Number 76      November 1995

MAFF UK - SURVEY OF THE INTAKE OF SWEETENERS BY DIABETICS

Index to MAFF UK Food Surveillance Information Sheets, 1995

See also:

46: MAFF,UK: Survey of the Intake of Sweeteners by Diabetics (November 1994)

Summary

MAFF has recently completed a survey of intakes by diabetics of the four intense sweeteners (acesulfame K, aspartame, saccharin and thaumatin) and six bulk sweeteners (hydrogenated glucose syrup, isomalt, lactitol, mannitol, sorbitol and xylitol) currently permitted in the UK. Results show that intakes are within the acceptable limits. The survey provided reassurance that whilst it is likely that there will always be a number of individuals who exceed the ADI, it may not always be the same individuals.

Background

Diabetics need to control their intake of sugars and it is therefore particularly useful for them to have alternative sweetening agents available. The sweeteners permitted under the 1983 Sweeteners in Food Regulations (as amended) may be used in diabetic foods as alternatives to glucose and sucrose, allowing diabetics to consume a wider range of sweetened foods. In addition diabetics may also use low calorie, sugar-free or diet products. Since diabetics may thereby be exposed to higher than average amounts of sweeteners for a long period it is important to check that intakes remain within acceptable limits and cause no adverse effect on their health.

Intakes of sweeteners by both the general population and a selected population of diabetics were first examined in 1987 and 1988 respectively and the results published in Food Surveillance Paper No. 29 (1990). The results were also considered by MAFF's Food Advisory Committee (FAC) and the Department of Health's Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT). Although the results of these surveys were considered to be generally reassuring a few people, notably diabetics, were found to exceed the Acceptable Daily Intake (ADI) for one of the intense sweeteners, saccharin. Following advice from the FAC, Ministers announced an initiative to help reduce these intakes of saccharin through an advisory leaflet and voluntary labelling of saccharin based table-top sweeteners used in tea and coffee. In addition, the FAC recommended that a fuller survey be carried out to obtain more accurate information on the sweetener intake of the British diabetic population and to monitor changes in their diet resulting from the introduction of newer sweeteners on the market.

Survey

The survey was carried out by the University of Southampton. In order to ensure that the survey was as wide-ranging as possible, diabetics were studied across the full age range from 2 to 65 years and over. The study was constructed so as to give a model of the British diabetic population as a whole.

The consumption of foods by diabetics was determined using a Food Frequency Questionnaire which had three components:

(i) a structured interview on meal patterns;

(ii) recall of food intake; and

(iii) a food checklist on usual consumption.

The food checklist contained 37 foods likely to contain sweeteners together with 70 other foods to disguise the purpose of the survey. The main classes of sweetener-containing foods consumed by those individuals who participated in the survey were beverages, dairy products, confectionery, savoury sauces, canned products, biscuits, cakes, desserts, prepared salads, jams, marmalades and table top sweeteners for use in tea and coffee. Care was taken to ensure that the consumption data were recorded in sufficient detail (food type, brand and flavour) so that products could be accurately matched to sweetener concentration information.

The results of the food frequency questionnaire were validated by comparing its predictions against actual consumption determined by a seven day weighed record. This validation study was performed using 50 selected diabetics whose demographic profile reflected the range of the survey. The results of the validation study showed good overall agreement between the predictions of the food frequency questionnaire and the weighed record.

The recruitment and interviewing of the participants involved in the main survey took place mostly during the spring of 1994. The low incidence of diabetes among children delayed recruitment in the younger age groups. Results are, however, now complete with a total of 940 participants surveyed.

In order to calculate the intake of the sweeteners by diabetics it was necessary for a sweetener concentration database to be constructed. This was done by asking food manufacturers to supply information on the concentration of sweeteners used in their products. The consumption data collected from the subjects was converted from portion sizes into g/week or ml/week as appropriate (except for table top sweeteners which were in tablets per week) using the conversion figures provided by the MAFF estimates (frequency of consumption x weight of standard portion x number of standard portions = g food/day). This information was then combined with the sweetener concentration data to give intakes of sweeteners for each participant in the survey.

