Lactose intolerance is a digestive issue most people are familiar with. Do you know the exact reason so many people have trouble digesting dairy?

Read on to learn about the critical role of lactase in this process. Below we will cover what exactly lactase is, what it does, and why we just can’t seem to get enough of it.

What Is It?

Lactase [1] is an enzyme, produced by and found in the small intestine. Typically, this enzyme is found in lower levels as we age. This is because its biological function was originally only intended for babies.

What Is Its Biological Role?

The one and only purpose of lactase is to break down lactose [2] so that it can be properly absorbed by our bodies. Lactose is the sugar found in milk, and therefore, in all dairy products. Lactose is a disaccharide, meaning it is composed of two separate sugars that are bound together to form the lactose molecule.

These sugars are glucose and galactose. Lactase is the only enzyme in our bodies that can sever the bond between these two monosaccharides. With the bond remaining intact, proper digestion is disrupted, which results in the condition commonly known as lactose intolerance. Lactase levels in our bodies drop as we age, because human lactase was evolutionarily intended to help infants digest their mother’s breast milk.

The idea was that, once children were weaned, they would follow in the footsteps of every other mammal on earth and cease to consume milk at all. We humans had a slightly different idea. The domestication of cattle meant that we started to consume their milk throughout our lifetimes, and transformed it into other dairy products such as cheese and ice-cream.

However, many of us still do not have the amount of lactase in our body needed to properly digest all the lactose we consume, which means we also miss out on fully absorbing any nutrients consumed at the same time as the lactose. This is why digestive aid lactase supplements were created, they temporarily increase the amount of lactase in your body, allowing you to digest dairy.

How Does It Help Bodybuilders and People Who Work Out?

Regardless of how you work out, most people who spend a lot of time in the gym know their way around a protein shake. They’ll have favorite brands, flavors, even blender bottles. Bodybuilders and competitive athletes in particular, tend to favor protein blends that contain casein or whey protein.

This is because these proteins are particularly suited for muscle growth. The downside is that they also come from dairy. Even though they are powdered, isolated forms of the protein, they still contain at least some lactose. Now, lactose intolerance occurs at varying levels.

Even if it isn't enough to make you feel like vomiting, minor lactose intolerance may keep you from getting the most out of your workouts and protein shakes by slowing you down and keeping you from absorbing all the nutrients you’re putting in your body.

This is why, if you consume dairy regularly and have a focus on optimal nutrition, it can be beneficial to take some lactase supplements when you consume dairy to ensure you are really reaping the benefits of your diet and exercise plan.

What Foods Contain It?

Lactase occurs only in our bodies, and in digestive enzyme supplements. It is something naturally produced by mammals to handle the digestion of lactose and so can only be found from the aforementioned sources.

How Much Of It Do You Need?

How much lactase your body uses depends on how much lactose it needs to digest. If you eat a lot of dairy, your body is going to need more lactase to break it down. There is no officially recognized recommendation for consuming lactase enzyme supplements--if you choose to do this to alleviate symptoms of lactose intolerance, the best advice is simply to follow the dosing directions on the packing of your chosen lactase supplement.[3]

Are There Risks Associated With Consuming Too Much Of It?

All else being equal, there is no known danger in taking too high of a dose of lactase supplements. Its only function is to act on lactose’s disaccharide bond so that your body can properly digest it.

However, always consult with your primary doctor to ensure this does or does not apply to you as well, only you and your doctor know what your body is capable of handling.

Are There Risks Associated With Consuming Too Little Of It?

Too little lactase in your body results in a condition known as lactose intolerance. Lactose intolerance results in unpleasant digestive distress whenever lactose is consumed, including nausea, stomach cramps, and diarrhea. Interestingly, this condition is technically quite normal.

Called Lactase Non-Persistence (LNP), your body’s sudden decrease in lactase levels is scientifically considered natural and an expected part of the weaning process all infants go through.

Most people are able to cope with moderate lactose intolerance by simply avoiding dairy and suffering the occasional stomach ache from accidental exposure. That stomach, though, does mean you miss out on digesting essential nutrients.

So if you are a fitness enthusiasts who relies on protein shakes to give you an edge at the gym, it may be time to consider lactase supplements.


[1] Wikipedia. Lactase., 2017.

[2] Pritchard, Joseph. What Are The Functions of The Enzyme Lactase?., 2015.

[3] WebMD. Lactase: Uses, Side Effects, Interactions and Warnings., 2015.