Wheat is a popular grain well known for its palatability, versatility and health benefits. It is a staple ingredient across households and cuisines throughout the world and is used to make a variety of food products including bread, pasta, pastry and cereal. Wheat primarily consists of carbohydrates, protein, fibre and micronutrients. Fructans, which are a specific type of carbohydrate found in wheat, are particularly relevant while on the low FODMAP diet.
Fructans are considered high FODMAP as they fall under the ‘O’ for oligosaccharides within the FODMAP acronym, meaning wheat must be limited while undertaking the elimination phase of the low FODMAP diet. For some, limiting wheat is often one of the most challenging aspects of the low FODMAP diet, simply due to its widespread use in our diets.
Here at FODMAP Friendly, we’re always looking for innovative ways to help you include more variety in your diet while eating low FODMAP. So, we decided to put wheat pasta to the test to determine if varying cooking time and preparation methods resulted in an increased low FODMAP serving size!
First things first, what are fructans?
Understanding fructans and how they fit into the low FODMAP diet can be difficult. As mentioned, fructans are a type of carbohydrate found in a variety of plant foods, including wheat, rye and barley, but also in onion, garlic and ripe bananas. Fructans are also known for their ability to resist digestion within the human gut, meaning they move from the small intestine to the large intestine mostly intact.
Now, in a well-functioning gut this process can lead to positive health benefits including gut microbiome diversity, improved satiety levels and healthy bowel habits. However, for those with a sensitive gut or medically diagnosed Irritable Bowel Syndrome (IBS), digesting fructans can trigger undesirable symptoms including altered bowel habits (diarrhoea/constipation), excessive gas, bloating and abdominal pain.
Now, you may not have heard of fructans before, because gluten typically gets the blame for gut symptoms associated with wheat. But what is gluten? Put simply, gluten is a protein that is found in wheat, rye and barley and is very different to fructans. As gluten is not a carbohydrate, it is therefore not a FODMAP, meaning the varying gluten content of foods will not change the allowed serving size of wheat based foods while on the low FODMAP diet. Of course, IBS is a very different condition to coeliac disease, which does require a life-long, strict gluten free diet.
Our goal at FODMAP Friendly
Here at FODMAP Friendly, we decided to investigate whether different cooking times and preparation methods impacted the fructan content of wheat pasta. Because, who doesn’t love the idea of eating more pasta? We wanted to compare raw pasta, undercooked pasta (5 minutes), pasta cooked to the recommended cooking time (9 minutes), cold pasta chilled overnight, and reheated pasta after chilling overnight.
We sent various samples of pasta to two independent NATA approved* laboratories.
Testing products at two different laboratories can provide a number of benefits over testing at only one laboratory. Some of the key reasons why it can be advantageous to use multiple labs for testing include:
1. Increased accuracy: By having two labs independently test the same sample, it can be easier to identify errors or inconsistencies within the results. If the results from both labs match, it provides stronger evidence that the results are accurate and reliable.
2. Reduced bias: Even with the best practices, testing can sometimes be subject to bias or errors due to a variety of factors such as equipment and method differences or even human error. Having two labs test the same sample can help mitigate these biases by cross-checking which reduces the likelihood of a systematic error.
3. Improved confidence: When two independent labs agree on results, it increases the confidence in the results, especially when the testing is complex, important, or may have significant impacts on decisions.
4. Greater reproducibility: By having multiple labs test the same sample, it can be easier to reproduce the results in the future. If one lab’s results are not consistent, another lab may be able to identify the problem and replicate the results.
Overall, using two labs instead of one can help to reduce errors, increase accuracy, and improve the reliability of the results obtained from testing. As you can see below in the results, both labs produced very similar results meaning we can confidently conclude that the results are reliable.
Graph 1: Fructans in Wheat Pasta
On graph 1, the vertical axis shows the amount of grams considered a low FODMAP serve. The horizontal axis highlights the cooking time and/or preparation differences. As expected from previous data on our app, raw pasta was found to have the highest level of fructans, which is indicated by a very low FODMAP serve of only 23 grams. As the pasta was cooked, the fructan level reduced and the serving size was increased, up to a serve of 74 grams for pasta cooked to the recommended 9 minutes.
This makes sense as we know FODMAPs are water soluble and will therefore inevitably leach out into the water the longer they are cooked. Straining off and discarding the water then removes some of the fructans. This is supported by research that shows boiling and straining lentils and kidney beans reduces the oligosaccharide content (Biersiekierski et al., 2011).
Interestingly, cooking wheat pasta, draining it and then chilling it overnight, caused an increase in fructans and a decrease in the low FODMAP serving size. It is unclear the reason for this, however this difference may also be explained by the solubility of fructans as mentioned previously. Perhaps, if there was residual water leftover after draining, the chilled pasta was able to re-absorb this while cooling down in the fridge (which would then make it higher FODMAP). This may mean that consuming chilled wheat pasta could trigger gut symptoms for some.
Lastly, and perhaps the most exciting part of testing, was discovering that cooking wheat pasta for 9 minutes, chilling it overnight and then re-heating it in the microwave for 1 minute the next day had the lowest level of fructans and can be consumed in the highest amount (126 grams). Again, the reasons for this are unclear but could be due to evaporation of residual water in the microwave. This means that you can consume more of that leftover pasta the next day if cooked!
So what does this mean for you? Well, if wheat fructans is something that you have been limiting while on your low FODMAP journey, our research has shown that you can now consume up to 126 grams of cooked, chilled and reheated pasta without eliciting adverse symptoms!
Happy pasta eating!
*NATA stands for the National Association of Testing Authorities in Australia. NATA is Australia’s leading national accreditation body, recognised by government to assess organisations against a number of international standards to allow increased confidence in the quality of products/services produced. Accreditation with NATA shows that an organisation is meeting or exceeding minimum standards in the production and delivery of its assessment activities. This allows consumers to have confidence in testing to make safe, healthy and reliable choices.
Biesiekierski, J. R., Rosella, O., Rose, R., Liels, K., Barrett, J. S., Shepherd, S. J., … & Muir, J. G. (2011). Quantification of fructans, galacto‐oligosacharides and other short‐chain carbohydrates in processed grains and cereals. Journal of Human Nutrition and Dietetics, 24(2), 154-176.