IBS--Free at Last!

What about vinegar?

Sprinkling your own oil and vinegar on salad is the FODMAPS-friendly way to dress it, since most commercial salad dressings have one or more ingredients that are not allowed during the elimination phase of the diet. I am often asked which vinegars are OK to use? The answer is that any filtered vinegar will do, in a 1 tablespoon portion. Filtered vinegars include white vinegar, white or red wine vinegar, champagne vinegar, rice or rice wine vinegar, and most flavored vinegars.

Unfiltered cider vinegar does retain some sugar in it, and it has an excess of fructose, so it is probably not appropriate during the elimination phase unless it is a minuscule portion. You can recognize unfiltered cider vinegar because it is cloudy in appearance, not transparent, like filtered or distilled vinegars are.

Balsamic vinegar has a 2 grams of sugar in a 1 Tb. portion, but luckily for us balsamic lovers, there is more glucose than fructose in it, so it is allowed on the elimination phase. For more information about the role of the fructose to glucose ratio, click here.

Polyols 101

Many of my clients tell me that even a few small pieces of sugar-free candy or gum cause diarrhea. Ditto for the well-know effect of prunes or cherries. What do these foods have in common? They contain polyols, also known as "sugar alcohols".

Technically, they are FODMAPS carbohydrates, and they are sweet! Most polyols are poorly absorbed, and wind up in the large intestine when they are consumed. In the large intestine, polyols are fermented by gut bacteria. They are also capable of drawing water into the large intestine. Together, the excess gas and excess fluid can cause distension of the colon, which cause bloating, flatulence and looser stools for the IBS sufferer. In a double whammy, eating or drinking sugar alcohols worsens fructose intolerance!

Some sugar alcohols, such as sorbitol, occur naturally in fruits such as apples, pears, and the "stone fruits," which include plums, prunes, apricots, peaches, cherries and so on. Sugar alcohols are often used to sweeten "sugar-free" foods (such as candy, gum, low-carb items, and bubbly water) and liquid medications. They can be recognized on the food label's list of ingredients by the ending "-ol". Examples are xylitol and maltitol.

Note that erythritol seems to be an exception. Studies have shown it is well absorbed and unlikely to cause GI symptoms.

High Performance Energy Sources

I've had several endurance athlete-clients lately looking for an appropriate energy source to use during competition that won't cause bloating and gas. During long events, a large FODMAPS load can be consumed, especially if the product used contains more fructose than glucose. Watching the Olympic games tonight, I was inspired to search for a product to recommend, and I found one: Raspberry PowerBar Gel Blasts energy chews. The web site for the product states that the ratio of glucose to fructose is 2:1--very favorable. Even so, each person has a maximum threshold for fructose absorption, so it's still possible to overdo--too much of a good thing. Do you have a favorite high-energy competition product that doesn't aggravate your IBS?

Which Tomato Products are FODMAPS-Friendly?

Fresh tomatoes contain fructose in very small amounts. They are FODMAPS-friendly. However, when tomatoes are processed into tomato paste, the fructose is concentrated a great deal. According to one of my favorite references, Cook's Thesaurus, just 1tablespoon of tomato paste is equivalent to 1 medium tomato! So tomato paste is NOT allowed during the elimination phase of a FODMAPS-elimination diet. Depending where you are in the world, tomato paste may be called tomato puree or tomato concentrate, so check food labels for all these terms.

Check the nutrition facts on the label to see how the product compares to fresh tomatoes (2 grams sugar per 1/2 cup) versus tomato paste (16 grams sugar per 1/2 cup). This tip assumes the product has no sugar added as an ingredient, and that the sugar listed on the nutrition facts panel is all coming from the natural sugars in the tomato.

After reading the label, if you're still not sure whether the tomato product you have is OK to eat during the elimination phase, you may have to open the can and look inside. Whole canned tomatoes or diced canned tomatoes with watery-looking juice in the can are OK to eat during the elimination phase of the diet. if the juice in the can is thicker than water, transfer the contents to a a freezer-safe container, stash in the freezer, and wait until the fructose challenge phase to eat this tomato product.

Fructose 101

Fructose is known as "fruit sugar". It is present in fruits, some vegetables, honey, granulated sugar, agave syrup and high-fructose corn syrup. In the past, the human diet was lower in fructose than it is today--think of how hard it was to get honey in the wild, for example, or what a treat it would have been in the past to have fruit out of season, much less a never-ending supply of ketchup, cookies, candy and other sweets. Now it seems as though fructose is everywhere in our food supply.

