DNC News




Subject: Rarely has a food sounded so good for one's health, yet sounded so unappealing to eat as natto.


I drove to Costco yesterday and turned in a 20 ounce container of shredded aged parmesan cheese. I'd noticed dark green clumps bonding the shreds together while sprinkling it on my dinner a few nights before; it had gone moldy and there was no way I was going to eat anymore of it. One look at the bottle, a grimaced, “Yuuk” and Yvonne at the service counter handed me a crisp ten dollar bill as a refund.


I went into the store and bought a half wheel of Rosenborg Danish Blue Cheese instead. Moldy parmesan cheese is intolerable, but moldy Blue cheese is a special treat. Since then, I've been marveling at the strength of our cultural perceptions regarding what is edible and what is inedible: what is moldy spoiled rot, versus a cultured, fermented delicacy.


No doubt I noticed these inconsistencies in my perception because I've been reading and thinking about another fermented food and trying to work up my nerve to taste it. The food in question is a traditional Japanese food made from fermented soy beans called natto. This is different from the Indonesian food tempeh. Natto is soybeans fermented by bacteria, tempeh is fermented by fungus.


I've never eaten natto. If the descriptions I've read are accurate, it is disgusting; one of the more difficult to acquire tastes you'll ever find.


Nevertheless it might well be a taste that we should be cultivating.


Natto has been made in Japan since the later years of the Edo Period (1600-1868). Traditionally it was made by packing cooked soybeans in a bed of rice straw and leaving them in a warm place. A bacteria in the straw, Bacillus subtilis natto, feeds off the beans, and turns them into a slimy stinking goop held together by sticky spider-webish strands with an odor that some describe as Oriental limburger. Natto is now made in commercial factories using sterile conditions and clean cultures. The end product sounds no better. We could let this drop as an example ofdifferent people have different tastes if it wasn't for a peculiar circumstance.


Natto is a regional food in Japan. People who live to the east of Mt. Fuji don't care much for it, while people to the west adore it. Those easterners happen to get osteoporosis far more often than people on the western side. Researchers are able to chart a fairly direct correlation: the more natto eaten and the less likely people develop osteoporosis. In fact they can chart an inverse correlation between natto consumption and osteoporotic fracture rates in every canton of Japan.


Osteoporosis protection from natto is due to its vitamin K-2 content. Recall that Vitamin K-1 is found in green leafy vegetables and can only be converted into vitamin K-2 by bacterial fermentation. This typically occurs in our lower intestines and unfortunately is too far down stream to be absorbed. Natto is one of the few and may be one of the best dietary sources of vitamin K-2. The vitamin K-2 we use in nutritional supplements is made by natto bacteria.



Vitamin K-2 is not the only nutritionally important compound in natto. Natto is also a source for vitamin B-12 and soy isoflavinoids.

Yet Nattokinase is getting the brightest spotlight. This is an enzyme found in large amounts in natto. The bacteria make it in order to digest the soy beans. Advertisements promote it as ‘Nature's clot buster'. This proteolytic enzyme when taken orally as a supplement or consumed as natto, degrades fibrin in the blood reducing the likelihood of forming life threatening blood clots. The formation of blood clots is a complex and essential process that is always occurring in the body. Without it we would be constantly leaking blood. When carried to an extreme we may form a thrombus, or blood clot, large enough to block circulation and blood flow. When this happens in the heart, we call it a heart attack, in the brain, a stroke. The process starts with the enzyme thrombin getting released. Thrombin causes the soluble protein fibrinogen to precipitate into microscopic filaments called fibrin which forms a protein mesh forming a clot. Tiny clots are always being formed and dissolved throughout the body. As the clots are formed they are dissolved by enzymes in a process called fibrinolysis. There is a careful balance required. Too much fibrinolysis and the body can't patch its leaks. Too little and clots become too large and block circulation.


The drugs which doctors give when a patient has a stroke or hear attack are synthetic versions of the body's own fibrolinolytic enzymes, the tissue plasminogen activators {TPA), that are used to break up the clots. These drugs must be given immediately after the event event to stop further damage. Nattokinase is being promoted for its weaker fibrinolytic action and a person can use preventively over the long term to stop major clots.


Eating natto can cut the time it takes the body to dissolve a routine clot in half. Higher doses in tablet form are able to open up veins that are completely blocked with blood clots.


