Is Natto High in Sugar? A Look at the Nutritional Facts

According to the USDA, a one-cup serving of natto contains approximately 8.6 grams of naturally occurring sugar. This fact makes the Japanese fermented food a relatively low-sugar option, especially when compared to many common processed foods, challenging the assumption about its sweetness.

Quick Summary

Natto is a fermented soybean product with a surprisingly low sugar content, thanks to its high fiber and the fermentation process. It is a nutritious superfood with proven health benefits.

Key Points

• Low Natural Sugar: Natto is not high in sugar, with a typical 100g serving containing less than 5 grams of naturally occurring sugar.

• Fermentation Reduces Sugars: The bacteria used to ferment natto, Bacillus subtilis, consume some of the soybeans' sugars during the process, further contributing to its low sugar profile.

• High Fiber Content: A large portion of natto's carbohydrates comes from dietary fiber, which slows down the digestion and absorption of sugars, preventing blood sugar spikes.

• Condiments Are the Culprit: The sauces and condiments often served with natto are the primary source of added sugars, not the fermented beans themselves.

• Beneficial for Blood Sugar Control: Studies have shown that consuming natto can help suppress postprandial blood glucose levels, making it potentially beneficial for managing diabetes.

The Nutritional Profile of Natto

Natto is a traditional Japanese food made from soybeans fermented with Bacillus subtilis bacteria. While its pungent aroma and stringy, sticky texture are its most recognizable traits, its impressive nutritional profile is why it is often praised as a superfood. Rich in protein, fiber, and essential micronutrients like vitamin K2, natto offers significant health benefits without a high sugar load.

Understanding Natto's Macronutrients

Natto's nutritional breakdown is key to understanding its place in a healthy diet. A 100g serving contains about 211 calories, 19.4g of protein, and 12.7g of total carbohydrates. The total carbohydrate count is important to look at more closely, as not all carbs are created equal. A large portion of natto's carbs come from dietary fiber, which slows down digestion and the absorption of sugar, contributing to better blood sugar control. The remaining sugar content is naturally occurring and is not considered a high amount.

Natto vs. Raw Soybeans: The Impact of Fermentation

Fermentation is the key to natto's unique properties, including its relatively low sugar levels. The Bacillus subtilis bacteria consume some of the carbohydrates and sugars in the soybeans during the fermentation process. This process not only changes the flavor and texture but also increases the bioavailability of nutrients, making the finished product more digestible and nutrient-dense than the raw soybeans it started as. This process is crucial for anyone monitoring their sugar intake, as it actively reduces the sugar content.

Why Natto Is Not High in Sugar

Several factors contribute to natto's low sugar status, making it a smart choice for those concerned with blood sugar levels.

The Role of High Fiber Content

Natto is an excellent source of dietary fiber, with about 5.4g per 100g serving. This high fiber content is critical because it mitigates the effects of any sugar present. Fiber is not digested by the body and helps to slow the absorption of carbohydrates, which prevents a rapid spike in blood sugar. This effect is beneficial for everyone, but particularly important for individuals managing diabetes or metabolic syndrome.

The Misleading Role of Condiments

For many, any perception of natto being high in sugar stems from the sauces and condiments often added to it. Many packaged natto products come with small packets of sauce (tare) and mustard (karashi), which can contain added sugars. If you are watching your sugar intake, it is best to check the ingredients of these packets or opt for a simple, homemade sauce using low-sodium soy sauce and a pinch of your own mustard. This simple substitution allows you to enjoy natto's health benefits without the unwanted added sugar.

Health Benefits Beyond Low Sugar

Natto’s low sugar content is just one part of its appeal. The food offers a range of other health benefits that make it a worthy addition to your diet:

• Rich in Probiotics: The fermentation process creates beneficial bacteria that support a healthy gut microbiome, which is linked to improved digestion and overall immune function.
• Source of Vitamin K2: Natto is one of the richest dietary sources of Vitamin K2, a vital nutrient for bone health and cardiovascular health.
• Cardiovascular Support: The enzyme nattokinase, produced during fermentation, has been shown to help with blood circulation and lower the risk of heart disease.

