FODMAP Explained: “P” Stands for Polyols
Welcome back to my “FODMAP Explained” Series! This is a set of articles dedicated to explaining the acronym FODMAP and giving practical tips to avoid symptoms while including as wide a variety of foods as possible. In this final issue, I discuss the last letter in the acronym FODMAPs – “P” for Polyols.
The P in FODMAP stands for Polyols, also called “sugar alcohols”. You can recognize them as their name almost always ends with “ol” (sorbitol, maltitol, erythritol, etc.). Why are these carbohydrates problematic? They are slowly absorbed in the small intestine and, while they are lingering there, they have an osmotic effect: they draw water, contributing to symptoms of bloating and diarrhea.
They may also be poorly absorbed and end up in the large intestine, where they are fermented by bacteria, which produce gas. Whether you get symptoms usually depends on the amounts of polyols you eat at one meal, and what other FODMAPs have been consuming in the same meal or day.
Polyols in the low FODMAP Diet
There are two polyols that are naturally found in some fruits and vegetables and need to be avoided or minimized during the elimination phase of the low FODMAP diet:
Sorbitol: found mostly in fruit, for example, blackberries, avocadoes, and stone fruits;
Mannitol: found mostly in vegetables like mushrooms, cauliflower and celery.
Other polyols are found in sugar-free products such as mints, gums, and some candy bars or products for diabetics. These are manufactured to be used as low-calorie sweeteners (xylitol, erythritol, maltitol, lactitol and isomalt are the most common ones). You may have noticed the warning that eating excess amounts of these sugar-free products may cause diarrhea.
Bottom line: what can you eat?
During the elimination phase it is best to avoid all sources of polyols, including the fruits and vegetables mentioned above and all sugar-free products (see the Monash University FODMAP App for more guidance).
During the re-challenge phase, your dietitian will guide you on how to re-challenge mannitol and sorbitol separately to find out which ones may be triggering symptoms for you. Many people can tolerate one but not the other. Others may tolerate both but in small amounts.