Does The FODMAP Diet Reduce Gas and Bloating

Written by Dr. Steve Chaney on . Posted in Diets, FODMAP Diet, Gas and Bloating

Author: Dr. Stephen Chaney

 

fodmap dietCan the FODMAP diet help reduce gas, bloating, diarrhea, and constipation? Everyone suffers from one or more of these symptoms, but nobody talks about them. For some they represent an annoyance. For others they can be incapacitating.

When the symptoms become frequent and start to affect quality of life, the medical community starts to give them names. When the symptoms occur at least 3 days/month for at least 3 months and there are no known diseases causing the symptoms, it is called irritable bowel syndrome (IBS). If the symptoms are also associated with inflammation, it is called inflammatory bowel disease (IBD). The principle forms of IBD are Crohn’s disease and ulcerative colitis.

A Primer On IBS And IBD

IBS is fairly common. Between 10-15% of the US population has been diagnosed with IBS, but experts estimate that as much as 25% of the population experiences symptoms consistent with IBS.

It is also important to understand that IBS is a collection of symptoms, not a disease. The only difference between IBS and the gas, bloating, and diarrhea (or constipation) that many people experience on a fairly regular basis is the frequency and severity of symptoms – and that is an arbitrary distinction. Someone experiencing those symptoms an average of 2 days/month is not significantly different than someone experiencing those symptoms 3 times/month.

While severe IBS can be incapacitating, it does not appear to cause lasting damage to the intestine or predispose to other diseases. Finally, the causes of IBS are largely unknown. Stress, obesity, and food sensitivities may all play a role.

IBD is much less common (0.4% of the US population), but much more severe. It can cause permanent damage to the intestine and can predispose to several diseases, including cancer. For that reason, you should always consult with your physician if you have severe, chronic gastrointestinal issues.

Standard treatment of IBS and IBD has traditionally consisted of recommendations to:

  • Reduce weight if overweight
  • Increase exercise
  • Reduce stress
  • Limit caffeine and alcohol
  • Limit fatty foods
  • If diarrhea is the primary symptom, limit dairy products, fruits, and sweeteners such as sorbitol and xylitol.
  • If constipation is the primary symptom, increase dietary fiber

These interventions generally provide only partial relief of the symptoms, so medications are frequently prescribed to control the symptoms. Unfortunately, many of those medications have significant side effects.

Fortunately, research over the past decade suggests that there is a natural, holistic approach that can significantly reduce the symptoms associated with IBS and IBD, thus decreasing the reliance on medications to treat those diseases. It is something called the FODMAP diet. The FODMAP diet is rapidly becoming the standard of care for IBS and IBD, and the same diet also appears to significantly improve symptoms in people who merely experience gas, bloating, and diarrhea more frequently than they would like. More importantly, the principles behind the FODMAP diet can help almost everyone who experiences occasional gas, bloating, diarrhea and/or constipation.

What Is The FODMAP Diet?

The FODMAP diet was devised over a decade ago by a group of scientists in Australia. Basically, they identified all of the kinds of foods that were known to cause gas, bloating, diarrhea, and/or constipation in susceptible people and put together a diet that was low in all of them.

FODMAP is an acronym that stands for:

  • F – fermentable carbohydrates
  • O – oligo-saccharides
  • D – di-saccharides
  • M – mono-saccharides
  • P – polyols

Of course, that statement comes under the “Aren’t you glad you asked?” category. It is meaningless to most people. A better way to understand this is to look at foods in the FODMAP category. They include:

  • gas and bloatingLactose, found in milk and milk products (especially for people who lack the enzyme lactase)
  • Fructose in high concentrations, found in foods like apples, pears, honey and agave syrup. (30-40% of individuals have problems absorbing fructose).
  • Fructans, found in foods like wheat, onions and garlic.
  • Galacto-oligosaccharides, found in foods like beans, lentils, and soybeans.
  • Polyols such as sorbitol and mannitol, found in fruits such as cherries, apricots, and apples, and as sweeteners added to many “sugar-free” foods.

These are all foods that are poorly digested or poorly absorbed, so they are fermented by intestinal bacteria. It is the fermentation of these foods by intestinal bacteria that causes the gas, bloating, and diarrhea.

Does The FODMAP Diet Work?

The evidence that the FODMAP diet is effective is pretty impressive. For example:

What Does This Mean For You?

