JustTheScience

As levels of diabetes, obesity, and other dietary issues increase (diabetes alone has increased 763% from 1935 to 1996 in the united states (Gross et al 2004)) studies have been conducted to investigate whether the 1,000% rise in the use of High Fructose Corn Syrup (HFCS) from 1967 to 2000 in the American food industry is a major contributor (Bray et al 2004).^{1  2} In this article, we will examine whether or not HFCS is truly a factor in this significant increase.

Early studies found that there were possible clinical explanations for metabolic differences derived from HFCS ingestion and other sweeteners; primarily that it did not trigger insulin creation and thereby was thought to not trigger satiety signals (Reiser et al 1989) (Elliott et al 2002) (Bray et al 2004) (Teff et al 2004) .^3 4 5 6  However, more recent studies have found no difference in resulting satiety in men or women resulting from HFCS, sucrose, or milk, (Soenen and Westerterp-Plantenga 2007) (Melanson et al 2008) (Akhavan and Anderson 2007),^7 8 9 and that HFCS yields similar metabolic responses to other caloric sweeteners. (Angelopoulos et al 2009),¹⁰ Stanhope et al 2008 and Melanson  et al 2007 determined that sucrose and HFCS do not have significantly different short-term metabolic effects,^11 12 and moderate levels (~1.5 grams of fructose per kilogram of body mass) of HFCS intake  does not cause ectopic lipid deposition or insulin resistance in healthy humans (Le et al 2006).¹³

Although HFCS is not itself responsible for the increase in dietary and metabolic disorders, other studies have demonstrated that increasing levels of excess energy consumption in general is a cause (Gross et al 2004).¹⁴  For thousands of years humans consumed fructose amounting to 16–20 grams per day, largely from fresh fruits (Gross et al 2004). ¹⁵ Westernization of diets has resulted in significant increases in food with added fructose, leading to typical daily consumptions amounting to 85–100 grams of fructose per day (Gross et al 2004). ¹⁶  For example, a 12 ounce Coke contains 39 grams of fructose and the USDA Recommended Daily Allowance allots for 32 grams of carbohydrates in a 2,000 calorie diet.¹⁷  A single 12 ounce Coke therefore contains significantly more than an individual’s entire excess dietary energy allowance for a day.  Raben et al 2002 found that people have a very difficult time compensating for increased levels of calories associated with increased sugar intake by lowering caloric intake elsewhere.¹⁸  While moderate ingestion of HFCS will not specifically cause harm to oneself, it is advisable to monitor and limit consumption as much as possible.

1. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity [↩]
2. Fructose, insulin resistance, and metabolic dyslipidemia [↩]
3. Fructose, weight gain, and the insulin resistance syndrome [↩]
4. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity [↩]
5. Dietary Fructose Reduces Circulating Insulin and Leptin, Attenuates Postprandial Suppression of Ghrelin, and Increases Triglycerides in Women [↩]
6. Day-long glucose, insulin, and fructose responses of hyperinsulinemic and nonhyperinsulinemic men adapted to diets containing either fructose or high-amylose cornstarch [↩]
7. No differences in satiety or energy intake after high-fructose corn syrup, sucrose, or milk preloads [↩]
8. High-fructose corn syrup, energy intake, and appetite regulation [↩]
9. Effects of glucose-to-fructose ratios in solutions on subjective satiety, food intake, and satiety hormones in young men [↩]
10. The Effect of High-Fructose Corn Syrup Consumption on Triglycerides and Uric Acid [↩]
11. Twenty-four-hour endocrine and metabolic profiles following consumption of high-fructose corn syrup-, sucrose-, fructose-, and glucose-sweetened beverages with meals [↩]
12. Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women [↩]
13. A 4-wk high-fructose diet alters lipid metabolism without affecting insulin sensitivity or ectopic lipids in healthy humans [↩]
14. Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessment [↩]
15. Fructose, insulin resistance, and metabolic dyslipidemia [↩]
16. Fructose, insulin resistance, and metabolic dyslipidemia [↩]
17. Carbohydrates [↩]
18. Sucrose compared with artificial sweeteners: different effects on ad libitum food intake and body weight after 10 wk of supplementation in overweight subjects [↩]

Energy drinks are a common way for individuals to presumably increase their energy level.  In addition, more and more varieties of energy drinks with various ingredients are constantly appearing, all claiming to be the most effective.  We intend to examine whether or not energy drinks are really physiologically effective, what ingredients increase energy levels most effectively, and whether or not there are any possibly harmful side effects.

