What are polyols? A Definitive Guide to Their Functions, Types, and Usage

Have you ever wondered: what are polyols? Polyols are a type of FODMAPs, presenting the “P”.

In this blog post, we will discuss what polyols are, which foods they can be found in and their positive and negative impacts on our health and well-being.

What are polyols?

Polyols, also known as sugar alcohols, are a group of organic compounds characterised by their sweet taste and structural similarities to sugars and alcohols. 

Despite their name, polyols are neither sugar nor alcohol but are classified as “sugar alcohols” due to their molecular structure.

They are derived from naturally occurring sugars or starches through a process known as hydrogenation.

Types of polyols

Polyols are naturally present in different types of fruits and vegetables and numerous processed foods added by the food industry. 

This section will present types of polyols and where they can be found.

Sorbitol

Sorbitol has a pleasant taste and can retain moisture, enhancing the texture of baked goods and confectionery.

It can be found naturally occurring in (1):

• Apples
• Apricots
• Blackberries
• Cherries 

This sweetener is also widely used in sugar-free and low-calorie products due to its sweet taste, similar to sugar but with fewer calories.

Also, it is commonly used as a humectant and stabiliser in bakery and pastry applications, extending shelf-life by maintaining the moisture content of foodstuff.

Xylitol

Xylitol naturally occurs in small quantities in (2, 3):

• Strawberries
• Raspberries
• Oats
• Corn cobs

It is a popular polyol known for its sweetness and dental benefits – inhibiting the growth of bacteria that causes tooth decay (4).

It is often used in chewing gum, toothpaste, and sugar-free candies as it has no aftertaste.

Erythritol

Erythritol is a zero-calorie polyol that occurs naturally in fruits and fermented foods.

It is naturally present in (5):

• Pears
• Melons
• Soy sauce
• Mushrooms 

This polyol is added to foodstuffs to reduce sugar content and energy value. It is usually added to ice cream to improve the texture.

Erythritol is frequently used in diabetic-friendly products and is known for its digestive tolerance. 

A study showed that gut microbiota can not ferment it, so there is no gas production. It is thought that erythritol is excreted unchanged (6).

Mannitol

Mannitol is commonly used in various food products as a sweetener, bulking agent, and humectant. It has a cooling effect and is often found in sugar-free chewing gum.

Mannitol is present in (1):

• Celery
• Chicory leaves
• Cauliflower
• Porcini mushrooms etc.

Mannitol has also been used in medicine as an osmotic diuretic.

It is sometimes administered intravenously to help increase urine production and reduce fluid retention in certain medical conditions, such as brain swelling (7).

Maltitol 

Maltitol is a type of polyol which is not naturally found in foods. It is a sugar alcohol derived from maltose, a type of sugar.

Maltitol is another popular polyol commonly used as a sugar substitute in various food products, including (8):

• Chocolates 
• Cakes
• Jams
• Chewing gums

Maltitol has similar sweetness and texture to sugar but with fewer calories.

Lactitol 

Lactitol is a sugar alcohol derived from lactose, the natural sugar in milk. It has a sweet taste and is often used in sugar-free candies, chocolates, baked goods, and dairy products.

It is also classified as a pharmaceutical product and is used for the prevention and treatment of constipation (9).

Isomalt 

Isomalt is derived from beet sugar and has a similar sweetness and taste to regular sugar.

It has an interesting property – it is resistant to browning during cooking and baking (10). 

Unlike regular sugar, which tends to caramelise and brown when exposed to high temperatures, isomalt retains its original colour and transparency (10). 

This makes it a preferred choice for creating clear or translucent candies, decorative elements, and edible displays that require a visually appealing and vibrant appearance (10).

Are polyols in foods healthy?

Polyols can positively or negatively affect our health. 

Polyols have fewer calories compared to regular sugar (11). Therefore, replacing sugar with polyols can benefit individuals aiming to reduce their overall calorie intake or manage weight.

Earlier this year, the World Health Organisation (WHO) released new guidelines on using non-sugar sweeteners (12). 

WHO does not recommend using non-sugar sweeteners, such as aspartame and stevia, to control body weight or reduce the risk of noncommunicable diseases (12).

However, this does not apply to the use of polyols, according to WHO.

Another positive effect of polyols is dental health.

Certain polyols, such as xylitol, have been shown to have dental health benefits. They can help prevent tooth decay by reducing the growth of harmful bacteria in the mouth (13).

Do polyols raise blood sugar?

Polyols have a minimal impact on blood sugar levels, making them suitable for individuals with diabetes or those aiming to manage their blood glucose levels (14). 

Polyols and gut issues

While polyols are generally considered safe for consumption, some individuals may experience digestive discomfort, including:

• Bloating
• Gas
• Diarrhoea

This happens as polyols are poorly absorbed in the gut, and when they arrive in the colon, they draw in water, which results in diarrhoea.

Being aware of your tolerance and consuming polyols in moderation is crucial.

In people with IBS, polyols can also worsen abdominal pain and cramps. To learn more about IBS symptoms, read our article: What are the symptoms and causes of IBS?

If you follow a low FODMAP diet or malabsorb polyols, choose low FODMAP fruits and vegetables, like (1):

• Firm banana
• Kivi
• Pineapple
• Carrots
• Spinach
• Zucchini 

You should also check the labels to detect polyols added to the foods. As this looks quite restrictive, many low FODMAP options are still available.

You can choose between various low FODMAP sweeteners, including:

• Stevia
• Sucralose
• Aspartame

If you want to read more about which sweeteners are low FODMAP, click here.

Summary

Polyols are a type of FODMAP and are also known as sugar alcohols.

The most common are sorbitol, xylitol, mannitol, and erythritol. They can naturally occur in fruits or vegetables or be added to foods while food processing.

These sugar substitutes offer sweetness, reduced calorie content, and improved dental health while enhancing the texture and stability of various products. 

Polyols can, in some individuals, cause digestive problems, such as flatulence and diarrhoea, as they are poorly absorbed and osmotically active substances.

Written by Barbara Lešnik, Student Dietitian, reviewed by Kirsten Jackson, Consultant Dietitian BSc Hons, RD, PG Cert