On the surface, this seems to be a good news, bad news story.

good news bad newsThe good news is that the FODMAP diet is incredibly effective at decreasing frequent gas, bloating, abdominal discomfort, diarrhea and constipation – and it really doesn’t matter whether you have been diagnosed with IBS or IBD, or you are just someone who suffers from those symptoms more frequently than you would like.

The bad news is that the FODMAP diet is very restrictive. You can appreciate that when you look at the list of high FODMAPs foods you need to avoid. That means:

  • The diet is very difficult to stick to long term. In the follow up study described above only 30% of the participants were able to stick with the diet for the full 16 months.
  • The diet restricts so many foods that you would really need the guidance of a registered dietitian to design a nutritionally adequate diet plan.

 

The reality, however,is that very few people actually need to restrict all the high FODMAP foods to enjoy significant relief from their symptoms. Clinically, most physicians test various FODMAPs in their IBS and IBD patients and only restrict the ones that cause symptoms. You can do exactly the same thing yourself. Start by reducing groups of high FODMAP foods on the list. Once you have identified which food groups cause your symptoms, you can test foods within that group one by one.

The most important news is that the FODMAP diet concept may help many people who struggle with occasional gas, bloating, and diarrhea. Let me give you one example:

  • Let’s suppose you have discovered that foods made from wheat flour cause you g.i. problems. You have concluded that you are gluten intolerant and carefully avoid foods containing gluten, but you still have occasional gas, bloating and diarrhea. You might be sensitive to the fructans in wheat, not the gluten. If so, a quick glance at the FODMAPs list suggests a number of fructan-containing foods you may be sensitive to that you would never have expected if you just focused on avoiding gluten. For example:
  • Vegetables: garlic, onions, asparagus, artichokes and snow peas might be causing you trouble.
  • Fruits: grapefruit, nectarines, plums and watermelon could be causing you problems.
  • Processed foods: Inulin, a naturally occurring fiber, found in Jerusalem artichokes, is primarily a fructan. Inulin and several other naturally occurring fructans are added to many processed foods to increase their fiber content. These foods might also be causing you trouble.

This is just the tip of the iceberg. Most of us have probably identified one or two problem foods that we know give us gas. By using the FODMAPs list we may be able to identify other foods we should avoid.

 

The Bottom Line

  • By restricting all foods known to cause gas, bloating, diarrhea and constipation in susceptible individuals, scientists and clinicians have created something called the FODMAP diet.
  • The FODMAP diet has proven to be very effective at reducing those symptoms in people with IBS or IBD, but it is also equally effective at eliminating symptoms in individuals who simply suffer from gas, bloating, abdominal pain, diarrhea and/or constipation more frequently than they would like.
  • The low FODMAP diet is also very restrictive, but the good news is that most people don’t need to eliminate all of the foods in the diet. You can systematically test and eliminate the individual foods that cause your symptoms.
  • Most importantly, the FODMAP concept can help us identify problem foods that we might have otherwise never suspected of giving us gas. You will find an example of how this concept works in the article above.
  • Gas, bloating, abdominal pain, diarrhea and constipation can also be caused by a number of serious diseases. For that reason, you should always consult with your physician if you have severe and chronic gastrointestinal issues.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (2)

  • Nancy Pcsolyar, MA, DA, LDN

    |

    Thank you, Dr. Chaney. for addressing the FODMAP test. Little is written about it but yet the information is essential for people suffering from bloating, gas, etc.

    As always, your unbiased critique of various studies is priceless information especially for those of us working in the medical field .

    Reply

  • Anson Kibby

    |

    What an excellent article. Thank you SO much.

    Reply

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Latest Article

Should We Use Supplements For Cardiovascular Health?

Posted July 10, 2018 by Dr. Steve Chaney

Are You Just Wasting Your Money On Supplements?

Author: Dr. Stephen Chaney

 

supplements for cardiovascular health wast moneyYou’ve seen the headlines. “Recent Study Finds Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.”  You are being told that supplements are of no benefit to you. They are a waste of money. You should follow a healthy diet instead. Is all of this true?

If I were like most bloggers, I would give you a simple yes or no answer that would be only partially correct. Instead, I am going to put the study behind these headlines into perspective. I am going to give you a deeper understanding of supplementation, so you can make better choices for your health.

