Does Fruit Have Too Much Sugar?

Heather Bray, RD

If I could change one misconception in the world of nutrition, it might be this one. Almost daily someone asks me if they should be avoiding fruit because they think it contains too much sugar. So I’m here to set the record straight.

*Disclaimer: the views and opinions of this article are based on the best available evidence and my professional opinion as a Registered Dietitian. This article is not meant to act as a substitute for medical or medical nutrition advice. For medical or medical nutrition advice that is designed for your individual needs, please consult your doctor or Registered Dietitian.

Thanks to the rise and popularity of keto and other forms of very low carbohydrate diets, the idea that “carbs are bad for you and should be avoided at all costs” has become mainstream (and has been for a very long time). This concept has become so pervasive that people are starting to avoid fruit because they think it has too many carbohydrates or sugar (yikes!).

Low carb diets have always existed, in fact the earliest low carb diets date back to 1860! The infamous Atkins Diet, along with The Zone diet and South Beach diets are also variations of this. So it’s no wonder people are starting to avoid fruit, carbs have been public enemy #1 for a LONG time.

The question is “Does fruit have too much sugar?” And, “Does fructose from fruit pose a risk to human health?”.

There are even a handful of doctors (not all of whom are medical doctors by the way) online who claim that all sugars are toxic and should be avoided at all costs. Again, yikes! These fear mongering tactics and big eye-catching, headline-worthy claims (with very little evidence to back them up) leave people feeling confused and frustrated about nutrition advice.

When looking at studies on the effects of sugar consumption and its effect on health, you will often find that the negative health effects associated with sugar (in any form) come from an overconsumption issue. Some of the types of sugar or carbohydrates being over-consumed include high-fructose corn syrups, sucralose and other syrups. None of the studies that I’ve come across have specifically singled out fruits. [1], [2], [3] As always, we need to remember that it's the dose that makes the poison, especially when it comes to nutrition.

Fruit contains sugar in the form of a certain type of carbohydrate called fructose. Fructose in fruit is not to be confused with high fructose corn syrup or the fructose found in sucrose. High fructose corn syrup can be found in foods such as fountain pop and packaged baked goods and other highly processed sweets (e.g. chocolate bars, packaged cookies or pastries and in some juices, condiments and ice creams). Fructose is also found in sucrose (i.e. table sugar or white sugar) which is made up of both glucose and fructose. Sucrose is often extracted from plants such as sugarcane or sugar beet (source) and refined to what we know as “sugar”. All of these forms of fructose are highly refined and influence blood sugar levels much more than fruit itself ever could, more on this shortly.

In 2015 the World Health Organization published an information paper about Sugar. Where they divide sugars into two different categories: free sugar and intrinsic sugar.

Free sugars are defined as the sugars added by manufacturers in food production and those derived from honey, syrups and fruit juice concentrates (sucrose and high fructose corn syrup would fit in this category).

Intrinsic sugars are those found naturally in fruit (fructose), dairy (lactose) and even vegetables. In this report the WHO states:

“Free sugars are different from intrinsic sugars found in whole fresh fruits and vegetables. As no reported evidence links the consumption of intrinsic sugars to adverse health effects, recommendations in the guideline do not apply to the consumption of intrinsic sugars present in whole fresh fruits and vegetables.”

The WHO has since produced a new recommendation paper in 2023. In this they mirror their previous recommendations backed by updated evidence stating that the majority of carbohydrate consumption in both adult and children’s diets should be from whole grains, fruits, vegetables and pulses (a.k.a legumes).

In fact, they go on to state that consuming more of these foods results in a “significant decrease in risk of mortality and disease” and that there is “no evidence that higher intakes of whole grains, fruits, vegetables and pulses increase risk of disease or even biomarkers that indicate disease risk”.

Download and read this paper here.

What is the Glycemic Index and Why is it Important?

In order to understand the sugar in fruit debate one needs to understand a little about the digestion and metabolism of carbohydrates and the glycemic index. Whenever you eat a carbohydrate, be it a fruit, oatmeal or a cookie, the breakdown of that food begins in your mouth (via. chewing and enzymes in saliva called amylase which is specifically formulated to help break down carbohydrates). Once this food has been chewed and swallowed it enters the stomach. It is further broken down into its smallest possible form (called molecules) to be carried around in the bloodstream in both the small and large intestine. The molecules that come from any food containing a carbohydrate are called glucose (aka sugar) and this is what provides the cells in your body with energy.

All carbohydrates ultimately become glucose (aka sugar), but it’s the rate at which that breakdown into glucose and absorption of that glucose into the body’s cells makes all the difference.

This is where something called the glycemic index comes in. The glycemic index is basically a measurement of how quickly and how high your blood sugar (glucose) will spike after eating a particular food (see diagram below). As you can see, your blood sugar always goes up to some degree after eating, this is normal and is what’s supposed to happen. What we don’t want to have happen is BIG spikes and dips in blood sugar all the time (note the red line in the diagram).

