Why Whole Wheat Bread Is Not Healthier Than White
By Jay Wiener
Founder & CEO, WeightZone Factor
Everyone knows that whole wheat bread is healthier than white bread, right? Everyone except me.
There are two traditional reasons to choose whole wheat over white. The small reason: whole wheat flour has important nutrients that have been processed out of white flour. The large reason: white flour makes your blood sugar spike quickly and then crash; whole wheat doesn’t. Everyone knows this. Is everyone wrong?
Back in the nineties, I wrote an article making a then-preposterous claim: fruit is fine on a low-carb diet. I reasoned, “fruit juice is clearly unhealthy–the sugar is absorbed into the blood stream faster than candy. However, raw fruit takes hours to digest, so its sugars trickle into the body slowly, without much impact.”
No one wanted to publish the article. The idea was too far from mainstream thinking, and more important, there was no research to back up my theory.
Regardless, I thought my logic was irrefutable (massive ego, folks), so I kept the article in my computer. For twenty years. In 2015, I rewrote that article. I finally had proof: original research published in the British Medical Journal scientifically proved the obvious: whole fruit is fine on a protein-centered diet.
Time to try again–with wheat. A few weeks ago we had dinner in San Francisco, in a restaurant that makes Disney World look like a non-profit charity. They served freshly baked San Francisco Sour Dough, one of the finest artisanal breads in the country. One of the finest white breads. While trying to talk myself into having a slice (okay, a second slice), I started thinking about white flour versus wheat.
Do We Need the Additional Nutrients in Whole Wheat?
If the nutrients processed out of white flour are irreplaceable, how come so many people live healthy, happy lives without consuming any wheat at all? People on gluten-free diets, Atkins, the Paleo Diet, et cetera, live with little or no wheat and stay healthy, so there are no irreplaceable nutrients in wheat. That said, what’s wrong with a healthy diet that includes some white bread?
The answer is easy. Everyone knows that white flour makes your blood sugar spike up and then collapse. Lucy the Australopithecus knew that. But…
An intact kernel (berry) of wheat has three parts: bran, germ and endosperm. If you eat a whole wheat berry, your teeth will crack it, then your stomach will reduce it to a pasty mess before it travels through your gastrointestinal tract. Some of the nutrients will slowly leach out, some will not, and your blood sugar levels will not be affected. Clean and simple. Well, simple.
Flour is different. Flour particles are vanishingly small: 0.5 to 10 microns. (If you put ten or twenty thousand flour particles in a row, your row will only be about an inch long.) Whole wheat flour consists of micron-sized particles of endosperm, bran or germ. White flour particles are mainly endosperm; they have all the carbs but little fiber, vitamins or other nutrients.
Now, here is the part that most people miss: Whether flour is whole wheat or white, each individual particle is pure: pure bran, pure wheat germ or pure endosperm. When particles of endosperm pass through the intestines, they are quickly converted into glucose, a basic sugar. It doesn’t matter if the original flour was whole wheat or white; it is converted and absorbed at the same speed. This means that whole wheat bread and white bread should have identical effects on blood sugar. Also, the bran and wheat germ do not have any nutrients that aren’t easily obtainable elsewhere. What’s so special about whole wheat?
Anyway, that was my theory over the dinner table, or at least my excuse for having another slice of sourdough. (It worked.)
But everyone knows that whole wheat bread is healthier than white bread. Every article on nutrition written during the last 50 years says so. So I decided to look for the original studies, to learn why my theory was wrong.
I couldn’t find any.
I tried Google, and then Bing, and finally PubMed–the best source for original medical research studies. I did not find a single study showing that the nutrients in whole wheat flour are difficult to obtain from other sources, or that white flour affects blood sugar differently than whole wheat flour does. I did find two small studies from the 1980’s, but each one tested fewer than 20 people. Meaningless. However, I did find an endless list of copycat articles about nutrition claiming that “everyone knows that whole wheat bread is healthier than white bread.” Without proof.
Is there Proof that Whole Wheat Bread Is Not Healthier Than White?
Is it possible that no one has ever proven the most popular claim in modern nutrition?
But wait! How about the Glycemic Index? Doesn’t that prove… something? Two things. First, according to Harvard Heath, whole wheat and white bread have about the same glycemic index: 71 and 73. Second, the Glycemic Index sucks carbs. It is a miserable metric; according to Wikipedia, researchers separated out carbohydrates from foods and then tested the carbohydrates, not the actual foods we eat. They measured how high blood sugar rises in response to eating those carbohydrates, but not how rapidly it rises and falls in response to actually eating the foods themselves. Useless.
The Glycemic Load is a better number, but not by much. Unlike the glycemic index, it considers realistic portions of food; however, both the GI and the GL were computed using just a few test subjects held under strictly controlled, completely unrealistic laboratory conditions. The results have little to do with the real world. And one last thing: the glycemic loads of both types of flour are almost identical–and very low. The effect on your blood sugar is the same.
So Here’s My Surprising Conclusion:
Everyone knows that whole wheat bread is healthier than white bread, and everyone is wrong. Whole wheat bread is not healthier than white.
If you are going to eat wheat products, there is no reason to avoid white flour. Just follow certain basics:
- Read the ingredient label–many breads are loaded with sugars, preservatives and other unnecessary additives. Just like dog biscuits.
- Don’t make white flour a major part of your diet–eventually, you will miss the various nutrients that were processed out.
- Don’t make whole wheat a major part of your diet, either–save room for all of the grains: oats, rice, corn, et cetera. And yes, whole grains are healthier if grains are a major part of your diet. If you are a vegetarian, whole grains are a better choice. If you follow a protein-centered program and eat grains just a few times a week, relax and enjoy whatever you select.
And if you’re lucky enough to get some freshly baked, artisanal San Francisco Sour Dough bread, eat as much as you can, as fast as you can, before someone else eats it first. Everyone knows that.
Have Something to add?
One last note: If you know of any original research about the effects that whole wheat and white breads have on blood sugar, please let me know about it in the comments.
About Jay Wiener
Jay is both a professional mathematician and a humorist–a rare combination. After maintaining a 100+ pound weight loss for many years, he created a popular diet and fitness blog that makes wellness fun. It has helped countless people to lose weight and get healthier.
Jay is also the developer of WeightZone, a free algorithm that predicts a healthy zone of weight based on body stats, health history and exercise history. WeightZone has replaced the standard BMI and is considered to be the most accurate healthy weight guide available online.
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The views and opinions of guest authors do not necessarily reflect the views and opinions of Full Circle.