The most nutritious parts of almost all plants are their skins. Unfortunately with brown and white rice, you are basically eating the opposite of that... the skin (hull) is removed and you're just consuming the fibrous pulp from inside.
With red rice, its husk is fully or at least partly intact. For that reason alone right off the bat, you can make an educated guess that it will likely be healthier.
Given that the husk is intact, many would expect it to have a Glycemic Index lower than brown rice and quinoa but it's actually about the same. All have GI ratings between 50 and 55.
However there is one thing that separates the scarlet from the crowd. This test confirms its antioxidant benefits really are worth paying more money for, as it outranks all other rice varieties as well as ivory/white quinoa.
Where it comes from
Along the eastern Himalayan mountains bordering China is the Kingdom of Bhutan. It's a very small landlocked Asian country. In fact, it is one of the smallest countries on earth in terms of population; just 770,000 people as of 2015 (1). On the international scale they're not known for much, with one major exception; Bhutanese red rice.
Grown high up in the mountains at elevations of 8,000 feet, Bhutan is almost entirely responsible for growing the world supply of this crop. Major brands including Bob's Red Mill, Lundberg Organic, and Lotus Foods are said to purchase most or all of their red rice from this country. It is also cultivated in China albeit a smaller amount.
How its antioxidant content compares
When it comes to the most common nutritional values such as calories, carbs, and protein, all varieties of this grain measure out to be identical or very close to it.
The only way they differ is with vitamins, minerals, antioxidants, and glycemic index (GI). The latter however is largely determined by preparation methods. Rice that has to be cooked from scratch will have a lower glycemic rating and therefore is best for diabetics. All of the instant and quick cook varieties are that way due to processing; they were either partly cooked beforehand or they have tiny slits cut in them to speed up the cooking process.
Whatever the case, all of the faster cooking types - including instant red rice - will not be as healthy for you because they will have a higher glycemic index. The most nutritious are those which are the least processed and yes, that does mean more time on the stove-top cooking, but the benefits are worth the wait!
The leading methodology for testing how much antioxidants are in a food is a procedure called ORAC. It is a rather complicated series of tests which measures the total in vitro content of antioxidant activity found within 100 grams - or about 3.52 ounces - of a given food or beverage.
Here's a look at how red rice versus white rice measures for antioxidants, along with brown, black, and quinoa.
|Antioxidant Content Comparision (ORAC value in umol TE/100g)|
|Growth Stage||Red Rice||White Rice||Brown Rice*||Black Rice||Quinoa*|
|*values sourced from other studies|
Why red rice is so healthy for you is because of the anthrocyanins, which are a class of antioxidants that are responsible for the red, purples, and blue pigments in plants. It's the same thing that gives blueberries and goji berries much of their nutritional value. Unfortunately though, anthrocynanins do degrade when they are heated (1). Not a problem for fruits consumed raw, but definitely a drawback for foods you must cook, like rice.
Even when you take that into account, red rice is much better for you than white, brown, and black. Not only will you be getting exponentially more antioxidants (even after degradation), but the content for many minerals tends to be higher, too. According to Lotus Foods, one of the largest sellers of red in the United States, it contains significantly more magnesium and higher potassium than Gatorade.
One of the better GF choices
Most gluten free grains have a high glycemic index rating, which of course is bad for you even if you aren't diabetic. White and rice flours (even when they're made from brown) are the most common examples of this. Unlike those, red rice is a complex carbohydrate. With its skin intact, it takes longer to digest and spikes your blood sugar less.
How to cook
Black is very good for you too, but it takes a staggering 60 minutes to cook, assuming you haven't pre-soaked it. Most people simply don't have the time for that. How long you cook red rice for is only 20 minutes. That's a very reasonable amount of time and is actually the same as the unprocessed versions of brown.
Which rice is the healthiest to eat? Bhutanese red rice, without a doubt. Best of all, it's usually cheaper than both black and quinoa.
Shao Y, Xu F, Sun X, Bao J, Beta T. Phenolic acids, anthocyanins, and antioxidant capacity in rice (Oryza sativa L.) grains at four stages of development after flowering. Food Chem. 143:90-6. NIH Jan 2014