Diet Tips:A dietitian’s day on a plate - Week 1 of 2

By Shirley Webber (Research dietitian)

As someone who has struggled with IBS for many years, I was relieved when I found out about the low FODMAP diet. Throughout my high schooling, I thought that having an upset stomach was “normal” and constantly feeling tired and like my head was in a giant cloud was just me being a typical teen. It wasn’t until I went to University that firstly, I realised these symptoms were not normal and secondly, I began to suspect that the symptoms may have been triggered by dietary factors.

I subsequently underwent testing to rule out serious illnesses, including coeliac disease, all of which came back negative. As a last resort, my GP suggested I have a breath tests to check my tolerance of lactose and fructose. When I found that I malabsorbed both sugars, my GP then gave me a list of all fructose and lactose containing foods that he found on the internet and told me to “never eat these foods”. That was the problem solved as far as my GP was concerned. Having seen this doctor for most of my schooling life, I trusted his every word and followed a very restricted diet for three years. I felt anxious when I ate out and found growing up in a family where food was at our core very difficult.  Increasingly, I felt that my highly restricted diet was difficult to follow and just not good enough for me.

This all changed when I read a magazine article about research into diet and gut health. This article sparked my interest in dietary research and health. At a similar time, my dad discovered that he had the same food intolerances as I did and after consultation with a dietitian, we became aware of the low FODMAP diet. Importantly, we discovered that foods should not be restricted for life, but rather reintroduced slowly to identify tolerance to specific FODMAPs. Over the next two years, I gradually tested my tolerance to new foods, reintroducing foods I was previously “not allowed”. This saw me find a much healthier diet that I could happily live with.

My personal interest in nutrition and food intolerances grew to the point that I decided to do further post graduate studies in Dietetics to better understand the complexities of food intolerances.

So now you have my personal IBS story. Next week I will give you an idea of what I eat to keep myself healthy and my symptoms at bay…a dietitian’s ‘day on a plate’.

 

Diet Tips:What is lactose intolerance?

By Lyndal McNamara (APD)

As a dietitian, I often see patients who have just been diagnosed with lactose intolerance and understandably assume that this means they need to avoid all dairy products. You will be relieved to know that this is certainly not the case! In fact, most dairy products can still be enjoyed on a low lactose diet. But first, what exactly is lactose and what does a diagnosis of lactose intolerance really mean in terms of diet?  

What is lactose and what is lactose intolerance?

Lactose is a type of sugar found most commonly in milk and other dairy products. When foods/drinks containing lactose are consumed, the body needs the help of an enzyme named lactaseto break down the lactose sugar into smaller pieces for digestion and absorption (see picture below). Individuals who have lactose intolerance make less lactase enzyme, so may find it difficult to digest lactose properly when they consume a large amount of a lactose-containing food/drink. This can ultimately result in unpleasant symptoms such as bloating, wind, stomach cramps and diarrhoea.

What is the difference between lactose intolerance and an allergy to dairy?

Lactose intolerance should not be confused with a dairy allergy. A true food allergy is an adverse reaction to a food that involves the body’s immune system and can result in severe symptoms that can even be life threatening. Someone with a dairy allergy may experience severe symptoms even if they consume minute quantities of a dairy product; it is therefore usually essential that they strictly avoid all dairy. Lactose intolerance is different in that consumption of small to even moderate amounts of lactose may not actually trigger any symptoms. Despite the symptoms of lactose intolerance being unpleasant, exposure to too much lactose will not result in life threatening symptoms. Strict avoidance of lactose is therefore unnecessary. 

How much lactose can I have before experiencing symptoms?

This will vary between individuals, however research suggests that most people with lactose intolerance can tolerate 12-15g of lactose per day (equivalent to up to 250ml of regular milk) and possibly even more if lactose consumption is spread throughout the day rather than in a single sitting. (1-3)

Is there anything I can take/do to improve my tolerance to lactose?

Lactase enzyme products (tablets or drops) are available at most pharmacies and may assist with lactose digestion when taken with a lactose containing food. Consuming lactose containing foods together with other foods may also improve tolerance.(3)

How much lactose do dairy products actually contain?

As you can see from the table below, this is very variable! Whilst regular milk is high in lactose, many common cheeses such as cheddar, feta and even soft cheeses like brie and camembert contain virtually no lactose in a typical serve. Whilst yoghurt is listed as a high lactose food, there are many varieties available that are low lactose or even lactose free that are usually well tolerated. Try yoghurts that have added live bacterial cultures, as these are usually easier to digest. Lactose free varieties of many dairy products including cow’s milk, cream, sour cream and cream cheese are also now readily available. These products are identical to the regular variety, they simply have some lactase enzyme added to them, and so the lactose has already been digested for you!

