Diet Tips:Are gluten-free foods actually better for you?

Journal review by Shirley Webber (Research dietitian)

The gluten-free diet has been getting a lot of attention for a number of years now. However, there is still some confusion about whether or not this is actually a healthy diet.

A gluten-free diet restricts wheat, barley, rye and oats. Following this diet is essential for those who are diagnosed with coeliac disease. For this small portion of the population, gluten can be damaging to the gastrointestinal tract. 

There are many other people following a gluten-free diet, whether it be due to suspected sensitivity to gluten, or just because they think it is a healthier way to eat. Studies have shown that gluten intolerance without coeliac disease is rare, so for many people following a gluten-free diet for other reasons, what impact does choosing gluten-free products have on their nutritional status?

A study by researchers from the University of Sydney recently considered the nutrient differences of major gluten containing food groups which included: dry plain pasta, breads, and ready-to-eat cereals. Comparisons were made by analysing the nutrition information panel on gluten-free products (those stating on the packaging that it is gluten-free certified) and gluten containing foods in this category. Nutrients were also compared using the Health Star Rating - a nutrient profiling initiative implemented by the Australian Government. 

Analysis of the three food categories showed that there was, in fact, a very similar nutritional profile for both the gluten-free and gluten containing foods, however, with one notable difference in the protein levels: gluten-free foods contained consistently less protein than gluten containing foods, in particular in pasta and bread. There was also variation in the fibre content of gluten versus gluten-free foods.

This study also considered discretionary foods which cover: cereal bars, cake mixes/cakes, sweet biscuits, ice cream, corn and potato chips, cured meats, sausages and hot dogs, and sugar based confectioneries. For four of these discretionary foods (cereal bars, cake mixes/cakes, sweet biscuits, and cured meats, sausages and hot dogs), the Health Star Rating did not change for gluten versus gluten-free products. In three of the categories (ice cream, corn and potato chips, and sugar based confectioneries) the total energy density was lower in gluten-free products than in gluten containing products. Despite slightly better nutritional quality in gluten-free options, overall discretionary foods are all high in sodium, saturated fat, and sugar.

This study highlighted that gluten-free doesn't mean healthier, particularly when looking at some commonly used cereals, pastas, and bread, which make up a big component of the Australian and western diet. More research needs to be conducted to assess the vitamin and mineral differences of these gluten versus gluten-free products.

Wu, J. H. Y., et al. (2015). “Are gluten-free foods healthier than non-gluten-free foods? An evaluation of supermarket products in Australia.” British Journal of Nutrition 114: 448-454.
 

Diet Tips:Grain-based foods on a low FODMAP diet

By Jane Varney 

Grain-based foods have been demonised by a number of dietary trends in recent years (think paleolithic diets, low carbohydrate diets and gluten free diets). However, this reputation is ill-earned, with robust scientific evidence to suggest that diets rich in whole grains confer protection against a range of diseases, including type 2 diabetes, obesity, cancer, and cardiovascular disease.

If you’re following a low FODMAP diet, you might feel it’s easier to restrict your intake of grain-based foods as many of them are high in FODMAPs and off limits anyway. Well this is far from true, as there are an abundance of healthy, tasty, low FODMAP grains to choose from. If you’re willing to expand your repertoire and try less traditional varieties, this will provide more choice, as will choosing grains that may be rated red/amber at a full serve, but green (low FODMAP) at a half serve.

Grain-based foods include those made from wheat, oats, rice, corn (maize), barley, sorghum, rye, millet, farro (emmer), freekeh, kamut, spelt, triticale, amaranth, buckwheat and quinoa. Processing greatly affects the nutrient composition of the grain-food end product, with whole grains being nutritionally superior to refined grains. Whole grains are those left intact after food processing and thus contain all three layers of the grain (the bran, endosperm, and germ). By contrast, refined grains are those that have had one or more parts of the grain removed during food processing, e.g. the bran. From a nutrition perspective, choosing foods rich in whole grains in preference to refined grains is preferable as they are more nutrient dense: rich in carbohydrates, protein, fibre, iron, magnesium, iodine, folate, and thiamine.

So which grains are low in FODMAPs? The following is a list of whole grain foods that Monash has tested and found to be low FODMAP at either a full or half serve: 

• Amaranth (puffed)
• Bourghul
• Buckwheat (kernals, flour
•  Corn (cob, polenta, tortilla, popcorn)
•  Millet (grain, flour)
• Oats (whole, quick, oatmeal)
• Quinoa (grain, flakes, flour, pasta)
•  Rice (brown)
• Sorgham (flour)
•  Wheat (wholemeal bread)

In future blogs, we’ll discover how to identify whether a processed food is likely to contain whole or refined grains and discuss uses of some of the less traditional grains. Stay tuned!

