Food has a social component that is integral to every culture and society on our planet. However, food can be foe as well as friend, food intolerances can negatively impact our quality of life and in the case of food allergies they can even be lethal. If we ask Google, from headaches to acne nearly every single ailment can be attributed to a food or diet and usually the cure is also attributed to a different food or diet.

The “free from” industry is booming, when I first moved to the city I currently live in if I wanted gluten free products I would have had to go to a pharmacy and, with luck, they would be in the corner collecting dust along with those weird herbal sweets your grandmother used to love.

Fast forward two years and now entire sections of supermarkets are dedicated to gluten and lactose free products. This is obviously a great thing, especially for people with genuine diagnosed conditions such as celiac disease. The increased awareness of food related problems has led many of us to question “is this headache/lack of energy/lack of sleep caused by a food intolerance?”

There are plenty of people who will tell you the answer is yes and their advice usually comes with a large price tag. This article will explain to you why the IgG antibody food intolerance test is a waste of both time and money.

I want to make it very clear that although I will be mentioning food allergies this article is not about whether you should or shouldn’t test for a suspected food allergy.

If you suspect that you may have a food allergy then go to your physician, and by that I mean a real doctor that works in a clinic or a hospital, not some charlatan on the internet with MD after their name. What I will be discussing in this article is the food intolerance blood tests that are advertised on the internet and in some pharmacies.

What Is the Test?

The test is pretty straight forward—you order a testing kit online from one of the labs offering the test. Once it arrives you take a blood sample and then send that blood sample back to the lab.

The lab will test your blood for IgG antibodies that are specific to a wide range of foods, usually in the range of 200 different foods. What I mean by specific is that, for example if when they test your blood against a sample of chicken protein some of the IgG antibodies bind to that protein they are “specific” to that protein or food.

Once the lab has tested all the foods they will return a report to you with the results. Different labs may do it differently but the ones I have seen use a traffic light system.

Red for foods with high amounts of IgG binding which should be avoided. Yellow for foods that are “borderline” and should only be eaten in moderation. Finally, green for foods that have little or no IgG which means you can eat them to your heart’s content.

So, what’s the problem?

It all sounds so simple, do the test and then avoid the red foods. However, there are two pretty large problems with this method of food intolerance testing. The first is related to the testing procedure, and the second is with the actual function of the IgG antibody.

True Food Intolerances

We’ll start with the method and we’ll assume that the IgG antibody is involved with food intolerances (that will be tackled in the next section).

When I did my allergy certificate at university we were repeatedly told that the most important part of an allergy diagnosis was the patient history.

Without a detailed patient history, the blood test results are at best unhelpful. The sole presence of antibodies is not sufficient enough to give a diagnosis, there has to be a history of symptoms in order to be certain that you are indeed allergic (or in this case intolerant) to a particular food.

Blood test results without patient history become unhelpful. As I said before both symptoms and the presence of antibodies are needed for a diagnosis. Just the presence of antibodies (with the absence of symptoms) to a particular food protein is known as sensitisation.¹

When it comes to food allergies, if a person is sensitised to a food but does not have any allergic symptoms then the last thing they should do is stop eating that particular food.

By ceasing to eat the food they are sensitized to could actually push the immune system away from tolerance towards allergy and the next time they encounter that food they could have a reaction.²

This is why in immunotherapy it is vitally important that the patient continues to eat the food they were allergic to even if (as is often the case) they do not like it.

Coming back to food intolerance, just receiving a report of hundreds of foods, some of which you now have been told you cannot eat, is likely to lead to you following an unnecessarily restrictive diet resulting in increased risk of nutrient deficiencies and even worse, less gains in the gym.

The IgG Antibody

Before we get too in depth about antibodies I think it’s important to clarify what is allergy and what is intolerance because these words are often used interchangeably and causes confusion.

Both allergy and intolerances are known as hypersensitivities which means they are reactions against something that a “normal” person would not react to. An allergy is a hypersensitive reaction that is driven by the immune system whereas an intolerance does not involve the immune system.³

A good comparison would be lactose intolerance and a true milk allergy. A person who is lactose intolerant does not produce any or insufficient amounts of the enzyme lactase which helps us digest the sugar lactose, so when they consume milk they cannot break down lactose and this causes digestive issues, these issues are not caused by the immune system.

