Dietitian’s Guide to the Health Benefits of Oats

You probably hear that oats are healthy all the time…but why? Let this registered dietitian teach you about all the incredible health benefits of oats, as well as how to use the different kinds of oats.

Beloved by grannies everywhere, rolled oats are more than just a cheap breakfast staple for when you blow your grocery budget on spin classes. I mean, what’s not to love about a scrumptious bowl of apple pie oats, or the ease of a nutrient-dense overnight oats?

As a dietitian, I love oats for their versatility, wonderful texture and yes, their nutrition.

Even without all the Instagram-worthy toppings, rolled oats are nutrient-dense and packed with research-backed health benefits that might have you giving these humble grains another look. Not convinced?

Read on for why oats are a true plant-based nutrition staple —and whether or not they’re actually gluten free. And if you need more support on your plant-based journey, consider picking up a copy of my nutrition-focused cookbook Eat More Plants!

Health Benefits of Oats
Why Soluble Fibre is Good For You
Are Oats Gluten Free?
A List of The Different Types of Oats
How to Cook Oats
Some of My Favourite Recipes with Oats

The Science-Backed Health Benefits of Oats

In the quest to eat more colourful plants, oats aren’t exactly the first food to come to mind. Don’t let that beige exterior fool you: oats are incredibly nutrient-dense. Whole grain rolled oats are known for phytochemicals called avenanthramides that have antioxidant, anti-inflammatory, and even anti-histamine properties. Ever take an oat bath to soothe your skin? That’s why it works.

1/2 cup of dry rolled oats – a typical serving – contains almost 8 grams of fiber and 6 grams of plant-based protein.

Oats also contain more vitamins and minerals than you might expect. A few of the big ones critical for those on a plant-based diet:

Iron: 1/2 cup of rolled oats contains 2.5 mg of plant-based iron that helps you build hemoglobin to oxygenates your tissues, supports immune function, and fights fatigue
Magnesium: calming to the nervous system, supports proper muscle contraction, and fights inflammation
Copper: maintains cellular energy, supports iron metabolism, and builds cellular antioxidants
Zinc: the same serving of oats contains about 1.5 mg of zinc – critical for wound healing, gut cell metabolism, and immune function
Phosphorus: an important structural component of bone (it’s not just about calcium!)
Potassium: 1/2 cup of rolled oats contains almost 400mg of heart healthy potassium!

And we can’t have a discussion about oats unless we talk about soluble fibre. Yep, the oatmeal story just gets sexier, doesn’t it?

Why Soluble Fibre Is So Good For You

It’s official: we need to eat more high fiber foods. Fiber is the part of plant foods our bodies can’t digest or absorb. It is the reason leafy greens have crisp cell walls and the reason oats form a sticky gel when cooked. Because you don’t digest and absorb fibre, it travels to your colon, where it gets fermented by bacteria, creating byproducts that keep us feeling amazing.

However, oats have a type of fibre that is not as common: soluble fibre, namely, beta glucan soluble fibre. Beta glucan does a whole bunch of amazing things you might not expect.

Helping control blood sugars: Soluble fibre is soluble in water (hence its name), forming a gel slows down stomach emptying and binds to glucose in our small intestine. The result? Slower glucose absorption into our bloodstream and more stable blood sugars and energy levels.

Reducing cholesterol: Our liver creates bile from cholesterol to help us digest and absorb the healthy fats we eat. Again, soluble fiber has a binding role: it binds bile in our small intestine, forcing bile to be excreted instead of getting recycled back to the liver. In order to make more bile, our liver has to pull more cholesterol out of the blood. The result? Lower blood cholesterol. Yay!

Keeping you fuller, longer: Oats are a nutritionally-balanced food with plenty of protein, fibre and slow burn carbohydrates. All of these things are known to be satisfying. However, soluble fibre helps slow digestion and absorption of nutrients in the gut. And if we are digesting slower, we should stay fuller, longer…and the evidence suggests that beta-glucan may be supportive of satiety.

Supporting growth of beneficial bacteria in the gut: If you want them to thrive, you need to feed your gut bacteria well. What do they want to eat? Fermentable FIBRE. (Surprise!) Bacteria ferment fibre, and create a host of byproducts such as short chain fatty acids that nourish our gut cells and support our immune system. Not all fiber is fermentable, beta glucan is.

Improving constipation: Yes. I’m talking poop. Being constipated sucks: if you’re not going daily, you need to do something about it. Oats help alleviate constipation by feeding beneficial bacteria, sweeping the gut clear, and adding weight to the fecal contents making them easier to pass.

Ta Da! Now you can go tell all your friends about the benefits of fibre. Just don’t do it at a dinner party, okay? Ha! Who am I kidding … I am the queen of inappropriate dinner party convo.

FAQ: Are Oats Gluten Free?

I promised to talk gluten — and I didn’t forget! Oats do not contain glutenin, the gluten fraction that causes autoimmune reactions in gluten intolerant folks. HOWEVER, most oats are cross-contaminated with gluten across every stage of production, from seed and grain storage to manufacturing.

So, on a gluten free diet, you must buy certified gluten free oats. These are specially grown and processed to ensure no cross-contamination. Happily, they are pretty easy to get these days.

In addition, if you’re celiac and are new to a gluten free diet, the Canadian Celiac Association recommends you lay off oats until your gut is healed. Why? Oats contain a protein called avenin, which some people with celiac disease may cross-react to. It’s NOT gluten, but it might aggravate those with gluten intolerance.

All the Different Types of Oats

Ever gone to the store and been totally confused by which oats to buy? While they are all still oats, the different varieties differ in texture and processing, cooking time required, and nutritional content (the less processing = slightly more nutritional value = longest cooking time).

First things first: all unsweetened oats are healthy. Don’t let anyone tell you otherwise.

Oats grow as an oat groat (the oat kernel). We don’t eat those very often, but you can actually cook them like farro or wheat berries. What we do to that oat groat produces the types of oats we use for oatmeal.

Here’s how the different kinds of oats are made!

Steel Cut Oats: these are the whole oat groat cut into pieces. They have a nutty/chewy texture, take the longest to cook and are a bit more nutrient-dense.
Rolled Oats (quick, old fashioned or thick): rolled oats are steamed and – you guessed it – rolled to increase surface area and decrease cooking time. The amount of rolling and steaming produces thick, old fashioned or quick rolled oats.
Instant Oats: these are rolled oats that are precooked, dried and chopped so can make oatmeal without cooking, just pour some boiling water and let them sit.

How to Cook Oats

If you’re making oatmeal, each variety of oats will differ in the water to oats ratio and cooking time. For each variety (except instant), you’re going to bring the water and oats to a boil. Then, turn down the heat to medium low, cover with the lid ajar and simmer for the specified time, stirring occasionally.

Here’s your cheat sheet to cooking a single serving of oats:

Steel-cut: 1/2 cup oats to 1 1/2 cups water; 25-45 minutes to prepare

Rolled oats: 1/2 cup oats to 1 cup water; 10-15 minutes to prepare

Quick cooking oats: 1/2 cup oats to 1 cup water; 2-5 minutes to prepare

Instant oats: 1/3 cup oats to 1/2 cup boiling water; 1 min to prepare

Love steel cut oats but don’t have time to prepare them? Try this genius method: boil oats for 5 mins the night before, turn off the heat and leave on the stove with the lid on. The next morning, you’ll wake up to fully cooked oats you just need to quickly reheat! Or, try my steel cut overnight oats recipe.