Oat Milk vs. Rice Milk – Is One Healthier?

As the demand for dairy alternatives continues to rise, plant-based milk alternatives have exploded. Oat milk is one of the most popular with newcomers to the dairy-free lifestyle, but rice milk is a classic with a dedicated fan base. When choosing between oat milk vs. rice milk, how can you determine which one is right for you?

In this post, I’ll discuss the nutrition profile, health benefits and risks, sustainability, and culinary uses of these two non-dairy milk options so that you can make the most informed decision on which best meets your needs.

What is oat milk?

Oat milk is a popular non-dairy milk alternative made by¹ mixing oats with water, adding enzymes to break the natural carbohydrates down into smaller sugars (a process called “hydrolysis”), and using heat to kill any bacteria. Many brands also fortify their oat milk with vitamins and minerals to improve its nutrition profile.

The process may vary slightly depending on the brand. For example, not all brands use hydrolysis to break the carbohydrates down into simpler sugars.

What is rice milk?

Rice milk is produced very similarly to oat milk, which makes sense considering they’re both grain-based beverages. Commercially available rice milk is made either with brown or white rice, depending on the brand.

To produce rice milk, rice is blended with water. Like many brands of oat milk, rice milk can also undergo hydrolysis in which enzymes are used to break the carbohydrates into smaller, starchier pieces. 

Rice milk may also be fortified with vitamins and minerals, with the types and amounts varying depending on the brand. 

Oat milk vs. rice milk nutrition 

To demonstrate how oat milk and rice milk stack up nutritionally, let’s compare two of the most popular brands: Oatly Original Oatmilk and DREAM Original Classic Ricemilk.

Oat milk and rice milk are both plant-based alternatives to dairy milk made from grains and as such are rich in carbohydrates. 

Per cup, oat milk is higher in protein, fat, and dietary fiber compared to the same amount of rice milk. Rice milk contains more carbohydrates. Oat milk and rice milk are about equal in calories.

Calcium and vitamins A, D, and B12 are often added to oat milk but are notably missing in DREAM Original Classic Ricemilk. Of course, these are only two products out of many options. The amounts of these micronutrients will vary based on how much a brand decides to add to its products, so be sure to read the nutrition facts label for each non-dairy milk.

Note that DREAM also makes an enriched version of their Original Classic Ricemilk, which contains calcium and vitamin D. It isn’t fortified with vitamin B12.

Unfortunately, neither oat milk nor rice milk are very good sources of protein. Soy milk, pea milk, and non-dairy milks with added pea protein are the best high-protein plant-based milks, so I typically recommend that vegans use one of these as their primary non-dairy milk. 

Ingredients

The ingredients in Oatly Original Oatmilk are: 

Oat base (water, oats). Contains 2% or less of: low erucic acid rapeseed oil, dipotassium phosphate, calcium carbonate, tricalcium phosphate, sea salt, dicalcium phosphate, riboflavin, vitamin A, vitamin D2, vitamin B12.

DREAM Ricemilk Original Classic has the following ingredients:

ORGANIC RICEMILK (WATER, ORGANIC HYDROLYZED RICE), ORGANIC CANOLA OIL AND/OR ORGANIC SUNFLOWER OIL, SEA SALT.

These non-dairy milks have similar ingredients, with both containing their respective grain (oats or rice), canola oil (rapeseed oil is the same as canola), and salt. The main difference is that this oat milk is fortified with extra vitamins and minerals, including potassium, phosphorus, calcium, riboflavin (vitamin B2), and vitamins A, D, and B12. 

Neither product contains sweeteners as an ingredient. The added sugars on the label refer to the hydrolyzed oats and rice. Remember that this process breaks down the natural carbohydrates into simpler sugars, and these sugars act the same way as cane sugar or other sweeteners in the body. Because of this, the FDA² requires that they be labeled as added sugars.

Of course, these are just two examples. Other types of oat or rice milk don’t use the hydrolysis process, and would list zero added sugars on the nutrition facts label. On the other hand, flavored products like chocolate oat milk may contain extra added sugars from sweeteners like cane sugar. 

Health implications

Bone health

Adequate consumption of calcium and vitamin D is crucial for maintaining strong bones and teeth and preventing osteoporosis as we age.

While calcium is present in many plant-based foods, it can be difficult to get enough as a vegan if your diet isn’t balanced and doesn’t prioritize these foods.