           

Diet Tips:Dietary Fibre Series- Soluble Fibre

By Shirley Webber (Research Dietitian)

Eating enough fibre on a low FODMAP diet can be challenging, but did you know that getting the right mix of fibres is also important? Food is made up of different types of fibres, namely insoluble fibre, soluble fibre, and prebiotic fibres (including resistant starch). 

These fibres serve different functions in the bowel and eating them in combination may promote different health benefits. Over the next few weeks we will discuss the different fibres types, including their function in the bowel and low FODMAP food sources. Let’s begin with soluble fibre.

Soluble fibre dissolves in water and forms a thick gel in our digestive tract. This slows gut transit time and helps us to feel fuller for longer. The gelatinous substance formed by soluble fibre also acts like a sponge during digestion, attracting fluid and softening stools to make it easier for waste to move through the bowel.

There are many health benefits associated with including soluble diet in your diet. Soluble fibre helps to stabilise blood glucose levels in people with diabetes. Soluble fibre may also lower levels of low density lipoprotein cholesterol (LDL-C), also known as bad cholesterol level. This may reduce risk of heart disease and bowel cancer. For those with constipation predominant IBS, including a variety of fibres in your daily diet can assist with maintaining regular bowel habits.

What foods contain soluble fibre?

Soluble fibre is found in some vegetables and fruit, oats, lentils, legumes, nuts and seeds. Including small quantities of these foods may improve stool consistency, but avoid large quantities which may exacerbate symptoms. 

Fibre supplements such as psyllium husks are also rich sources of soluble fibre. However, being fermentable, psyllium husks are tolerated by some people with IBS, but not all, so include in small doses initially and/or under the guidance of your dietitian.

Here are a few examples of foods you can trial in your diet to increase your soluble fibre intake:

• Breakfast: Add 30g of rolled or quick oats to your yoghurt or breakfast smoothie in the morning
• Snack: Have a fruit such as orange, passionfruit or banana.
• Lunch: Include wholegrain bread, brown rice or beans as an element of your meal
• Snack: Try a handful of low FODMAP nuts and seed
• Dinner: Include a variety of vegetables into your meal. High soluble fibre options include: brussels sprouts, sweet potato, turnip, collard greens, eggplant, carrots, potato, okra and green beans. Refer to the Monash app for serving size suggestions.
• Dessert: Try making a chia seed pudding: http://fodmapmonash.blogspot.com.au/2015/11/strawberry-chia-pudding-recipe.html

Diet Tips:Dietary Fibre Series - Resistant Starch

By Dr Jaci Barrett 

This is part 4 of our series on dietary fibre. This week we’re talking about resistant starch! 

What is resistant starch?

As suggested by the name, resistant starch is starch that escapes digestion by the small intestine. There are four types of resistant starch:

• RS1 is not accessible by digestive enzymes – sources include partially milled grains and legumes
• RS2 escapes digestion because of the nature of the food – sources include underripe bananas and high-amylose starches
• RS3 is produced when foods are cooked and then cooled – sources include bread, tortillas, cooked then cooled potatoes, rice and pasta
• RS4 is a chemically modified starch

What does resistant starch do in the gut?

Resistant starch and other types of fibre move through the gut to the large intestine where they act as food for the gut bacteria. Resistant starch acts as a prebiotic – see previous blog post in this series ---link. Fermentation of resistant starch releases beneficial short chain fatty acids which promote a healthy colon.

Resistant starch is slowly fermented in the large intestine. It differs from FODMAPs due to this slow fermentation rate. FODMAPs are rapidly fermented and result in rapid increases in intestinal gas which, in IBS, can induce symptoms of pain, bloating and discomfort. 

Resistant starch is slowly fermented over time. The gradual release of gas does not result in the same degree of gaseous distension and discomfort as with FODMAPs.

What are some good food sources?

Food sources of the different subtypes of resistant starch are listed above, but the following table outlines the amount of resistant starch per serve in foods with a green low FODMAP serve, so that you can seek out high resistant starch foods to include in your diet to improve bowel health.

Food	Resistant Starch (g)
Underripe banana, 1 medium	4.7
Rolled oats, 1/4 cup, uncooked	4.4
Oats, 1 cup, cooked	0.5
Lentils, 1/2 cup, cooked	3.4
Hi-maize resistant starch, 1 tablespoon	4.5

Reference: Murphy MM, Douglass JS, Birkett A. Resistant starch intakes in the United States. J Am Diet Assoc. 2008;108(1):67-78.