Natto vs. Common Foods: A Sugar Comparison

Food (100g)	Sugar (g)	Fiber (g)	Notes
Natto	4.9	5.4	Naturally low in sugar, high in fiber
Greek Yogurt (plain)	3.6	0	Can have added sugars in flavored versions
White Rice (cooked)	0.05	0.4	High glycemic index, converts to sugar quickly
Apple	10.4	2.4	High natural sugar, but balanced by fiber

Note: Nutritional information can vary depending on the product and preparation. This table highlights how natto’s sugar content is on the low end compared to many other staple foods, reinforcing its suitability for a sugar-conscious diet.

Is Natto High in Sugar? The Conclusion

So, is natto high in sugar? The answer is a clear no. As a naturally fermented soybean product, natto contains a modest amount of naturally occurring sugar, with a significant portion of its carbohydrates offset by a high dietary fiber content. The key to keeping your sugar intake low when consuming natto is to be mindful of the added sauces and condiments. By focusing on its nutrient-dense profile and avoiding high-sugar additives, you can fully embrace this superfood's impressive health benefits without concern for excessive sugar. For more insight into fermented foods and their benefits, consider reading this comprehensive guide on the topic.

References

[1] NIH. National Institutes of Health (NIH) | (.gov). Nutritional Health Perspective of Natto: A Critical Review. https://pmc.ncbi.nlm.nih.gov/articles/PMC9616652/ [2] Japan-Experience. Natto: Japan's unique fermented soybean delicacy. https://www.japan-experience.com/plan-your-trip/to-know/japanese-food/mito-natto [3] ResearchGate. Effect of Intake of Natto and Soybeans on Postprandial Blood Glucose Levels in Healthy Adults. https://www.researchgate.net/publication/316847129_Effect_of_Intake_of_Natto_and_Soybeans_on_Postprandial_Blood_Glucose_Levels_in_Healthy_Adults [4] Verywell Fit. Natto Nutrition Facts and Health Benefits. https://www.verywellfit.com/natto-nutrition-facts-and-health-benefits-4781758

Frequently Asked Questions

Does fermentation increase the sugar content of natto?

No, the fermentation process for natto actually reduces the sugar content of the soybeans. The bacteria, Bacillus subtilis, feed on the sugars in the beans, leading to a finished product that is lower in sugar than the unfermented soybeans.

Is natto a good option for diabetics?

Yes, natto can be a good option for diabetics. Its low sugar and high fiber content help regulate blood sugar levels, and studies have shown its potential to suppress postprandial blood glucose. However, it is essential to avoid using sugary sauces or condiments.

How can I avoid added sugar when eating natto?

To avoid added sugar, you should skip the sauce packets that come with many commercially packaged natto products. Instead, season the natto with a low-sodium soy sauce or tamari, a dash of plain mustard, and chopped green onions.

Does natto have a high glycemic index?

Natto has a low glycemic index due to its high fiber and protein content. This means it causes a slower, more stable rise in blood sugar compared to high-carb foods like white rice.

What is the net carb count for natto?

Net carbs for natto are relatively low. For a one-cup serving with about 22.2g of total carbs and 9.5g of fiber, the net carbs would be approximately 12.7g.

Can the sticky texture of natto affect its sugar content?

No, the sticky, stringy texture of natto is caused by poly-gamma-glutamic acid, a polypeptide produced by the fermenting bacteria, not by a high sugar content. In fact, fermentation contributes to both the texture and the low sugar levels.

Is natto sweeter than other fermented soy products?

No, natto is not sweeter than most other fermented soy products. It has a strong, savory, and umami flavor profile. Its sugar content is low, especially compared to some flavored fermented foods that may have added sugars.