They can however consume lactose free milk. In the case of a milk allergic individual, their immune system has created antibodies against milk proteins so when they consume milk their immune system attacks it and the individual has the classic allergy symptoms, itchy rash, swelling, and difficulty breathing.

A milk allergic individual could not consume lactose free milk because it still contains the milk proteins, however they could consume a hydrolysed or amino acid formula with lactose.

Moving on to antibodies, these are made by the B-cells of our adaptive immune system. Our immune system is made up of two parts, the innate and the adaptive. The innate is pretty basic in that it attacks anything that is not “us.”

On the plus side it is very quick to respond. The adaptive immune system is a bit slower to respond but it has a “memory” so to speak, so the next time it encounters anything nasty it usually deals with it before we even notice we’re sick.

One of the chief weapons in the arsenal of the adaptive immune system is the antibody (or immunoglobulin), the B-cells make several different types of antibody each with a different role in the immune system. The most famous antibody is probably IgE. The original role of IgE was to deal with parasitic infections but it is more widely known as the antibody behind allergic reactions.⁴

When the B-cell makes an antibody they are “specific” to a particular protein (in the case of food allergy a food protein), when the antibody next encounters that protein they attach to it and drive an immune response.

In the case of IgE they sit on top of certain immune cells (mast cells), and when they encounter the specific protein or antigen they bind to it and cause these cells to release histamine. It is this histamine that causes your typical allergic reactions and also why people with allergies usually carry antihistamines with them.

Moving on to the IgG antibody, there are actually four subclasses of IgG antibody, IgG1, IgG2 etc. each with a slightly different function. All the IgG subclasses are very good at enhancing a process called phagocytosis which involves certain cells of the immune system (macrophages) engulfing bacteria and destroying them.

IgG1 for example is very good at a process known as ADCC (Antibody-Dependent Cell-mediated Cytotoxicity), here the IgG1 will attach to a target cell and immune cells will recognise that attachment as a signal that that particular cell needs to be destroyed.⁴

IgG Food Interolence Science

Proponents of the IgG food intolerance tests will point to the antibody’s ability to activate several cells of the immune system as “evidence” that the antibody can and does mediate non-allergic reactions to foods.

However, when we examine the role of IgG4 we see that this is not the case. In 2012 researchers from Norway examined the link between IgG, IgG4 and IBS (irritable bowel syndrome). IBS is a condition related to food that has many of the symptoms of food intolerances, bloating, and change in bowel habits so there have been attempts to link the condition to IgG antibodies.⁵

In the Norwegian study they compared IgG and IgG4 food specific antibodies of IBS subjects and healthy symptom free subjects. Not only did the researchers find that the IBS group’s IgG and IgG4 antibodies did not match to their trigger foods (foods they know exacerbate their symptoms), but there were no differences in levels of IgG and IgG4 between the IBS and control group.

What the researchers did find was that the higher levels of the antibodies matched foods that both groups ate regularly, in the case of the IBS group these were their “safe foods” and in the control group merely foods that they ate often.

The researchers concluded that it was unlikely that IgG and IgG4 antibodies played a role in IBS and that the presence of these antibodies merely reflected ones diet.⁶

In other words, the more you eat of something the more IgG specific to that food you have. In recent years it has become apparent that IgG, and in particular IgG4, is not just a reflection of a diet but a marker of tolerance and is protective against allergic reactions.

For non-allergic people we make IgG4 antibodies (as opposed to IgE) against proteins to mark them as “safe” and prevent any chance of an allergic reaction. This has been labeled an IgG4/IgE ratio. Non-allergic bee keepers have been shown to have an IgG4/IgE ratio 1000 times higher than individuals who are allergic to bee venom.⁷

During immunotherapy, allergic individuals gain tolerance not by reducing their numbers of IgE but by increasing their numbers of IgG1 and in particular IgG4. The IgG4 antibodies compete with the IgE antibodies and prevent them attaching to the mast cells and so prevent them from causing reactions.⁸

Proceed with Caution

When it comes to food proteins, the IgG antibody and in particular the IgG4 subclass appear to have anti-inflammatory effects that prevent allergic (and intolerance) reactions in both allergic and non-allergic individuals.

