According to us fruits deserve the nickname “nature’s healthy fast foods” because they are generally affordable, accessible, and loaded with nutrients.
Unfortunately, the belief that fruit is healthy has been challenged mainly due to its high content of sugar relative to other foods, particularly of fructose the so-called “bad sugar”.
However, this thinking is both unfair and incorrect because the naturally-present fructose in fruits is not equal to the added fructose in processed foods.
Let us see the reasons to not fear fruits.
Fruit Rhymes With Fructose
The sugar fructose was so named because of its natural presence in fruits (“fru”=fructose=fruit sugar).
Fructose has been linked to the development of obesity, insulin resistance, diabetes, hypertension and fatty liver disease (1).
Fructose can indeed cause harm but this is dependent on the amount consumed. The dose makes the poison, as goes the saying. Being a published fructose researcher (4) I can attest to this.
Certainly, because fruits contain fructose doesn’t make them dangerous.
The fructose dose ingested from the recommended daily intake of fresh fruits is relatively small.
How is naturally-occurring fructose in fruits different from added fructose in processed foods?
Scenario A: Ingesting fructose from fruits
Let us take the example of apples.
One large apple contains 23g of sugar, 13g of which is fructose.
How many large apples can a person eat in one sitting? 2-3 at most before feeling full and satisfied. That’s about 39g of fructose.
Apples, like the majority of fruits, contains a lot of fibre which makes quite filling and difficult to overeat.
Importantly, the fibre also ensures that the fruits are slowly digested so that the fructose is slowly released and has time to be metabolised by the liver (5).
The liver is the main site where fructose is metabolised in the body after it is absorbed from the intestines. If too much fructose hits the liver rapidly, the liver starts to synthesise fats as a means to get rid of the excess fructose (6).
This is how a long-term high fructose diet can lead to fatty liver and the deposition of fat in other tissues like muscle leading to insulin resistance and diabetes.
With whole fruits, the is no such worry as the fibre ensures a slow supply of fructose to the liver to allow complete metabolism (7).
Scenario B: Ingesting fructose from soft drinks
Now contrast this with a 500ml bottle of soft drink which contains about 50g of sucrose, 25g of which is fructose (sucrose is 50% fructose and glucose bound together).
The soft drink, unlike whole fruits, has little effect on satiety so it is easy to overdrink. You can feel a little thirsty on a hot day and go for the whole bottle within an hour.
Besides, soft drinks (and clear fruit juices, as we will see below) are devoid of fibre.
The result is that the fructose hits the liver rapidly and the liver has no time to metabolise it. The result is an excess production of fats in the liver leading to the problems highlighted above.
“You cannot compare 20g of fructose from whole fruits with an equivalent dose from soft drink”
Let’s Not Forget the Other Goodies in fruits!
A. Nature’s Multivitamins & Minerals
Fruits are excellent sources of nutrients like vitamins, minerals, and bioactive compounds like enzymes, polyphenols and other phytochemicals, all of which can positively impact health (8).
A medium orange packs about 116% of your DV of Vitamin C and 10% of Folate.
Polyphenols are compounds found in fruits that have been associated with benefits like improved blood sugar control in diabetics (9), reduced DNA damage and improved cardiovascular health.
A diet rich in the polyphenol called flavonoids (e.g. 50ml/ day of pomegranate juice) significantly reduced blood pressure in hypertensives (10).
Another group of polyphenols called anthocyanins are abundant in dark-colored fruits like blueberry. Many studies suggest that increased consumption of anthocyanins lowers the risk of type 2 diabetes (11).
Fibre does more than just keep your bowel movements regular. Fibre has been found to contribute to reduced cholesterol levels, improved blood sugar control, increased satiety contributing to weight loss.
Something that you may not know about is that fibre also contains polyphenols locked in. These are called non-extractable polyphenols and are liberated by the action of bacteria in the intestines.
Fibre also serve as a source of food for beneficial bacteria in your intestines and beneficial bacteria make do more than just make B-vitamins as previously thought: they fight off harmful bacteria and produce mood-regulating hormones.
Getting Your Daily Fruit
Is Fruit Juice Okay?
While whole fruits are healthy, the same cannot be said for fruit juices
Juicing eliminates the fibre in fruits or greatly reduces the content and that’s the root of most of the problems with fruit juices.
A recent study reported that replacing blueberry juice with an equal amount of whole blueberries decreases the risk of developing type 2 diabetes by an astounding 33% (12).
Commercial fruit juices are worse because they often contain added colourants to make them more attractive, preservatives to extend the shelf life and added sugar to make them sweet.
You are invited to check our our post on whole fruits vs fruit juices.
What about Dried and Frozen Fruits?
Dried fruits have a higher concentration of fructose because the dehydration process concentrates the sugar.
Dried fruits are yummy and it is possible to overeat and ingest a high dose of fructose. These should be consumed in moderation.
Crystallised fruits are to be avoided as they are cooked in sugar and the sugar content can be astronomical.
Frozen fruits contain more or less the same amount of fructose as fresh fruits.
Freezing may be a good option for keeping your fruits for a longer time. Frozen fruits lend themselves well to smoothies and are a great way to load up on micronutrients and fibre.
Recent studies have shown that freezing preserves most vitamins better than storage at room temperature and refrigerating (13)
Veeraj Goyaram, MSc (Med) Exer. Sci (UCT) cum laude,
BSc (Hons) Biology with Human Nutrition
Veeraj’s passion revolves around researching and developing nutritional products for optimal health and performance, with a particular interest in sports, child and diabetic nutrition products. Veeraj was previously based as a graduate student at the University of Cape Town, where he examined the effect of exercise and nutrition on the function of genes in muscle. His research was published in renowned scientific journals and medical textbooks on Diabetes and Exercise (PubMed listing). Veeraj keeps healthy by regularly lifting weights and taking daily walks.