 Should we use supplements for cardiovascular health?

In today’s article I will give you a brief overview of the subject. Here are the topics I will cover today:

  • Is this fake news?
  • Did the study ask the right questions?
  • Is this a question of “Garbage In – Garbage Out?
  • Reducing Heart Disease Risk. What you need to know.

All these topics are covered in much more detail (with references) in my book “Slaying The Supplement Myths”, which will be published this fall.

 

How Was This Study Done?

supplements for cardiovascular healthThis study (D.J.A. Jenkins et al, Journal of the American College Of Cardiology, 71: 2540-2584, 2018 ) was a meta-analysis. Simply put, that means the authors combined the results of many previous studies into a single database to increase the statistical power of their conclusions. This study included 127 randomized control trials published between 2012 and December 2017. These were all studies that included supplementation and looked at cardiovascular end points, cancer end points or overall mortality.

Before looking at the results, it is instructive to look at the strengths and weaknesses of the study. Rather than giving you my interpretation, let me summarize what the authors said about strengths and weaknesses of their own study.

The strengths are obvious. Randomized control trials are considered the gold standard of evidence-based medicine, but they have their weaknesses. Here is what the authors said about the limitations of their study:

  • “Randomized control trials are of shorter duration, whereas longer duration studies might be required to fully capture chronic disease risk.”
  • “Dose-response data were not usually available [from the randomized control studies included in their analysis]. However, larger studies would allow the effect of dose to be assessed.”

There are some other limitations of this study, which I will point out below.

Is This Fake News?

supplements for cardiovascular health fake newsWhen I talk about “fake news” I am referring to the headlines, not to the study behind the headlines. The headlines were definitive: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” However, when you read the study the reality is quite different:

  • In contrast to the negative headlines, the study reported:
    • Folic acid supplementation decreased stroke risk by 20% and overall heart disease risk by 17%.
    • B complex supplements containing folic acid, B6, and B12 decreased stroke risk by 10%.
    • That’s a big deal, but somehow the headlines forgot to mention it.
  • The supplements that had no significant effect on heart disease risk (multivitamins, vitamin D, calcium, and vitamin C) were ones that would not be expected to lower heart disease risk. There was little evidence from previous studies of decreased risk. Furthermore, there is no plausible mechanism for supposing they might decrease heart disease risk.
  • The study did not include vitamin E or omega-3 supplements, which are the ones most likely to prove effective in decreasing heart disease risk when the studies are done properly (see below).

Did The Study Ask The Right Question?

Most of the studies included in this meta-analysis were asking whether a supplement decreased heart disease risk or mortality for everyone. Simply put, the studies started with a group of generally healthy Americans and asked whether supplementation had a significant effect on disease risk for everyone in that population.

That is the wrong question. We should not expect supplementation to benefit everyone equally. Instead, we should be asking who is most likely to benefit from supplementation and design our clinical studies to test whether those people benefit from supplementation.

supplements for cardiovascular health diagramI have created the graphic on the right as a guide to help answer the question of “Who is most likely to benefit from supplementation?”. Let me summarize each of the points using folic acid as the example.

 

Poor Diet: It only makes sense that those people who are deficient in folate from foods are the most likely to benefit from folic acid supplementation. Think about it for a minute. Would you really expect people who are already getting plenty of folate from their diet to obtain additional benefits from folic acid supplementation?

The NIH estimates that around 20% of US women of childbearing age are deficient in folic acid. For other segments of our population, dietary folate insufficiency ranges from 5-10%. Yet, most studies of folic acid supplementation lump everyone together – even though 80-95% of the US population is already getting enough folate through foods, food fortification, and supplementation. It is no wonder most studies fail to find a beneficial effect of folic acid supplementation.

The authors of the meta-analysis I discussed above said that the beneficial effects of folic acid they saw might have been influenced by a very large Chinese study, because a much higher percentage of Chinese are deficient in folic acid. They went on to say that the Chinese study needed to be repeated in this country.

In fact, the US study has already been done. A large study called “The Heart Outcomes Prevention Evaluation (HOPE)” study reported that folic acid supplementation did not reduce heart disease risk in the whole population. However, when the study focused on the subgroup of subjects who were folate-deficient at the beginning of the study, folic acid supplementation significantly decreased their risk of heart attack and cardiovascular death.  This would seem to suggest using supplements for cardiovascular health is a good idea.