To paraphrase EAACI (the European Academy of Allergy) the testing of IgG for food intolerances is “irrelevant” and should not be performed.⁹

The companies that continue to promote the IgG blood tests either do not fully understand the function of the IgG antibody or worse, they do and are continuing to sell their product anyway. I really hope it isn’t the latter.

References:

1. Van Ree. R et al. 2014. Allergic sensitization: host-immune factors. Clinical and Translational Allergy. 4:12.

2. James. LK et al. 2011. Long-term Tolerance After Allergen Immunotherapy is Accompanied by Selective Persistence of Blocking Antibodies. Journal of Allergy and Clinical Immunology. 127:509-516.

3. Johansson. SGO et al. 2004. Revised nomenclature for allergy for global use: Report of the Nomenclature Review Committee of the World Allergy Organization, October 2003. Journal of Allergy and Clinical Immunology. 133 (5): 832-836.

4. Owen. J et al. 2013. Kuby Immunology, 7th Edition. Macmillan.

5. Philpott. H et al. 2013. Alternative Investigations for Irritable Bowel Syndrome. Journal of Gastroenterology. 28: 73-77.

6. Ligaarden. S et al. 2012. IgG and IgG4 Antibodies in Subjects with IBS: A Case Control Study in the General Population. BMC Gastroenterology. 12:166.

7. Carballido. JM et al. 1993. T-cell Epitope Specificity in Human Allergic and Non-Allergic Subjects to Bee Venom Phospholipase A2. Journal of Immunology. 150:3582-3591

8. Bischoff SC & Sellge G. 2014. Food Allergy: Adverse Reactions to Foods and Food Additives, Fifth Edition. Chapter 2: The Immunological Basis of IgE-Mediated Reactions. John Wiley & Sons, Ltd.

9. Stapel. SO et al 2008. Testing for IgG4 Against Foods is Not Recommended as a Diagnostic Tool: EAACI Task Force Report. Allergy. 63: 793-796.

The post Food Intolerances: Should I Get Tested? appeared first on Breaking Muscle.

The carbohydrate has had a bit of a hard time recently. Carbs make us fat, sugar is evil, and we should all switch to a high-fat diet or we will get diabetes. While that may sound extreme it certainly isn’t a rare opinion. We, humans, love to see things in black and white and nowhere is a better example of this than in the fitness and nutrition world.

People love to put themselves in one group or another. Try telling a cyclist they should do some strength work, or tell a bodybuilder a bit of cardio won’t make their training go amiss and you’ll quickly find yourself in an argument. It is a similar situation with the popularity of low-carb diets. There is some basis for advocating a reduction in carbohydrate consumption, especially refined carbs, and simple sugars. But does that mean we should all go from the classic high-carb diet to a ketogenic diet?

The more we learn about the human body the more we realize that, while there are some basic concepts that work for everyone, the “one size fits all” diet just doesn’t exist. Rigidly sticking to any dietary dogma is not going to be very helpful in your journey towards your training goals let alone your mental well-being. You have to be flexible with your diet and this is the fundamental concept of periodized nutrition.

Most people who read this site will be familiar with the concept of periodization of training, the progressive approach to planning training as you move towards your goal. Periodized nutrition (or nutrition periodization) can be thought of as tailoring your diet to meet the demands of your current training regimen. In the same way that you should be planning your training, you should be planning your nutrition. Below I am going to give an example of when deciding to reduce your carbohydrate intake is a good idea and also when it is not.

Evaluate Your Carbs

When thinking about how much or how little carbohydrate to include in your diet you should ask yourself two questions:

1. What is my current goal?
2. How hard is my current training regimen?

These may seem like very simple questions, but they can keep you focused on benefitting as much as possible from your diet. Do you want to lose weight? Do you want to gain weight? Are you a football/rugby player who plays a match every weekend and trains twice a week? Do you have a marathon next month? Are you training for an Ironman? Whatever your current goal is it will have a direct effect on how hard your training sessions are and also your dietary needs.

Nutrition Coach Wayne Bradley of Valladolid, Spain

Notice how I have said “current goal”—it is possible to have several athletic goals throughout the year. For example, somebody who has an Ironman event in August may want to lose a few kilos in January, therefore their training and diet will look very different in the winter than it will in the late spring.

