Not All Sugar Is Created Equal
An apple has as much sugar as a candy bar. Why is the apple’s sugar okay?
Science is clear that consuming too much sugar comes with some significant risks: A high-sugar diet contributes to health issues like obesity, diabetes, tooth decay, and even heart disease. Other research suggests that consuming too much sugar can lead to an increased risk for cancer, nonalcoholic fatty liver disease, and cognitive decline.
Despite the growing body of research suggesting its dangers, sugar is still a staple in the American diet. According to the USDA, more than half of the population consumes more than the recommended amount.
While it’s clear that sugar can negatively affect health, not all sugar is created equal. The main culprit in chronic disease risk is added sugar, like table sugar and high fructose corn syrup, rather than the naturally occurring sugars found in fruit. Technically, a piece of whole fruit and a candy bar are similar in sugar content: A medium-sized apple contains around 19 grams of sugar, while a Snickers bar has about 20 grams. But nutritionists say these two foods do very different things to the body.
For example, heart disease risk goes up with the percentage of added sugar you consume. According to one study that tracked participants’ added sugar intake and risk of heart disease for 15 years, individuals who consumed 25% or more of their daily calories as added sugar were more than twice as likely to die from heart disease, compared to participants whose diets included less than 10% added sugar. In contrast, a high-fruit diet is actually shown to reduce the risk of cardiovascular disease.
And because many foods with added sugar are higher in calories than other foods, Anastasia Snelling, PhD, chair of the Department of Health Studies at American University, says a diet high in added sugar can quickly lead to a calorie imbalance. “This overconsumption of calories can put someone in an overweight or obese category, which brings increased susceptibility to conditions like high blood pressure, diabetes, and heart disease,” she says.
According to Snelling, one main difference between added and naturally occurring sugars is the way the body breaks them down.
Fruit contains a natural sugar called fructose. Added sugar, like sucrose (table sugar), is much more rapidly digested than fructose in fruit. Rapidly digested sugar can lead to a spike in blood glucose levels, which can be detrimental for people with diabetes or anyone who’s sensitive to fluctuating blood sugar (like those with hypoglycemia).
While table sugar may be riskier for your health than, say, a bowl of fresh strawberries, highly processed sugars like high fructose corn syrup, a common sweetener found in processed foods and beverages like candy, juice, and soft drinks, are even more concerning.
According to the FDA, high fructose corn syrup comes from corn starch, which is a chain of simple sugar molecules joined together. High fructose corn syrup is made when the corn starch breaks down into individual sugar molecules. Snelling says the body metabolizes high fructose corn syrup differently than other sugars, so it can spike blood glucose levels even more—especially in people more sensitive to blood sugar swings, like small children or people with diabetes.
And since high fructose corn syrup is made to taste a lot sweeter than table sugar or fruit sugar, it can be harder to go back to less-sweet-tasting food later on, which could lead to a higher-calorie, higher-sugar diet over time, which in turn poses more health risks.
“High fructose corn syrup is villainized, and rightfully so,” Snelling says. “It’s very sweet, and some folks say it’s addicting. We become accustomed to the sweeter taste, and the lower-sugar items don’t appeal to us anymore.”
Another issue with processed sugars like high fructose corn syrup and table sugar is that they often come as an additive in already processed food, which has health risks of its own. Research shows that the consumption of highly processed foods, like cereals, soda, processed meat, and frozen meals, is linked to increased risk of high blood pressure, high cholesterol, and some cancers. Plus, to facilitate a sweeter taste, high fructose corn syrup is typically added in much higher amounts that you would ever find in fruit.
So, if a candy bar and a serving of fruit contain a similar number of calories and sugar, what makes the sugar from fruit so different?
Shannon Weston, MPH, RD, nutritionist supervisor of the Nourish Program at UTHealth’s School of Public Health, says the primary differentiator is the nutrients found in fruit. Yes, an apple may be high in sugar, but it also contains vitamin C, potassium, a good amount of water, and other important antioxidants.
“Fruit is a package deal that comes with other nutrients, like fiber, along with other beneficial vitamins and minerals,” Weston says, “while table sugar and processed sugar are empty calories, offering virtually no nutritional benefit.”
When it comes to the sugar issue, Weston says fiber is the most important ingredient. Since fiber (usually found in a fruit’s peel) drastically slows the digestion of sugar, eating an apple probably won’t lead to the same sugar spike as a rapidly digested candy bar or a can of sugary soda. This means even consuming 100% juice or applesauce without added sugar doesn’t come with the same benefits as a whole apple, since neither of these contain fiber.
“Any sugar that is accompanied by fiber will slow down digestion, since our bodies don’t digest fiber. The fiber basically cleans out your intestines, and then you excrete it,” Weston says.
“Fruit is a package deal that comes with other nutrients, like fiber, along with other beneficial vitamins and minerals, while table sugar and processed sugar are empty calories, offering virtually no nutritional benefit.”
Consuming sugar with fiber (as in whole fruits) can also lead to eating less sugar in general. Fiber makes foods more satiating, leading you to feel fuller, faster. So, while you can quickly plow through a pint of ice cream or bag of candy without necessarily feeling full, you’re unlikely to eat a whole bag of apples (or suffer any negative health consequences from the fructose in them).
If you’re concerned about overdoing it on natural sugar, you can slow the digestion of fruit even more — and feel fuller when you’re eating a fruit snack — by eating it with something else. Weston recommends pairing your fruit with a protein-rich food, like nuts, nut butter, meat, or cheese. This practice is especially important for diabetic individuals, who are at a higher risk for fluctuations in blood glucose when consuming any kind of sugar.
In general, Weston believes the benefits of fruits outweigh the potential risks of eating too much fruit sugar, and she would like to see Americans eat a lot more of them. “I want people to consume more whole foods, so I’m a huge proponent of people not being scared of the sugar in fruit,” she says. “You’re not going to get as much sugar from fruit as you would processed foods, and there are so many added benefits.”
Update: An earlier version of this article stated that high fructose corn syrup contains sucrose. It does not.