Vitamin D is naturally lacking in plant-based foods (besides irradiated mushrooms), and it can be difficult to produce enough from sunlight if you wear sunscreen (recommended to prevent skin cancer), live in an area without much sun, don’t spend enough time in the sun, or have a darker skin tone. 

It’s easier to find oat milk that is fortified with calcium and vitamin D, which makes it a better choice for your bones. The best thing to do is to check the nutrition label on any oat or rice milk product you’re considering and make sure they’ve been fortified with calcium and vitamin D.

Vitamin B12 deficiency

Vitamin B12 is naturally lacking in plant-based foods. Foods and beverages that are fortified with B12 can help vegans avoid the severe neurological impairments that can result from a B12 deficiency.

As with calcium and vitamin D, it’s usually easier to find oat milk fortified with vitamin B12. We saw earlier that the most popular brand of rice milk (DREAM) doesn’t contain vitamin B12, so oat milk may be a better choice for vegans.

Good for lactose intolerance

Oat milk and rice milk are both lactose-free, making them safe choices for vegans and people with lactose intolerance.

Arsenic content

A recent health concern about rice milk and other rice-based products is its arsenic content. Arsenic is a naturally occurring compound in the earth’s crust and is present in soil, air, and water. It’s toxic in its inorganic form and long-term exposure has been linked to skin lesions and skin cancer, according to the World Health Organization³.

A 2014 study⁴ tested many brands of rice milk and found that, on average, the arsenic content of these beverages ranged from 2.7 to 17.9 micrograms per liter (mcg/L). Some of these brands contained more arsenic than the limit for drinking water set by the EPA, WHO, and EU, which is 10 mcg/L.

This aligns with the results of a 2008 study⁵ that tested rice milk in the UK and determined that the concentration of inorganic arsenic in 80% of their samples exceeded the 10 mcg/L limit for water.

Since rice milk isn’t classified as water, it isn’t held to this limit. If arsenic present at these concentrations in water poses a health risk, the same could be true for rice milk. That said, humans drink a much higher volume of water over their lifetimes than non-dairy milk, so it isn’t clear whether the levels of arsenic in rice milk are high enough to cause problems.

Culinary uses

Oat milk has a pleasantly creamy texture and a slightly sweet flavor. It works well in hot beverages, froths nicely for lattes, and adds creaminess to smoothies, soups, and baked goods.

Rice milk has a thinner, more watery texture than oat milk and tastes sweeter. Its thin consistency makes it a great choice for recipes where you don’t want a strong flavor or where you need moisture without creaminess.

Sustainability

It has been scientifically established that plant-based milk of any type is better for the environment than cow’s milk in terms of land use, water use, and carbon footprint, so both oat milk and rice milk are good options for people concerned about the environmental impact of their food choices.

Between the two, oat milk has the advantage in terms of greenhouse gas emissions. 

According to a 2022 study⁶, the greenhouse gas emissions in gram carbon dioxide equivalents associated with the production of a 6.8-ounce glass of cow’s milk, rice milk, and oat milk are as follows:

• Dairy milk: 213 CO₂ equivalents
• Rice milk: 149 CO₂ equivalents
• Oat milk: 60 CO₂ equivalents

While both plant-based beverages fare better than dairy, oat milk comes out on top.

How to choose between oat milk and rice milk

Choosing between oat milk and rice milk ultimately comes down to personal preferences and dietary considerations. Here are a few factors I recommend considering when making your decision:

1. Fortified with calcium, vitamin B12, and vitamin D. Choosing fortified non-dairy milk is one of the easiest ways for vegans to get enough calcium and vitamin D to support bone health and vitamin B12 to prevent neurological issues. Oat milk seems to be fortified with these nutrients more often than rice milk.
2. Sustainability. While both oat and rice milk are more environmentally friendly than dairy milk, the production of oat milk has a smaller carbon footprint than rice milk.
3. Arsenic content. Rice milk is particularly high in inorganic arsenic, which is toxic when consumed long-term in high amounts. While it isn’t clear whether drinking rice milk contributes too much inorganic arsenic to the diet, it may be best to alternate or choose other non-dairy milks more often just in case.
4. Taste and texture. Oat milk generally has a creamy and slightly sweet taste, similar to dairy milk. It has a smooth texture that works well in coffee, tea, and cereal. Rice milk, on the other hand, has a thinner consistency and a slightly sweeter taste. Some people prefer the lighter flavor of rice milk, while others enjoy the creaminess of oat milk.
5. Allergies and food intolerances. Oat milk is made from oats, which are naturally gluten-free. However, cross-contamination during processing is possible, so if you have gluten intolerance, look for certified gluten-free oat milk. Rice milk is naturally gluten-free and should be safe for those with Celiac disease or Non-Celiac Gluten Sensitivity. If you’re allergic to oats or rice, you should obviously avoid these options.
6. Culinary uses. Think about how you plan to use your plant-based milk. Oat milk tends to work well in hot beverages, froths nicely for lattes, and adds a creamy texture to recipes like smoothies, soups, and baked goods. Rice milk’s lighter texture makes it suitable for recipes where you don’t want a dominant flavor, such as in some desserts or sauces.
7. Age of the consumer. If purchasing for toddlers and young children, keep in mind that neither oat milk nor rice milk is considered an appropriate milk alternative due to their low protein content. Fortified soy milk, pea milk, and non-dairy milk with added pea protein are recommended instead.

