Sourdough Bread vs Whole Wheat: A Guide to Which is Better

We’ve all been told for decades now that whole wheat is always best when it comes to bread. But now there’s a new sheriff in town. Sourdough bread has increased in popularity over the last few years along with its reputation for being good for you. So how does it compare to whole wheat? Which is better? And is there a better option available?

Although Sourdough bread can boast a low Glycemic Index, better digestibility and an increased nutritional profile, whole wheat has been known to have increased health benefits due to its higher fiber content and nutritional levels.

I wanted to know which one was better, so I dug in and did a little more research…Here’s a list of benefits that each bread has, a comparison between the 2, and a guide to which is better…

The Benefits of Whole Wheat Bread

First, let’s take a look at the overall benefits of whole wheat bread, and why it’s been touted for being the clear cut better option when compared to white breads. What’s so special about it?

Whole Wheat Bread has a Higher Fiber Content

Whole wheat breads generally have a far higher fiber content than white breads, because it includes the bran part of the wheat (which is where all the fiber is). Fiber helps keep you regular, and feeling fuller for longer. A regular slice of whole wheat bread contains just under 2g of fiber. (7% of your RDA)

Whole Wheat Bread has a Lower Glycemic Index than White Bread

Having a lower Glycemic Index than white bread means that whole wheat is the better choice when it comes to keeping your sugar levels more stable. It also means you are less likely to crave sugary foods by staying fuller for longer. Regular white bread has a GI in its 70’s and higher, whereas whole wheat breads have a lower GI which around 50.

Whole Wheat Bread is Rich in B Vitamins

Unlike white bread, whole wheat is naturally richer in a range of B vitamins. Here’s a break down:

Vitamin B1 – Otherwise known as Thiamin. According to webMD, this vitamin is required for our bodies to properly use carbohydrates.

Vitamin B2 – Otherwise known as Riboflavin. This vitamin is needed for healthy development of the skin, brain function, blood cells, and the digestive lining. [Ref]

Vitamin B3 – Known as Niacin. This one is good for general overall health [Ref]

Vitamin B9 – Also known as Folic Acid or Folate. This vitamin is needed for making healthy new cells in the body. [Ref]

Whole Wheat Bread is Richer in Minerals than White Bread

Whole wheat bread contains a higher amount of minerals than white bread, such as:

• Iron– This is an essential mineral that helps your blood cells carry oxygen around the body. It’s also needed to maintain healthy skin, hair and nails. [Ref]
• Magnesium – This is important for a whole host of functions in the body: [Ref]
  • regulating muscle and nerve function
  • renewing/making protein, bone and DNA
  • regulating sugar levels in the blood
• Selenium – A trace mineral that is important for
  • a healthy immune system
  • fertility (for men and women)
  • the brain’s cognitive function
  • protection against infection
• Zinc – this is an essential mineral that is required in small amounts to help with healthy cell function, and is essential for a healthy immune system. [Ref]

Whole Wheat Bread Contains Resistant Starch

Resistant starch is a componant found in some foods, that when consumed, produces short chain fatty acids, which are good for us. Whole wheat bread can contain up to a whopping 14% resistant starch. Something most foods cannot boast about.

General Nutrition of Whole Wheat Bread

Here’s a look at the nutritional breakdown of 100 grams of whole wheat bread: [Ref]

Protein	13 grams
Carbs	41 grams
Sugar	6 grams
Fiber	7 grams
Fat	3.4 grams
Calories	247

The Benefits of Sourdough Bread

For more detailed information about the benefits of sourdough bread, check out my post “Is Sourdough Bread Good for you? 7 Things you need to know”

Here, we’re going to take a look at the individual benefits of white sourdough, and later on do an overall comparison between the two types of bread.

Sourdough bread has a Low Glycemic Index

White sourdough bread can boast a lower Glycemic Index than conventional white bread, because the method of fermentation lowers the overall starch and sugar content in the bread. The Glycemic Index of white sourdough bread is around 50, which is considered low GI. We will look into how it compares to whole wheat bread later on in the comparisons section.

