Michael Draney and Dr. Robert Davidson, Nutritional Sciences
Millions of people throughout the world suffer from osteoporosis. It is a degenerative disease that is characterized by increased bone fragility and decreased bone mineral and bone density.
Although limited research has been done linking vitamin K and bone health, vitamin K may inhibit bone loss due to osteoporosis. Japanese studies1,2 have shown that vitamin K decreases and even reverses bone loss due to ovariectomy in rats, but these findings have not been duplicated or supported anywhere outside of Japan.
Japan has performed studies whose results assert that a high vitamin K diet decreases and even reverses osteoporosis in ovariectomized rats.1,2 However, these results have not been duplicated anywhere outside of Japan. Previous attempts3 to replicate these results have probably failed due to the differences in time or factors in the diets. The Japanese studies were conducted for six months and the failed attempts for only three. The other factor could be the differences in fat used in the rats’ diets. The fat content in the Japanese diet is largely acquired from fish oils which have a high content of omega-3 fatty acids. Animal diets in the United States utilize corn oil, which is high in omega-6 fatty acids, but low in omega-3 fatty acids. This could have a large effect in the experiments because omega-3 fatty acids have also been found to increase bone mineralization4.
Taking into account the difference in the Japanese diet, our experiment was designed to last eight months and used diets with high or normal levels of vitamin K combined with either corn or fish oils, to account for and analyze the differences in effect on bone. We have replicated the results found with a diet combination of high omega-3 fatty acid and high vitamin K content and show why American studies have not been able to reproduce these results. This uncovers valuable information on the influence of vitamin K in promoting bone health and treating osteoporosis in humans.
We hypothesized that a diet high in vitamin K with high levels of fish oils (omega-3 fatty acids), would reduce the effects of osteoporosis in ovariectomized rats. After extraction, three different tests were performed on the rat femurs to test bone density (DEXA scans), strength (bone breaking), and mineral content (ashing). These different tests had separate results, but each was designed to confirm the others’ results and support our hypothesis.
Originally, it was planned that I would help in administering the diets to the rats, sacrifing them, and ashing the bones. However, as the research proceeded I took a large part in measuring the bones to standardize the information in preparation for all of the tests as well as helping in performing the bone breaking test. Although I was involved in other areas of the research, the focus of my work and these results are the effect the diet high in vitamin k and omega-3 fatty acids had in reducing the negative effects of osteoporosis, in this case, the loss of bone mineral content.
Our results supported our hypothesis in that the diet high in vitamin K and high in omega-3 fatty acids significantly decreased the negative effects of osteoporosis. Our results are summarized below with a box plot of the means of each group and a statistical analysis. With a .05 p-value in the Dunnett’s Upper One-Sided Multiple-Comparison Test With Control, the only two groups that were significantly different from the control group (normal vitamin K and low omega-3) were the SHAM group and the treatment group (high vitamin K and high omega-3). The SHAM group being significantly different, this being expected and known beforehand, proves that ovariectomized rats are a good model for osteoporosis. Our treatment group being significantly different in this test, demonstrates that the treatment diet had a significant effect in decreasing osteoporosis. We concluded that normal and high omega-3 and omega-6 fatty acids had no preventative effect on bone loss, but pharmacological vitamin K significantly reduced bone loss in ovariectomized rats and increased femoral strength and structural integrity.
The overall results are noteworthy because they possibly explain why these observations have not been duplicated outside of Japan and because they propose a new way to treat osteoporosis. Obtaining the results that all of the other diet groups were not significantly different from our control group indicates that the other diets did not have an effect in reducing the negative effects of osteoporosis. This can explain the difference in observations between the Japanese and other researchers. Japan used high omega-3 with their high vitamin k diet, whereas, most other researchers used high vitamin K by itself or coupled with high omega-6, which is commonly used in the United States. Our results show that the only diet that significantly decreased the effects of osteoporosis was the same diet used by the Japanese (high vitamin K and high omega-3) and no other diet combination showed significant results. Our observations with the bone ash data indicate that a diet high in vitamin K and high in omega-3 fatty acids can treat and even reverse the negative effects of osteoporosis in bone mineral. Our results were presented at the Biological Research Conference in Washington, D.C., last April to promote that more research be done to replicate and support these results and to test the effects that our treatment diet may have in humans and a possible way to implement it into society.