Diet Tips:Research studies: Cooking legumes

By Caroline Tuck (APD, PhD Candidate)

Research is currently underway to look at ways we can make it easier for patients with IBS to follow a low FODMAP diet. One strategy that our group is looking at is if changing the way we cook foods can reduce the FODMAP content, hence potentially making it easier to people to tolerate them.

The main FODMAPs present in legumes are the oligosaccharides. Oligosacchardies are water soluble, which means that when the food is put into water, the oligosacchardies can leach out of the food and into the water. At Monash University, we have recently been testing if any reduction in FODMAP content will occur through this process. We have found that when legumes e.g. red lentils are boiled in water, the liquid they are cooking in becomes higher in oligosacchardies.

This has shown that straining legumes after cooking may help to reduce their FODMAP content. This is a great strategy to trial at home to see if it helps you tolerate legumes better and increase your legume intake.

Diet Tips:Including Legumes on a Low FODMAP Diet

By Lyndal McNamara (Dietitian)
 

 

Legumes (otherwise known as pulses) include all types of beans, peas and lupins. The health benefits of regular consumption of legumes are well known (see table 1), predominately because they are low in saturated fat, have a low GI, are an excellent source of dietary fibre and contain a variety of phytochemicals (natural plant chemicals with health promoting effects).

Table 1: Health Benefits of Legumes

Nutritional characteristic	Associated health benefits
High in dietary fibre	-          Can assist with weight management by promoting a feeling of fullness after eating -          Contain insoluble fibre, which adds bulk to stools and assists with preventing constipation -          Contain soluble fibre, which assists in maintaining healthy blood glucose and cholesterol levels -          Contain prebiotic fibre, which is fermented by colonic bacteria to short chain fatty acids and promotes overall digestive health
High in phytochemicals	-          Contain antioxidants and other bioactive compounds, which help to protect the body against disease
Low glycaemic index (GI)	-          Contain slowly digested carbohydrates, that improve blood glucose control and insulin response in those with diabetes and reduce risk of diabetes in healthy people
High in protein	-          Legumes are a great non-animal source of protein for vegetarians and vegans
Low in saturated fat	-          Assist with maintaining healthy cholesterol levels and reducing risk of cardiovascular disease

References: please see an extensive list of references on the Grains & Legumes Nutrition Council (GLNC) website http://www.glnc.org.au/legumes/legume-references/

Legumes on a Low FODMAP diet

For those following a low FODMAP diet, legumes can be a troublesome food because they are naturally high in oligos; including galacto-oligosaccharides (GOS) and fructans.

The good news is that legumes do not need to be strictly avoided by people following a low FODMAP diet, with suitable ‘green’ serve information available for many legumes on the Monash app.

Because oligos dissolve in water, cooking and processing methods can affect the FODMAP content of legumes. For example, canned legumes or those that have been boiled and drained tend to be lower in FODMAPs as some oligos ‘leach’ out into the canning/cooking water and are removed when they are drained and rinsed. Read more here 

Dietary Recommendations for Legumes

The GLNC recommends enjoying legumes 2-3 times per week for maximum health benefits. Here are some suggestions for how to easily incorporate more legumes into a low FODMAP diet:

- Add a small can (125g) of chickpeas to stir-fries or curries – try this ‘low FODMAP Vegan Coconut & Pumpkin Curry’

- Substitute half of the meat in bolognaise sauce/casseroles for canned lentils- try this ‘low FODMAP slow cooked Lamb Casserole’:

- Sprinkle ¼ cup (53g) of cooked mung beans (boiled & drained) over salads  

- Add canned butter beans to homemade soups or stews

- Mix ¼ cup (42g) canned chickpeas with a small tin of tuna for a protein and fibre rich snack

- Add legumes to homemade dips- try this ‘Roasted Red Pepper & Pumpkin Hummus’

- Top an egg on toast for breakfast with homemade baked beans (using ¼ cup (35g) canned butter beans per person)

- Substitute meat in Asian style dishes for firm tofu or tempeh- try this low FODMAP ‘Marinated Tofu with Asian Greens and Rice’ or ‘Hot & Sour Asian Soup’:
 

Enjoy!