There's a lot of hype about fructose and sugar floating around the media. The general public typically associate fructose with fruit, not knowing that most of our daily fructose consumption comes from non-fruit sources.
"HOW COME? ISN'T FRUCTOSE FOUND JUST IN FRUIT? I DON'T UNDERSTAND..."
Well, it is. Fructose makes up a portion of the carbohydrate in fruit. However, a majority of our fructose intake is not from fresh fruit, but from high fructose corn syrup and sucrose (found in soft drinks, processed foods, sweets and sadly in almost every bag or box).
What is more, we're not getting in only from high corn syrup or fructose (HFCS), but also when we're ingesting sucrose (since sucrose-table sugar, is made up of glucose and fructose).
THERE YOU HAVE IT, ECONOMIC ADVANTAGES!
Yea, the food manufacturing industry found a pretty cheap way to extract pure sucrose from sugar cane and high fructose syrup from corn. Since corn is cheaper than cane sugar, HFCS is cheaper to produce than sugar. That's why major soft drink manufacturers switched to HFCS as their primary sweetener.
Research is showing that total sugars contribute to 15 to 25% of energy intake in several European countries (the highest consumption being for children and teens). While there is no recommended threshold of appropriate intake for total sugars, there are recommendations about free sugars, set by WHO at 10%. *
THE FRUCTOSE ITSELF
Fructose is a monosaccharide, meaning it contains only one sugar group (thus they can't be broken down any further). Each subtype of carbohydrate has a different effect on the body depending on the structure and source (where it comes from).
The chemical structure affects how easily(quickly) the carbohydrate molecule is being absorbed (digested). The source of it affects whether other nutrients are provided along with the carbohydrate. For example, whole fruit and fruit juice.
As said already, whole fruit contains additional nutrients along with fibre, which affects digestion and absorption of the fructose. Moreover, the amount of fructose in the medium apple is much less than in average can of juice.
SHOULD WE BLAME SUGAR FOR OBESITY?
Well, I would say yes and no. In my opinion, obesity is a cause of multiple factors: poor eating habits, less activity and yea, sugar.
WHAT DOES THE RESEARCH SAY?
Based on the most recent studies, people should get no more than 50 g of added fructose per day. This includes sugar, high fructose corn syrup, juice, honey and other sweeteners. However, whole foods like fruit don't seem to contribute to the sugar problem because of their fibre, water and phytonutrient content.
Moreover, some healthy active people can have more than 50 g daily (usually the sedentary people are more at risk for metabolic disruption.)
WHAT DOES THAT MEAN IN REALITY?
ORANGE JUICE FOR A HEALTHY START IN THE MORNING
Like whole fruit, fruit juice contains some vitamins and minerals. That's good, right? But, there's a catch...
Despite a seemingly healthy choice, these vitamins and minerals come with a large dose of sugar and very little fibre. There can be just as much sugar in fruit juice as there is in a sugary drink like Coke.
The same is true for »Vitamin water«, flavoured water and bottled smoothies. A bottle of regular »vitamin water« contains about 32 grams of sugar.
Let's look at the fructose concentration and fructose to glucose ratio (sodas/sports drinks) in »most famous« beverages.
Fructose content in: Coca-Cola= 51 g/L; Pepsi= 42 g/L= Gatorade, 23 g/L.
As you can see, it's pretty easy to rack up sugar when you drink sweetened beverages. Now combine it with other sweetened , and you're above the limit in no time.
Another seemingly healthy choice are protein bars. While there are some good protein bars on a marker, there's also a wide range of those that contain around 30 grams of added sugar, making them similar to a candy bar.
Pre-Made soup is another food that you usually don't associate with sugar. When »home-made«, made with fresh ingredients, it's a healthy choice and can be a great way to increase vegetable consumption. However, many commercially prepared soups have a lot of added ingredients, including sugar!
Now, let's look at how an average person might eat in a day:
That's 174 grams of sugar! If most of that is table sugar, then about half of it is fructose (87 grams). What is more, some people might even consider it healthy, because after all, they chose the light, nonfat frappuccino and low-fat yoghurt...
The primary site of fructose metabolism is liver. In the liver, fructose can be converted to glucose derivates and stored as liver glycogen(which is good if you're a physically active individual). However, the liver's ability is limited. This means, the remainder will be stored as fat (this is much more pronounced in people with insulin resistance, high blood lipids or type 2 diabetes).
What is more, high intake of fructose can also fail to stimulate the production of leptin (leptin is a hormone that sends you those »I'm full« signals). This means you keep eating...
The higher up on the list the ingredient is, the higher its content in the product and watch out for a list of small amounts of different sugars, as that's another sign the product could be high in total sugar.
However, I don't want you to be anxious about fructose now! The goal of this post was to make you more aware. With whole minimally processed foods, it's a lot tougher to get that much fructose or sugar in general. Keep in mind, no matter which sweetener you choose, the real issue is quantity. If it makes up more than 5-10% of your diet, that's probably bad news for your health.
* Azaïs-Braesco, Véronique, et al. “A Review of Total & Added Sugar Intakes and Dietary Sources in Europe.” Nutrition Journal, BioMed Central, 21 Jan. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5251321/.