Latex-fruit syndrome: digging a bit deeper

As there were many requests to expand on my latex-fruit syndrome Instagram post, I thought: why not to make a short blog post about it? So here it is!

Just to recap for those of you who missed it, latex-fruit syndrome (or as some people call it latex-food syndrome or latex-fruit allergy) is an example of "cross-reactivity", when our body is confused, between similarly looking proteins found both in natural rubber latex and some fruits, into "thinking" they are actually the same.

Why does this matter? Well, usually when we talk about food allergies, we talk about a basic two- step process. Step 1 is so-called “sensitization”, when we eat the food and our immune system creates igE antibodies against specific proteins in that food. Step 2 is an allergic reaction itself, which may happen the next time we eat that particular food.

Latex-fruit syndrome doesn’t follow this process. In this case, you are sensitized to one thing (for example, antibodies are made against one or more latex proteins) and the allergic reaction is being provoked by a different thing (for example, proteins in bananas). This is, so to speak, a “cross-reaction” in its essence.

Most commonly, cross-reaction happens between latex and fruits such as banana, avocado, kiwi and chestnuts. However, an increasing number of other foods is being added to the list, such as apples, strawberries, carrots, tomatoes, celery, potato and many others. Bananas seem to be one of the most common foods that cross-reacts with latex, but I have noticed that more and more people are also mentioning potatoes and tomatoes.

This cross-reactivity chain can get even more complicated, as plants can also cross-react within their own botanical families. So you sometimes hear stories when, for example, someone with allergy to potatoes is also reacting to other foods from the nightshade family, such as tomatoes or bell peppers.

Although all this may seem scary and somewhat depressing, the good news is that latex-fruit syndrome is not as common as some may think. It seems that on average, of people who react to latex, 30% will also cross-react to certain fruits, or vice versa. In other words, the majority of people with allergy to latex will not develop an allergy to fruits, and the majority of people with fruit allergies will not react to latex. And even if that happens, oftentimes only one or very few foods are involved.

Perhaps the most important point here is that latex-fruit syndrome is very individualized! As such:

Tip 1: Don’t stop eating lots of foods unnecessarily (just because they were listed on some food blog as potentially “cross-reactive”). Chances are you have no allergic reaction to any of those fruits (or latex), or if you do, its only likely to be one or a few, not all.

Tip 2: If you think you might have stopped eating some foods for the wrong reason, but you have other severe allergies, always talk to your allergist before trying to bring these foods back.

Tip 3: There are various proteins in latex and different people react to different ones. Some of those proteins are heat-sensitive, meaning that you may react only to raw or uncooked fruits, but not to the same fruit when cooked. Other proteins are more potent and heat stable, so whether you heat them or not, the reaction may happen anyways.

And there is more and more…

So, as I always say, know YOUR allergy and what is safe /unsafe for YOU. Also, talk to an allergist and a food allergy dietitian to help you navigate through this complexity, and safely enjoy as many different foods as possible. Love you all and til next!