A study by Alford et al (2001) found that the intake of energy drinks is correlated with improved aerobic endurance and anaerobic performance, as well as significant improvements in choice reaction time, concentration, and memory.¹ Horne and Reyner (2001) found that energy drinks significantly improved the reaction time and reduced lane drifting of sleepy individuals when compared to a placebo, with the greatest improvement lasting an hour after ingestion.² Scholey and Kennedy (2004) determined that the combination of caffeine and sugar found in most energy drinks have a possibly synergistic relationship which results in improved secondary memory and speed of attention.³

Since it has been demonstrated that energy drinks do have a physiological effect on the body, it’s important to investigate which ingredients are contributing to this effect.  The most common ingredients found in energy drinks are: sugar, caffeine, taurine, guarana, and ginseng.  Studies on taurine’s impact on the body are predominantly inconclusive (Triebel et al 2006), although it has been noted that this free amino acid may play an important role in osmoregulation, immunomodulation, and bile salt formation (Bouckenooghe et al 2006), and consuming energy drinks with taurine increases taurine levels in the cerebellum (Roser et al 1998). ^4 5 6  A separate study by Geiß et al (1994) found that energy drinks with taurine led to lower sustained levels of the hormones epinephrine and norepinephrine, which led to significantly longer endurance times in cyclists.⁷  Guarana and ginseng extract are believed to be stimulants that affect cognition (Kennedy et al 2004). ⁸  A study by Haskell et al 2007 determined that Guarana improves memory and general attentiveness,⁹ and Sorensen and Sonne (1996) reported that ginseng improved simple reaction performance as well as abstract thinking.  Other studies have found ginseng supplementation has no effect on physical performance, psychomotor performance and cognitive function, immunmodulation, diabetes mellitus and herpes simplex type-II infection (Engels and Wirth 1997) (Vogler et al 1999) (Persson et al 2003). ^{10 11 12 13}

Despite all of the alleged beneficial properties of including the aforementioned ingredients in energy drinks, a study by Clauson et al (2008) found that popular energy drinks do not have high enough levels of Guarana, Taurine, or Ginseng to have any beneficial physiological or psychological effects, and that the only ingredients in high enough concentrations to have effects are caffeine and sugar (Clauson et al 2008). ¹⁴  Caffeine levels in energy drinks can range from 0mg per serving to 141.1mg which is almost a three fold increase over Coke which contains ~44.5mg per serving (McCusker et al 2006).¹⁵  Additionally, Candow et al 2009 found no improvement in physical endurance as a result of sugar free energy drinks.¹⁶

While the research around caffeine and sugar intakes will require articles of their own, some studies have been done regarding the risks of energy drinks themselves.  Aside from the high level of sugar in energy drinks which could contribute to diabetes, studies have shown that people who have had prior psychiatric issues should avoid energy drinks as it may cause a relapse (Chelben et al 2008) and that the drinks have significant erosive effects on dental enamel (Kitchens et al 2007).^17 18  The effects of energy drinks and hypertension has had conflicting research and is as of this writing, unresolved (Hirata et al 2003) (Winkelmayer et al 2005).^19 20

1. The effects of Red Bull Energy Drink on human performance and mood [↩]
2. Beneficial effects of an “energy drink” given to sleepy drivers [↩]
3. Cognitive and physiological effects of an “energy drink”: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions [↩]
4. Is taurine a functional nutrient? [↩]
5. Rapid analysis of taurine in energy drinks using amino acid analyzer and Fourier transform infrared (FTIR) spectroscopy as basis for toxicological evaluation [↩]
6. Dangerous Increase of Taurine in the Human Brain after Consumption of an ‘Energy Drink’? [↩]
7. The effect of a taurine-containing drink on performance in 10 endurance-athletes [↩]
8. Improved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng [↩]
9. A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans [↩]
10. No ergogenic effects of ginseng (Panax ginseng C.A. Meyer) during graded maximal aerobic exercise [↩]
11. A double-masked study of the effects of ginseng on cognitive functions [↩]
12. The memory-enhancing effects of Ginseng and Ginkgo biloba in healthy volunteers [↩]
13. The efficacy of ginseng. A systematic review of randomised clinical trials [↩]
14. Safety issues associated with commercially available energy drinks [↩]
15. TECHNICAL NOTE: Caffeine Content of Energy Drinks, Carbonated Sodas, and Other Beverages [↩]
16. Effect of Sugar-Free Red Bull Energy Drink on High-Intensity Run Time-to-Exhaustion in Young Adults [↩]
17. Effects of amino acid energy drinks leading to hospitalization in individuals with mental illness [↩]
18. Effect of Carbonated Beverages, Coffee, Sports and High Energy Drinks, and Bottled Water on the in vitro Erosion Characteristics of Dental Enamel [↩]
19. Caffeine increases aortic stiffness in hypertensive patients [↩]
20. Habitual Caffeine Intake and the Risk of Hypertension in Women [↩]