What is Lactose and Why Avoid It?

More of us read ingredient labels than ever, and one word that comes up a lot is lactose. Some people avoid it because it upsets their stomach, others because they eat plant-based. But what is lactose, why does it cause problems for some people, and do you really need to avoid it?

Here's what you need to know, and where a lactose-free protein powder fits in.

What Is Lactose and How Does Your Body Digest It?

Lactose is the natural sugar in milk and dairy foods.

To digest it, your small intestine makes an enzyme called lactase. Lactase splits lactose into two simpler sugars, glucose and galactose, which are absorbed into your bloodstream and used for energy.

Many adults make less lactase as they get older. That's called lactose malabsorption, and it's very common: about two-thirds of adults worldwide have it.²

What Is Lactose Intolerance?

When your body doesn't make enough lactase, undigested lactose moves into your large intestine, where bacteria ferment it. For some people, that causes symptoms like bloating, gas, diarrhea, nausea and stomach pain. That's lactose intolerance.¹

Not everyone with lactose malabsorption has symptoms. An NIH expert panel found that most people with lactose malabsorption don't have clinical lactose intolerance, and that many people who think they're lactose intolerant actually aren't.³ Most people with lactose intolerance can still have some lactose without symptoms.¹

Do You Need to Avoid Lactose?

Not necessarily. If dairy doesn't bother you, there's no need to avoid lactose. If it does, many people only need to limit it rather than cut it out completely.¹

One caution: people who avoid dairy can end up short on calcium and vitamin D, which matter for bone health.³ If you cut back on dairy, get those nutrients from fortified plant milks, leafy greens, tofu made with calcium, or a supplement if your doctor recommends one.

Lactose in Protein Powders

Whey is one of the most popular protein supplements in the world, and it comes from milk. Whey protein concentrate still contains some lactose. Whey isolate has most of the lactose filtered out, so many people with lactose intolerance tolerate it better, but it's still a dairy product.

If you're lactose intolerant, eat plant-based, or just want to skip dairy, a plant protein powder is naturally lactose-free.

What Else to Look for on the Label

Some lactose-free and dairy-based protein products include extra ingredients you may want to check for:

• Sweeteners like sucralose or stevia, used to make shakes taste sweet.
• Emulsifiers and thickeners like lecithin, carrageenan or gums, used for texture. Some research in mice has found that certain emulsifiers can disrupt gut bacteria and promote inflammation,⁴ though it isn't yet clear how this applies to people.
• Long ingredient lists in general. If you prefer simple formulas, compare labels.

fitppl's Optimal Plant Protein is made with 4 ingredients, organic pea and brown rice protein, vanilla and monk fruit, with no dairy, gums or emulsifiers.

Dairy-Free Milk Alternatives

There are plenty of plant milks to choose from. Hemp, cashew, almond, oat and soy milk all work well in coffee, smoothies and cereal. Look for unsweetened versions fortified with calcium and vitamin D.

How to make almond milk

Add a handful or two of raw almonds to a high-speed blender with enough filtered water to cover them by ½ to 1 inch. Blend on high for 3 to 5 minutes, then strain. For a little sweetness, add 1 or 2 medjool dates before blending. Homemade almond milk isn't fortified, so it won't have the added calcium and vitamin D of store-bought versions.

The Bottom Line

Lactose is the natural sugar in milk. Many adults digest it less well with age, but not everyone gets symptoms, and many people with lactose intolerance can still have some dairy.

If dairy doesn't agree with you or you eat plant-based, a lactose-free plant protein powder is an easy way to get your protein without the discomfort.