Sourdough Bread Has Increased Mineral Absorption

A by product of sourdough bread’s fermentation process, means that we are better able to absorb the available minerals in sourdough bread. In particular, minerals such:

• magnesium
• copper
• zinc
• iron

have an increased rate of absorption in our bodies. There is also an increased level of antioxidents, which other breads do not contain. This is down to the lactic acid present in sourdough. [Ref]

Sourdough Bread Contains Resistant Starch

Resistant starch has relatively recently been discovered as being beneficial to your health, and sourdough fermentation increases bread’s resistant starch level by about 6%. [Ref] However, this is still not nearly as much as whole wheat contains.

Sourdough Bread has a whole host of Gut Friendly Benefits

Due to the process of slow fermentation, sourdough has a number of added benefits that are good for your gut and digestion, which whole wheat bread doesn’t have. For more information about gut bacteria and sourdough bread, check out my article “Does Sourdough Contain Probiotics and is it Good for your Gut?”

General Nutrition of White Sourdough Bread

This is what the nutritional profile of 100 grams of white sourdough bread looks like: [Ref]

Protein (less)	12 grams
Carbs (more)	56 grams
Sugar (less)	2.6 grams
Fiber (much less)	2.4 grams
Fat (less)	1.8 grams
Calories (more)	289

For more nutritional information, have a read of my post “Is Sourdough Bread Low Carb? Calories, Carbs, Fats and More”

A Comparison Between the Two Breads

Now that we have looked into some of the main benefits of each bread type, let’s compare the two.

I’ve compiled a table of comparison between the two breads, with like for like, of 100 grams of each bread type so that we can easily see the difference:

	White Sourdough Bread (100 grams)	Whole Wheat Bread (100 grams)
Protein	12 grams	13 grams
Carbohydrates	56 grams	41 grams
Sugars	2.6 grams	6 grams
Fat	1.8 grams	3.4 grams
Resistant Starch	6%	14 %
Fiber	2.4 grams	7 grams
Calories	289	247
Glycemic Index	53	50

Here are some conclusions we can draw from looking at the table above:

Whole Wheat Bread is Better than Sourdough because:

It has a higher fiber content – Sourdough bread, because it is white, has very little fiber. So whole wheat bread trumps sourdough when it comes to the fiber content. We need about 25 grams per day of fiber in our diets, and most of us don’t get enough of it. Eating whole grain in general is a better option to help increase our intake of fiber.

It has a higher resistant starch level – Because whole wheat bread contains all the bran, there is a high level of resistant starch in it. Far higher than what is found in sourdough bread. Resistant starch is not found in too many foods, so whole wheat bread is a good way of getting some into your diet.

It has a higher protein content – Although not by too much, whole wheat bread contains a slightly higher protein content than sourdough bread. Protein content in foods partly helps us to stay fuller for longer.

It contain less calories, carbohydrates and sugars – Because of the higher fiber and bran content, whole wheat bread contains less carbohydrates and sugars than white sourdough (and therefore less calories). What’s interesting though, is that even though this may be the case, the Glycemic Index levels of both breads are pretty much the same.

Sourdough Bread is Better than Whole Wheat Bread because:

It has a higher mineral absorption level – This is a really interesting one. According to this study, sourdough bread has a much higher mineral absorption rate than whole wheat. This is fascinating because whole wheat bread contains a higher amount of minerals, but these minerals aren’t actually absorbed so well. So even though sourdough bread contains less minerals, we benefit more from sourdough breads minerals because our bodies are better able to absorb them, when compared to those found in whole wheat bread.