Vitamin K-2 is useful in cancer. I've written about its use in preventing liver cancer in hepatitis C patients. Two recent studies have come out suggesting that Vitamin K-2 may prove useful in treating lung cancer. We have been using a synthetic version of vitamin K, menadione or vitamin K-3 in combination with vitamin C in treating other cancers. It may be that this natural form works as well.


The information sounds good even if I'm not in a rush to see if natto tastes good. You can buy natto at Pacific Mercantile on the corner of Lawrence and 19th in downtown Denver (a few blocks from the Coors Field). I confess I haven't raced down to buy any yet. I'm still enjoying my blue cheese.


A great deal of information on natto including detailed instructions to make your own and a source for pure natto bacteria culture to make it with can be found at. http://www.gaia21.net/natto/natto.htm





For more detailed information on Vitamin K-2 on bone health

Vitamin K-2 and liver cancer

Vitamin K-2 and lung cancer

Vitamin K-3 click here.





Natto Abstracts:


Nutrition. 2003 Mar;19(3):261-4. 

Dietary supplementation with fermented soybeans suppresses intimal thickening.


Suzuki Y, Kondo K, Ichise H, Tsukamoto Y, Urano T, Umemura K.


Department of Pharmacology, Hamamatsu University School of Medicine, Shizuoka , Japan . yapplel@hama-med.ac.jp


Although soy foods have been consumed for more than 1000 y, it is only in the past 20 y that they have made inroads into Western diets. We investigated the effect of dietary supplementation with natto extracts produced from fermented soybeans on intimal thickening of arteries after vessel endothelial denudation. Natto extracts include nattokinase, a potent fibrinolytic enzyme having four times greater fibrinolytic activity than plasmin. Intimal thickening was induced in the femoral arteries by intravenous infusion of rose bengal followed by focal irradiation with a transluminal green light. Dietary natto extract supplementation was started 3 wk before endothelial injury and continued for another 3 wk after. In ex vivo studies, euglobulin clot lysis times were measured 3 wk after the initial supplementation. Neointima formation and thickening were also initiated successfully. The intima media ratio 3 wk after endothelial injury was 0.15 +/- 0.03 in the control group. Dietary natto extract supplementation suppressed intimal thickening (0.06 +/- 0.01; P < 0.05) compared with the control group. Natto extracts shortened euglobulin clot lysis time, suggesting that their thrombolytic activities were enhanced. These findings suggest that natto extracts, because of their thrombolytic activity, suppress intimal thickening after vascular injury as a result of the inhibition of mural thrombi formation.


PMID: 12620531 [PubMed - indexed for MEDLINE]


Life Sci. 2003 Jul 25;73(10):1289-98.

Dietary supplementation of fermented soybean, natto, suppresses intimal thickening and modulates the lysis of mural thrombi after endothelial injury in rat femoral artery.


Suzuki Y, Kondo K, Matsumoto Y, Zhao BQ, Otsuguro K, Maeda T, Tsukamoto Y, Urano T, Umemura K.


Department of Pharmacology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu City , Shizuoka 431-3192, Japan . yapplel@hama-med.ac.jp


We have previously demonstrated that natto-extracts containing nattokinase (NK) inactivates plasminogen activator inhibitor type 1 and then potentiates fibrinolytic activity. In the present study, we investigated the effects of dietary supplementation with natto-extracts on neointima formation and on thrombolysis at the site of endothelial injury. Endothelial damage in the rat femoral artery was induced by intravenous injection of rose bengal followed by focal irradiation by transluminal green light. Dietary natto-extracts supplementation containing NK of 50 or 100 CU/body was started 3 weeks before endothelial injury and then continued for another 3 weeks. Intimal thickening in animals given supplementation was significantly (P<0.01) suppressed compared with controls and the intima/media ratio in animals with 50 and 100 CU/body NK and control group was 0.09 +/- 0.03, 0.09 +/- 0.06 and 0.16 +/- 0.12, respectively. Although femoral arteries were reopened both in control animals and those treated with NK within 8 hours after endothelial injury, mural thrombi were histologically observed at the site of endothelial injury. In the control group, the center of vessel lumen was reopened and mural thrombi were attached on the surface of vessel walls. In contrast, in NK-treated groups, thrombi near the vessel wall showed lysis and most of them detached from the surface of vessel walls. In conclusion, dietary natto-extracts supplementation suppressed intimal thickening produced by endothelial injury in rat femoral artery. These effects may partially be attributable to NK, which showed enhanced thrombolysis near the vessel wall.


