Effects of artificial sweeteners on body weight, food and drink intake

Transcription

1 Acta Physiologica Hungarica, Volume 97 (4), pp (2010) DOI: /APhysiol Effects of artificial sweeteners on body weight, food and drink intake É Polyák 1, K Gombos 2, B Hajnal 3, K Bonyár-Müller 1, Sz Szabó 1, A Gubicskó-Kisbenedek 1, K Marton 1, I Ember 2 1 Department of Nutritional Sciences and Dietetics, Institute of Physiotherapy and Nutritional Sciences, Faculty of Health Sciences University of Pécs, Pécs, Hungary 2 Institute of Public Health, Faculty of Medicine, University of Pécs, Pécs, Hungary 3 Department of Languages for Specific Purposes, Faculty of Health Sciences University of Pécs, Pécs, Hungary Received: October 9, 2009 Accepted after revision: September 8, 2010 Artificial sweeteners are widely used all over the world. They may assist in weight management, prevention of dental caries, control of blood glucose of diabetics, and also can be used to replace sugar in foods. In the animal experimentation mice were given oral doses of water solutions of table top artificial sweeteners (saccharin, cyclamate based, acesulfame-k based, and aspartame) the amount of maximum Acceptable Daily Intake (ADI) ad libitum. The controls received only tap water with the same drinking conditions as the treated groups. The mice were fed chow ad libitum. We measured food intake and body weight once a week, water and solutions of artificial sweeteners intake twice a week. The data were analysed by statistical methods (T-probe, regression analysis). Consumption of sweeteners resulted in significantly increased body weight; however, the food intake did not change. These results question the effect of non-caloric artificial sweeteners on weight-maintenance or body weight decrease. Keywords: artificial sweeteners, body weight changes, food intake, fluid intake In the last decades, the growing concern about health and life quality have encouraged people to exercise, eat healthy food and decrease the consumption of food rich in sugar, salt and fat. Changes in eating habits and lifestyle are mainly due to the incessant search for health. With increased consumer interest in reducing sugar intake, food products made with sweeteners rather than sugar have become more popular. The discovery of artificial sweeteners has triggered the development of sugar-free products, particularly in diabetes, in energy-controlled diet, in special diets and in obesity (12). The low-calorie artificial sweeteners, such as aspartame, saccharin, acesulfame-k and cyclamate, have become sugar alternatives to replace sucrose, and have been widely used in dairy products in Europe and in the USA. The taste of artificial sweeteners added to foods is similar to that of sucrose. Intense sweeteners, however, are generally from several hundred to several thousand times sweeter than sucrose. Most do not contain any calories, except of aspartame. Each one has specific characteristics of sweetness intensity, persistence of the sweet taste, coating of the teeth and aftertaste effect. Corresponding author: Éva Polyák Vörösmarty u. 4, H-7623 Pécs, Hungary eva.polyak@etk.pte.hu X/$ Akadémiai Kiadó, Budapest