The study showed the availability of minerals in sourdough bread to be much higher than in whole wheat yeasted bread, even though the whole wheat contained higher levels. In particular, the following minerals were avalilable in higher levels in sourdough than in whole wheat:

• magnesium
• iron
• copper
• zinc

Here’s a quick summary of the advantages of eating each type of bread compared to the other:

Pros of eating whole wheat bread	Pros of eating sourdough bread
Low Glycemic Index	Low Glycemic Index
More Resistant Starch	More Mineral Availability
More Fiber	Contains Antioxidents

Which Is Better for you? Sourdough or Whole Wheat Bread?

From the comparison table above, we can see that both whole wheat bread, AND sourdough bread come with their own individual benefits. But if you had to choose one, which would be the better choice?

With both breads boasting a good glycemic Index level, whole wheat beats sourdough when it comes to its fiber and resistant starch levels. But, sourdough bread is more of a nutritional powerhouse when it comes to breads, due to it’s bio-availability.

The Best of Both Worlds: Whole Wheat Sourdough!

Maybe you don’t have to choose! If you wanted the benefit of both breads, there is an option to choose something even better. A whole wheat sourdough bread. Although not as common, whole wheat sourdough is a brilliant option for people looking to get the benefits of both breads, and more.

The Benefits of Whole Wheat Sourdough

Here’s a list of benefits of whole wheat sourdough bread when compared to both white sourdough, AND regular whole wheat bread.

Whole Wheat Sourdough has an even Lower Glycemic Index

Remember, the Glycemic Index of whole wheat bread is very similar to white sourdough, even though the sourdough is made of white flour. The process of making sourdough means that many of the starches and sugars are reduced during its fermentation time. This is the the reason why sourdough bread is considered low GI, even though it is made with white flour.

Now, when you exclusively use whole wheat flour to make sourdough bread, you already start off with a lower GI flour, and then fermenting it with sourdough reduces the Glycemic Index of the bread even further. Whole wheat sourdough bread can boast a Glycemic Index of around 39. This is extremely low for a bread! So, if you are looking to stay full for long, and keep your sugar levels steady, whole wheat sourdough is definitely the way to go!

Whole Wheat Sourdough has even Better Mineral Availability

We learned earlier, that although white sourdough bread has less minerals in it than whole wheat, the availability of those minerals is much higher in sourdough, than in whole wheat. Therefore, if you use whole wheat flour to make sourdough bread, you already have an increased amount of vitamins and minerals in the bread to begin with. This makes whole wheat sourdough a highly nutritious bread to eat, compared to other breads.

Whole Wheat Sourdough Bread has an even Higher Level of Resistant Starch

Regular whole wheat bread is up to 14% resistant starch, and we know that traditionally fermenting bread through sourdough increases its resistant starch by about 6%. This means that whole wheat sourdough can contain up to 20% resistant starch. It’s hard to find many foods that can compare to those levels.

Whole Wheat Sourdough is High in Fiber

Although white sourdough bread contains very little fiber, the advantage of whole wheat sourdough is that all the fiber of the whole grain remains in the bread.

Whole Wheat Sourdough Contains Antioxidents

Sourdough bread is one of the few breads that contain antioxidents. Something ordinary whole wheat bread lacks.

Whole Wheat Sourdough Bread contains a Wide Range of B vitamins

The benefits of using whole grain flour in a sourdough is that there is a much higher range of B vitamins in it than white sourdough. (These are mentioned above under the whole wheat bread section).

Why Isn’t Whole Wheat Sourdough Bread as Popular?

Whole wheat sourdough, although extremely flavorful, can be very dense, and so it’s not everyone’s cup of tea! However, mixing whole wheat flour with a portion of white bread flour when making sourdough bread at home, can be an excellent way of getting the benefits of whole wheat sourdough without it being too dense.

I have a guide to using different flours in sourdough bread and how to make it work here.

If you’d like to learn how to make sourdough bread, my online course covers making loaves with whole wheat flours as well as other types of flour to make nutritious sourdough bread. We also go into detail about how to make sourdough soft and fluffy, and fit it into a busy schedule. Check it out here.