Lactose content of common dairy foods

Dairy product	Lactose content /serve	Serving size	Lactose classification/serve
Full cream milk	15.75g	250ml	High
Low-fat milk	15.25g	250ml	High
Skim milk	12.5g	250ml	High
Natural Yoghurt	8.5g*	170g	High
Regular flavoured yoghurt	5.8g*	170g	High
Thickened Cream	3.75g	125ml	Moderate
Sour cream	3.13g	125ml	Moderate
Cream cheese	2.0g	80g	Moderate
Ricotta Cheese	1.6g	80g	Moderate
Cottage cheese	0.7g	36g	Low
Feta Cheese	0.13g	125g	Low
Cheddar (tasty) Cheese	0.04g	40g or 2 slices	Low
Camembert Cheese	0.04g	40g	Low
Brie Cheese	0.04g	40g	Low

 

*The lactose content of yoghurt varies significantly between brands and this value reflects the average lactose content only.

Data source: NUTTAB 2010 database

Will I miss out on any essential nutrients if I follow a lactose free diet?

Many dairy foods containing lactose are important sources of calcium in the diet, so if you avoid dairy products for any reason, it is important that they are replaced with suitable calcium rich alternatives. The range of lactose free dairy products available on the market mean that you can consume a low lactose, calcium rich diet very easily. Choose lactose free milk, probiotic yoghurts or lactose free yoghurts and choose naturally low lactose cheeses from the list above. If you do this you will still get enough calcium in your diet. Alternatively, if you choose non-dairy, lactose free milks including those made from soy, rice, nuts such as almonds and even coconut, it is important to ensure that you buy a brand that contains added calcium, as these products do not naturally contain much calcium. Ideally look for a variety that has 200-300mg of calcium per 250ml serve. Remember to always speak to your dietitian before making major changes to your usual diet to ensure you will not be missing out on any important nutrients!

References:

1.            Savaiano DA, Boushey CJ, McCabe GP. Lactose intolerance symptoms assessed by meta-analysis: a grain of truth that leads to exaggeration. The Journal of nutrition. 2006;136(4):1107-13.

2.            Suarez FL, Savaiano D, Arbisi P, Levitt MD. Tolerance to the daily ingestion of two cups of milk by individuals claiming lactose intolerance. The American journal of clinical nutrition. 1997;65(5):1502-6.

3.            Shaukat A, Levitt MD, Taylor BC, MacDonald R, Shamliyan TA, Kane RL, et al. Systematic Review: Effective Management Strategies for Lactose Intolerance. Annals of Internal Medicine. 2010;152(12):797-803.

Diet Tips:Food Allergy or Food Intolerance?

By Lyndal McNamara (APD)

The terms food allergy and food intolerance are often confused as they can have similar symptoms, but they actually refer to two very different conditions. Whilst both ‘food allergy’ and ‘food intolerance’ broadly describe an adverse reaction that occurs in response to exposure to a particular food, there are a number of important differences between the two conditions.

Food Allergy

A food allergy results when the body’s immune system has an abnormal reaction after exposure to a particular food protein. Exposure may be via eating the food. However, in severe cases it may also be triggered by simply touching the food. In allergic individuals, the body’s immune system responds by releasing various chemicals into the blood stream, which can affect many different parts of the body. 

These chemicals are responsible for the often-severe symptoms associated with a food allergy including an itchy skin rash (hives), swelling of the lips, mouth and tongue, vomiting, diarrhoea, abdominal cramping and even breathing difficulties. Extremely severe allergic reactions to food, known as anaphylaxis, can even be life threatening and require urgent medical attention. 

Onset of symptoms in someone with a food allergy can be extremely rapid (within minutes), however, delayed reactions are also known to occur (taking several hours). Exposure to even trace amounts of the responsible food protein is often enough to trigger activation of the immune system and result in symptoms. 

For this reason, strict avoidance of the food protein is necessary and being able to confidently read and understand food labels is key to avoiding unintentional exposure. Food allergies are typically first recognised and diagnosed in infancy or early childhood and new diagnosis as an adult is rare. True food allergies are diagnosed by an allergist, who uses a detailed medical and symptom history in combination with skin prick testing. 

Food Intolerance

Food intolerances on the other hand have many different causes, with the key difference being that they DO NOT involve activation of the body’s immune system. The symptoms of food intolerance predominately affect one system. Gut symptoms due to food intolerance typically result due to components within a food (such as FODMAPs) not being digested and/or absorbed well. This in turn can result in higher levels of gas production by bacteria that live in the large intestine or cause excess water to be drawn into the bowel, leading to symptoms such as bloating, abdominal pain and changes in bowel habit (i.e. diarrhoea or constipation). 

The skin can be affected by certain chemicals found naturally in or added to food, for example the natural chemical group, amines in beef, tomato and cheese can trigger eczema in sensitive individuals. Despite the symptoms of food intolerance being unpleasant, they are not life threatening. Onset of symptoms is also usually quite delayed (several hours to several days) and may not occur every time the offending food is consumed. 