PMID: 12850244 [PubMed - indexed for MEDLINE]



Biol Pharm Bull. 1995 Oct;18(10):1387-91.

Thrombolytic effect of nattokinase on a chemically induced thrombosis model in rat.


Fujita M, Hong K, Ito Y, Fujii R, Kariya K, Nishimuro S.


Biotechnology Research Laboratories, JCR Pharmaceuticals Co., Ltd., Kobe , Japan .


Nattokinase is a new fibrinolytic enzyme which cleaves directly cross-linked fibrin in vitro. In this study, we investigated the thrombolytic effect of nattokinase on a thrombus in the common carotid artery of rat in which the endothelial cells of the vessel wall were injured by acetic acid. When a section of occluded vessel was stained for CD61 antigen by immunofluorescence utilizing a monoclonal antibody, the antigen was localized around the surface of the occluded blood vessels. This result suggests that the occlusive thrombosis was caused by platelet aggregation. In addition, thrombolysis with urokinase ( UK ; 50000 IU/kg, i.v.) or tissue plasminogen activator (tPA; 13300 IU/kg, i.v.) in our model was observed to restore the blood flow over a 60 min monitoring period. The results indicate that our chemically induced model is useful for screening and evaluating a thrombolytic agent. We evaluated the thrombolytic activity of nattokinase using this model and compared it with fibrino(geno)lytic enzyme, plasmin or elastase. On a molar basis, the recovery of the arterial blood flow with nattokinase, plasmin and elastase were 62.0 +/- 5.3%, 15.8 +/- 0.7% and 0%, respectively. The results indicate that the thrombolytic activity of nattokinase is stronger than that of plasmin or elastase in vivo.


PMID: 8593442 [PubMed - indexed for MEDLINE]



Acta Haematol. 1990;84(3):139-43.


Enhancement of the fibrinolytic activity in plasma by oral administration of nattokinase.


Sumi H, Hamada H, Nakanishi K, Hiratani H.


Department of Physiology, Miyazaki Medical College , Japan .


The existence of a potent fibrinolytic enzyme (nattokinase, NK) in the traditional fermented food called 'natto', was reported by us previously. It was confirmed that oral administration of NK (or natto) produced a mild and frequent enhancement of the fibrinolytic activity in the plasma, as indicated by the fibrinolytic parameters, and the production of tissue plasminogen activator. NK capsules were also administered orally to dogs with experimentally induced thrombosis, and lysis of the thrombi was observed by angiography. The results obtained suggest that NK represents a possible drug for use not only in the treatment of embolism but also in the prevention of the disease, since NK has a proven safety and can be massproduced.


PMID: 2123064 [PubMed - indexed for MEDLINE]




J Nutr Sci Vitaminol ( Tokyo ). 2004 Apr;50(2):114-20.

Promotion of bone formation by fermented soybean (Natto) intake in premenopausal women.


Katsuyama H, Ideguchi S, Fukunaga M, Fukunaga T, Saijoh K, Sunami S.


Department of Public Health, Kawasaki Medical School , Kurashiki 701-0192, Japan . katsu@med.kawasaki-m.ac.jp


A therapeutic agent of vitamin K2 is approved for the treatment of osteoporosis in Japan . However, little is known about the efficacy of dietary intake of vitamin K2 for bone health. We compared the effects of various levels of fermented soybeans (Natto) intake, which contains plenty of vitamin K2, on bone stiffness and bone turnover markers in healthy premenopausal women. Seventy-three healthy premenopausal women were randomly divided into four groups matched for age and parity categories. Natto was supplied as follows: Group 1 (no intake), Group 2 (once per month), Group 3 (once per week) and Group 4 (three times per week). Subjects took Natto at a lunch for 1 y, and the stiffness index by quantitative ultrasound and bone turnover markers were assessed at baseline, 6 mo and 1 y. There was no statistical difference in the stiffness index during the 1 y observation. However, bone specific alkaline phosphatase (BAP) in Group 4 was higher than that in Group 3 at 1 y and undercarboxylated osteocalcin (Glu) in Group 4 was significantly lower than those in Groups 1, 2 and 3 at 6 mo. Logistic regression analysis showed that the risk of reduction of bone formation markers declined to 0.07 in Group 4 based on that in Group 1. In premenopausal women who had to keep the stiffness index as high as possible before menopause, Natto intake may have contributed to the promotion of bone formation.