Results

Intense sweeteners

The results for the intense sweeteners show that intakes of saccharin exceed the ADI for only a very small number of individuals (7 members out of a survey population of 940, i.e. less than 1 percent). One individual exceeded the ADI for aspartame. Using data on the nationwide prevalence of diabetes it has been possible to calculate results for a representative British diabetic population. High level intakes of each intense sweetener as measured by the 97.5th percentile are all within acceptable limits, see table 1. The 97.5th percentile level of consumption is generally taken to be representative of the upper limit of normal dietary behaviour. The intense sweetener thaumatin was not encountered during the survey.

The survey shows a number of trends in the intake of intense sweeteners. A slightly greater proportion of younger members than older members are consumers of these sweeteners. Trends in the intake of individual sweeteners reveal that for saccharin, diet squashes are the most significant source for the youngest two age groups (2 to 19 years), whereas, table-top sweeteners provide the greatest source for the older age groups (20 years +). Intakes of aspartame are largely attributable to consumption of diet carbonated drinks which provide the greatest source of this sweetener for all but the oldest age group. Acesulfame K is used in a wide variety of products. However, because it has a slightly bitter taste when used individually at high levels, it is frequently combined with other sweeteners (usually aspartame) to provide a greater quality of sweetness. In the survey, intakes of acesulfame K are mainly attributable to diet soft drinks, although there are a number of other significant uses such as yoghurts and table-top sweeteners.

Bulk sweeteners

The polyol sweeteners have been classified by the COT as acceptable for use in food, and by the EC's Scientific Committee for Food (SCF) as ADI "not specified". ADI's have not been set because the polyol sweeteners are of such low toxicity that their maximum potential intake is not considered to be an identifiable hazard to health. However because the polyol sweeteners and the carbohydrate fructose may have a laxative effect it is recommended that consumers do not exceed a combined intake of 25g per day. Although a small proportion of individuals (14 members out of a survey population 940, i.e. less than 2 percent) did consume in excess of the recommended level due to high intake of sorbitol, the average intake of this sweetener is less than 2g per day. The survey results show that sorbitol is the most important source of bulk sweetener, occurring in diabetic jams and marmalades, and in chewing gum. Intakes of other bulk sweeteners are all very low with averages of less than 1g per day. However, 2 individuals consumed in excess of 25g per day due to their intake of a combination of sweeteners. There is evidence that tolerance to polyols may vary quite markedly from individual to individual and that the laxative effect is dependent on the type of polyol, the nature of the food product and the quantity consumed at any one time.

Re-survey

The top 1 percent of sweetener consumers were re-surveyed approximately 4 months later, to provide more information on the dietary behaviour of these individuals and to determine whether they were consistently high consumers. However, these individuals were not informed that they were "high level" consumers.

Of the eleven high level saccharin consumers re-surveyed only two maintained a high intake of saccharin due to high consumption of table top sweeteners. The remaining individuals reported a change in their diets, e.g. from carbonated drinks to squashes or a change of brands. The high level aspartame consumer, a child of low body weight, drastically reduced their consumption of diet carbonated drinks, from the equivalent of 4-5 cans per day to 3-4 cans per week, thus reducing their intake of aspartame. These results indicate that whilst it is likely that there will always be a number of individuals who exceed the ADI for a given sweetener, most individuals would not continuously do so.

It should be noted that the trends observed in the re-survey are different from those in the validation exercise. This can be explained by the much shorter time lapse before the repeat survey in the validation exercise, during which changing dietary habits were not observed.

Contact Point

For further information please contact:

Dr Esther Heller
MAFF, Food Safety and Science Group
Additives and Novel Foods Division,
Rm 225, Ergon House c/o Nobel House
17 Smith Square
London SW1P 3JR.

Tel. No. (+44) (0)171 238 6234
Fax. No. (+44) (0)171 238 5331.

^a ADI set by COT in 1990
^b ADI set by COT in 1992
^c ADI set by SCF in 1984

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