Oats may boost nutritional profile of gluten-free diets

Kilned or unkilned oats were found to increase levels of vitamin B1, magnesium and zinc during six months of an oat-enriched gluten-free diet, according to results published in the European Journal of Clinical Nutrition​.

According to scientists led by Tarja Kemppainen from the University of Kuopio in Finland, gluten-free diets have been shown to be deficient in nutrients in some of the patients. Results from their new study indicate that 100 grams of oats a day may increased intakes of various nutrients in adult celiac patients in remission.

The gluten-free market is growing rapidly. According to a recent report from Packaged Facts, the market has grown at an average annual rate of 28 per cent since 2004, when it was valued at $580m, to reach $1.56bn last year. Packaged Facts estimates that sales will be worth $2.6bn by 2012.

The market researcher said it expected to see a much wider range of gluten-free products on shelves by 2012, and said that this will be driven by companies reformulating existing products for gluten-free acceptability, as well as by releasing new ones.

Care with oats ​

It should be noted that, although oats do not actually contain gluten there is some concern over their presence in foods since they are commonly contaminated during processing with gluten from wheat, rye or barley, according to Coeliac UK.

Study details​

Kemppainen and co-workers recruited 13 men and 18 women with celiac disease in remission and assigned them to receive a gluten-free diet with kilned or unkilned oats. At the end of the study, addition of kilned oats to the diet increased intake of vitamin B1 and magnesium, while the unkilned oats increased intakes of magnesium and zinc, said the researchers.

Antioxidant boost​

The results were supported by another study from Scandinavia. Writing in the e-SPEN​, the European e-Journal of Clinical Nutrition and Metabolism, Astrid Lovik and her co-workers from Oslo University Hospital report that gluten-free oats allowed people on gluten-free diets to achieve their recommended daily intakes of fibre, as well as increasing levels of the antioxidant bilirubin in coeliac disease patients.

“So far there are no documented clear nutritional advantages of oats in gluten-free diet, except for increased dietary fibre intake,”​ wrote Lovik. “Results from our pilot study of nineteen patients and supportive evidence from a large cohort of patients, suggest increased levels of bilirubin after oats intake. ​

“To confirm this finding, controlled and randomised studies in oats consuming and oats non-consuming coeliac disease patients have to be performed,” ​they concluded.

The researchers gave 19 people with coeliac disease 50 grams per day of gluten-free rolled oats for 12 weeks. At the end of the study, the gluten levels of only three people were outside of the proposed safe levels. Bilirubin levels were significantly higher following oat consumption.

In a separate experiment with 136 coeliacs and 141 healthy controls in the general population, the researchers noted that bilirubin blood levels were higher amongst oat consumers..

“In healthy subjects, lower serum bilirubin levels are associated with endothelial dysfunction and increased carotid intima-media thickness, while moderately increased serum bilirubin levels are connected to reduced risk for atherosclerosis,”​ wrote the researchers. “Whether serum bilirubin in oats consuming coeliac disease patients is an independent and inversely related predictor of atherosclerosis has yet to be studied,” ​they added.

Source: European Journal of Clinical Nutrition​
2010, Volume 64, Pages 62-67, doi:10.1038/ejcn.2009.113
“Nutrient intakes during diets including unkilned and large amounts of oats in celiac disease”​
Authors: T.A. Kemppainen, M.T. Heikkinen, M.K. Ristikankare, V-M. Kosma, R.J. Julkunen

e-SPEN​, the European e-Journal of Clinical Nutrition and Metabolism
Pages e315-e320
“Oats in a strictly gluten-free diet is associated with decreased gluten intake and increased serum bilirubin”​
Authors: A. Lovik, A.U. Gjoen, L. Morkrid, V. Guttormsen, T. Ueland, K.E.A. Lundin