2 402 Polyák É et al. Over the last couple of decades there has been a dramatic increase in the consumption of artificially sweetened foods and low calorie light beverages, but at the same time obesity has also continued to increase. Some consumers may feel bewildered with the effects these sweeteners will have on their appetite, food intake, and body weight (14). Several hypotheses on the effect of sweetness without energy on food intake have been formulated. One hypothesis is that energy-reduced sweet foods assist individuals in preventing weight gain, presumably because the body s appetite systems does not indicate the missing energy. The most controversial hypothesis is that ingestion of beverages with sweetness flavour triggers body systems to expect ingested energy and when the energy is not supplied an increase in appetite and subsequent food intake occurs (1). In 1986 in a preliminary report Blundell and Hill (8) suggested that the consumption of aspartame solution in water resulted in an increase of appetite compared with the control condition, in which water was consumed. Two years later in another survey Rogers et al. (13) found that the actual food intake after the consumption, of aspartame, acesulfame-k, saccharin containing drinks did not decrease significantly. In a rat study where rats were fed the regular feed and yogurt sweetened with no-calorie saccharin more total calories were taken and more weight was gained than in rats given the regular feed and yogurt sweetened with sugar. Swithers and Davidson (16) suggest that, by interfering with the meaning of sweet taste, artificial sweeteners upset an ancient physiological system that evolved to regulate food intake and energy use. The long-term effects of artificial sweeteners on food intake and body weight are less clear. Some researchers said, that animal studies are the only systematic investigations of the possible mechanisms through which intense sweeteners could affect hunger and food intake (14, 17). Materials and Methods A total of 30 female and 30 male CBA/CA inbred mice were used. They were approximately 5 weeks of age at the beginning of each experiment. The male and female mice were separated and were housed in cages. Group sizes were 6 mice for each cage. The mice were maintained at standard circumstances. Mice were given oral doses of water solutions of artificial sweeteners (saccharin, cyclamate based table top sweetener, acesulfame-k based table top sweetener, aspartame) the amount of maximum ADI ad libitum. The controls received only tap water with the same drinking conditions as the treated groups. The mice were fed chow ad libitum. Food consumption was estimated by subtracting the amount of food left on the grid and the amount of spilled food from the initial weight of food supplied. Water and solution intake was calculated on the basis of the difference between the 300 ml and amounts of consumed fluid at a certain time of the week. We measured body weight individually and food consumption once a week, water and solution intake of artificial sweeteners twice a week. Our experimental period lasted 25 weeks. Our table top sweeteners are available in trade.

3 Artificial sweeteners, body weight, food and drink intake 403 Ingredients of Table-top Sweeteners 1. T Aspartame ingredients: E-640, E-152, E-500, lactose, aspartame 18 mg/tablets. Product description: aspartame tablets use the popular high intensity sweetener to formulate non-nutritive sugar substitute tablets. For sweetening: hot beverages, including coffee, tee, cakes, and good for canning. They are suitable for diabetics on a medically prescribed diet. Each tablet is the equivalent of one teaspoon of sugar. The product is available in a dispenser containing 150 tablets, total weight is 9 g. Nutritional values in 100 mg of product: Energy: 333 KJ/ 80 kcal, protein: 0 g, carbohydrates: 0.2 g, fat: 0 g. Not suitable for phenylketonurics contains phenylalanine. The maximum acceptable daily intake from aspartame for mice was total of 80 mg. 2. Saccharin table top sweetener. Product description: non-nutritive sweetener for people with diabetes. One tablet contains 12.5 mg Na-saccharin. The dispenser contains 1000 tablets. The maximum daily intake is 5 mg/bodyweight. Each tablet sweetens like two teaspoons of sugar. The maximum acceptable daily intake from saccharin for mice was a total of 10 mg. 3. Süssina is based on a mixture of saccharin and cyclamate. Content: 650 tablets per dispenser, in total of 39 g. Sweetener is suitable for cooking. Ingredients: Na-cyclamate 34.7 mg/tablets, Na-saccharin 9.3 mg/tablets, Na-bicarbonate, mono-na-citric acid. Sweetening effect of all tablets replaces 3.9 kg of sugar. One tablet (60 mg) sweetens as much as 6 g of sugar. The maximum daily intake for adults is 23 pieces of tablets. Keep in a dry place! The maximum acceptable daily intake from cyclamate for mice was a total of 22 mg. 4. Fan Sladidla is based on a mixture of aspartame and acesulfame-k. It contains: 130 tablets per dispenser. Its sweetening effect replaces at least 6 g of sugar. Ingredients: lactose, aspartame (9 mg/tablets), acesulfame-k (9 mg/tablets), leucine. Not suitable for phenylketonurics contains phenylalanine. Nutritional values in 100 grams of product: Energy 1354 KJ, carbohydrates 56 g, protein 0 g, fat: 0 g. The maximum acceptable daily intake from acesulfam-k for mice was a total of 18 mg. The solutions were prepared using 300 ml tap water and the calculated amount of sweetener. The control group received only tap water of the amount of 300 ml. Statistical analysis We used independent two-sample t-test with software Microsoft Excel We examined food and drink consumption as well as weight growth with multiple lineal regression models in the groups. In all cases, p<0.05 was considered to be statistically significant. Results Our study focused on the effect of intense sweeteners on body weight, food and drink intake in mice. Figure 1 summarizes the tendency of body weight gain in female groups. In the female saccharin group we found significant differences in weight gain compared to the control group (p=0.0495). There were no significant differences between the other treated groups and the control group. Upplying a regression analysis in the groups where aspartame, saccharin and cyclamate were used our data showed a positive correlation, and in the acesulfame-k group there was a slight negative correlation according to the control group.

