Clinical testing of Natto

Clinical testing of Natto in treatment of patients with a low density bone structure and therefore with a higher risk of bone fractures

Background
Natto – a product made from boiled soy beans and added a culture of bacteria, contains large quantities of the vitamin K2. The intake of both soy and K2 is shown to have a connection with higher density of bone mass. In parts of Japan where they eat Natto at a daily basis, like the Norwegians consumed cod-liver oil in earlier times, the population has a lower ocurrence of bone fractures than in other parts of Japan. Further research in Japan has also shown that we can find this positive connection between Natto and density of bone mass both in animal and in human experiments. There are also interesting results regarding the risk factors for cardiovascular diseases. Norway is especially interesting in this matter because the country has the world's highest ocurrence of bone fractures.

Questions to be answered

1. Will patients who consume Natto have a lower ocurrence of bone fractures compared with patients receiving placebo?

2. Does Natto influence the risk of cardiovascular diseases?

Material and method
Participants in the study will be volunteer women over the age of 54 with a low density of bone mass. Detailed planning will continue after the pilot studies are concluded.

Completed pilot studies
During 2001 and 2002 three pilot studies have been completed. These show that Norwegians probably have little or no intake of vitamin K2 in their diet. They also show that the intake of Natto and the follow-up of the participants can be done without any special challenges.

Completed introductory studies
During spring 2004 an introductory study was completed in which we have decided which dosage of Natto will be used on the Norwegian post-menopausal women. The results will be published in the course of fall 2004/spring 2005.

Collaborating partners
Tromsø Osteoporose Studie (TROST) and the Institute of Pharmacy at the University of Tromsø

Contact: Vinjar Fønnebø