Is refined sugar just sweet and delicious or is it an addictive toxin poisoning us slowly? Sugar seems to be the newest dietary scapegoat but is it really that bad? There are plenty of theories floating out there about this refined carbohydrate and it can be confusing to make sense of them all. Let’s examine some of these claims to find out whether they are indeed fact or fiction (or perhaps somewhere in between).
Sugar is Toxic
By now you’ve probably heard the claim that sugar is toxic. Some even liken sugar to cigarettes. Perhaps you are among the 5 million plus people who have viewed the viral video Sugar: the Bitter Truth and are convinced that sugar is indeed a toxin causing a number of our society’s health problems. The toxicity of sugar isn’t a straightforward issue and there seem to be a number of people on either side of the “sugar is toxic” fence.
First, let’s step back and look at what toxic means. The word toxic refers to a substance which is capable of causing death or injury. If you look deeper into the toxicity of substances, you’ll learn that they can either be acutely toxic, in which a single exposure to a substance will cause adverse effects, or chronically toxic, in which adverse effects come after repeated exposure. And to complicate the matter further, toxicity is dose dependent. Many seemingly harmless substances in which we need for life, like water and oxygen, can be toxic in large enough doses. And individual genetic factors can influence the level at which a substance is toxic. So, a dose that may be toxic to one person may cause no effects in another. Complicated, isn’t it?
I think we can agree that sugar does not cause an acute toxicity, or else most of us wouldn’t be here right now. But does sugar cause a chronic toxicity after many years of repeated exposure? Some studies show that diets high in refined sugars are associated with increased rates of diabetes, heart disease, unfavourable cholesterol profiles, and chronic inflammation. While not all research shows an association between sugar and chronic disease, there is enough to be wary of consuming too much. Keep in mind that many of these studies that show positive associations between sugar intake and health conditions are just associations and do not prove cause and effect. There could be other factors in these high sugar foods or in concurrent dietary and lifestyle choices that contribute to these illnesses. Typically, foods that contain a high amount of simple sugars like sucrose or high fructose corn syrup are not healthy, wholesome foods. They likely contain other ingredients that don’t support health and may contribute, in part, to chronic illnesses.
Considering all the evidence pointing to the negative health impacts of eating a too much sugar, then one could justify calling sugar toxic: more specifically chronically toxic. Some people could be meeting and exceeding the specific sugar dose in which causes themselves adverse effects and, perhaps, the dose at which it is chronically toxic is lower than we think. However, one could argue, that in order to call sugar toxic you would have to prove that it is sugar, without a doubt, causing the ill effects. And that is difficult to do. While it could be sugar causing these illnesses, it could also be other dietary, lifestyle, or genetic factors leaving one susceptible to disease.
Aside from whether sugar is toxic or not, I do have an issue with actually calling sugar toxic because after all, water, oxygen and probably bananas and apples are toxic at a certain level, too. Describing refined sugars as toxic, poison, or evil is a scare tactic and a hyperbolic. Using these words probably works to sell more books and to garner more media attention but do we really need to use scare tactics to encourage healthy eating? No one should not be afraid to enjoy a piece of birthday cake or give their child a freshly baked chocolate chip cookie. These are some of the most wonderful things in life. There is no evidence that eating sugar once and a while is harmful. And, yes, it is true that we don’t know the individual doses in which repeated exposure to sugars causes health problems. However, what we do know is that diets high in fruits, vegetables, legumes, nuts and high-fiber whole grains are associated with lower rates of disease. So if you are eating an overall healthy diet I really don’t feel you should worry about sugar toxicity while mindfully enjoying the occasional brownie.
Natural Sugars are Better for You
You may have heard that some sugars are better for you than others. Sugars like raw organic cane sugar, evaporated cane juice, agave nectar, brown rice syrup, and honey are all touted to be better (i.e. healthier) than white sugar. Advocates of using these sugars instead of white sugar claim that they are more natural and contain more trace vitamins and minerals. And while there may be small differences in available nutrients in these “natural” sweeteners, it really isn’t significant enough to make a difference. You would have to be eating quite a bit of these sugars to benefit from their added nutrient content, which is something no sane nutritional professional would recommend. There isn’t much evidence that these natural and less processed sugars are better for you.
