Main differences between added sugar and fruit sugar explained
Fruit is often labelled as "full of sugar" but is it the same as the sugar found in cakes, chocolate and soft drinks?
You've undoubtedly heard claims that fruit is "full of sugar" and that it contains the same sugar found in cakes, chocolate and fizzy drinks. You may also have encountered so-called health influencers suggesting you should avoid fruit, or at minimum restrict your consumption, for this very reason.
But what's the truth? Is fruit sugar identical to added sugar and do they affect your body and weight in the same way? A prominent heart surgeon is among those who have recently tackled the question. Dr Jeremy London was asked whether the two sugars are identical.
Dr London, who holds board certification in general surgery, vascular surgery and thoracic surgery, and regularly shares guidance through social media and interviews, said: "Chemically, the sugar is identical. An apple has sugar, a glazed doughnut has sugar, but the way we metabolise those two things is completely different.
"An apple has fibre, it has water, polyphenols, antioxidants. These things slow the digestive process and affect how your body is processing the sugar.
"Now, when I say whole fruits, I do mean whole fruits, because with fruit juices and dried fruits you lose these components.
"Whole fruit is more satiating, calorie for calorie, than sugary drinks or processed sugar. In the end, sugar is sugar but what it comes with makes a tremendous difference."
What is sugar?
Sugar is a form of carbohydrate that supplies energy (in the form of calories) from the food and drink we consume.
Without delving too deeply into the science, there are two subcategories of sugar: monosaccharides and disaccharides.
The former encompasses glucose, fructose and galactose, which occur naturally in fruit. The latter includes lactose, which is present in dairy products.
What's the difference between fruit sugar and added sugar?
Harvard Medical School concurs with Dr London that "an increasingly important distinction among sugars as they pertain to health is whether they occur naturally in foods such as fruit, vegetables, and dairy, or whether they are added sugars (added to foods and beverages during manufacturing, processing, or preparation)".
The primary sources of added sugars in our diet are fizzy (or soft) drinks (which have previously been labelled "liquid death" because of their impact on health), confectionery and breakfast cereals.
A considerable number of these foods fall within the ultra-processed food category, many of which offer little nutritional value alongside the added sugar.
Fruit, on the other hand, contains a wealth of nutrients that deliver numerous positive health benefits and help reduce the risk of serious conditions such as heart disease and cancer.
Harvard Medical School states: "Natural and added sugars are metabolised the same way in our bodies.
"But for most people, consuming natural sugars in foods such as fruit is not linked to negative health effects, since the amount of sugar tends to be modest and is 'packaged' with fibre and other healthful nutrients.
"On the other hand, our bodies do not need, or benefit from, eating added sugar."
Why is added sugar harmful?
Consumption of added sugar has been linked to weight gain, which consequently increases the risk of type 2 diabetes, cancer and cardiovascular disease. It is also responsible for tooth decay.
However, this doesn't mean added sugar must be eliminated entirely from your diet. Moderate consumption is perfectly acceptable.
The NHS advises that added sugars "should not make up more than 5% of the energy (calories) you get from food and drink each day."
For instance, this means adults should consume no more than 30g of free sugars daily (approximately equivalent to seven sugar cubes).
What qualifies as added sugar?
The NHS excludes naturally occurring sugars found in milk, fruit and vegetables from its definition of added sugars (termed "free" sugars).
Added sugar encompasses the obvious culprits, such as white and brown sugar granules, sugar incorporated during food processing, honey and syrups, as well as fruit juices and smoothies.
While many have long considered fruit juice and smoothies to be wholesome choices, experts warn that the juicing process diminishes the fruit's nutritional benefits and causes the sugars to enter the bloodstream more rapidly, triggering blood sugar spikes and inflammation.
Some specialists suggest that consuming large quantities of fruit juice may prove detrimental to liver health.
Does sugar cause cancer?
Another widespread health misconception is that sugar directly causes cancer. However, nutritionist Nichole Andrews clarifies that this simply isn't accurate: "As a cancer dietician, let me clarify: sugar all on its own will not cause cancer [or] have your cancer grow quicker.
"If you have a diet high in sugar, you're probably going to have excess calories... and then you're going to gain weight, gain fat tissue and it's the fat tissue that increases cancer risk."
Only two foods are known to directly cause cancer and they are very common — you can read what they are here.
