It has been a basic defining fact of my life, since I was a pretty small kid, that I don’t like fruit. I’ve had a million iterations of this conversation: “Yes, all fruit. Haha, yes, I know that covers a lot of variety. Oh, a few exceptions, like I’ll sometimes have raspberry jam or orange juice. Yes, haha, I do eat tomatoes, you got me there.”
I’ve also spent most of my life feeling at least a little unwell. I’m a little embarrassed by this, and it feels totally self-indulgent and maybe melodramatic to talk about. I’m not going to enumerate a full list of petty complaints, but suffice to say I could come up with one that would make a hypochondriac blush. But, for instance, I recently mentioned to someone that I remember repeatedly having the experience in childhood of almost throwing up, pretty much at random — feeling my gorge rise and swallowing hastily, and being pleased with myself to catch it in time. I thought this was a common childhood experience, so I was a little unprepared for her reaction of complete horror at the very idea. So, huh, maybe not normal.
I was aware of the phenomenon of fructose malabsorption, in part through reading up on the low-FODMAP diet. Some people have less ability to absorb free fructose directly through the gut lining, which means that it passes down to the lower intestine. Too much excess fructose, or a bad balance of gut bacteria, and fermentation of that fructose can contribute to significant digestive distress.
I also probably had encountered the common caveat, “Fructose malabsorption should not be confused with hereditary fructose intolerance, which is typically diagnosed in infancy and can cause kidney and liver failure and even death if left unrecognized.” So, ok, I’m not an infant, and I’m not dead, so that can’t apply to me, right?
Except now I’m wondering.
Hereditary fructose intolerance is indeed a very different problem, where fructose is absorbed just fine but cannot be fully metabolized due to an impaired ability to manufacture the necessary enzymes. It’s not a gut issue at all. It’s an inability to efficiently clear partially metabolized fructose, which can cause liver and kidney damage if left unchecked.
There are known examples of HFI remaining undiagnosed until adulthood … because the affected person developed a strong aversion to fructose- and sucrose-containing foods from childhood. Aversion to sweets limited their exposure, and it only came to light later in life.
Now, that’s not exactly me. Because although I have a strong aversion to fruit, I also have a sweet tooth for sucrose-containing foods. I am definitely not an obvious candidate for classic HFI, having seemingly eaten enough sugar in my life to have killed me several times over.
I started to wonder, is there such a thing as partial fructose intolerance? And with some careful sifting and poking around, I was able to turn up an article from ten years ago that suggests this might be possible. The authors include a reference to a case study from the 1990s where a patient experienced severe effects after being given fructose intravenously during clinical-surgical management of other conditions. A liver biopsy of that patient showed that F1P aldolase activity was 30% of normal, and FBP aldolase activity was normal (where typically in HFI patients, these values are 0-6% and 10-50% of normal, respectively). The authors tie this to other unspecified examples from their 20 years of clinical practice to suggest that acute symptoms of HFI may appear only after massive fructose intake in previously asymptomatic patients who carry an incomplete set of HFI gene mutations.
I can’t help but wonder if that’s me? Because maybe “asymptomatic” can also mean “nothing that has landed you in the hospital.” If you’ve had years of relatively mild complaints that could be attributed to any number of things, then I can’t see how you would ever be tested for this particular genetic condition, unless maybe you happened to have a family history. Whereas for me, the only hint in this direction is that I have a lifelong visceral aversion to fruit.
And the thing is, I suppose I could take all this to a physician and see if I could, what, see if I could finagle some advanced genetic testing? Get a liver biopsy? Do a fructose tolerance challenge and see how my body reacts?
Or … I could just cut out sugar.
I mean, really cut out sugar. Militantly. Not just fruit and fructose, but anything with sugar in the ingredient list, or where sucrose is the main component sugar (because sucrose = fructose + glucose).
Have you ever tried to do this? God almighty, so much label reading. So much repeatedly looking things up. So much having to question and rethink every assumption that goes into making food choices.
But my birthday is coming up at the end of the year, and I’m going to call this my birthday present to myself. I’m going to the hard work now to give this a shot. I mean, from a health perspective, there’s really not any downside to meticulously cutting out sugar for a couple months. And maybe, just maybe…
Maybe I’ll end up feeling…good?