Fermentable short-chain carbohydrate (FODMAP) content of common plant-based foods and processed foods suitable for vegetarian and vegan-based eating patterns
Tuck C, Ly E, Bogatyrev A
Journal of Human Nutrition & Dietetics (2018) https:doi.org/10.1111/jhn.12546
An estimated 10% of the world’s population are following either a vegetarian or vegan eating pattern. Key nutrients at risk of deficiency within plant-based diets include protein, iron, zinc, calcium and vitamin B12. These nutrients can be sourced from legumes, wholegrains, nuts and seeds and soy-based foods. However, because the compositional data to date has shown that many of these foods also contain significant quantities of FODMAPs, their intake is limited on a low FODMAP diet.
Journal of Human Nutrition & Dietetics (2018) https:doi.org/10.1111/jhn.12546
An estimated 10% of the world’s population are following either a vegetarian or vegan eating pattern. Key nutrients at risk of deficiency within plant-based diets include protein, iron, zinc, calcium and vitamin B12. These nutrients can be sourced from legumes, wholegrains, nuts and seeds and soy-based foods. However, because the compositional data to date has shown that many of these foods also contain significant quantities of FODMAPs, their intake is limited on a low FODMAP diet.
Expansion of the current FODMAP database to provide more food sources of key macro- and micro nutrients for vegetarians and vegans is needed. Furthermore, increased understanding of the opportunity to reduce FODMAP content of plant-based foods via food processing and cooking techniques may also help to improve nutritional adequacy in this patient group.
The first part of this study aimed to quantify the FODMAP content of plant-based foods available to vegetarians and vegans. A second part of the study aimed to investigate the effect of food processing and cooking on FODMAP content of plant-based foods. Thirty five common vegetarian and vegan foods/ constituents were chosen by a group of 8 specialist dietitians to be analyzed for FODMAP content by the Department of Gastroenterology, Monash University. Plant-based food items that had undergone additional food processing were also selected, including activated nuts, pickled vegetables (beetroot, artichoke, garlic and onion) and fermented foods. Comparison was made against FODMAP content in the same foods analyzed previously in their fresh, unprocessed form. In addition, 6 types of grains and legumes were chosen to be sprouted. To compare differences between canned and dried legumes, red kidney beans and adzuki beans in dried and canned form were analyzed in ‘as eaten’ form. To assess the impact of cooking conditions on FODMAP content, red lentils and red kidney beans were simmered in water for variable lengths of time, with and without straining and pre-soaking.
In the first part of the study, twenty of the foods analyzed were found to be low in total FODMAP content, these included: canned coconut milk (used in cooking), coconut yogurt, soya cheese and tempeh. Foods that did not meet the low FODMAP criteria included coconut flour, soy yogurt, textured soya protein and quinoa milk. In the second part of the study, the FODMAP content was lowered for all types of activated and pickled foods compared to that of their fresh variants. All types of sprouted grains and legumes also had a lower FODMAP content with the exception of chickpeas. The most substantial changes were seen with pickling, where the FODMAP content was lowered by 97% in garlic alone. Pickling lowered the FODMAP content of garlic, onion and beetroot sufficiently to be classed as low FODMAP. Canning red kidney beans lowered the FODMAP content compared to the equivalent dried, soaked and cooked forms. On average, the oligosaccharide content of dried, soaked and cooked red kidney beans was almost 3 times higher than the canned and cooked form. Simmering of red lentils for 5 minutes reduced the oligosaccharide content by 43%, although longer simmering times caused no further reduction. Straining the lentils after 30 minutes of simmering caused a further 12% reduction in oligosaccharide content compared to unstrained lentils. Simmering also reduced the oligosaccharide content of red kidney beans, and this continued to decline with increased cooking times.
