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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Comments

[Linda Simon]

Thanks for your critical eye and keeping us up to date. There is so much we don't know yet.

[Julie]

Patsy-
REALLY interesting. It never ceases to amaze me how the body throws out signals that there are problems...and even more amazing, the research that goes into discovering these signals and what to do about them. Thanks for sharing!

[Linda Simon]

Patsy,
Thanks for your thoughtful and even handed review.

[Janice]

I discovered fructose malabsorption during the spring of 2009. I had already given up anything that was wheat related, but kept having abdominal pain. I tried going to dextrose (glucose), but since it is made from corn it has residual sulfites in it (and, of course, I have a sulfite sensitivity also). Went cold-turkey a few months ago, and don't use any type of sweetener, except that I can use milk products. My diet is quite simple, which makes shopping very very easy.

I eat steaks, ground buffalo meat (mostly because I've never heard of a recall of ground buffalo), green vegetables, potatoes, butter, and whole milk. I make a tea blend of peppermint, spearmint, and black tea, which I drink with half-and-half to give it the illusion of sweetness. I will sometimes cook up a little rice, but I have to be careful not to do that more than once a week. I also will sometimes grate up unsweetened chocolate, mix it with half-and-half, and nuke it.

Now, I have never been known as an even-tempered person. I fly off the handle easily, and always have. Been known to feel depressed at times, too. After being on a sugar free diet for two or three months, I turned to my beautiful husband, and asked him if he felt my behavior had improved. He said that I had become quite even-tempered, with mood swings that were very slight compared to what they had been previously.

In addition to that, though, my complexion has cleared up, hemorrhoids aren't acting up as much, abdomen does not hurt at all any more, and some persistent sores on my lips have disappeared.

I won't say it isn't hard to maintain this diet, because so many social activities involve food. But having lived with pain for most of my 57 years, I would say the decrease in pain is well worth it. I think my husband feels the decrease in mood swings is well worth it.

[Patsy Catsos]

Always interesting to hear how powerful diet change can be. Clearly,
you had some serious food sensitivities! The diet you have worked out
sounds very strict, but Im glad it is working for you, both physically
and emotionally. Perhaps eventually youll be able to liberalize it a
bit so you can enjoy a greater variety of foods. Time will tell.

[Patsy Catsos]

It makes me very happy to hear that you are feeling better! Thanks for letting me know. Its always good to know we are doing everything we can to help our health by managing our diet.

[sugar]

Fructose may lead to health problems, but both sugar & HFCS contain fructose in similar amounts

[Georg]

Dear Patsy. I have suffered from depression, anxiety and lots of other mental problems for most part of my life and I have problems with my digestion since the day I was born. I´m convinced that there is a conection between my diet and my mental issues but I still havent figured out what exactely it is.

I experienced symptomfree periods that lasted up to months maintaining a strict diet consisting of merely white rice and a few green vegetaples. The problem is that I always end up extremely underweight. maintaining this diet also restricts my social life and makes travelling nearly impossible.

How can I find out what kind of Intollerances I have? I live in Spain and here the doctors don´t even seem to know what a fructose malabsorption or fodmaps are. they usualy tell my I´m anorexic, give me some antidepressives and tell me to go for a walk in the sunshine.

maybe you know a way how I could get to the root of my diet problems.

[Patsy Catsos]

Hello Georg,

While I cannot give individualized advice in this kind of forum, I can say that the gastrointestinal disorder most related to mental health is celiac disease and non-celiac gluten sensitivity. Alternatively, when I hear about gut problems that go back to infancy was born it makes me wonder about inborn errors of metabolism such as galactosemia or hereditary fructose intolerance. A genetic specialist might be able to help. With regard to food sensitivities and intolerances, my knowledge of the scene in Europe is limited, but my impression is that a lot is going on in Italy--Dr. Alessio Fasans group at University of Salerno for example.

[Aurametrix]

Another article that showed association between carbohydrate (fructose and lactose) malabsorption and depression: Varea et al., 2005: http://journals.lww.com/jpgn/Fulltext/2005/05000/Malabsorption_of_Carbohydrates_and_Depression_in.6.aspx. Their study group was also small but included males.
Here is a blog on altered tryptophan metabolism and happiness: http://dysbiosis.blogspot.com/2011/05/tryptophan-in-food-will-it-make-you.html

[Patsy Catsos]

Thanks for sharing those links. Interesting.