No Thanks, I Am Sweet Enough: The Negative Effects of Sugar-Sweetened Beverages
By: Jeb H. Naylor
Among the greatest health risks to Americans are cardiovascular disease (CVD), diabetes, and obesity. The risks of these conditions are increased by countless risk factors. This paper focuses on the effects that sugar-sweetened beverages (SSBs)–colas, other carbonated sugar-sweetened beverages, and non-carbonated sugar-sweetened beverages–have on the prevalence of these three health risks. Although SSBs are unregulated, everyday products they may have serious negative health effects.
Americans face many health problems in today’s world. The health problems faced by Americans are increasingly lifestyle related ones. As they are lifestyle related many can be in large part prevented and/or lessened by making some simple changes to diet, behavior, etc. Among the greatest of these health risks are obesity, diabetes mellitus, and cardiovascular disease (CVD). These health concerns are affected by numerous risk factors, many of which may go overlooked in general as they are commonplace in everyday life. One such risk factor that has become the subject of much research over the past few years is the consumption of sugar-sweetened beverages (SSBs).
Sugar sweetened beverages are made up of colas, other non-cola carbonated beverages, and noncarbonated beverages sweetened with sugar. According to Yang et al. (2014), SSBs are the main source for added sugar in the American diet, ringing in at 37.1 percent, adding also that one can of soda contains around 35 grams of sugar, which accounts for seven percent of total daily calories. The study goes on to mention that the American Heart Association recommends no more than 100 calories per day for most women and no more than 150 calories per day for most men from added sugar. Yet most regular sodas contain between 130 and 150 calories. Pomeranz (2012) states that although the FDA has set recommendations and limits for other food components there is no set limit for sugar and added sugar, saying, “manufacturers could not claim that food was healthy if it contained ‘disqualifying nutrient levels’ of total fat, saturated fat, cholesterol, or sodium. Sugar was not included in these criteria.” (p. e14).
With sugar-sweetened beverages matching and/or exceeding the added sugar limits deemed by The World Health Organization and the American Heart Association there must be health risks associated with the consumption of these beverages, as these limits are based on consumption and adverse health outcomes. Despite the risks associated, SSBs are extremely commonplace and are even marketed to all age groups. Many other products that have been considered to increase health risks are regulated, such as alcohol, and tobacco products, and many believe that sugar-sweetened beverages should be as well. Yet these beverages are not only unregulated they are also very readily available.
Just how much of a health risk are these readily available products? The answer lies in multiple facets of health. As they are rather common topics of discussion the focus will be on the negative effects of sugar-sweetened beverage consumption on three particular areas of human health, obesity, diabetes, and cardiovascular disease.
Obesity is becoming more and more of a health concern for Americans. The statistics of obese and overweight Americans continue to reach higher and higher numbers. The percentage of obese adults moves closer to 50 percent, and those who are considered overweight and obese have already passed that mark. According to the Centers for Disease Control and Prevention’s website a 2009-2010 study showed 35.9 percent of adults in the United States are obese, and 69.2 percent of adults fall into the category of overweight including obese (“Obesity and Overweight”, updated 2013) . The intensity of the problems on health due to obesity can be seen in America’s healthcare expenditures. Brownell et al. (2009) say, “Medical costs for overweight and obesity alone are estimated to be $147 billion – or 9.1% of U.S. healthcare expenditures” (p. 1602). These statistics show that without a doubt something has gone very wrong.
There are many factors that contribute to the risk of becoming obese. Genetic factors do play a role in the process. Lack of physical activity also greatly contributes to the development of obesity, as do age, medical conditions, and a number of other factors. Perhaps the most common factor in the development of obesity is the consumption of excessive amounts of calories. Bleich, Wang, Wang, and Gortmaker (2009) explain, “Although the complex interactions between factors that cause obesity are not fully understood, it is widely accepted that a positive energy balance (higher caloric intake than energy expenditure) leads to weight gain” (p. 372).
A great deal of these excessive calories that contribute to a positive energy balance come from added sugar. As previously mentioned, the primary source of added sugar in the American diet is the consumption of sugar-sweetened beverages. Bleich, Wang, Wang, and Gortmaker (2009) note that although the 2005 Dietary Guidelines for Americans recommends against drinks with added sugar SSBs make up a vast amount of total daily caloric intake and are the primary source of beverage calories.