The symptoms of food intolerance are therefore ‘dose responsive’, meaning that symptoms will not be experienced until a certain amount or ‘threshold dose’ of the food has been eaten. This ‘threshold dose’ can vary significantly between individuals. First onset of a food intolerance can occur at any age, but unlike food allergies, food intolerances cannot be diagnosed using any specific test. 

Elimination and food rechallenge dietary approaches, such as the low FODMAP diet, are therefore often necessary to pinpoint particular foods that may be triggers of food intolerance symptoms. As these diets can be overly restrictive, it is highly recommended that individuals with suspected food intolerance consult with a dietitian before attempting to modify their diet. A dietitian will help ensure that these diets are implemented in such a way that they are effective but also provide adequate amounts of essential nutrients.

Summary – Food Allergy vs Food Intolerance

Food Allergy	Food Intolerance
An adverse reaction to food that involves activation of the immune system	An adverse reaction to food that DOES NOT involve activation of the immune system
Symptoms occur rapidly (within several minutes to hours) after exposure to even minute quantities of the food allergen            Symptoms will always occur when exposed to the food allergen	Symptoms may not occur unless exposure to the trigger food exceeds the individual's ‘threshold dose’            Symptoms can occur several hours or even days after exposure to the trigger food
The food allergen must be strictly avoided to prevent an allergic reaction	The trigger food does not need to be strictly avoided as consumption of small amounts may not cause any symptoms
Symptoms are often severe and potentially life threatening	Although symptoms may be unpleasant, they are not life threatening
Able to be diagnosed using immunological testing (blood test or skin prick testing)	Unable to be accurately diagnosed using any specific test            Diagnosis relies on food elimination and rechallenges
Diagnosis usually occurs in infants and young children            New diagnosis in adults is rare	Diagnosis is common at any age

References:

Turnbull JL, Adams HN, Gorard DA. Review article: the diagnosis and management of food allergy and food intolerances. Alimentary pharmacology & therapeutics. 2015;41(1):3-25.

 

 

Diet Tips:Adding glucose to high FODMAP foods – does it really help?

By Marina Iacovou (PhD Candidate and Accredited Practising Dietitian)

In an earlier blog post this year (http://bit.ly/1WvWU5Y) we speculated that although early studies suggested adding glucose to fructose may improve tolerance, the strategy was not looking promising – instead all it was doing was adding more sugar to the overall diet.  There was confusion around this strategy with individuals adding glucose to all FODMAPs, not just fructose, which is the only FODMAP that could benefit from glucose addition. Consuming glucose tablets became common practice for many people when eating onion and garlic, foods rich in fructans, not fructose, which scientifically will not improve symptoms.

We can now confidently tell you that adding glucose to foods to help with the absorption of FODMAPs, even fructose, does not work.

One of our PhD candidates, Caroline Tuck, has published work on this very topic. If you want to read the full publication, please click here.

A brief summary of the study and its findings:

• Patients with a positive fructose breath test (“fructose malabsorption”) and functional bowel disorders such as IBS, were recruited. Healthy participants were recruited as a reference/control group
• Participants were provided with 6 different sugar solutions (PART A) – some acted as control solutions (glucose only) and others were combinations of fructose and glucose, and fructans and glucose which were compared to fructose alone and fructan alone
• Additional studies (PART B) were undertaken. where glucose was added to whole foods high in excess fructose
• It was a series of two randomised controlled, double or single-blinded crossover trials – this means that the participants (and in part A the researchers) were not aware what solutions were being consumed and the solutions were given in a random order. As such the results are more reliable
• Overall, breath hydrogen scores and patient symptoms did not improve with the addition of glucose to fructose or fructan solutions, or to whole foods
• Breath hydrogen responses in healthy participants were similar to patients with functional bowel disorders – showing that “fructose malabsorption” is normal
• The results of the study, question the reliability of breath hydrogen tests in a clinical setting. 

So we can conclude that: 1) breath hydrogen tests, particularly to fructose, are unreliable – this is consistent with a previous study we posted about http://bit.ly/2fSaVcn and 2) Overall, the strategy of adding glucose to drinks or foods to lessen the effects of dietary FODMAPs on functional gastrointestinal symptoms, has no evidence.

Some of you may have been doing this already – taking glucose tablets with high fructose foods. If you really feel it helps, you can continue, but remember these points:

• Your total sugar intake will increase significantly
• Your tolerance to FODMAPs, including fructose, can fluctuate over time, so maybe this strategy is working because your tolerance to fructose has improved and you can drop the glucose without significant symptoms

Something to consider…

Tuck CJ, Ross LA, Gibson PR, Barrett JS, Muir JG. Adding glucose to food and solutions to enhance fructose absorption is not effective in preventing fructose-induced functional gastrointestinal symptoms: Randomised controlled trials in patients with fructose malabsorption. J Hum Nutr Diet. 2016.