Publication Types:

Clinical Trial

Randomized Controlled Trial


PMID: 15242015 [PubMed - indexed for MEDLINE]



J Nutr Sci Vitaminol ( Tokyo ). 2002 Jun;48(3):207-15.

Usual dietary intake of fermented soybeans (Natto) is associated with bone mineral density in premenopausal women.


Katsuyama H, Ideguchi S, Fukunaga M, Saijoh K, Sunami S.


Department of Public Health, Kawasaki Medical School , Kurashiki , Japan . katsu@med.kawasaki-m.ac.jp


Fermented soybeans (Natto), a traditional Japanese food, contain more than 100 times as much vitamin K2 as various cheeses and are considered to promote gamma-carboxylation. Thus it is conceivable that Natto may play a preventive role in the development of osteoporosis. In this study, the relationships between the bone stiffness index measured by ultrasound, bone turnover markers, and lifestyle factors, including Natto intake, were examined in relation to vitamin D receptor (VDR) polymorphism. Among 117 premenopausal volunteers, approximately 75% were bb homozygotes, 20% were Bb heterozygotes, and only 5% were BB homozygotes. The B allele group and the bb group were subdivided according to Natto intake. In a monovariate analysis, no significant differences in indices for dietary intake, including Ca and vitamin D intake, were observed. The stiffness index in the B allele group, however, was slightly lower than in the bb groups when there was no Natto intake. There were no significant differences in serum ALP and Gla-osteocalcin, bone formation markers, or NTx and Ca in urine, bone resorption markers. A logistic regression test, including the interactional effect of Natto intake and VDR RFLP, indicated that the B allele group was a risk factor of bone mineral loss and that Natto was effective in maintaining bone stiffness in this group. Although the present study was cross sectional and requires longitudinal investigation, Natto may improve the bone health of people who have a low affinity receptor for vitamin D.


PMID: 12350079 [PubMed - indexed for MEDLINE]




Nutrition. 2001 Apr;17(4):315-21.

Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk.


Kaneki M, Hedges SJ, Hosoi T, Fujiwara S, Lyons A, Crean SJ, Ishida N, Nakagawa M, Takechi M, Sano Y, Mizuno Y, Hoshino S, Miyao M, Inoue S, Horiki K, Shiraki M, Ouchi Y, Orimo H.


Department of Geriatric Medicine, University of Tokyo Graduate School of Medicine, Tokyo , Japan .


Increasing evidence indicates a significant role for vitamin K in bone metabolism and osteoporosis. In this study, we found a large geographic difference in serum vitamin K2 (menaquinone-7; MK-7) levels in postmenopausal women. Serum MK-7 concentrations were 5.26 +/- 6.13 ng/mL (mean +/- SD) in Japanese women in Tokyo, 1.22 +/- 1.85 in Japanese women in Hiroshima, and 0.37 +/- 0.20 in British women. We investigated the effect of Japanese fermented soybean food, natto, on serum vitamin K levels. Natto contains a large amount of MK-7 and is eaten frequently in eastern ( Tokyo ) but seldom in western ( Hiroshima ) Japan . Serum concentrations of MK-7 were significantly higher in frequent natto eaters, and natto intake resulted in a marked, sustained increase in serum MK-7 concentration. We analyzed the relation between the regional difference in natto intake and fracture incidence. A statistically significant inverse correlation was found between incidence of hip fractures in women and natto consumption in each prefecture throughout Japan . These findings indicate that the large geographic difference in MK-7 levels may be ascribed, at least in part, to natto intake and suggest the possibility that higher MK-7 level resulting from natto consumption may contribute to the relatively lower fracture risk in Japanese women.


PMID: 11369171 [PubMed - indexed for MEDLINE]



J Bone Miner Metab. 2000;18(2):71-6.


Prolonged intake of fermented soybean (natto) diets containing vitamin K2 (menaquinone-7) prevents bone loss in ovariectomized rats.

Yamaguchi M, Kakuda H, Gao YH, Tsukamoto Y.

Laboratory of Endocrinology and Molecular Metabolism,
Graduate School of Nutritional Sciences, University of Shizuoka , Japan .