The glycemic index, or impact of a food on our blood glucose, of these sugars (with the exception of agave nectar) are similar enough ranging from 55-68. And considering you probably won’t be eating pure sugar (right?), there will be other factors like the fiber, protein or fat content of the sugar containing foods that will alter the effects of these sugars on your blood glucose levels.
Agave nectar is a bit of a different story as it contains quite a high percentage of fructose (approximately 70-90%) and, thus, does not significantly affect blood sugars . This is great, right? Well, no, not exactly. There is some research that shows diets high in fructose cause high blood triglycerides (or blood fats), and may increase risk of fatty liver disease and insulin resistance. However, more research in the area is needed as there is some conflicting evidence on the subject. Although agave syrup does not influence blood sugars, its high fructose content may impact health negatively, especially if consumed regularly and in large amounts.
When you look at the sugars we eat from the point of view of our small intestine, the site of sugar absorption, there isn’t much difference between them. There are very little differences in sugars once digested. Your small intestine doesn’t know whether the final products of sugar digestion come from honey, white sugar, maple syrup or organic cane sugar. To the tiny cells that transport the sugars into the bloodstream, a sugar is just a sugar. Sure there are slight differences in ratios of glucose to fructose, or a few trace minerals that may accompany the sugars but in reality when you get down to it, a sugar is just a sugar. Really, it should just be up to preference. Some sugars provide a slightly different flavour in which you may enjoy in your baking or whatever you use sugar for. There really isn’t a sugar that is better for you. Period.
Sugar Causes Behavioral Problems in Children
It’s a common assumption that when kids are given sugar that hyperactivity and behavioral problems ensue. There have been many studies regarding the effects of sugar on behavioral problems, hyperactivity and attention deficit hyperactivity disorder (ADHD) but none have found conclusive evidence that there is a connection.
It has been found in double-blind controlled studies, in which parents are unaware if their kids have been fed sugar or a placebo, that parent’s perception of their children’s behaviors are worse if they think they have been fed sugar. It could be an ingrained assumption that sugar makes kids behave poorly that makes parents pick up on negative behavior more easily and blame them on sugar. Or perhaps, children exhibit more energy, hyperactivity and behavioral problems in environments where high amounts of sugar are served (i.e. birthday parties, holiday celebrations). What is clear from the evidence available is that sugar does not cause behavioral problems in children.
Sugar Causes and Feeds Cancer
Cancer has a huge impact on our society and, as such, a large amount of resources are put into both finding out its causes and potential cures. Along with valid scientific research, there are also a lot of less scientific theories, cures and quackery into why people develop cancer and how to cure it. Among the lists that circulate on the internet, sugar is often pointed at as a culprit that both causes and feeds those nasty cancer cells. So, how valid is this? Do cancer cells really feed on sugar? And can we fight cancer by eliminating all sugar?
First, let’s discuss whether a high sugar intake is associated with higher cancer rates. Unfortunately, there isn’t a clear answer for this. The evidence is mixed. There are studies that show both an increased risk of cancer with high sugar consumption while others show no association. Some studies show that certain types of cancer are more prevalent when intake of specific sugars, such as fructose, are high but not necessarily with an elevated intake of total sugar or carbohydrate.
How could this be? Well, a lot of these these studies looking at dietary factors and cancer risk are observational, meaning that they take a large amount of data and try to make conclusions from what they find. Observational studies can’t prove a cause and effect relationship, rather they can find associations between two factors. Although researchers have ways of controlling for, or singling out, a certain factor like sugar when assessing their data, there still can be unknown factors that could be influencing the outcome being studied. These observational studies also can’t assess genetic susceptibility to cancer which may explain why some people, despite poor dietary and lifestyle choices, don’t develop cancer. Observations studies are great for finding trends and helping us pinpoint what needs to be studied in a more controlled, cause and effect type of investigation.
