One of my favourite recipes is this chocolate brownie recipe from healthyfood.co.nz which is made without butter and uses unsweetened apple sauce instead of sugar. It allows me to over-indulge in the chocolate flavour and avoid the added richness of butter.
However, for many people this ‘healthy’ version of a brownie is anything but healthy. It may cause diarrhoea, farting, pain, bloating and stomach gurgling. This is because the recipe is high in short-chain carbohydrates known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) which are poorly absorbed by about fifteen percent of the population.
FODMAPs are very small particles, and therefore draw water into the small intestine. This causes diarrhoea, and also pain. When FODMAPs arrive in the colon they are rapidly fermented by bacteria, which causes farting and bloating.
Everyday foods high in FODMAP include wheat flour and bread, apples, honey, pistachios, legumes and, for some people, milk. Those who can’t absorb these products are much better not to consume them. Happily, there is a good alternative version of chocolate brownie, even though it is higher in sugar and fat and lower in fibre, qualities we traditionally regard as less healthy. Here is the recipe:
No-FODMAP Chocolate Brownie
115 g butter
1 c white sugar
¼ c cocoa
½ tsp vanilla essence
¾ c gluten free flour, sifted
½ tsp baking powder, sifted
¼ c chocolate chips
Preheat oven to 180C.
Melt the butter.
Mix all the other ingredients into the butter in order listed above until combined.
Place into a brownie baking tin and bake for 20-30 minutes or until the top just starts to crack.
Cool and slice.
As a clinical dietitian I was fascinated to learn how this recipe – which in many ways goes against what we teach in nutrition – prevents bowel discomfort. What we are learning is that the bacteria in our bowels affects how we process food. A large study in Israel has shown that the bacteria in our bowel, along with the genes they contain and the proteins they express, can significantly affect blood glucose levels. Thus a food which has no ill effect on me might have a really large effect on someone else.
My entry in the recent University of Otago Bake Your Thesis competition was designed to illustrate this. For anyone with irritable bowel syndrome (IBS), for example, the FODMAP-free chocolate brownie at the bottom of the image is really the health brownie, even though it contains butter and more sugar. This chocolate brownie will hopefully make your poos look more like a remodelled bliss ball and less like a smear of Nutella.
In my PhD research, I studied a large group of people with and without IBS. I looked at their symptoms, dietary intake, and microbiota (all the microorganisms in the colon). However, although there were large differences in all these factors between individuals, we were not able to link any particular factor with having IBS or presenting with similar clinical symptoms. Further, dietary intake did not appear to affect the microbiota, although we clearly saw that the information people gave about dietary intake seemed implausible … but could you estimate how many apples or peas or chickens you have eaten over the past year?
In one study I collected daily faecal and urine samples and weighed food records from two participants, one with, and one without, IBS. The urine samples are going to be used to investigate the metabolites produced by the microbiota. Halfway through the data collection the two participants went on a high (galacto)-oligosaccharide diet. They did this by increasing the amount of legumes, pistachios, cashews, onion and garlic in their diet. I supplied recipes and made some hummus and spreads for them. In the participant without IBS we saw an increase in the relative abundance of beneficial bacteria such as Faecalibacterium prausnitzii and Roseburia but did not see these changes in the participant with IBS.
I also used a wireless motility capsule or smartpill to examine changes in pH, temperature and pressure throughout the gastrointestinal tract when participants with IBS changed from their usual diet to a low FODMAP diet. I wanted to see if there was a change in pH or in transit time, especially in the first part of the colon. pH indicates how much fermentation is occuring in the colon: the lower the pH, the more fermentation. Unfortunately, because of large differences between individuals we did not see any changes in the group. This only spurs me on to ask further questions and do more research in this area.
Ruth Harvie worked as a clinical dietitian before taking time out to complete a PhD and is relieved to have handed in her soft covered thesis.
Ruth Harvie’s chocolate brownies were an entry in the University of Otago’s recent Bake Your Thesis competition. Read how some of the other entrants cooked up their research ideas: