"Chris Kresser, M.S., L.Ac is a globally recognized leader in the fields
of ancestral health, Paleo nutrition, and functional and integrative
medicine." The Paleo diet excludes dairy and grains. I eat both dairy and grains myself. I am not advocating the Paleo diet, but it may be beneficial for those with allergies or sensitivities to milk or grains or gluten intolerance.
In the following article, he discusses the benefits of vitamin K2.
by Chris Kresser
"A study recently published by the
European Prospective Investigation into Cancer and Nutrition (EPIC)
has revealed that increased intake of vitamin K2 may reduce the risk of
prostate cancer by 35 percent. The authors point out that the benefits
of K2 were most pronounced for advanced prostate cancer, and,
importantly, that vitamin K1 did not offer any prostate benefits.
The findings were based on data from more than 11,000 men taking part
in the EPIC Heidelberg cohort. It adds to a small but fast-growing body
of science supporting the potential health benefits of vitamin K2 for
bone, cardiovascular, skin, brain, and now prostate health.
Unfortunately, many people are not aware of the health benefits of
vitamin K2. The K vitamins have been underrated and misunderstood up
until very recently in both the scientific community and the general
public.
It has been commonly believed that the benefits of vitamin K are
limited to its role in blood clotting. Another popular misconception is
that vitamins K1 and K2 are simply different forms of the same vitamin –
with the same physiological functions.
New evidence, however, has confirmed that vitamin K2’s role in the
body extends far beyond blood clotting to include protecting us from
heart disease, ensuring healthy skin, forming strong bones, promoting brain function,
supporting growth and development and helping to prevent cancer – to
name a few. In fact, vitamin K2 has so many functions not associated
with vitamin K1 that many researchers insist that K1 and K2 are best
seen as two different vitamins entirely.
A large epidemiological study from the Netherlands illustrates this
point well. The researchers collected data on the vitamin K intakes of
the subjects between 1990 and 1993 and measured the extent of heart
disease in each subject, who had died from it and how this related to
vitamin K2 intake and arterial calcification. They found that
calcification of the arteries was the best predictor of heart disease.
Those in the highest third of vitamin K2 intakes were 52 percent less
likely to develop severe calcification of the arteries, 41 percent less
likely to develop heart disease, and 57 percent less likely to die from
it. (Geleijnse et al., 2004, pp. 3100-3105)
However, intake of vitamin K1 had no effect on cardiovascular disease outcomes.
While K1 is preferentially used by the liver to activate blood
clotting proteins, K2 is preferentially used by other tissues to deposit
calcium in appropriate locations, such as in the bones and teeth, and
prevent it from depositing in locations where it does not belong, such
as the soft tissues.(Spronk et al., 2003, pp. 531-537) In an
acknowledgment of the different roles played by vitamins K1 and K2, the
United States Department of Agriculture (USDA) finally determined the
vitamin K2 contents of foods in the U.S. diet for the first time in
2006. (Elder, Haytowitz, Howe, Peterson, & Booth, 2006, pp. 436-467)
Another common misconception is that human beings do not need vitamin
K2 in their diet, since they have the capacity to convert vitamin K1 to
vitamin K2. The amount of vitamin K1 in typical diets is ten times
greater than that of vitamin K2, and researchers and physicians have
largely dismissed the contribution of K2 to nutritional status as
insignificant.
However, although animals can convert vitamin K1 to vitamin K2, a
significant amount of evidence suggests that humans require preformed K2
in the diet to obtain and maintain optimal health. The strongest
indication that humans require preformed vitamin K2 in the diet is that
epidemiological and intervention studies both show its superiority over
K1. Intake of K2 is inversely associated with heart disease in humans
while intake of K1 is not (Geleijnse et al., 2004, pp. 3100-3105), and
vitamin K2 is at least three times more effective than vitamin K1 at
activating proteins related to skeletal metabolism. (Schurgers et al.,
2007) And remember that in the study on vitamin K2’s role in treating
prostate cancer, which I mentioned at the beginning of this article,
vitamin K1 had
no effect.
All of this evidence points to the possibility that vitamin K2 may be
an essential nutrient in the human diet. So where does one find vitamin
K2 in foods? The following is a list of the foods highest in vitamin
K2, as measured by the USDA:
Foods high in vitamin K2
- Natto
- Hard cheese
- Soft cheese
- Egg yolk
- Butter
- Chicken liver
- Salami
- Chicken breast
- Ground beef
Unfortunately, precise values for some foods that are likely to be
high in K2 (such as organ meats) are not available at this time. The
pancreas and salivary glands would be richest; reproductive organs,
brains, cartilage and possibly kidneys would also be very rich; finally,
bone would be richer than muscle meat. Fish eggs are also likely to be
rich in K2.
It was once erroneously believed that intestinal bacteria are a major
contributor to vitamin K status. However, the majority of evidence
contradicts this view. Most of the vitamin K2 produced in the intestine
are embedded within bacterial membranes and not available for
absorption. Thus, intestinal production of K2 likely makes only a small
contribution to vitamin K status. (Unden & Bongaerts, 1997, pp.
217-234)
On the other hand, fermented foods, however, such as sauerkraut,
cheese and natto (a soy dish popular in Japan), contain substantial
amounts of vitamin K2. Natto contains the highest concentration of K2 of
any food measured; nearly all of it is present as MK-7, which research
has shown to be a highly effective form. A recent study demonstrated
that MK-7 increased the percentage of osteocalcin in humans three times
more powerfully than did vitamin K1. (Schurgers & Vermeer, 2000, pp.
298-307)
It is important to note that commercial butter is not a significantly
high source of vitamin K2. Dr. Weston A. Price, who was the first to
elucidate the role of vitamin K2 in human health (though he called it
“Activator X” at the time) analyzed over 20,000 samples of butter sent
to him from various parts of the world. As mentioned previously in this
paper, he found that the Activator X concentration varied 50-fold.
Animals grazing on vitamin K-rich cereal grasses, especially wheat
grass, and alfalfa in a lush green state of growth produced fat with the
highest amounts of Activator X, but the soil in which the pasture was
grown also influenced the quality of the butter. It was only the
vitamin-rich butter grown in three feet or more of healthy top soil that
had such dramatic curing properties when combined with cod liver oil in
Dr. Price’s experiments and clinical practice.
Therefore, vitamin K2 levels will not be high in butter from
grain-fed cows raised in confinement feedlots. Since the overwhelming
majority of butter sold in the U.S. comes from such feedlots, butter is
not a significant source of K2 in the diet for most people. This is yet
another argument for obtaining raw butter from cows raised on green
pasture.
New research which expands our understanding of the many important
roles of vitamin K2 is being published at a rapid pace. Yet it is
already clear that vitamin K2 is an important nutrient for human health –
and one of the most poorly understood by medical authorities and the
general public."
http://chriskresser.com/vitamin-k2-the-missing-nutrient