This study shows that food processing and cooking can lower FODMAP content of a range of plant-based foods. Legumes are an important source of protein, fiber and key micronutrients, in addition to pre- biotics. The likely health benefits associated with their consumption highlight the importance of identifying varieties and processing techniques that will improve tolerance for IBS patients. Interestingly, the FODMAP content of legumes found in this study were considerably lower than those reported by previous Australian researchers, despite similar methodology. This may be the result of different growing and harvesting conditions, or seasonal changes. Pickling, canning and increased cooking times with straining of cooking liquid may assist in reducing the FODMAP content of various plant-based foods, the water solubility of FODMAPs is likely to be one of the main mechanisms by which these observations are achieved. Dietitians should educate their patients on the effect of food processing and cooking on FODMAP content and encourage patients to trial such techniques to determine their individual tolerance.
Link to original study: http://onlinelibrary.wiley.com/doi/10.1111/jhn.12546/abstract
The first part of this study aimed to quantify the FODMAP content of plant-based foods available to vegetarians and vegans. A second part of the study aimed to investigate the effect of food processing and cooking on FODMAP content of plant-based foods. Thirty five common vegetarian and vegan foods/ constituents were chosen by a group of 8 specialist dietitians to be analyzed for FODMAP content by the Department of Gastroenterology, Monash University. Plant-based food items that had undergone additional food processing were also selected, including activated nuts, pickled vegetables (beetroot, artichoke, garlic and onion) and fermented foods. Comparison was made against FODMAP content in the same foods analyzed previously in their fresh, unprocessed form. In addition, 6 types of grains and legumes were chosen to be sprouted. To compare differences between canned and dried legumes, red kidney beans and adzuki beans in dried and canned form were analyzed in ‘as eaten’ form. To assess the impact of cooking conditions on FODMAP content, red lentils and red kidney beans were simmered in water for variable lengths of time, with and without straining and pre-soaking.
In the first part of the study, twenty of the foods analyzed were found to be low in total FODMAP content, these included: canned coconut milk (used in cooking), coconut yogurt, soya cheese and tempeh. Foods that did not meet the low FODMAP criteria included coconut flour, soy yogurt, textured soya protein and quinoa milk. In the second part of the study, the FODMAP content was lowered for all types of activated and pickled foods compared to that of their fresh variants. All types of sprouted grains and legumes also had a lower FODMAP content with the exception of chickpeas. The most substantial changes were seen with pickling, where the FODMAP content was lowered by 97% in garlic alone. Pickling lowered the FODMAP content of garlic, onion and beetroot sufficiently to be classed as low FODMAP. Canning red kidney beans lowered the FODMAP content compared to the equivalent dried, soaked and cooked forms. On average, the oligosaccharide content of dried, soaked and cooked red kidney beans was almost 3 times higher than the canned and cooked form. Simmering of red lentils for 5 minutes reduced the oligosaccharide content by 43%, although longer simmering times caused no further reduction. Straining the lentils after 30 minutes of simmering caused a further 12% reduction in oligosaccharide content compared to unstrained lentils. Simmering also reduced the oligosaccharide content of red kidney beans, and this continued to decline with increased cooking times.
This study shows that food processing and cooking can lower FODMAP content of a range of plant-based foods. Legumes are an important source of protein, fiber and key micronutrients, in addition to pre- biotics. The likely health benefits associated with their consumption highlight the importance of identifying varieties and processing techniques that will improve tolerance for IBS patients. Interestingly, the FODMAP content of legumes found in this study were considerably lower than those reported by previous Australian researchers, despite similar methodology. This may be the result of different growing and harvesting conditions, or seasonal changes. Pickling, canning and increased cooking times with straining of cooking liquid may assist in reducing the FODMAP content of various plant-based foods, the water solubility of FODMAPs is likely to be one of the main mechanisms by which these observations are achieved. Dietitians should educate their patients on the effect of food processing and cooking on FODMAP content and encourage patients to trial such techniques to determine their individual tolerance.
Link to original study: http://onlinelibrary.wiley.com/doi/10.1111/jhn.12546/abstract
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