4 404 Polyák É et al. Fig. 1. Body weight gain across 25 week artificial sweetener consumption in different female groups Fig. 2. Body weight gain across 25 week artificial sweetener consumption in different male groups During the study where male mice were administrated cyclamate (p=0.0034) and the saccharin (p=0.0304) they gained significantly more weight than the control. The body weight gain did not differ in the aspartame and the acesulfame-k groups compared to the control group. We found positive correlation in all treated groups. Figure 2 shows the body weight changes in male groups. There were no differences in food intake among the female groups consuming aspartame, saccharin, cyclamate and the control group. Despite the fact that saccharin consumption caused greater weight gain in the treated females than in the controls; the food intake of the saccharin group did not increase. In these treated groups according to the regression analysis the correlation was negative. In the female group acesulfame-k administration caused significantly lower food intake than in the control group (p=0.0424). In this treated group the correlation was also negative.

5 Artificial sweeteners, body weight, food and drink intake 405 There were no significant differences in food intake between the male treated groups and the control group. The correlation was negative in all of the treated groups compared to the control group. Sweetener consumption did not increase the drink intake in treated female groups. The female data show negative correlation in all the treated groups. In males in the acesulfame-k group the drink consumption increased considerably (p= ) compared to the controls. We suppose that the initial increase was caused by the sweet taste of the solution. In males the correlation was negative in all of the treated group. Figures 3 4 summarize the mean weight gain, the mean food intake and the mean drink intake of the groups. Fig. 3. Comprehensive bar diagram of the female mice groups (*p < 0.05) Fig. 4. Comprehensive bar diagram of the male mice groups (*p < 0.05)

6 406 Polyák É et al. Discussion Artificial sweeteners, also called sugar substitutes, are substances that are used instead of sucrose to sweeten foods and beverages. As artificial sweeteners are many times sweeter than table sugar, smaller amounts are needed to create the same level of sweetness. They may assist in weight management, prevention of dental caries, and control of blood glucose for diabetics. The artificial sweeteners have been the subjects of controversy regarding their effects on appetite and weight management (3 5, 18). Several studies suggest that saccharin consumption may be followed by increased food intake, but this finding requires further investigation (7, 17). Some researchers have reported increases in ratings of hunger associated with aspartame consumption; most have found that aspartame is associated with decreased or unchanged ratings of hunger (5, 6, 14). In the present study we investigated the effects of aspartame, saccharin, cyclamate, acesulfame-k administration on body weight, food and drink intake. We found that saccharin consumption caused significant weight gain in both sexes, although the nutritional habits did not change. The final bodyweight significantly increased in the group consuming saccharin compared to the control. Swithers and Davidson (16) stated that normally, sweet tastes indicate that the body is about to receive a lot of calories, and the digestive system prepares to react. When sweet tastes are not followed by lots of calories, as in the case of artificial sweeteners, the body becomes conditioned against a strong response. In that study the researchers found that saccharin, may have the same effect. Male mice administered cyclamate gained significantly more weight, but the nutritional habits did not change. We used table-top sweeteners. Cyclamate was mixed with saccharin in 10:1 ratio of cyclamate to saccharin. This mix provides the intense sweetness of saccharin combined with the ability of cyclamate to lessen the bitter aftertaste of saccharin. Bachmanov et al. (2) have found that although cyclamate tastes sweet to humans, mice do not experience it as sweet neither showed preference for it. The finding that consuming sweetened drinks contributed to more weight gain, but did not change the food intake appears to pose difficulties for views that emphasize the homeostatic aspects of energy regulation (9, 11, 15). However on a metabolic level, there are no data indicating that intrinsic properties of noncaloric sweetener modify energy balance independently of their influence on macronutrient and energy intake (10). We did not find the same results in case of cyclamate effect, because the literature is very poor in this kind of investigation. We want to continue the study with cyclamate administration, and find the cause of its ability to gain weight. Aspartame administration did not affect the nutritional habits and weight changes. The consumption of acesulfame-k did not increase the weight, but significantly decreased the food intake in females and significantly increased the drink intake in males. There is no clear evidence that artificial sweeteners augment appetite by activating cephalic phase responses, altering osmotic balance, or enhancing food palatability. Indeed, there is emerging evidence that selected non-caloric sweeteners may stimulate the release of satiety hormones, despite the link between these hormones and energy intake (10). These results question the effect of non-caloric artificial sweeteners on weightmaintenance or body weight decrease. Although these were caloric free artificial sweeteners they do not follow the fact that their consumption reduces or does not influence bodyweight.