Despite the excessive calories from added sugar and warnings and recommendations against such intake, SSB consumption continues to rise. This rise goes hand in hand with America’s rising obesity problem. The trends are increasing simultaneously. Bleich, Wang, Wang, and Gortmaker (2009) state that SSBs are linked to America’s obesity epidemic, noting that between the years of 1977 and 2001 the energy intake from soft drinks and fruit drinks (the two most commonly consumed types of SSBs) increased by over 130 percent, while the incidence of adult obesity doubled. The report also emphasizes that in the same time these changes took place the percentage of calories from all beverages rose more than 50 percent.
Not only have studies linked sugar-sweetened beverage consumption to obesity for the nation as a whole, increased consumption has been found to influence weight gain and increase body mass index (BMI) in individuals. Schulze et al. (2004) found significant increases in both weight and BMI in women who increased consumption of sugar-sweetened soft drinks from low to high than in those who reduced maintained their current levels whether those levels be low or high. The report by Brownell et al. (2009) takes note of two particular prospective studies that show similar results. The first of which followed middle-school students for two school years and found a 60 percent increase in risk of becoming obese for each additional per day serving of sugar-sweetened beverages. The second study mentioned followed adult women for eight years. This study found an increase in weight of 8 kg in women who increased their SSB consumption in the fourth year.
Excessive amounts of added sugar may not be the only way in which sugar-sweetened beverages influence weight gain and obesity. Although SSBs contain copious amounts of calories, they do not give the satisfactory feeling that a meal of the same amount of calories would give. SSBs basically offer the calories of a small meal but with next to no nutritional value. SSBs are also often paired with a meal, which can potentially double the calories that would normally be consumed by the meal alone. Brownell et al. (2009) bring to light several mechanisms through which SSBs lead to increased body weight including the poor satiating effects of liquid sugar, consuming SSBs, unlike food, in the absence of hunger, consuming SSBs to satisfy thirst and for social reasons, and the possible effects on taste preferences and food acceptance.
More proof that sugar-sweetened beverages add to weight gain and the obesity epidemic can be found by looking at the regressive effects of reduced consumption of SSBs. Not only do studies show that increasing SSB intake increases weight gain several of these studies also show reduced weight gain and even increased weight loss with the reduction and elimination of SSBs. In the same eight year study previously mentioned that found an 8 kg increase in women that increased SSB consumption at year four it was also found that those who decreased consumption and maintained the decrease only gained 2.6 kg. This is found to be true not only in trials involving middle aged women but for other age groups as well. De Koning et al. (2012) say, “In trials among overweight children and adolescents, subjects randomized to consume fewer sugar-sweetened beverages lost significantly more weight than participants in control groups” (p.1739). The reduction of SSB consumption is also commonly accompanied by other healthy life choices such as increased physical activity and exercise and better overall diet quality. These changes may be due in part to the diagnosis of a number of health problems brought on by the consumption of SSBs including diabetes, obesity, and cardiovascular disease.
Diabetes mellitus is a medical condition that affects many Americans. In fact, 17 million individuals in the United States suffer from type 2 diabetes according to a report by Schulze et al. (2004). The most common type of diabetes mellitus is type 2 diabetes (T2D), and this is the type focused on in this paper. T2D is also known as adult-onset diabetes and non-insulin-dependent diabetes. People affected by type 2 diabetes mellitus suffer from insulin resistance, by which the body cannot properly use the insulin produced in the pancreas. In extreme cases an insulin deficiency may develop in which pancreas is not able to produce adequate insulin.
This type of diabetes is widely considered to be a preventable disease. It can be prevented, lessened, and even controlled through diet and exercise. Although many factors including genetic factors, inactive lifestyle, age, and family history of diabetes all increase the risk of type 2 diabetes poor diet quality remains a significant contributor to the problem. Much of the problem of poor diet quality can be attributed to the consumption of sugar-sweetened beverages.
Schulze et al. (2004) claim that the incidence of diabetes has increased at a rate similarly as rapid as the obesity epidemic in the past few decades, noting that these events have also coincided with a 61 percent increase in U.S. adult soft drink consumption. The report also mentions that soft drink consumption in children and adolescents has more than doubled. This increase in consumption can potentially have devastating effects on the human body as several reports have linked sugar-sweetened beverage consumption to increased risk of type 2 diabetes mellitus. Brownell et al. (2009) takes note of three particular prospective studies of three different demographics that all showed positive associations linking SSB consumption to increased risk of type 2 diabetes. It should also be noted that the development of type 2 diabetes in children shows how severe the problem has become, as T2D generally develops in adults hence the name adult-onset diabetes.