Now onto whether cancer cells feed on sugar. The short answer is yes. Cancer cells, like all of our cells, use glucose as an energy source. However, compared to healthy normal cells, cancer cells use up more glucose. Cancerous cells are glucose hogs; they take resources away from our healthy cells. There is evidence that certain cancer cells die when starved of glucose in the laboratory setting. Interestingly enough, other researchers have found that if glucose is restricted, some cancer cells will use glutamine, an amino acid or component of protein, for fuel. So even if sugars are not available there is the potential that some cancer cells may find other energy sources to keep themselves growing.
If we know that cancer feeds on glucose, can low sugar diets be used to fight the disease? Surprisingly, there have been relatively few good quality, large studies or randomized controlled trials examining the role of low sugar diets and cancer (or at least, that I have found). There have been only a few small, short studies and case reports that have found improvement in tumor size and disease progression after following a low or no carbohydrate diet in conjunction with standard medical treatment. Studies with mice show that very low carbohydrate diets (not low sugar diets) do slow tumour growth. It was found, however, that if the carbohydrate content of the diet was too low that the mice experienced significant weight loss, up to 20% more weight loss than controls. These very low carbohydrate diets are more restrictive than following a no sugar diet and can put cancer patients at higher risk for weight loss. Considering significant weight loss is an indicator of poor prognosis in cancer patients, encouraging a diet that may further compromise their health may be unethical until further, well designed studies are done. After all, those with cancer are often dealing with a host of other symptoms that limit their dietary intake including nausea, and loss of appetite. To load on a restrictive diet may not be feasible or ethical. Seeing positive outcomes in mice and in the lab is one thing but if it translates to humans we have yet to find out.
It’s important to keep in mind that it could be (and most likely is) a combination of factors that leaves one susceptible to cancer. We know that both genetic and environmental factors (including diet) influence cancer risk. So it may very well be that sugar plays a role in the development and growth of cancer but maybe only in susceptible people. For now, we don’t have a clear picture.
High Fructose Corn Syrup is Worse Than Table Sugar
In recent years there has been a significant amount of discussion about the evils of high fructose corn syrup (HFCS) and how its replacement of sucrose (i.e. table sugar) in our food supply has contributed to the obesity epidemic.
Developed in the late 1960’s, HFCS entered our food supply as cheap alternative to sucrose. So, what is so different about HFCS? Well, it appears that it isn’t much different than table sugar. Table sugar is composed of 50% glucose and 50% fructose while HFCS is either 45% glucose/55% fructose (typically seen in sweetened beverages) or 58% glucose/42% fructose (seen in breads and non-beverage type foods). These ratios are not that much different. Calorically speaking, both HFCS and table sugar offer 4 kilocalories per gram. Thus, when you compare the two sugars there really isn’t much difference. Despite their chemical similarities, there still remains some debate on whether HFCS is worse than sucrose. However, at this time there is no conclusive evidence that HFCS is worse or the sole cause of our expanding waistlines.
When it comes to HFCS, it’s still a good idea to avoid the food products that contain it. Now, why would I recommend this when I just said there is very little evidence that it is worse than sucrose? Well, products that use HFCS (and a lot of other added sweeteners, for that matter) are not typically those foods that are good for us. Many high calorie, nutrient poor foods use HFCS. The presence of HFCS should simply be used as an indicator that it’s probably not the best food to be including regularly in your diet.
The truth is that we need to limit our sugar intake, especially that of added sugars. Some estimate that 75% of all American food and beverages contain added sugars. Yikes! The sugars found naturally in wholesome foods like fruits should not worry us as they contain many other nutrients, including fiber, that are beneficial to our body. And instead of focusing so much on sugar alone, we should take a step back and look at the types of food these added sugars are found in: cakes, cookies, soda, and commercially made food items. And many times sugar is not the only ingredient in these unhealthy foods that makes them a poor nutritional choice. Focus on the food, not the nutrient. Choose fresh, whole foods that are minimally processed to give your body the most healthful food and leave the sugar for special occasions.
Learn more about carbohydrates here.