Which Milk Has the Highest Amount of Lactose?

November 7, 2025 •

3 min read

According to the National Institutes of Health, human breast milk contains more lactose than cow's milk. This might be surprising, but concentrated dairy products can contain even higher levels, so understanding which milk has the highest amount of lactose requires looking beyond the basic liquid varieties.

Quick Summary

This article explores the lactose content in different types of milk, revealing that concentrated forms like milk powder and condensed milk are the highest. It provides a detailed comparison of lactose levels in cow's, goat's, and human milk, clarifying common misconceptions.

Key Points

Concentrated milks have the most lactose: Dried milk powder, sweetened condensed milk, and evaporated milk contain significantly more lactose than fresh milks due to water removal.
Human breast milk is naturally high in lactose: It contains a higher concentration of lactose (7.5 g/100 mL) than cow's milk (around 5 g/100 mL).
Goat's and sheep's milks have varying levels: Sheep's milk has a slightly higher lactose content than cow's milk, while goat's milk has a slightly lower amount.
Fermentation reduces lactose: Cultured products like hard cheeses and yogurt have much lower lactose content because bacteria consume the lactose during fermentation.
Fat content can affect symptoms: The higher fat content in whole milk can slow digestion, potentially lessening the severity of lactose intolerance symptoms compared to skim milk.
Lactose-free milk is still dairy: Lactose-free dairy milk is created by adding the lactase enzyme to regular cow's milk, but it is not suitable for those with a dairy allergy.
Plant-based milks are lactose-free: Alternatives like soy, almond, and oat milk are naturally free of lactose.

Understanding Lactose and Lactose Intolerance

Lactose is a disaccharide (a type of sugar) found in milk and other dairy products. To be digested, it requires the enzyme lactase, which breaks it down into simpler sugars, glucose and galactose. Many people, an estimated 75% of the global population, produce less lactase as they age, leading to lactose intolerance. This can cause uncomfortable symptoms such as bloating, gas, and diarrhea when consuming lactose-rich products.

The Surprising Truth About Lactose Levels

While many people assume standard cow's milk is the highest in lactose, the reality is more complex. The highest concentrations are found in processed and condensed dairy products where the milk solids have been concentrated.

Which milk has the highest amount of lactose?

The surprising winner for the highest concentration of lactose is dried milk powder. During processing, the liquid is removed, leaving behind a highly concentrated powder of milk solids, including lactose. Following milk powder, condensed and evaporated milks, which have also had their water content significantly reduced, rank extremely high on the lactose scale. Among fresh, unprocessed milks, human breast milk and sheep's milk contain slightly higher lactose percentages per 100 grams than cow's milk, though the difference is not as dramatic as with concentrated products.

A Comparison of Lactose Content in Milk and Dairy Products

To provide clarity, here is a comparison table of different milk and dairy products, listing their approximate lactose content per 100 grams:


Product	Lactose Content (g per 100g)
Dried Milk Powder	36-52
Sweetened Condensed Milk	10-16
Evaporated Milk	12.7
Human Breast Milk	7.5
Sheep's Milk	5.1-5.4
Cow's Milk (Whole or Skim)	4.6-5.0
Goat's Milk	4.1-4.7
Plain Yogurt	4.0-4.8
Hard Cheeses (e.g., Cheddar, Parmesan)	<0.1 to 1

Factors Influencing Lactose Content

Several factors can influence the final lactose content of a dairy product. These include:

Processing: As shown with dried and condensed milk, removing water concentrates the lactose.
Fermentation: The fermentation process in cultured dairy products like yogurt and cheese significantly reduces lactose levels. The bacteria used in fermentation consume the lactose, converting it into lactic acid. This is why many people with mild lactose intolerance can tolerate yogurt and hard cheeses.
Species: Different mammals naturally produce milk with varying amounts of lactose. While human milk contains the highest, there is slight variation among ruminants like cows, goats, and sheep.
Fat Content: While not a major factor, some studies indicate that fat content can play a role in how the body processes lactose. One study showed that for lactose-intolerant individuals, symptoms were less severe with whole milk than with skim milk. This is thought to be because the fat slows down digestion, spreading the lactose exposure over a longer period.

What This Means for Lactose Intolerance

For individuals with lactose intolerance, understanding these differences is crucial. Simply avoiding milk might not be enough if a person is consuming other high-lactose products like condensed milk in baked goods or milk powder in protein shakes. Hard, aged cheeses are often well-tolerated due to their low lactose content, while soft cheeses and concentrated milk products can be triggers for symptoms.

How to Manage Lactose Consumption

For those who wish to reduce their lactose intake, several strategies can be employed:

Choose Lower-Lactose Options: Opt for fermented products like plain yogurt, kefir, or hard cheeses.
Use Lactose-Free Products: Most supermarkets now carry a wide range of lactose-free dairy products, including milk, cream, and yogurt. These products have been treated with the lactase enzyme, pre-digesting the lactose.
Try Plant-Based Alternatives: For those avoiding dairy completely, plant-based milks like soy, almond, and oat milk are naturally lactose-free.
Use Lactase Supplements: These over-the-counter supplements can be taken with meals containing dairy to help the body break down lactose.

Conclusion

In summary, while human breast milk has a higher natural lactose content than other fresh mammalian milks, concentrated products like milk powder and sweetened condensed milk contain the highest amount of lactose overall due to processing. For those with lactose intolerance, this distinction is vital for managing their diet. By opting for fermented dairy, lactose-free products, or plant-based alternatives, and by being aware of hidden lactose in concentrated products, individuals can control their lactose intake effectively. A careful approach allows many to continue enjoying the nutritional benefits and taste of dairy while minimizing digestive discomfort.

For more information on nutrition and health, consult with a registered dietitian or visit authoritative health sources like the National Institutes of Health.

Frequently Asked Questions

Human breast milk has the highest natural lactose content, containing about 7.5 grams per 100 mL, which is significantly more than cow's milk.

There is slightly less lactose in goat's milk compared to cow's milk. Goat's milk contains about 4.2% lactose, while cow's milk has nearly 5%.

Condensed and evaporated milks have a higher lactose concentration because a significant amount of water is removed during processing, leaving behind a more concentrated form of milk solids, including lactose.

Yogurt contains less lactose than fresh milk because the bacterial cultures used in its fermentation process break down a portion of the lactose into lactic acid, making it easier to digest.

No, the lactose content varies by cheese type. Hard, aged cheeses like Cheddar and Parmesan are very low in lactose, but softer, fresher cheeses like cottage cheese and ricotta can have higher amounts.

No. Lactose-free milk is still a dairy product made from cow's milk, so it should be avoided by anyone with a dairy allergy.

While lactose is a dairy sugar, it is often added during the processing of other foods, such as certain baked goods, processed meats, and dressings, so it's always important to check ingredient labels.