When to Go Low Carb

Without getting lost down a biochemistry rabbit hole we can work with the generalization that if we take on more energy than we expend we will gain weight. Obviously, from the science point of view it is more complicated than that, but from a practical point of view of it really doesn’t have to be complex.

But why should we reduce carbs and not fat or protein? The simplest answer is because the carbohydrate usually makes up the largest proportion of our diet (often at least 50%), so if we reduce our carbohydrate intake we are reducing our overall energy intake.

The more complicated answer is when carbohydrate (glucose) is being used as a fuel it reduces lipolysis, the process by which fat is used as a fuel. To add to this when energy intake is higher than demand (i.e. we are eating more than we need to once muscle and liver glycogen stores are filled) the excess glucose is converted to fatty acids and sent to the adipose tissue to be stored as body fat.¹

So, carbohydrate hinders fat utilization and can be stored as body fat pretty easily. In terms of protein intake, while it is also possible for excess protein to be converted to fatty acids and stored as fat, this rarely happens and current evidence suggests that during dieting protein intakes should actually be increased in order to preserve muscle tissue.²

I’m fairly certain I don’t need to explain why preserving muscle tissue is a good thing. In our clinic, we often see an overreliance on animal protein so we change some for vegetable sources to increase fiber content of a diet. But in terms of total amount of protein, we rarely see someone who is overdoing it.

When my partner and I are assessing somebody’s diet who wants to lose weight the first two places we look are alcohol intake and what we call “junk” or “wasted” calories. Alcohol is an obvious one, but it is difficult to deal with because often you can’t get an honest answer from your client about their alcohol intake and/or they are unwilling to significantly reduce it. But if you are serious about your diet and your training goals then reducing your boozing will only have positive effects.

Moving on to the wasted calories, in our experience, these are nearly always excess carbohydrate, usually in the form of added sugars, which can easily be removed from the diet. Breakfast cereals, fizzy drinks, pasta, rice, and potatoes—these are all things that can be reduced or removed from your current diet quite easily without having to go to the extreme of a ketogenic diet.

Ultimately, if you want to lose weight or improve body composition and/or your training load is not particularly high then a reduction in carbohydrate intake will be helpful. In terms of numbers, between 3g and 5g per kg of body weight is the current recommendation.³

If you keep a diary of your intake on an online tracker, which if you are trying to diet I recommend that you do, then you will notice you can hit that 3-5g/kg amount pretty easily, so we always recommend getting most of your carb intake from vegetables and legumes before touching the pasta, rice, etc. to ensure a good intake of fiber and micronutrients.

Another area of interest within nutrition periodization and low carb living that has increased in popularity recently is the idea of “training low.” This is essentially training with limited access to or complete avoidance of carbohydrate, or training in a state of glycogen depletion. The proposed benefits include increased protein synthesis and increased fat oxidation, the double Holy Grail for strength and endurance enthusiasts alike.⁴

There are several methods of training low, but the most widely used is probably fasted training. I would wager that most early morning exercisers (or those that ride/run to work) perform fasted training without intention. It is basically training before you have breakfast.

Early research is promising regarding this method of training, especially in terms of increased fat oxidation. However, it is too early to give specific recommendations in terms of duration, frequency, etc. If you want to include fasted training into your program I would recommend keeping the duration quite short (around 60 minutes) and keep the intensity low.

When Not to Go Low Carb

At first glance, the reasoning behind advocating a low carb even ketogenic diet is pretty sound. We only have a small amount of stored carbohydrate (stored as glycogen in the muscle and liver), whereas we all have a practically limitless supply of body fat. Why not teach the muscles to preferentially use fat as a fuel and leave the precious carbohydrate to tissues that use glucose either exclusively or preferentially, such as red blood cells or the brain?

The problem with low carb or ketogenic diets is with performance. Several studies have shown that following an LCHF (low carb high fat) diet will certainly increase your capability to use fat as a fuel, but sadly this does not translate into improved performance.⁵

The advocates of the LCHF movement often cite research showing improved TTE (time to exhaustion) after reducing carb intake to a minimum and becoming what they term “keto-adapted”—the process by which your body has begun to use ketones as a major fuel source.⁶

There is a rather large “but” here and it is the fact that TTE studies are not performance studies. TTE is as it sounds, a participant exercises at a given intensity until they are completely exhausted and have to stop. Can you think of a single sport where the athletes all start at the same time and keep going until they drop one by one? You won’t be able to because such a sport does not exist.