Sugar-sweetened beverages may weigh quite heavily on increased risk of developing type 2 diabetes. De Koning, Malik, Rimm, Willett, and Hu (2011) say, “One serving of sugar-sweetened beverages per day was significantly associated with a 16% increased risk of type 2 diabetes, which was primarily due to colas and carbonated noncolas” (p. 1324). Schulze et al. (2004) reported 741 new cases of type 2 diabetes during a follow-up, attributing progressively higher risk of T2D to greater sugar-sweetened soft drink consumption. The study also found that as the main contributors sugar-sweetened colas alone shared similar results with all other sugar-sweetened soft drinks combined. Both of these studies carefully accounted for several possible confounding factors showing that SSBs may influence risk of type 2 diabetes independent of other factors.
Several avenues through which sugar-sweetened beverages may increase the risk of type 2 diabetes have been proposed. De Koning et al. (2011) suggest three particular routes through which this may occur. The first of which is excessive weight gain and body fat amounts, claiming this to be the most important factor. Next are the extremely large quantities of easily and rapidly absorbable carbohydrates found in sugar-sweetened beverages that increase glycemic load and insulin concentrations. The third proposed route is through other additives, particularly caramel coloring, which contains ingredients that have been shown to induce insulin resistance. Other studies support these suggestions through similar findings.
Schulze et al. (2004) point out an interesting fact that even though fruit punch consumption produces similar risks and physiological consequences as sugar-sweetened soft drinks, fruit juice consumption was not associated with increased diabetes risk, suggesting that naturally occurring sugars may not have the same metabolic effects that added sugars do. Another interesting discovery as stated by de Koning et al. (2011) is the type 2 diabetes risk reduction associated with coffee consumption. The study reports a 6 percent lower risk with one serving of coffee per day. This risk reduction jumps to 17% when one sugar-sweetened beverage is replaced with one cup of coffee.
The primary health concern that is associated with sugar-sweetened beverages is the relationship between SSBs and cardiovascular disease (CVD). According to de Koning et al. (2012), “For a 1-serving-per-day increase in sugar-sweetened beverage intake, the risk of [coronary heart disease] CHD increased by 19%” (p.1739). Yang et al. (2014) note that as percentage of calories from added sugar increased, the risk of CVD mortality increased exponentially. The report goes on to mention that the risk of CVD mortality was 38% higher for participants who consumed 17% to 21% of calories from added sugar when compared to those who consumed 8%, and the risk more than doubled for those who consumed 21% percent or more. These statistics suggest that SSBs may be much more dangerous to cardiovascular health than previously assumed.
As mentioned earlier sugar-sweetened beverage consumption can lead to both obesity and diabetes, and obesity and diabetes themselves are known risk factors for cardiovascular disease. As diabetes is developed the risks of CVD are increased in a number of ways. According to the World Heart Federation website (“Diabetes,” n.d.), those with diabetes are two to four times more likely to develop CVD, are more prone to atherosclerosis, plaque buildup inside the arteries that restricts blood flow, at a younger age, and have a two to three fold greater risk of heart failure. Kannel and McGee also mention that the incidence of CVD is twice as high in diabetic men and three times as high in diabetic women (1979). Therefore, SSB consumption can indirectly increase the risk of CVD.
Although sugar-sweetened beverages increase the risk of cardiovascular disease indirectly by means of obesity and diabetes there are many other direct threats of CVD through SSB consumption. Many of the studies observed link SSB consumption to CVD after obesity and diabetes are accounted for. Yang et al (2014) say, “The biological mechanisms underlying the association added sugar intake and CVD risk are not completely understood. Emerging evidence supports the hypothesis that excessive intake of added sugar might play a role through multiple pathways” (Discussion section para.5). De Koning et al. (2012) add that SSB consumption may even add risk beyond traditional risk factors.
Of the many mechanisms with which SSBs affect CVD one of the most talked about is the link between sugar-sweetened beverage intake and inflammatory responses which are key factors in the development of cardiovascular disease. Inflammation is particularly significant in the pathology of atherosclerosis. Fung et al. (2009) describe in some detail the process of how SSBs affect inflammation saying,
Serum glucose and insulin concentrations can rise quickly after SSB consumption. Therefore, SSB consumption can substantially contribute to the glycemic load of the overall diet. An increase in glycemic load can increase C-reactive protein concentrations. Inflammation influences not only atherosclerosis but also plaque stability and thrombosis. Therefore, SSB consumption can affect CHD risk in a relatively short time of a few years. In our cohort, a high glycemic load was shown to be associated with a higher risk of CHD. (p. 1040)
SSBs also have a significant effect on blood pressure and can influence hypertension, the most common form of cardiovascular disease. Several studies have found SSB consumption can increase blood pressure independent of other factors. According to de Koning et al. (2012), a previous study has shown that decreasing SSB consumption was associated with significant decreases in systolic and diastolic blood pressures, showing that eliminating SSBs from the diet can reverse the negative effects that SSBs can have on blood pressure. Hypertension is a very serious threat to cardiovascular health, and removing any possible factor is crucial.
