Tag Archives: health

The FODMAP Diet: An IBS diet based upon peer-reviewed science

I’m extremely lactose intolerant. What this means, biologically, is that I no longer produce enough lactase to process lactose sugar. Because I can’t process lactose in my small intestine, it moves on intact to my large intestine where bacteria eat the sugar. The byproduct of their digestion, gas, causes bloating, pain, cramping and, well, you know the rest.

What is IBS and what causes it?

Irritable Bowel Syndrome (IBS) is an incredibly common malady, affecting 6-46% of the population, depending upon the study. It’s a diagnosis resulting from the lack of a diagnosis; it’s diarrhea, bloating, stomach pain, and cramping that can’t be explained by celiac disease, lactose intolerance, fructose intolerance, or other understood gut disorders.

IBS is thought to be caused by visceral hypersensitivity, or over-sensitivity to pressure on the intestines. Imagine two people eat broccoli and get a bit gassy: the person with IBS would feel pain and discomfort while the other person might be bloated but otherwise fine.

It’s often implied that IBS is psychological as much as physiological. Anxiety and depression are common in people with IBS. In my experience, the perceived psychological component, the lack of simple treatments, and the lack of life-threatening consequences can lead doctors to be blasé about IBS. They recommend fiber, exercise, and routine, and shrug if that does little. Small wonder that people might feel blue. But gut science is improving, and the FODMAP approach is a new and widely successful strategy for reducing the symptoms of IBS.

What is the FODMAP approach, and what is different about it?

The FODMAP diet is based upon known biochemistry and the hypothesis that visceral hypersensitivity causes IBS. There are many molecules that, like my undigested lactose, tend to be digested in the large intestine and produce gas. The FODMAP diet eliminates a wide range of such molecules.

FODMAP, introduced in 2005 by Monash University, is a peer-reviewed diet based upon a concrete biological hypothesis supported and improved by scientific trials. It is not a weight-loss diet. FODMAP stands for Fermentable Oligo- Di- and Mono- Saccharides And Polyols. Catchy, right? But the concept is simple—FODMAPs are short-chain sugars that we know most people digest poorly (meaning bacteria digest them), and you avoid FODMAPs on the FODMAP diet. (For the biochemists, that means avoiding fructans (oligosaccharide), lactose (disaccharide), fructose (monosaccharide), and all sugar alcohols such sorbitol (polyols).)

Many other diets have questionable scientific bases and are profit driven. The Atkins Diet was published by a cardiologist who never published any peer-reviewed work, but several books. The Paleo Diet was published by an “exercise scientist untrained in paleobiology”. This is not to say that these diets cannot be beneficial in any way. But they have not been tested and refined in the way the FODMAP diet has been, and their fundamental science is hazier. Putting the cart before the horse, they have been developed first for profit, and then researched afterwards, often with mixed results. To be fair, the scientific process is slow and contentious and doesn’t always lend itself well to studies as broad and complex as diet. But FODMAP was developed, tested, and improved using the scientific process. If you’re skeptical of diets, as I am, you can read up and convince yourself that this diet has a reasonable basis and good results.

What’s a FODMAP diet like?

If you are considering a FODMAP diet, you will have to do some research, and be able to prepare food often from scratch. The internet is a phenomenal tool, and there are even some dieticians you can consult online. FODMAP sensitivity is not the same thing as an allergy. You don’t have to absolutely eliminate FODMAP foods, you simply must aim to minimize them for a period of time.

To follow the FODMAP diet, you avoid FODMAP-laden foods for two weeks to two months (different sources vary in their recommendations, and provide rationales). After this time, you re-introduce foods in a controlled manner to identify trigger foods. Most IBS-sufferers are not sensitive to all FODMAPs. Many people report benefits within a few days of starting the diet, and 70% of IBS patients in peer-reviewed studies reported improvements following the diet. I personally had much less bloating within a few days. Following a FODMAP diet revealed that some of my symptoms are due to gastritis, which I’m now treating. I see now that I’ve had gastritis symptoms for a while, but I was unable to separate various gastrointestinal symptoms before this diet. I remain on the full FODMAP diet after three months, but I have eliminated one side issue.

