Updated: Mar 11
What's the real difference between white rice and brown rice and why it's important to know the difference.
Rice is the world's largest food crop, providing the caloric needs of millions of people daily. There are two distinct types of domesticated rice, Asian rice or Oryza sativa, and African rice or Oryza glaberrima.
During the long-term domestication and cultivation, rice has evolved into 2 major ecotypes.
One (Indica) of which grows in tropical and subtropical regions, such as India, southeast Asia, and southern China; whereas the other type (Japonica) is mostly grown in temperate regions, such as east Asia, northern China, and southern Europe. (2)
Yes, even Europe. Italy is the largest rice production country in Europe. Nearly all rice varieties grown in Italy are japonica ecotype, being adapted to the temperate climate.
They likely originate from Northern China due to the close genetic relationship. (2)
Therefore, maybe the tales of Marco Polo having contributed to the introduction of rice in Italy may perhaps be true. (2)
Polished rice or white rice, which primarily consists of starch, is produced through a series of mechanized processes including hulling and milling, and it is the predominant type of rice consumed worldwide. (3)
It is the predominant type, but does that mean it is the most ideal type?
The difference between white rice and brown rice
What exactly is the difference between polished rice or white rice and unpolished rice or brown rice?
The darker color of brown rice is due to the outer bran layer and contains a host of vitamins and minerals.
Although there are differences between rice varieties, brown rice can roughly contain:
twice the amount of iron, zinc and vitamin B2;
over three times the amount of vitamin B3;
almost 6 times the amount of magnesium and vitamin B1;
up to 10 times the amount of vitamin E;
significantly more fiber;
These so-called phenolic compounds or phenols create responses in the body that are associated with anti-aging, anti-inflammatory effects and they have antioxidant and anti-proliferative activities. (6) Anti-proliferative is just a fancy way of saying it slows down tumor growth. At least in a petri dish.
That may all sound nice on paper, but a more important question is:
How does that carry over to the real world with actual people consuming this conglomeration or mishmash of nutrients?
Does polishing rice until it’s squeaky ‘clean’ have any negatives?
Risks of long term white rice consumption
Pooled data from a big meta-analysis, where a total of 350000 people were followed over the course of 4-22 years, suggest that higher white rice consumption is associated with an increased risk of developing type 2 diabetes in comparison with lower intake levels. (7)
Every serving of white rice was associated with an increased risk, which means the more white rice you eat the higher the risk of developing type 2 diabetes. In a fancy looking graph it looks something like this:
That thick green line shows an estimation how much more risk there is in relation to the quantity of white rice consumed. As consumption goes up so does the risk.
This association is stronger for Asian (Chinese and Japanese) populations than for Western populations, but they consume more rice in general. (7)
However, compared to another big meta-analysis from the United States, results were actually very similar.
The researchers estimated that replacing 50 grams/day (cooked, equivalent to ⅓ serving/day) intake of white rice with the same amount of brown rice was associated with a 16% lower risk of type 2 diabetes. (8)
What could be the reason for such a difference?
It could be because magnesium may lower risk of diabetes. It could also be because white rice lacks fiber, which allows the glucose in your blood to spike up more rapidly. Brown rice is absorbed at a slower pace, which results in a lower spike in blood glucose. (9)
Or it could be because of the improved insulin sensitivity you get from eating whole grain rice. (9), (10) We are not sure of the exact reason, because there are just so many more compounds in the whole grain version, that have potential protective effects.
The effects a single nutrient or component can have should not automatically be dismissed, but to only look at single nutrients here is not a good strategy.
I’m sure most people have heard of the brilliant soc..., football player, Lionel Messi. Apologies to my American friends, I tried my best there. Messi is an excellent player, but without a team he won’t truly shine on the field. Saying he is the only relevant player on the field would be an insult to his team.
In a similar way it would be an insult to the whole grain if we talk only about individual components. Although supplement companies would probably not mind if you stack up on magnesium while you continue to feast on white rice. Might as well buy some fiber along with it! That’s a win win… for supplement companies at least.
Although these study results are quite profound, the results could potentially be even more profound if we had groups of people go from eating white rice to brown rice to see if things improve and have people switch from brown to white to see if things worsen. Like in a 'cross-over clinical trial'. That would be pretty interesting right?
It so happens that the rice gods have blessed us with exactly that.
Switching from white rice to brown rice and vice versa
People that switched from white rice to brown rice improved on different levels. They lost some body fat as measured from hip and waist measurements, their blood pressure went down and the measured inflammatory marker also decreased.
When people made the switch from brown to white rice the opposite happened; they gained weight, their blood pressure went up and inflammation increased. (11), (12) Among obese people brown rice seemed to improve endothelial function as well, improving the ability for the blood vessels to dilate. (12) Endothelium is the inner lining of our arteries, that plays a pivotal role in regulating blood flow. (13)
Inflammation in this context isn’t the same as a local, acute inflammation everybody is familiar with where neutrophils migrate into injured tissue through diapedesis.
You know, like a wound that fills up with pus.
Here it means low-grade inflammation or systemic inflammation. Your whole body is involved. This kind of inflammation, over the long term (chronic inflammation), plays a role in the developing of chronic diseases like diabetes and cardiovascular disorders.
On top of that it increases the risk of depression, insulin resistance, certain cancers, such as gynecological, urological, and colorectal cancers and last, but not least, mortality. (14), (15), (16), (17), (18), (19), (20).
This kind of inflammation can be present in people with normal weight or a normal BMI, but it's more common among overweight and obese individuals, because the adipose or fatty tissue releases a host of inflammatory mediators; things that cause inflammation. (12), (14)
Since brown rice has significantly more nutrients and beneficial compounds in comparison to white rice, we could have anticipated at least some of these outcomes by having people switch from one rice to the other.
But how does that explain the weight loss?
Aren’t white and brown equal in calories?
If we compare an equal amount of weight of brown and white rice of the same variety, we can see that there is actually a difference.
As you can see, the difference doesn’t seem that big at first sight. Only 14 more calories for a big serving of white rice. But think about it in this way: That’s 5,7% more calories.
Imagine you eat one serving of rice daily. Then 5,7% more calories over time could allow you, in combination with the consumption of other foods that are less ideal, to gain weight gradually.
How often have you heard people say they slowly, but surely, seem to gain a tiny bit of weight every year. Maybe you can relate to that yourself.
Obviously white rice cannot be solely responsible for your weight gain, because there are other dietary components involved. Unless you eat heaps of rice every day. In that case it may play a significant role.
Maybe you consume rice so little, it’s not even relevant.
Even if this is the case, brown rice still seems a whole lot more favorable when we look at the bigger picture.
Although white rice looks inferior compared to it's whole grain older sibling, what about contamination?
Exposure to toxic contaminants in food is presumed to be one of the major public health challenges for the 21st century. Arsenic (As) is especially prevalent in the environment and can easily enter the food system through contaminated soil or water. (21)
Rice, unfortunately, can be easily contaminated with this substance, since it's grown in flooded plains where it can easily come in contact with contaminated water.
Rice has been shown to bio accumulate Arsenic at a much higher rate in comparison to some other grains. (22)
In our future articles about rice, we'll look what varieties of rice are most contaminated and less safe to eat and what varieties are least contaminated and safer to eat.
We'll also look into how different cooking methods can affect your exposure to arsenic absorption.