What Is Sugar?

• Sugar is a type of carbohydrate that comes in different molecular forms, like glucose, fructose, or sucrose.
• Glucose is a form of sugar and a vital energy source, especially for the brain.
• In general, it is healthier to eat the naturally occurring sugars found in fruits and vegetables than the added sugars in processed foods.

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Sugar can be a divisive word. While reducing excess sugar intake is important, it's essential to recognize that we also need sugars to survive. Let’s explore what sugar is, where it’s found, when we need it, and why it’s misunderstood.

What is sugar?

Sugar, in its simplest form, is a type of carbohydrate that the body uses as a primary source of energy. It comes in many molecular forms, but the most commonly discussed is glucose, which powers our cells and keeps vital functions going. Other common sugars are fructose and sucrose. Fructose is often known as “the fruit sugar,” and sucrose—better known as table sugar—is a molecule made up of one glucose and one fructose bonded together. We consume sugars naturally in fruits, vegetables, and dairy products, and in added forms like sweets, pastries, and sodas.

Unrefined sugars, like those found from sugarcane and date palm, “include a variety of bioactive compounds, minerals, fibers, antioxidants, and phytochemicals that help to decrease inflammation” (Arshad et al., 2022). For example, raw sugarcane juice contains phenolic food compounds, like flavonoids, that may have health benefits but are removed in the refining process. It is also only 10-15% sucrose, compared to the 99% sucrose in refined sugar.

When do we need sugar?

Sugar, especially glucose, is vital for energy production. Every time you eat, the body breaks down carbohydrates, converting them into simple sugars like glucose. Glucose is either used immediately for energy or stored in the liver and muscles as glycogen and triglycerides for future use. Our brain, which is only about 2% of our total body weight, uses around 20-25% of the glucose we consume (Herculano-Houzel et al., 2012). That's why we might feel tired or mentally foggy when blood sugar levels drop.

There are certain situations where sugars, especially glucose, are necessary:

• After exercise: When we engage in strenuous activity—especially endurance sports—our bodies deplete glycogen stores. Consuming sugar (or carbs in general) post-exercise helps replenish these stores quickly.
• During intense mental tasks: Sugar can be helpful during long periods of concentration or mental effort, as it ensures the brain has sufficient fuel to stay sharp.
• An example of this dynamic is the impact of low blood sugar, or “hypoglycemia,” on cognition. In a hypoglycemic state, people can struggle to make quick decisions, process information accurately, or stay alert.

Tip: This doesn’t mean you should grab a “sugary snack” like a candy bar to stay sharp. You can get glucose from complex carbohydrates like fiber, so grab a banana or some almonds instead!

Fun fact from ongoing research: The brains of children may use an even higher percentage of glucose to ensure proper development (Goyal et al., 2018).

Sugar isn't just about energy. Beyond fueling the brain and muscles, sugars play crucial roles in several biological processes. For instance, sugars are involved in cellular communication and DNA synthesis (Rodriguez-Emmenegger et al., 2019 and Mikkola et al., 2020).

When is sugar bad for us?

While sugar is important, it can also be harmful when consumed in excess. The main problem arises with added sugars—the sugars and syrups added to foods and beverages during processing or preparation.

Excessive consumption of added sugars can lead to a number of health problems:

• Weight gain and obesity: Added sugars, especially in sugary drinks, can cause calorie overload without providing much nutritional benefit. This can lead to weight gain (Malik et al., 2020).
• Increased risk of type 2 diabetes: Regularly spiking blood sugar levels with added sugars can contribute to insulin resistance, a precursor to diabetes (Meng et al., 2021).
• Heart disease: High sugar intake is linked to increased blood pressure, inflammation, and higher triglyceride levels, all of which contribute to cardiovascular problems (Morenga et al., 2014 and Narain et al., 2016).
• Tooth decay: Sugary foods and drinks promote the growth of harmful bacteria in the mouth, leading to cavities and dental problems (Moynihan et al., 2016).

The problem isn't sugar itself, but how much and what type. Naturally occurring sugars found in fruits and dairy products often don’t have the same magnitude of effect as the refined sugars in a candy bar or soda. When we consume naturally occurring sugars, we also receive the other nutrients in those foods like dietary fibers, which slow down sugar absorption and keep blood sugar levels stable.

Why is sugar misunderstood?

Sugar often gets a bad reputation, largely due to the rise in processed foods loaded with added, refined sugars. During the 1980s and 1990s, low-fat diets became popular, and sugar was often added to "fat-free" products to enhance flavor (Jahn et al., 2023). This led to an increased consumption of sugars, contributing to the misconception that "fat-free" equated to something being healthy, even when sugar content soared. And while this excess added sugar is not good for us, blaming sugar alone overlooks other factors like overall diet quality, physical activity, and lifestyle choices.

There is a tendency to lump all sugars together, failing to distinguish naturally occurring sugars in fruits and vegetables from refined sugars and syrups in processed foods. However, sugars are part of a healthy, balanced diet.

Embrace the benefits of sugar

Sugar, in moderation, is not the enemy. The key is consuming it in balance with your body's needs and opting for whole food sources of sugar over refined ones. Whole fruits, vegetables, and grains provide sugar in generally lower quantities than high-added-sugar processed foods, and alongside other important nutrients like fiber, vitamins, and minerals.

It’s important to note that glucose is an essential nutrient that powers the brain, fuels the body, and plays a crucial role in various physiological processes (Hantzidiamantis et al., 2024). You will still get glucose in low-carbohydrate and low-sugar diets. Widespread health issues arise in the overconsumption of added sugars and refined sugars in processed foods. Understanding where sugars are, what form they take, and the roles they play in the body are crucial to forming a balanced approach to nutrition.