Increased Need: There are many factors that increase the need for certain nutrients. However, for the sake of simplicity, let’s only focus on medications. Medications that interfere with folic acid metabolism include anticonvulsants, metformin (used to treat diabetes), methotrexate and sulfasalazine (used to treat severe inflammation), birth control pills, and some diuretics. Use of these medications is not a concern when the diet is adequate. However, when you combine medication use with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial.

Genetic Predisposition: The best known genetic defect affecting folic acid metabolism is MTHFR. MTHFR deficiency does not mean you have a specific need for methylfolate. However, it does increase your need for folic acid. Again, this is not a concern when the diet is adequate. However, when you combine MTHFR deficiency with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial. I cover this topic in great detail in my upcoming book, “Slaying The Supplement Myths”. In the meantime, you might wish to view my video, “The Truth About Methyl Folate.”

Diseases: An underlying disease or predisposition to disease often increases the need for one or more nutrients that help reduce disease risk. The best examples of this are two major studies on the effect of vitamin E on heart disease risk in women. Both studies found no effect of vitamin E on heart disease risk in the whole population. However, one study reported that vitamin E reduced heart disease risk in the subgroup of women who were post-menopausal (when the risk of heart disease skyrockets). The other study found that vitamin E reduced heart attack risk in the subgroup of women who had pre-existing heart disease at the beginning of the study.

Finally, if you look at the diagram closely, you will notice a red circle in the middle. When two or three of these factors overlap, that is the “sweet spot” where supplementation is almost certain to make a difference and it may be a good idea to use supplements for cardiovascular health.

Is This A Question Of “Garbage In, Garbage Out”?

supplements for cardiovascular health garbage in outUnfortunately, most clinical studies focus on the “Does everyone benefit from supplementation question?” rather than the “Who benefits from supplementation?” question.

In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.

Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.

 

Should We Use Supplements For Cardiovascular Health?

 

If you want to know whether supplements decrease heart disease risk for everyone, this meta-analysis is clear. Folic acid may decrease the risk of stroke and heart disease. A B complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but the analysis did not include vitamin E and/or omega-3s.

However, if you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.

I would be remiss, however, if I failed to point out that we know healthy diets can decrease heart disease risk. In the words of the authors: “The recent science-based report of the U.S. Dietary Guidelines Advisory Committee, also concerned with [heart disease] risk reduction, recommended 3 dietary patterns: 1) a healthy American diet low in saturated fat, trans fat, and meat, but high in fruits and vegetables; 2) a Mediterranean diet; and 3) a vegetarian diet. These diets, with their accompanying recommendations, continue the move towards more plant-based diets…” I cover the effect of diet on heart disease risk in detail in my book, “Slaying The Food Myths”.

 

The Bottom Line

 

You have probably seen the recent headlines proclaiming: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” The study behind the headlines was a meta-analysis of 127 randomized control trials looking at the effect of supplementation on heart disease risk and mortality.

  • The headlines qualify as “fake news” because:
    • The study found that folic acid decreased stroke and heart disease risk, and B vitamins decreased stroke risk. Somehow the headlines forgot to mention that.
    • The study found that multivitamins, vitamin D, calcium, and vitamin C had no effect on heart disease risk. These are nutrients that were unlikely to decrease heart disease risk to begin with.
    • The study did not include vitamin E and omega-3s. These are nutrients that are likely to decrease heart disease risk when the studies are done properly.
  • The authors of the study stated that a major weakness of their study was that that randomized control studies included in their analysis were short term, whereas longer duration studies might be required to fully capture chronic disease risk.
  • The study behind the headlines is of little use for you as an individual because it asked the wrong question.
  • Most clinical studies focus on the “Does everyone benefit from supplementation question?” That is the wrong question. Instead we need more clinical studies focused on the “Who benefits from supplementation?” question. I discuss that question in more detail in the article above.
  • In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.
  • Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.
  • If you want to know whether supplements decrease heart disease risk for everyone, this study is clear. Folic acid may decrease the risk of stroke and heart disease. A B-complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but they did not include vitamin E and/or omega-3s in their analysis.
  • If you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.
  • However, we do know that healthy, plant-based diets can decrease heart disease risk. I cover heart healthy diets in detail in my book, “Slaying The Food Myths.”

 

For more details, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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