Our capacity to absorb fructose is easily overwhelmed; it is almost considered normal to experience abdominal pain, flatulence, bloating or diarrhea when we overdo the amount of fruit or fruit juice we consume--many people have experienced this phenomenon. But some of us experience symptoms with much smaller intakes of fructose. And most of us overlook the impact that large portions of sugary sweets, baked goods and soft drinks can have. And what about those honey or fruit juice concentrate-sweetened energy bars? Interestingly, apples are part of the traditional BRAT diet sometimes recommended to fight diarrhea. Umm...maybe apples and apple juice aren't such a good idea for some people with diarrhea.

Diagnostic dietary fructose intolerance tests are available, but are not ordered as frequently in the US as they are elsewhere. If you suspect you don't tolerate fructose very well, try cutting back on soft drink and other sweets. Limit tomato paste. Choose small portions of fruits that are lower in fructose, such as kiwi, berries, citrus fruits, and bananas. Read labels, and avoid or limit portion sizes of foods sweetened with honey, fructose, high-fructose corn syrup, agave syrup and fruit juice concentrates.  See if you feel better!

Fructose malabsorption can occur on its own, or it can be part of the larger IBS picture.The FODMAPS elimination diet in IBS--Free at Last! can help you figure out how fructose fits into your IBS scenario.

It is important to distinguish dietary fructose intolerance, described in this posting, from hereditary fructose intolerance, which is a serious, hereditary disorder requiring a truly fructose-free diet.

Click here for more details about dietary fructose intolerance and how it causes GI symptoms.

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Fructose Malabsorption and Depression

Do an internet search for the terms "fructose malabsorption" and "depression" and you will find a lot of buzz over the possibility that the two are linked. Google returned over 6,800 hits on this combination. The idea seems to be taking on a life of its own, and is treated as fact on a number of web sites and blogs. I wondered if there was any of that pesky old evidence on the subject.

I've spent several evenings poking around the internet, reading abstracts and peer-reviewed research reports, most of them published in Europe. In fact there are a number of interesting published research reports that suggest there may be a link worthy of further study. It is far from proven, however. The handful of studies that have been done, most by a particular workgroup at the University of Innsbruck, Austria, included a very small number of study subjects. The researchers have tried to discover whether there was an association between fructose or lactose malabsorption and depression. They did find such an association, but only in females. But the studies simply weren't designed to prove that fructose malabsorption causes depression. It is intriguing, though, isn't it?

The researchers did some more small scale studies to explore possible mechanisms for the fructose or lactose malabsorption-depression link. They have discovered that there may be an association between fructose malabsorption and lower levels of tryptophan, zinc and folate in the blood. It is the job of scientists to speculate about how these observations could all fit together, and speculate they do. Could these nutrients be poorly absorbed because the fructose malabsorption causes diarrhea and reduces contact time between the contents of the GI tract and the absorptive surfaces of the small intestine? Could unabsorbed sugars be interfering with the absorption of tryptophan? Could fructose malabsorption be encouraging small intestinal bacterial overgrowth (SIBO)? Could the lower serum levels of tryptophan, zince and folate cause depression?

There are far more questions than answers, here. Scientists are choosing their words with care, using the terms "may" and "suggest" and "associated with," and they point out that further studies are needed.

What is the take-away message here for people with fructose and/or lactose malabsorption? If you're a woman, removing excess amounts of these sugars from your diet might make you feel better mentally as well as physically! That's all, folks.

The report that started it all? Fructose malabsorption is associated with early signs of mental depression, Ledochowski M, Sperner-Unterweger B, Widner B, Fuchs D. Eur J Med Res. 1998 Jun 17;3(6):295-8.

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Great news for avocado lovers!

Creamy, ripe avocados are one of my favorite foods! I know I'm not alone here. One of the top questions from newcomers to the FODMAPS elimination diet is, "Can I still eat avocados?" This is a fair question to ask, since avocados have rather more fiber in them than one might guess: almost 7 grams in half of an average avocado. To put this in perspective, this is approximately the same amount of fiber contained in 1/2 cup of kidney beans!

Luckily, the type of fiber in avocados is not unfavorable. Avocados have an almost undetectable amount of fructans in them. Fructans are a type of fiber found in wheat, onions, and certain other plant foods. Fructans are not digested or absorbed by humans--that's part of what defines them as dietary fiber. When they hit the colon (large intestine), they are highly fermentable by gut bacteria, and can cause painful gas and bloating in some individuals with IBS. In other good news, avocados contain far less free fructose than other vegetables, so are unlikely to cause symptoms for individuals with dietary fructose intolerance.

All in all, it looks like avocados can be added to the list of foods allowed on the elimination phase of the diet described in IBS--Free at Last! Check out my recipe for FODMAPS-friendly guacamole, and enjoy!

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Fructose Malabsorption and Fructose:Glucose Ratio

What's up with the fructose:glucose ratio? If I experience dietary fructose intolerance, why can I tolerate fructose better if there is an equal amount of fructose in the meal?