As sugar-sweetened beverages are loaded with excess sugar reports on the harms of excess sugar are often used to show the negative effects SSBs have on CVD risk independent of the consequences of diabetes. Such suggested pathways include the associations between added sugar in take and dyslipidemia and insulin resistance as suggested by Pomeranz (2012). The report by Yang et al. (2014) shows linkages between excessive sugar intake and de novo lipogenesis, triglyceride synthesis, and raised triglyceride levels in the liver which are risk factors for CVD.
Considering the information provided in these reports, sugar-sweetened beverages can potentially have serious consequences when it comes to cardiovascular risk. Many pathways have been identified through which this may take place. These pathways have been shown to be both direct and indirect. The indirect pathways are routed through the effects of diabetes and obesity have on CVD as SSB consumption contributes both to diabetes and obesity. Evidence has also been presented that reveals several direct pathways connecting SSBs to CVD independent of diabetes and obesity. Many of the studies note that the increased risks of CVD remain significant after accounting for diabetes, BMI, unhealthful diet, and lifestyle.
As these studies have researched the effects of sugar-sweetened beverages on the human body, the have all found similar results. The studies all found strong associations between sugar-sweetened beverage consumption and at least one of these three health problems (obesity, diabetes mellitus, and cardiovascular disease) that plague the health status of the United States. These associations found in these studies provide a strong case in proving the negative health effects that sugar-sweetened beverages have had and continue to have on consumers. The consistency of these results across multiple studies also strengthens the validity of the hypothesis.
Although these studies have found strong associations for all categories of sugar-sweetened beverages, there is one category that stands above them all. The researchers agree that colas are the greatest contributors to these risks. In the diabetes study Schulze et al. (2004) claim that colas alone share similar results with all other sugar-sweetened soft drinks combined, proving sugar-sweetened colas to be of exceptional concern. Colas are also consistently the most frequently consumed of all the sugar-sweetened beverages, which is an alarming fact considering the threat they present.
These studies also agree on another interesting fact. Not only have these studies found sugar-sweetened beverages, especially colas, to cause health risks they have also found that artificially sweetened beverages are not linked to these health problems. Any associations connected to artificially sweetened beverages are considered very weak. These weak associations are also easily dismissed after the researchers account for certain factors. Interestingly de Koning et al. (2011) did find a strong association between artificially sweetened beverages and type 2 diabetes in an age adjusted analysis, but the association was dismissed in a multivariate analysis. It is suggested that the association was due to reverse causality.
In addition to these studies finding similar results the majority of the studies collected data in similar manners. There were two primary methods of data collection used in these prospective studies. The most commonly used method of collecting data was the use of semiquantitative food-frequency questionnaires (FFQs) that were mailed to participants. The second source of data collection used in these studies is the results of the National Health and Nutrition and Examination Survey III (NHANES III). According to Yang et al. (2014) the participants in the NHANES studies not only completed household interviews but also underwent physical examinations at mobile examination centers.
Complete accuracy in these studies could not be fully achieved due to certain uncontrollable factors. Among these are missing data, lifestyle changes, and dietary changes. Other limitations as proposed by de Koning et al. (2012) include the fact dietary intakes may be measured with some errors, participants may be dissimilar to the general public, and a large number of cross-section associations were tested for. The researchers who conducted these studies accounted for these and other possible confounding factors in their research. After these factors and limitations were accounted for, the research continued to show strong associations between sugar-sweetened beverage consumption and the prevalence of obesity, type 2 diabetes mellitus, and a number of cardiovascular diseases.
To further control for confounding factors the researchers eliminated participants who had been previously diagnosed with these conditions and accounted for those who may have been in the early stages such diseases. Several endpoints were also used throughout these studies. These endpoints included but are not limited to: death, diabetes, cardiovascular disease, myocardial infarction, angina, and obesity.
In light of this information it is obvious that sugar-sweetened beverage consumption has a negative effect on health status. Through many different mechanisms, SSBs have been shown to increase the risk of obesity, diabetes, and cardiovascular disease. The results held true even after many factors were accounted for. The primary mechanism in each of these categories through which SSBs increase risk is the excessive calorie content of the sugar in these beverages. This is further reinforced through the fact that artificially sweetened beverages were not associated with increased risk in any category. Interestingly, in spite of these obvious health concerns, SSBs remain unregulated, easily accessible, and readily available to anyone and everyone.
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