The effect of the prolonged intake of dietary vitamin K2 (menaquinone-7, MK-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 micrograms MK-7/100 g diet) without or with supplemental MK-7 (containing 14.1 or 18.8 micrograms of MK-7 as total per 100 g diet) for 150 days. Feeding produced a significant elevation of MK-7 concentration in the serum of OVX rats. In this case, the femoral MK-4 content was significantly increased, but MK-7 was not detected in the femoral tissues, indicating degradation of MK-7. Serum gamma-carboxylated osteocalcin concentration was significantly decreased by OVX. This decrease was significantly prevented by the feeding of the natto diets with supplemental MK-7 (18.8 micrograms/100 g diets). OVX caused a significant decrease in femoral dry weight, femoral calcium content, and mineral density. These decreases were significantly prevented by feeding with diets containing natto with MK-7 (total, 18.8 micrograms/100 g diets). This study demonstrates that the prolonged intake of natto dietary including MK-7 has a preventive effect on bone loss induced by OVX. Dietary MK-7 may be useful in the prevention of osteoporosis.

PMID: 10701161 [PubMed - indexed for MEDLINE]


Effect of vitamin K2 (menaquinone-7) in fermented soybean (natto) on bone loss in ovariectomized rats.


Yamaguchi M, Taguchi H, Gao YH, Igarashi A, Tsukamoto Y.


Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka , Japan .


The effect of dietary vitamin K2 (menaquinone-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing menaquinone-4 (MK-4; 12mg/100g diet) or menaquinone-7 (MK-7; 18.1mg/100g diet) for 24 days; MK-4 and MK-7 were equal in molar concentrations. This feeding caused a remarkable increase of MK-4 and MK-7 concentrations in the serum and femur of OVX rats. OVX-induced decrease in the femoral dry weight and femoral calcium content was prevented by the feeding of dietary MK-4 or NK-7. In separate experiments, OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 microg MK-7/100g diet) without or with added MK-7 (37.6 microg/100g diet) for 77 days. Feeding produced a significant elevation of MK-4 and MK-7 concentrations in the serum of OVX rats. In this case, a significant increase in the femoral MK-4 content was observed but MK-7 was not detected in the femoral tissues. OVX-induced decreases in the femoral dry weight and femoral calcium content were significantly prevented by the feeding of diets containing natto with MK-7 added (37.6 microg/100g diets). This study demonstrates that the intake of dietary MK-7 has a preventive effect on bone loss caused by OVX. This effect may be partly caused by MK-4, which is formed by degradation of MK-7.


PMID: 10084398 [PubMed - indexed for MEDLINE]



J Nutr. 2004 Nov;134(11):3100-5.

Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study.

Geleijnse JM, Vermeer C, Grobbee DE, Schurgers LJ, Knapen MH, van der Meer IM, Hofman A, Witteman JC.


Department of Epidemiology & Biostatistics, Erasmus Medical Center Rotterdam , Rotterdam , The Netherlands .


Vitamin K-dependent proteins, including matrix Gla-protein, have been shown to inhibit vascular calcification. Activation of these proteins via carboxylation depends on the availability of vitamin K. We examined whether dietary intake of phylloquinone (vitamin K-1) and menaquinone (vitamin K-2) were related to aortic calcification and coronary heart disease (CHD) in the population-based Rotterdam Study. The analysis included 4807 subjects with dietary data and no history of myocardial infarction at baseline (1990-1993) who were followed until January 1, 2000 . The risk of incident CHD, all-cause mortality, and aortic atherosclerosis was studied in tertiles of energy-adjusted vitamin K intake after adjustment for age, gender, BMI, smoking, diabetes, education, and dietary factors. The relative risk (RR) of CHD mortality was reduced in the mid and upper tertiles of dietary menaquinone compared to the lower tertile [RR = 0.73 (95% CI: 0.45, 1.17) and 0.43 (0.24, 0.77), respectively]. Intake of menaquinone was also inversely related to all-cause mortality [RR = 0.91 (0.75, 1.09) and 0.74 (0.59, 0.92), respectively] and severe aortic calcification [odds ratio of 0.71 (0.50, 1.00) and 0.48 (0.32, 0.71), respectively]. Phylloquinone intake was not related to any of the outcomes. These findings suggest that an adequate intake of menaquinone could be important for CHD prevention.


PMID: 15514282 [PubMed - indexed for MEDLINE]





Ask the Doctor:
What's the difference between naturopathy and homeopathy?

[click here for the answer]

Submit your question here.

Enter your email to recieve the latest Health and Wellness newsletters from the clinic.