What foods are and aren’t allowed?

Following the most basic level of the FODMAP diet, one avoids all garlic, onion, and gluten-containing foods. It is not a gluten-free diet, but grains containing gluten overlap almost perfectly with grains containing the FODMAP fructan. Beer happily is the major exception; it is FODMAP-free due to the fermentation process.

I consider the FODMAP approach an alternative way of categorizing foods. There is a common perception that vegetables and fruit are healthful, and grains and meat are less healthful. At least from the perspective of IBS, that is not a useful framework. On the FODMAP diet, meats are okay. Roughly half of grains, dairy, vegetables and fruit contain FODMAPs, and these are avoided on the diet. Specifically, greens and squash are okay, but broccoli, leeks, and  brussels sprouts aren’t. Citrus and melon are okay, but peaches, cherries, and figs aren’t. Lactose-free milk and hard cheeses are okay, and ice cream, fresh cheeses, and sour cream aren’t.

For those considering the diet, this is my favorite exhaustive list of allowed and disallowed foods.


In short, the FODMAP diet requires research and it’s a pain to follow, but it offers real promise to the numerous people suffering from IBS. If you’re considering the diet yourself, good luck. I hope this provided a better explanation of the topic than the sources I encountered when trying to understand this diet. To others, maybe this will help explain why your friend has such a fiddly diet, and why you should support them.


Why I cook: food and science series

I cook a lot. I cook because it’s cheaper, but mostly I cook because I am absurdly lactose-intolerant, with a generally fussy tummy. As a kid, cooking seemed like something girly and irrelevant; food simply appeared. Now I see that eating is something we do every day and it can be either drudgery or exquisite.

This post is the first of a series I will post each Friday. Other posts will talk about specifics: science, recipes, and methods. Today I will talk more about how cooking became something I spend time on, and why cooking matters.

In college, I picked up some kind of food poisoning, probably on dorm food. I started to get sick a lot. I lost weight. I drank bulk-up drinks like body builders do. I became sensitive to milk products; I switched to lactose-free milk, and started drinking whole milk. I couldn’t move after meals, or else I’d get sick. If I ate even a bite too much, I got sick. If I got too hungry, I got sick. My lunches were often half a pizza slice. I bottomed out with a BMI below 18. Doctors seemed disinterested my inability to keep food, but they couldn’t explain the weight loss.

Finally, I started taking probiotics, which seemed to help. Now, seven years after my minimum weight, I’m at my high school weight, with gain more of a concern than loss. I cook most meals for myself, where I have control over my intake. Eating out with others isn’t easy, because I must be picky and inflexible about where and when I eat. I can’t wing it. If I deviate from the rules too much, I will get sick, which directly affects me for up to a day, and destabilizes me for the future. It’s manageable; some people with IBS get sick a dozen times a day, and digestive illnesses like Crohn’s disease can be life threatening.

The gut is understood very poorly, despite its importance. The enteric nervous system, or gut brain, is the site of 90% of serotonin and 50% of dopamine. With my ups and downs, I know well the relationship between gut health and mood. The digestive system is second in neurons only to the brain, and contains more neurons than the spinal cord. It is the engine of our body, and it functions in tandem with more bacteria than there are stars in the galaxy. Yet Americans spend the least time cooking of any country on Earth.

Loads of scientific evidence and my own personal evidence shows that a happy tummy goes a long ways towards a happy person, even in cases less extreme than mine. Good food can be a blissful experience, and in these posts I’ll talk about some methods toward good food. I don’t believe in diets or supplements or shortcuts, just making food that works. Good food can be made in a small kitchen on a limited budget with limited time. The primary ingredient is our own interest and curiosity, which I intend to share here.

Join the bone marrow registry from your couch

A couple of weeks ago I read about a shot-putter at University of New Hampshire named Cameron Lyle. He is giving bone marrow to a critically ill 28-year-old; unfortunately because he is a senior, donation will end his shot-putting career at the school. I’m glad to hear that the guy didn’t even think of it as a question. He knew he had to donate.

Lyle was found for donation because he was in the bone marrow donor registry, as part of a drive run by UNH. I was really glad to hear this. Perhaps I just don’t get out enough, but at my two universities, I’ve never heard of such things.