First, let's recall the context here: the goal is to manage gastrointestinal symptoms, not to eliminate fructose, per se, from the diet. That's just not necessary (unless one has hereditary fructose intolerance, another subject entirely). Next, recall that high fructose foods include many fruits, honey, and sweetening ingredients such as high fructose corn syrup, crystalline fructose, and fruit juice concentrates.

The ability of the small intestine to absorb fructose is limited, at best. This was less of a problem years ago, when our intake of fructose was also limited! As recently as 30 years ago, the average U.S. intake of fructose was only 2/3 of what is is today, due to changes in the food supply. Imagine the distant past, when honey would have been a rare sweet treat, requiring feats of courage and strength to obtain. Cane or beet sugar and a wide variety of fruits would not have been available to most people in the world, except on rare occasions. Now, our diets contain lots of fructose, although over half of us can't fully absorb a 50 gram serving of fructose. Any time you are eating fructose faster than your personal ability to absorb it, the unabsorbed fructose will be carried on into the large intestine, where it is fermented by the resident bacteria, causing gas, bloating and altered bowel habits.

It appears there are probably two way fructose is absorbed through the cell walls of the small intestine. The first way is a low-capacity type of diffusion, in which a fructose molecule can pass through the cell wall on its own. The second mechanism is transport system that only works when there is one glucose molecule available for every fructose molecule. If there is no glucose-fructose pair, there is no absorption.

This explains why granulated sugar, which contains an equal amount of glucose and fructose is well tolerated in moderation, even by fructose intolerant individuals. Also, fruits such as berries, certain melons, and citrus fruits, which do not have an excess of fructose compared to glucose, can be tolerated in small servings. The fructose intolerant individual could still experience symptoms if very large portions of these "allowed" foods or beverages are consumed.

If you learn that you have dietary fructose intolerance, but would still like to consume high fructose foods, you might be able to do so if  you take a glucose/dextrose tablet along with the food, to improve the fructose:glucose ratio. These inexpensive tablets are sold at your local pharmacy along with diabetic supplies.

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Agave

Agave nectar and agave syrup are the hot new sweeteners of the day. How do they fit into the FODMAPS elimination diet? Are they capable of causing IBS symptoms?

In my opinion, agave nectar and syrup products are sources of FODMAPS carbohydrates. I would not recommend using them during the elimination phase of a FODMAPS elimination diet.

According to the USDA, cooked agave plant has far more fructose than glucose in it. This is a set-up for fructose malabsorption and may cause symptoms for people with IBS. Also, cooked agave is about 10% dietary fiber. The type of fiber in agave is mostly inulin, which is defined a FODMAPS carb in the “fructans” category, and could also cause IBS symptoms.

The USDA nutrient database doesn't include agave nectar or syrup, so we don't have an authoritative source for nutrition information on these items. From what I gather, agave nactar and syrup are not standard products. Depending on how they are processed, the type and amount of sugars they contain can vary a great deal. The information I have seen on agave industry web sites indicates that agave nectars and syrups are high in fructose and osmotically active; these are described as selling points for the product.

I suggest holding off on agave sweetened products until the challenge phase of the diet; you could include during your fructose challenge.

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Lecture by Satish Rao, MD at FNCE

At the American Dietetic Association (ADA) Food and Nutrition Conference and Expo (FNCE), I attended an excellent lecture by Dr. Satish Rao from the University of Iowa Hospital and Clinics. His topic was primarily dietary fructose intolerance (DFI). Consumption of fructose in the US is on the rise, yet our capacity to absorb fructose in the small intestine is limited, and varies from person to person. Dr. Rao explained that dietary fructose intolerance is far more prevalent than commonly recognized, and can explain gas, pain, bloating and diarrhea in some individuals. He recommends individuals be tested for dietary fructose malabsorption.  His group's research shows that reducing the amount of free (or excess) fructose in the diet can improve fructose intolerance symptoms.

He referred to FODMAPS in his talk.  FODMAPS stands for Fermentable Oligo-, Di- and Mono-saccharides and Polyols.  Fructose is the "M" or monosaccharide in FODMAPS. When malabsorbed in the small intestine, it proceeds to the colon.  Fructose is osmotically active (capable of pulling fluid into the colon) and rapidly fermentable by the colonic flora, causing gas and bloating.

Those wishing to perform a fructose-only elimination diet could use my upcoming book IBS--Free at Last! to do so. The book includes menus and a shopping list that are low fructose (in addition to being low FODMAPS overall). There are lists of allowed fruits, which do not contain excess fructose.  Extensive label reading tips are provided, since fructose in many forms is a common food additive. Write to me at patsycatsos@gmail.com if you would like me to notify you when my book is available in print!

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