Natto Food vs. Nattokinase Supplements

Introduction

Nattokinase originated in natto, the traditional Japanese fermented soybean food. This raises a practical question: can eating natto provide the same benefits as nattokinase supplements, or are these distinct approaches? The answer involves more than just enzyme content, touching on vitamin K2, other bioactive compounds, and practical considerations.

This article examines the nattokinase content of natto, whether food provides equivalent benefits to supplements, the vitamin K2 consideration for those on blood thinners, and other bioactive compounds in natto beyond nattokinase. Understanding these differences helps inform the choice between food and supplement forms.

For information on supplement dosing, see the dosing article. Product quality considerations are addressed in the product quality article.

How much nattokinase is in a serving of natto?

The nattokinase content of natto varies based on fermentation conditions, bacterial strain, and serving size. A typical serving of natto (approximately 50 grams) contains roughly 1,000-2,000 FU of nattokinase, though this can vary substantially between commercial products. The original research by Sumi et al. characterized natto as having potent fibrinolytic activity, but did not standardize content across preparations (Sumi et al., 1987).

This means that eating a serving of natto might deliver a dose comparable to a standard supplement capsule. However, the variability in food-based nattokinase content makes precise dosing impossible. Supplements offer the advantage of standardized potency, while natto introduces uncertainty about exactly how much enzyme each serving provides.

The biological activity of nattokinase in food may differ from purified supplements. Natto matrix effects, gastric transit characteristics, and interactions with other food components could influence absorption. Animal studies using dietary natto have demonstrated vascular effects, suggesting that food-based enzyme retains activity (Suzuki et al., 2003).

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Does eating natto provide equivalent benefits to supplements?

The epidemiological evidence for natto consumption is intriguing. A large prospective cohort study of 92,915 Japanese adults found that higher natto consumption was associated with lower cardiovascular mortality, an association not seen with non-fermented soy products (Katagiri et al., 2020). This suggests that natto-specific compounds, potentially including nattokinase, contribute to cardiovascular benefit.

However, these observational associations cannot establish causation or determine which natto component drives the benefit. The clinical trials evaluating nattokinase have used purified enzyme supplements, not whole natto food. Whether natto’s cardiovascular effects derive from nattokinase, vitamin K2, isoflavones, or other bioactives remains unclear (Afzaal et al., 2022).

For patients seeking the specific effects documented in nattokinase trials, supplements provide more precise dosing and have been the form studied in clinical research. For those interested in broader potential benefits from natto’s multiple bioactive compounds, regular consumption of the food represents a reasonable alternative with limited downside beyond taste preferences.

What is the vitamin K2 content in natto?

Natto is the richest dietary source of vitamin K2, specifically the MK-7 form. A single serving can contain several hundred micrograms of MK-7, far exceeding the amounts found in other foods (Tsukamoto et al., 2000). This high vitamin K2 content has implications both positive and negative depending on the individual.

For bone health, vitamin K2 appears beneficial. Studies have found associations between natto intake and bone mineral density in elderly Japanese men, likely mediated through improved osteocalcin carboxylation (Fujita et al., 2012). Vitamin K2 may also benefit cardiovascular health through inhibition of arterial calcification, though this evidence is less established.

For patients on warfarin, natto’s vitamin K2 content creates significant problems. Warfarin works by inhibiting vitamin K-dependent clotting factor synthesis. High vitamin K2 intake from natto can overcome warfarin’s effect, reducing anticoagulation efficacy. Patients on warfarin should avoid natto or consume it in carefully controlled, consistent amounts if at all (Weng et al., 2017).

Are there other bioactive compounds in natto beyond nattokinase?

Natto contains numerous bioactive compounds beyond nattokinase. Isoflavones including genistein and daidzein have documented biological activity. Polyamines with potential anti-aging properties are present. Bacillus subtilis produces various peptides during fermentation that may have independent health effects.

Research on natto’s antioxidant properties demonstrates inhibition of LDL oxidation independent of nattokinase activity, suggesting that other natto components contribute to cardiovascular protection (Iwai et al., 2002). A crossover study found that a Japanese breakfast including natto improved insulin sensitivity and lipid metabolism in overweight subjects, effects likely involving multiple natto compounds (Taniguchi-Fukatsu et al., 2012).

Recent animal research suggests that natto’s benefits may involve gut microbiota modulation and vitamin K2 effects on inflammation, not solely nattokinase fibrinolysis (Kawamata et al., 2023). This complexity argues for potential advantages of whole natto consumption over isolated enzyme supplementation, though direct comparative studies have not been conducted.

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What’s the practical tradeoff between food and supplement forms?

Taste presents the most immediate consideration. Natto has a distinctive sticky texture and pungent odor that many find challenging, particularly those not raised with it in their diet. Starting with small amounts or mixing with other foods can improve acceptability, but some people never adjust to natto’s unusual characteristics.

Consistency and dosing favor supplements. A 2,000 FU capsule delivers a known amount of enzyme. The nattokinase content of different natto brands and batches varies, making precise dosing impossible. For patients tracking response to nattokinase, this variability introduces uncertainty.

Vitamin K2 interaction with warfarin makes supplements clearly preferable for anticoagulated patients. Nattokinase supplements can be produced without vitamin K, eliminating this interaction. For non-anticoagulated patients interested in vitamin K2’s potential bone and cardiovascular benefits, natto food provides this additional compound along with nattokinase.

Conclusion

Natto food and nattokinase supplements represent related but not identical approaches. Natto provides nattokinase along with vitamin K2, isoflavones, and other bioactive compounds in a whole-food matrix. Supplements deliver standardized enzyme doses without vitamin K2 interference.

For patients on warfarin, supplements clearly make more sense. For those interested in the broader potential benefits of fermented soy, regular natto consumption offers advantages beyond isolated nattokinase. For most others, the choice may reasonably depend on taste tolerance and preference for whole foods versus supplements.