Chapter 3: Status of carbohydrates and dietary fibre in the gluten-free diet

3.3 Dietary fibre intake by coeliac patients as well as non-coeliac subjects

The results of several studies reported in the literature on the consumption of carbohydrates, sugars and dietary fibre of coeliac disease patients are summarised and compared in Table 3.1 and Table 3.2. Table 3.1 summarises studies on the intake of these nutrients by the non-coeliac general public. Wild et al. (2010) analysed the data from 93 validated 5-day food diaries, observing that only 42 % of men and women got more than 47 % of their total energy intake from carbohydrate sources. These authors reported an intake of nonstarch polysaccharides of

13.7 g/day. Öhlund et al. (2010) performed a study of 25 children, at the age of 4-17 years, with confirmed coeliac disease and living on a gluten free diet. Using 5-day food records, it was shown that dietary fibre intakes were lower than the recommendations. The mean intake of carbohydrate met the recommendations. However, quality of carbohydrate was characterised by a high intake of sucrose and a low intake of dietary fibre. After recording the 3-day usual nutritional intakes of fifty randomly selected patients, Lee et al. (2009) reported that the standard gluten free diet did not meet the recommended intake for fibre. Hopman et al. (2006) evaluated the 3-day food records of 111 adolescent members of the Dutch coeliac society. They showed that the coeliac patients had an intake of fibre significantly lower than the recommended daily allowance (RDA). Thompson et al. (2005) concluded from a study employing 3-day estimated self-reported food records that seven out of eight males (88 %) and 18 out of 39 women (46 %) had estimated dietary fibre intakes that met or exceeded recommended daily intakes of 20-35 g/day. Seven out of eight males (88 %) and 34 out of 39 women (87 %) had estimated carbohydrate intakes within the acceptable range of 45-60 % from total calories. There is no information available on how much of these carbohydrates were sugars. From a study examining 47 adolescents, aged 10-20 years, with coeliac disease and 47 healthy age-matched control subjects using 3-day alimentary records, it was concluded that diets contained low amounts of carbohydrates and fibre. It was shown that fibre consumption was significantly reduced in subjects consuming a gluten free diet as compared to the healthy control subjects (Mariani et al. 1998). Grehn et al. (2001) published a study assessing the dietary habits of 49 Swedish adult coeliac patients as well as those of a control group. Using a 4-day dietary record it was shown that coeliacs as well as controls had too low an intake of fibre. Comparing the two groups, the fibre intake was significantly lower for the coeliac patients. The relative contribution of dietary fibre from bread was generally lower in coeliac disease sufferers (28 %) than in the controls (38 %). The energy intakes as well as the relative contributions of protein, fat and carbohydrate were in the same range in coeliac

patients and controls. Lohiniemi et al. (2000) used a 4-day food record of 58 adult coeliac disease patients, concluding that the daily fibre intake (13 g) was lower than the average consumption level in Finland (24 g).

All the above mentioned studies show too low an intake of dietary fibre among coeliac patients. Hence, more emphasis should be placed on the nutritional quality of the gluten free diet. However, regarding the dietary fibre uptake of the general non-coeliac population, intakes are as well commonly lower than recommended (Table 3.2). Yet, they are higher than in the coeliac patients. Fukuda et al (2007) used one day food records to evaluate dietary fibre intake among the Japanese general population, showing an average consumption of 18.4 g per day. Castetbon et al. (2009) used three 24 h recalls to describe the dietary intake of 2734 adults in France, concluding that compared to current recommendations, the intake of carbohydrates and total fibre was frequently unsatisfactory. Galvin et al (2001) used a 7-day food diary to collect food intake data of 1379 respondents. The resulting average fibre consumption was 20.2 g per day. Elmadfa and Freisling (2003) evaluated the macronutrient intake of the Austrian general population, concluding a too low fibre intake among all groups of the population. As a result of too high intake of protein and fat, the average consumption of carbohydrates was too low. Among children and adolescents, the intake of carbohydrates was sufficient. However, 12 to 19 % of carbohydrates consumed were sugars. Only the subjects of one study, including 4237 subjects and using food-frequency questionnaires, met the recommendations for dietary fibre intake. The determined average fibre consumption was 26.8 g per day. The average intake of carbohydrates was 41.3 % with 19.1 % coming from mono- and disaccharides (Van de Vijver et al. 2009).

Overall it must be concluded that the dietary fibre intake is too low in a substantial proportion of the population. This is likely to contribute to impaired bowel function and constipation, increased risk of chronic gastrointestinal diseases as well as coronary heart diseases and diabetes. The intake of carbohydrates as a percentage of the total energy consumed was

within the acceptable range in most studies. However, the intake of sugars was frequently very high, especially in children and adolescents.

Table 3.1 Results of several studies on the dietary fibre intake of coeliac disease patients

Nutrient Recommendations Mariani (1998) Lohiniemi (2000) Grehn (2001) Thompson (2005) Hopman (2006) Lee (2009) Öhlund (2010) Wild (2010)

Carbohydrates/Sucrose [%E] Children, Adolescents: 45-65*

Adults: 45-65*

43.2/N.I.A.

N.I.A. 49/N.I.A. 53.5/N.I.A.

54.0/N.I.A.

N.I.A.

54.2 /14.7

58.5/N.I.A.

Fibre [g/day] Children, Adolescents: 19-26*

Adults: 25-38* 8.5 13.0 10.8 22.3 17.0 5.0 9.9 13.7

*Dietary reference Intakes: Macronutrients; USDA United States Department of Agriculture;

http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=3&tax_subject=256&topic_id=1342&level3_id=5140; accessed 18/06/2010

Table 3.2 Results of several studies on the dietary fibre intake of non-coeliac subjects

Nutrient Recommendations Mariani (1998) Grehn (2001) Galvin (2001) Elmadfa (2003) Fukuda (2007) Castetbon (2009) Van de Vijver (2009)

Carbohydrates/Sucrose [%E] Children, Adolescents: 45-65*

Adults: 45-65*

48.4/N.I.A.

46.5/N.I.A. N.I.A.

52.0/13.5

43.5/9.6 N.I.A. 45.7/20.1 41.9/19.1

Fibre [g/day] Children, Adolescents: 19-26*

Adults: 25-38*

11.2

16.7 20.2

13.7

19.3 18.4 17.5 26.8

*Dietary reference Intakes: Macronutrients; USDA United States Department of Agriculture;

In document Cereal products for specific dietary requirements. Evaluation and improvement of technological and nutritional properties of gluten free raw materials and end products (Page 64-69)