Foods that cause these big spikes are often foods high in sugar and low in fibre. This is because fibre helps to slow down digestion, slower digestion = smaller blood sugar spike AND maximum nutrient absorption. This is why a piece of candy will cause a big spike in blood sugar like the red line in the diagram above. A fruit on the other hand does contain fibre will cause blood sugar elevations similar to that of the green line above. All fruits contain varying amounts of fibre, which slows digestion meaning that the blood sugar spike (glucose entering the bloodstream) is not as quick or highly concentrated.

It’s also worth noting that getting enough fibre can also help with:

• Preventing colorectal cancer,

• Preventing and managing diverticulitis/diverticulosis,

• Cholesterol lowering (both triglycerides and LDL),

• Helps with blood sugar management,

• Keeps bowel movements regular,

• Promotes satiety (i.e. feeling fuller longer),

• Aids in [some] hormonal regulation,

• Promotes a diverse and healthy gut microbiome

• Can help with gallbladder disease

• May help with Non-Alcoholic Fatty Liver disease

Are some fruits higher on the glycemic index?

Yes, but that does not mean we need to avoid that fruit simply for that reason. If you have normal blood sugar (glucose) control, you need not worry about the varying differences in glycemic index for certain fruits. Even those living with diabetes can consume those fruits - which, by the way there are only two in this category, watermelon and overripe bananas.

For more information in this check out the Glycemic Index Food Guide by Diabetes Canada

Here’s the thing, it's not only fiber that slows down digestion, absorption and subsequent blood sugar spikes, protein and fat play this role as well! This is one of the reasons why we aim to pair carbohydrate rich foods with foods that contain protein and fat (e.g. banana with peanut butter). This balancing act with macronutrients is what keeps us fuller and energized longer.

If I don’t already have you convinced that fruit is okay to eat and doesn’t have too much sugar here are 10 other reasons to consume fruit:

10 reasons why you should be eating more fruit:

1. Fruit provides you with energy making it an excellent snack option when paired with nuts, nut butters or yogurts.

2. Fruits such as citrus fruits, mangoes and kiwi offer Vitamin C which is an antioxidant meaning that it can help fight inflammation and has been shown to help decrease symptom severity and duration of cold and flu

3. All fruits contain phytochemicals which help to reduce inflammation, prevent cell damage and may even help to prevent cancer

4. Eating a variety of colourful fruits and vegetables may help decrease risk of developing cancers, diabetes, hypertension and heart disease (Stanford Medicine)

5. Fruits such as apples, pears and avocados are high in soluble fibre which can help add bulk to stool and lower LDL cholesterol

6. Many fruits offer potassium and magnesium which can help with muscle function and recovery and regular blood pressure

7. Fruits contain fluids that can help keep you hydrated

8. Fruit such as kiwi, pear, apple, grapes and berries are high in fibre and can help alleviate constipation

9. Many fruits are considered cultural staples and offer a sense of “home” and community when individuals have access to them

10. Some fruits such as apples, bananas and berries are great sources of prebiotics which are known to help support a healthy gut microbiome

BONUS REASON

1. Straight up, they’re delicious and that’s reason enough in my books!

Note: there are some medical conditions that require individuals to avoid certain fruits or limit their consumption. Grapefruit specifically can interact with many medications. If you’re concerned about fruit and a specific medical condition, talk to your doctor and Registered Dietitian.

Bottom Line

Fruits are highly nutrient dense. They do contain some sugar but as discussed in this article, not the type of sugar that we need to be concerned with. Fruits offer loads of health benefits and can be convenient snack options or tasty ingredients in meals. No, fruit does not have too much sugar.

References

[1] Qi X, Tester R. Is sugar extracted from plants less healthy than sugar consumed within plant tissues? The sugar anomaly. J Sci Food Agric. 2021 Apr;101(6):2194-2200. doi: 10.1002/jsfa.10905. Epub 2020 Nov 17. PMID: 33140445. https://pubmed.ncbi.nlm.nih.gov/33140445/

[2] Bantle JP, Raatz SK, Thomas W, Georgopoulos A. Effects of dietary fructose on plasma lipids in healthy subjects. Am J Clin Nutr. 2000 Nov;72(5):1128-34. doi: 10.1093/ajcn/72.5.1128. PMID: 11063439. https://pubmed.ncbi.nlm.nih.gov/11063439/

[3] Cohen DA, Sturm R, Scott M, Farley TA, Bluthenthal R. Not enough fruit and vegetables or too many cookies, candies, salty snacks, and soft drinks? Public Health Rep. 2010 Jan-Feb;125(1):88-95. doi: 10.1177/003335491012500112. PMID: 20402200; PMCID: PMC2789820. https://pubmed.ncbi.nlm.nih.gov/20402200/

[4] Diabetes Canada. Glycemic Index Food Guide

[5] Stanford Healthcare, Phytochemicals as part of You Cancer Diet

​​[6] World Health Organization, ISBN: 978-92-4-007359-3, Carbohydrate intake for adults and children: WHO guideline