7 Artificial sweeteners, body weight, food and drink intake 407 Intense sweeteners are part of a weight-control program; they could aid calorie control by providing palatable foods with reduced energy. It must be clear that consumption of intense sweeteners are really helpful in weight-maintenance or body weight decrease. References 1. Anderson GH, Saravis S, Schacher R, Zlotkin S, Leiter L: Aspartame: effect on lunch-time food intake, appetite and hedonic response in children. Appetite 3, (1989) 2. Bachmanov AA, Tordoff MG, Beauchamp GK: Sweetener preference of C57BL/6ByJ and 129P3/J mice. Chem. Senses. 26, (2001) 3. Bellisle F, Drewnowski A: Intense sweeteners, energy intake and the control of body weight. Eur. J. Clin. Nutr. 61, (2007) 4. Benton D: Can artificial sweeteners help control body weight and prevent obesity? Nutr. Res. Rev. 18, (2005) 5. Black RM, Tanaka P, Leiter LA, Anderson GH: Soft drinks with aspartame: effect on subjective hunger, food selection, and food intake of young adult males. Physiol. Behav. 49, (1991) 6. Black RM, Leiter LA, Anderson GH: Consuming aspartame with and without taste: differential effects on appetite and food intake of young adult males. Physiol. Behav. 53, (1993) 7. Blundell JE, Green SM: Effect of sucrose and sweeteners on appetite and energy intake. Int. J. Obes. 20, S12 S17 (1996) 8. Blundell JE, Hill AJ: Paradoxical effects of an intense sweetener (aspartame) on appetite. Lancet I: (1986) 9. Cummings DE, Overduin J: Gastrointestinal regulation of food intake. J. Clin. Invest. 117, (2007) 10. Mattes RD, Popkin BM: Non-nutritive sweetener consumption in humans: Effects on appetite and food intake and their putative mechanisms, Am. J. Clin. Nutr. 89, 1 14 (2009) 11. Murphy KG, Bloom SR: Gut hormones and the regulation of energy homeostasis. Nature 444, (2006) 12. Pinheiro MVS, Oliveira MN, Penna ALB, Tamime AY: The effect of different sweeteners in low-calorie yogurts: a review. Int. J. Dairy Techn. 58, (2005) 13. Rogers PJ, Carlyle JA, Hill AJ, Blundell JE: Uncoupling sweet taste and calories: comparison of the effects of glucose and three intense sweeteners on hunger and food intake. Physiol. Behav. 43, (1988) 14. Rolls BJ: Effects of intense sweeteners on hunger, food intake and body weight: a review. Am. J. Clin. Nutr. 53, (1991) 15. Seeley RJ, York DA: Fuel sensing and the central nervous system (CNS): Implications for the regulation of energy balance and the treatment for obesity. Obes. Rev. 6, (2005) 16. Swithers SE, Davidson TL: A role for sweet taste: Calorie predictive relations in energy regulation by rats. Behav. Neurosci. 122, (2008) 17. Tordoff MG, Friedman MI: Drinking saccharin increases food intake and preference: I. Comparison with other drinks. Appetite 12, 1 10 (1989) 18. Tordoff MG, Alleva AM: Oral stimulation with aspartame increases hunger. Physiol. Behav. 47, (1990)