Summary

As a dietitian, my first consideration is always nutrient density. If you’re looking for the healthiest choice between oat milk and rice milk, I give oat milk a slight edge. Oat milk tends to be fortified more often with calcium and vitamins D and B12 and is much lower in arsenic, which may be prudent to limit in non-dairy milk. It also has fewer greenhouse gas emissions than rice milk.

Unfortunately, neither oat milk nor rice milk provides much protein. For this reason, I recommend that vegans use fortified soy milk, pea milk, or non-dairy milk with added pea protein most often. This can make a meaningful difference in the nutrient density of your diet with minimal effort! If you’re already meeting your protein needs, however, fortified oat milk or rice milk can still provide healthful nutrients.

Ultimately, the best way to decide between oat milk and rice milk is to give both a try and see which one you prefer in terms of taste, texture, and how well it fits your dietary needs and preferences. If you need more guidance on choosing a non-dairy milk, check out A Vegan Dietitian’s Guide to Non-Dairy Milk.

And before you go, check out my post comparing Oat Milk vs. Coconut Milk if you want to see how oat milk stacks up to another popular milk alternative.

FAQs – Oat Milk vs. Rice Milk

What is healthier than oat milk?

Oat milk is often fortified with helpful nutrients like calcium, vitamin D, and vitamin B12, but is low in protein and may contain added sugars due to the hydrolyzed oats. Soy milk and pea milk are higher in protein and don’t use hydrolysis, so unsweetened versions are free from all added sugar. If fortified, they also contain calcium, vitamin D, and vitamin B12.

What non-dairy milk is healthiest?

The healthiest non-dairy milks are fortified with calcium, vitamin D, and vitamin B12 in order to mimic the micronutrient content of dairy. Soy milk and pea milk are the highest in protein, so choosing fortified versions as your primary non-dairy milk is a good choice for most people.

Is oat milk or rice milk better?

Oat milk is a better choice for many people as it is more often fortified with calcium, vitamin D, and vitamin B12 and is lower in arsenic than rice milk. Its production also results in fewer greenhouse gas emissions. If you need non-dairy milk with a thinner consistency and milder flavor, however, rice milk may work better for you.

The scientific information in this article was accurate at the time of publishing but may change over time as new research becomes available.

References

1. Oatly, Inc. Our process. https://www.oatly.com/stuff-we-make/our-process. Accessed May 24, 2023.
2. U.S. Food and Drug Administration. Guidance for Industry: Nutrition and Supplement Facts Labels Questions and Answers Related to the Compliance Date, Added Sugars, and Declaration of Quantitative Amounts of Vitamins and Minerals. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-nutrition-and-supplement-facts-labels-questions-and-answers-related-compliance. Accessed May 25, 2023.
3. World Health Organization. Arsenic. https://www.who.int/news-room/fact-sheets/detail/arsenic. Accessed June 6, 2023.
4. Shannon R, Rodriguez JM. Total arsenic in rice milk. Food Addit Contam Part B Surveill. 2014;7(1):54-56. doi:10.1080/19393210.2013.842941
5. Meharg AA, Deacon C, Campbell RC, et al. Inorganic arsenic levels in rice milk exceed EU and US drinking water standards. J Environ Monit. 2008;10(4):428-431. doi:10.1039/b800981c 
6. Singh-Povel CM, van Gool MP, Gual Rojas AP, Bragt MCE, Kleinnijenhuis AJ, Hettinga KA. Nutritional content, protein quantity, protein quality and carbon footprint of plant-based drinks and semi-skimmed milk in the Netherlands and Europe [published online ahead of print, 2022 Feb 23]. Public Health Nutr. 2022;25(5):1-35. doi:10.1017/S1368980022000453