How to join

In this post, I wanted to make sure that people knew that it is so easy to join the registry at marrow.org. It’s free (if you are under age 45), and involves no needles unless you match, which happens for about 1 in 540 people. You sign up on the marrow.org website. This is basically giving them your address, and a contact’s address so they don’t lose you in the future. A pack of q-tips come in the mail. You swab them in your cheeks, and send them back. And then you’re in the registry.

What to expect if you get selected, from my experience

I donated marrow several years ago to a family member. Most times, but not always, stem cells are induced into the bloodstream through a series of shots. Then when the stem cells are in your blood, you hook up to a machine which takes the stem cells out and puts the rest of your blood back in you. That separation process is called pheresis, and if you’ve ever given plasma, it’s a similar procedure. An out needle in one arm, and an in needle in the other. The biggest problem with this method, as one who experienced it, is using the restroom, because they want you well-hydrated and it takes a while. For young people, the stem-cell shots can cause some aches. I turned into the princess and the pea, sleeping on all the pillows in my house for a couple of days, but apparently that isn’t typical.

Sometimes they still do the old-fashioned big needle in the hip bone marrow transplant method. They often show this procedure on TV shows, but it’s less common than the stem cell donation I described above. It sounds like the shot-putter might be doing a marrow transplant, which would explain why he can’t shot put for a few weeks.

The point

But basically, it something that you can do for free with very little inconvenience. In the unlikely event you get selected, it’s still not terribly involved. Minorities and people of mixed background are especially needed. There are FAQs and other info at marrow.org, too. Hopefully this will give you the info and motivation to join the registry, or encourage others to join.

Why you should join the bone marrow registry

Tomorrow my brother Brian would have turned 31. When he was 25, he died of leukemia. I was his bone marrow donor.

He was a quiet and smart person. He was working on his doctorate in computer engineering when he got his diagnosis. He liked computer gaming and anime and was a complete geek without caring at all about the designation. He first introduced me to chaos when I was in high school by showing me the logistic map. “That’s nice,” I said, and went on to other things, only to take up research in the field after his death. He played racquetball somewhat poorly; he was too laid back and unaggressive to play as boldly as the game required. He wore Hawaiian shirts and shorts year round. He liked to be different and to ignore the puzzlement of others. He once had a bad review as a TA because he failed to button his shirt. He was 6’5″ and looked like a viking.

When he got sick he lost his hair and his burliness. He didn’t complain. I donated marrow stem cells once, and some other cell in a similar procedure another time. I complained a lot. He kept trying to work on his research. His greatest vexations in the hospital were getting switched rooms constantly and the poor quality of internet access. When things went bad he entered hospice, again, without drama. His gums would bleed, he was covered with bruises and he hallucinated often. It never broke his spirit. He kept watching anime and kept playing computer games and didn’t complain. He was obviously often upset; once when they made him switch rooms he was so frazzled he cried. But he didn’t complain and he did his best to be helpful to the nurses and document his medication well. Leukemia does not define my memories of my brother but it certainly curtailed them.

Not everyone has the luck to have a bone marrow donor when they need one.  When I was matched with my brother, I was told there is only a 25% likelihood of matching for each pair of siblings. The odds of matching go down significantly beyond sibling relationships. A little less than 50% of marrow donations in 2006 came from a non family member. Matches can be especially hard to find for minorities. We need more donors.

So join the bone marrow registry at marrow.org. It is totally free to join, and you are eligible if you are between 18 and 60 (I tried to look if this extends beyond the US; it should, but I couldn’t find it on their website). They will send you a free kit with several q-tips. You swab your cheeks with the q-tips and then send them back.

There is a 1 in 540 chance you will be selected to donate, but even then, you are not required to do so. When you donate, they sometimes still draw marrow from the hip like you may have seen in TV shows. More often, the donor is given a drug for several days that causes marrow stem cells to circulate in the blood stream. Then they draw blood and separate out those stem cells, and put the rest back. It’s a lot like giving blood except the procedure takes a few hours. If you have more questions, marrow.org has a lot of helpful information. Please join, and thanks!