The results from TTE studies are usually extrapolated to endurance sports, but the aim of endurance sports is to get from point A to point B in the quickest possible time. This is an important point because it renders TTE and LCHF studies useless in another way and that is that often the studies are performed at a moderate intensity (from 50% – 70% VO2 max), which, if anyone has run a marathon, done a triathlon or raced a bike will know that these are all performed at an intensity much higher than 70% VO2 max, often with periods of near maximal effort.

Once we get past a certain intensity, whether we are “keto-adapted” or not, our bodies will begin to use only carbohydrate as a fuel source because the process of using fat is just too slow.

Of course on paper the LCHF idea sounds perfect, we use more fat at the lower intensities and save more of our glycogen for when the going gets tough. The problem is that it appears that becoming keto-adapted hinders our ability to use muscle glycogen, so when we need it most we can’t access it.⁵

In a recent study by Louise Burke at the Australian Institute of Sport⁷ she revealed a performance decrease when elite race walkers switched from their habitual diet to an LCHF one, it is worth noting they used a performance test (a race) not TTE.

In terms of resistance training, while lifting weights does result in glycogen depletion, it is not currently thought to be the limiting factor in performance unless you are training more than once in a day or have not recovered properly and are starting a session with depleted glycogen.⁸

Even though many people do not train more than once a day, those that have a physically active job who then train in the evenings should keep in mind that they need to replenish their glycogen stores if they plan a hard session after work. This should be taken into account by team sports players, especially sports such as rugby where players would probably train in the weight room during the week and then play a match on the weekend.

You would want to ensure your glycogen stores are replenished come match day. To add to this, consuming carbohydrate (around 1g/kg body weight) after a workout with your usual post workout protein has been shown to decrease muscle protein breakdown.⁸ This is ideal for those of you who are wanting to gain muscle mass.

When performance is the goal of your training or you are mid-season or even if you simply want to gain muscle mass then following a low carbohydrate diet would not be optimal for your training needs. Current guidelines are 5-10g/kg body weight of carbohydrate. I would advise the lower end of that scale as realistically only professionals would require more than 7g/kg.³ And remember to include at least 1.6g/kg of protein from a mixture of animal and vegetable sources.

Periodize Your Nutrition to Work for You

When thinking about the periodization of your nutrition in relation to carbohydrate intake, following either a low or high carb diet throughout the year is not going to be optimal and may be in fact detrimental to your training and performance. If you want to lose weight and/or you are not currently training particularly hard, then reducing your carb intake is certainly worth considering.

Conversely, if your training load is high at that particular time, you are mid-season or if you want to bulk up, then you will need to consume a moderate to high amount of carbohydrate depending on how hard you are actually training. By “high training load” I mean 1-3 hours of daily training not spending most of your gym time taking selfies or spending your group rides sitting in the wheels pushing 130 watts.

References:

1. Gropper S.S, Smith J.L, 2012. Advanced Nutrition and Human Metabolism. Wadsworth

2. Stokes T. et al. 2018. Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Training. Nutrients. 10, 180.

3. American College of Sports Medicine, 2016, Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise. 48 (3) p543-568.

4. Jeukendrup, A, E. 2017. Periodized Nutirition for Athletes. Sports Medicine. 47 (Suppl 1)

5. Burke L.M, 2015. Re-examining High-Fat Diets for Sports Performance: Did we call the Nail in the Coffin Too Soon? Sports Medicine. 10, 1007.

6. Volek J. Phinney S. 2012. The Art and Science of Low Carbohydrate Performance. Beyond Obesity LLC.

7. Burke L.M, 2016. Low Carbohydrate, High Fat Impairs Exercise Economy and Negates the Performance Benefit from Intensified Training in Elite Race Walkers. Journal of Physiology 595 (9) p2785 – 2807.

8. Campbell B, 2014. Sports Nutrition, Enhancing Athletic Performance. Taylor and Francis Group LLC.

The post Periodized Nutrition: When to Go Low Carb appeared first on Breaking Muscle.