A recent study has demonstrated that vitamin K slows the progression of insulin resistance in elderly men, but has little effect on elderly women.
Insulin resistance is a precursor, as well as a characteristic of, type 2 diabetes. Insulin resistance results in high blood-glucose levels, which occur because of diminished ability to utilize insulin, which is produced in the pancreas. Insulin’s primary function is to convert sugar into energy, hence the higher levels of glucose in the blood associated with insulin resistance. Weight, genetics and age are some of the leading risk factors for insulin resistance.
The study focused on 355 elderly men and women between 60-80 years of age. None had diabetes, but due to their age are a high risk group with high incidence of insulin resistance. 500 milligram vitamin K supplements were given to both the men and women, while a control group was established that only received a multivitamin with significantly less vitamin K. Both groups were also given calcium and vitamin D supplements, though those played little role in the observations of the study. It’s noted by the authors that while vitamin K supplements were given to the participants in this study, sufficient levels of vitamin K can be attained by consuming vegetables such as broccoli, spinach, and other leafy greens.
The results of the study were very clear. “Men who received vitamin K supplementation had less progression in their insulin resistance by the end of the clinical trial. Conversely, we saw progression in insulin resistance in women who received vitamin K supplementation, and in the men or women who were not given vitamin K supplements,” says study author Dr. Sarah Booth.
While it appears clear that vitamin K can slow down insulin resistance in elderly men, there are some potential complications to the correlation, both in men and women. Dr. Booth cautions that “Vitamin K is stored in fat tissue. If there is excess fat, vitamin K may not be readily available to cells that require it to process glucose.” This means that for overweight individuals, both men and women, supplemental vitamin K may not be as effective. And to confuse matters more, Dr. Booth admits that “In our study, there was a higher prevalence of obese or overweight women in the vitamin K supplementation group compared to the male supplementation group,” making the seemingly negative results of vitamin K supplementation with women somewhat more inconclusive. The study was also only conducted on caucasians, giving no firm basis for whether the connection can translate to all races. “Also, our study is limited to caucasian adults. We acknowledge our findings may not apply to the general population,” says Dr. Booth.
Even with the limitations of the study, the results provide a substantial basis for further investigation into the connection. Insulin resistance, and the progression towards diabetes, is of frequent occurrence in the elderly, and any way to halt this process, would invariably bring a better quality of, and perhaps a longer, life.
Source: Defeat Diabetes Foundation: Booth, Sarah. Grossman, Andrea. Diabetes Care news release. November 2008.