"Given the results of this study and the similarity of sorghum to maize, it is highly likely that sorghum is a safe food for persons with coeliac disease," wrote the authors, led by Carolina Ciacci in the journal Clinical Nutrition.
"Sorghum is developing as a value added food for Western countries and if follow up studies confirm the results in this study, an important food product for coeliac populations," they added.
The free-from market was worth €90 million ($123 million) in 2005, and Mintel said that the gluten and wheat-free sector has benefited in particular from the nation's increasing interest in healthy eating. Sales of products such as wheat-free breads and cakes have grown by almost 120 per cent over the last three years alone, to reach €48 million ($65 million).
While previous studies have already looked at the potential for sorghum products for coeliacs, in Europe the crop remains mostly for animal feeds. This may change, however, if future studies continue to show benefits for people with coeliac's disease, a condition expected by the researchers to increase exponentially in the coming years.
Coeliac disease is caused by an intolerance to gluten - the protein found in wheat, rye and barley - and currently affects an average of one in 300 people in Europe. In Germany the figure is higher at one in 200, while the UK reports a figure of one in 100.
Ciacci and co-workers prepared sorghum bread from commercially available white food grade sorghum flour (Twin Valley Mills, USA), and tested in vitro and in vivo.
For the in vitro study, tissue samples from the duodenum of eight patients with coeliac disease and four non-coeliac controls were cultured for 24 h in the presence of digested wheat, sorghum, or nothing (control) and the immune response measured.
The researchers report that, while significant increases in markers of inflammation were observed when the tissues were cultured with wheat digest, no significant changes in the expression of inflammation markers was detected when cultured in the sorghum digest or control.
The in vivo study recruited two female coeliac patients to test sorghum products (bread, cookies, small cakes) for five days. The women were asked to complete a 20-item questionnaire on gastrointestinal and non-gastrointestinal symptoms and blood samples were taken to test for antibodies.
The researchers state that no gastrointestinal or non-gastrointestinal symptoms were reported by the women and that no changes in the levels of anti-transglutaminase antibodies was found.
"Sorghum-derived products did not show toxicity for celiac patients in both in vitro and in vivo challenge. Therefore sorghum can be considered safe for people with coeliac disease," wrote the researchers.
"Additional studies are needed to confirm the long-term safety and acceptability of sorghum-derived food for gluten intolerant people," they concluded.
The researchers came from: Department of Clinical and Experimental Medicine, Federico II, Napoli (Italy); University College, London; University of Foggia (Italy); Consiglio Nazionale delle Ricerche, Napoli; CRA, Sezione di Foggia (Italy); and USDA-ARS.
Source: Clinical Nutrition (Elsevier)
Published on-line ahead of print, doi:10.1016/j.clnu.2007.05.006
"Celiac disease: In vitro and in vivo safety and palatability of wheat-free sorghum food products"
Authors: Carolina Ciacci, L. Maiuri, N. Caporaso, C. Bucci, L. Del Giudice, D.R. Massardo, P. Pontieri, N. Di Fonzo, S.R. Bean, B. Ioerger, M. Londei
