger than, naturally occurring sugars (sucrose, fructose, maltose, etc) but without the added calories can be seen as an advantage for controlling for caloric intake. When looking at potential impacts of using these sweeteners in the diet, there are mixed results. In observational studies, there was a reported increase in LOW-nutrient dense foods with regular consumption of NNS beverages (non-nutritive sweetened beverages like diet sodas) which means that there was poor nutritional quality in those who drank NNS beverages (like diet sodas) compared to those that did not. (Chan, et al. 2017) This association was more pronounced in obese individuals which could allude to an INDIRECT association between intake of NNS and poor nutritional quality (which increases risk for micronutrient deficiencies, overweight, and obesity). (Chan, et al. 2017)
There are proposed mechanisms with which these NNS can play a role in modulating gut and brain activity as well as insulin signaling (through gut sweet taste receptors) as based on animal studies but where there is a lack of significant evidence of this association in human trials. (Chan, et al. 2017) In a human trial that aimed to look at this potential interaction, there was NO effect found in a blood glucose response (in a sample of diabetics) to the NNS sucralose (Splenda), even when given large doses equivalent to 5 (12 oz cans) of diet coke daily. (Grotz, et al. 2017) In this study, despite taking in large amounts of the NNS, there were no significant differences between the test group and the placebo group regarding blood glucose control, which could negate the theory of an interaction between NNS and the gut 'sweet taste receptors' affecting insulin signaling. (Grotz, et al. 2017) To this point, the NNS are currently characterized as being a 0 on the glycemic index scale, but there is still a need for further research. **It should be noted that there is largely a lack of evidence to suggest direct relationships between sugar or sweetener intake with diabetes, to where most of the observations may be based on indirect effects or dietary/lifestyle trends i.e. it's not a LITLLE bit of sugar that is doing it...
But what about that theory that artificial sweeteners can lead to cancer?
There are theories that some artificial sweeteners can increase risk for cancer based on older studies in rats. Some of these old studies included extremely high doses of saccharin (like in Sweet n'Low) being associated with increased risk for bladder cancer in rats or aspartame being associated with increased risk for cancer (likely due to the longer lifespan of the rats given high doses of aspartame). (Gallus, et al. 2007) However, these theories were later disproved due to differences in species-specific metabolism of sweeteners, the increased likelihood for rats to form neoplasms, and the unrealistically large doses of artificial sweeteners used to where these former studies cannot, and have not, been replicated or generalized to the human population. (Gallus, et al. 2007) As such, there is a lack of evidence to suggest a strong association between intake of artificial sweeteners and increased risk of cancer in humans. (Gallus, et al. 2007)
and when it comes to the gut...
Non-sugar sweeteners have been suggested to interfere with the gut microbiome while sugar alcohols (like sorbitol, mannitol, xylitol, and more) are possibly associated with bloating and mild laxative effects due to their incomplete absorption in the digestive tract. (Suez, et al. 2015) It is postulated that artificial sweeteners (and sugar alcohols) are 'metabolically inert' in mammals and therefore exhibit no physiological effects (pass undigested), but where this lack of digestion may lead to indirect consequences on the microbial environment. (Suez, et al. 2015) The foods and dietary intake we consume can provide fuel for the bacterial growth of our gut microbiota (and we need an appropriate balance of these bacterial populations). In this case, as the composition and function of the gut microbiome is associated with dietary intake, any distinct dietary trends (like a high fat diet, low carb diet, heavy use of artificial sweeteners, heavy use of antibiotics, etc) could therefore alter the gut microbiome potentially leading to a host of health complications like obesity, diabetes, metabolic syndrome and more. (Suez, et al. 2015) These observed effects of artificial sweeteners disrupting gut microbiota have been studied in animal trials but with conflicting results in human trials due to a difficulty in controlling for and quantitatively measuring intakes of artificial sweeteners with changes in the gut microbiome [while controlling for all other factors]. (Suez, et al. 2015) As such, there is a need to further research this possible association in order to determine more concrete risks or benefits for their use.
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