Animal milk contains natural sugars which provide health benefits. Plant milks may contain added sugars. Anyone wishing to limit or avoid sugars should read nutrition labels and choose milk products carefully.

Mammals, including humans, produce milk to feed their young. Lactose is the sugar present in milk and is in most animal-based dairy products, including cow’s, goat’s, and sheep’s milk.

The sugars in milk are essential for health. Lactose is a critical nutrient that provides energy, helps with digestion, and confers a range of health benefits, from increased immunity to lowered risk for heart attack.

Although milk sugars provide health benefits, some people may need to limit their intake for health reasons like type 1 diabetes, or because they follow a diet that restricts sugar intake, such as the keto diet.

This article explores sugar in milk, and the levels in various types of milk. It then explains the health effects of sugar in milk and how people can avoid milk with added sugar.

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Sugar in milk provides energy for growth and development.

Milk is a dietary staple of people worldwide. It provides minerals like calcium and phosphorus, vitamin D, protein, fat, and other essential nutrients. It also contains natural milk sugar, or lactose.

Before the body can use lactose, it must break it down into simpler forms to absorb quickly.

The enzyme lactase breaks down lactose into smaller glucose and galactose subunits for the body to absorb.

Without this process, the nutrients from the milk would pass through the digestive system without the body absorbing them and using them for energy production.

People with lactose intolerance are unable to digest milk because they have a lactase deficiency.

The natural sugars in milk are its primary carbohydrate, and they give milk its slightly sweet taste.

Milk sugars are not the same as added sugars that provide only calories and no nutrients.

Added sugars contribute to weight gain and metabolic syndrome, which increases an individual’s risk of a range of health conditions such as heart disease, stroke, and type 2 diabetes.

In animal milk, lactose is the primary milk sugar. However, plant-based milks such as oat, rice, and soy milk may contain other sugars such as fructose or fruit sugar, glucose, or sucrose.

People should read the nutrition label carefully to ensure the milk does not have high levels of added sugar.

The sugar content of milk depends on the source and whether the manufacturing process adds sugar to the finished product.

Animal milk may vary in sugar content according to the animals’ diet and hormone status.

Below are the sugar levels in 240 milliliters (ml) or 1 cup of various types of milk:

The amount of sugar or lactose in human’s milk depends on the stage of lactation and whether the lactating parent gave birth at term.

Lactose in human’s milk ranges from 6.7 to 7.8 g per 100 ml, which works out to between around 16–19 grams per 240 ml, making human’s milk much higher in sugar than cow’s milk.

If an individual needs to limit their sugar intake, unsweetened almond milk is a good choice as it contains almost no sugar.

In comparison, rice milk contains comparable sugar to cow’s milk.

Milk products with added sugar can contain extremely high levels. For example, sweetened chocolate milk has 24 g of sugar per 240 ml serving.

The United States Department of Agriculture’s (USDA) dietary guidelines recommend that individuals limit their sugar intake to less than 10% of their total calories, which for most people means around 50 g of sugar each day, assuming a 2,000 calorie daily diet.

Lactose is the primary sugar in milk, which the body then breaks down to galactose and glucose.

Galactose is a crucial energy source and structural element in the body. As babies and young children grow, they need galactose for their central nervous system development.

The body also relies on glucose as a significant source of energy for the muscles and brain. After the body has used its energy, it stores any leftover glucose as glycogen in the liver and muscles.

Aside from its calorific value, lactose can also act as a prebiotic to support the healthy bacteria in the digestive system and help the body absorb calcium and magnesium.

Not all types of sugar have the same effect on blood sugar. Milk sugars have a low glycemic index (GI) score.

The GI score is a scale of 0–100 that shows how foods affect blood sugar. A lower GI score means that foods raise blood sugars more slowly than a higher score.

Cow’s milk has a GI index of 47, whereas almond milk has a score of 64, and some rice milk may be as high as 100.

If an individual needs to consider their blood sugar levels or has diabetes, it is advisable that they include lower GI foods in their diet.

People can avoid milk with added sugar by opting for unsweetened varieties.

Individuals must pay attention to the nutrition label, which identifies how many grams of sugar manufacturers have added to food products.

In the United States, the Food and Drug Administration (FDA) has updated the rules on food labeling. Each product must explicitly state the quantity of added sugar it contains.

In other countries, nutrition labels may not state added sugar. Instead, they may use one of the many alternative names for sugar, including:

  • corn syrup
  • high fructose corn syrup
  • corn sweetener
  • brown sugar
  • invert sugar
  • molasses
  • syrup
  • fruit juice concentrates

If someone needs to monitor their sugar intake, they should opt for unsweetened products or read nutritional labels carefully to understand the sugar content.

Milk contains, lactose, a naturally occurring sugar that provides essential health benefits.

Lactose provides crucial brain and body energy and can aid digestion.

For individuals who need to monitor their sugar intake, cow’s milk has a relatively low GI score and may contain less sugar than plant-based alternatives containing added sugars.

However, individuals should read nutritional labels carefully to understand if the milk contains added sugar, which can affect health.