Selasa, 17 Maret 2009
Suriname starts free circumcision project (AFP)
PARAMARIBO (AFP) – Suriname has launched a three-month pilot project offering free circumcisions in a bid to cut sexually transmitted diseases, Health Minister Celsius Waterberg said Friday. Circumcision "could also minimize the risk of HIV infection", he said, adding the project would run in the capital city, Paramaribo. Some two percent of the Suriname population is HIV-infected, about 10,000 people, and the project aims to carry out the operations on 100 men aged between four and 21 years old over the next three months. If successful then the project will spread nationwide, Waterberg said. [Via]
Natural Supplements for Womens Health: Blood Sugar
Natural Supplements for Womens Health: Blood Sugar
One of the problems that women face is a blood sugar. There are a number of factors that can cause high blood sugar levels. Pregnancy and menopause change estrogen levels which affect metabolism and how body processes fat. In turn, that affects blood sugar levels. Menstruation also affects blood sugar, at least indirectly. Everyone has heard about "those pesky hormones" and all about craving certain foods like salty items such as chips or everyone's favorite treat, chocolate. With some dietary changes and a little help from supplements you can achieve a healthy balance in your blood sugar levels.
Tackling the Diet
Carbohydrates are important for your body, but eating too many of them in your diet can cause your blood sugar to have more drastic highs and lows. In addition, you'll find that more fat collects along your midriff and hips. By being selective in the types of carbs you ingest, you will still get what you need in your diet but without those blood sugar swings.
Just say no to processed foods. Basically white foods - anything with white flour and sugars - are converted more quickly to glucose in your body. This causes a spike in your blood sugar levels that lasts just a short time. Before you know it, your energy plummets and you feel lethargic because that "sugar rush" is gone. Then, in order to get that energy level back up, you eat more carbs and the cycle starts all over again.
By choosing carbohydrates that are found in whole grain foods, your body has to work harder to process them. What this means for you is that extreme high-low factor goes away and you are left with a more balanced blood sugar level and your energy level is more consistent. And because your body works harder to process these types of carbohydrates, you are expending calories, meaning less fat gets deposited in your mid-section.
Vitamins and Supplements
While taking care with your diet helps greatly, sometimes you just need an additional boost. This is where women supplements and vitamins for women come in. Business is booming with herbal supplements and special vitamin formulas. But which ones help with your blood sugar?
When your blood sugar levels fluctuate, it can be draining on your body and leave you feeling a bit sluggish. Taking supplements for women that contain chromium might give you a boost and alleviate some of that fatigue. If you have diabetes or might be prone to developing it, ginseng can also be beneficial. It has been known to boost metabolism and help control blood sugar.
If you are looking for vitamins or supplements you have to make sure you only buy high quality products. Always look for products from companies that only specialize in vitamins and supplements products for women. One of the companies that makes nutrients for women and specializes in supplements for women health is nutraOrigin.
There are a number of other women vitamins and supplements that could also be beneficial. However, be sure the check with your doctor to determine which ones might be best for you. If you are taking other medications, certain vitamins or women supplements might counteract with them.
It all boils down to common sense. Do your research into the different vitamins and supplements. Make positive changes in your diet. Women are built differently than men. Therefore, you must be more diligent with your body and what goes into it for your health.
Author Bio
This article was provided by nutraOrigin - the makers of nature-based supplements for women. For more information about various women health issues, tips and nutraOrigin products, visit http://www.nutraorigin.com/.
Article Source: http://www.ArticleGeek.com - Free Website Content
Senin, 16 Maret 2009
German researchers testing veggie Viagra: reports (AFP)
BERLIN (AFP) – German researchers are testing an impotency treatment for men made using only natural ingredients that in some cases works better than Viagra, newspapers reported Monday. "In clinical trials, 50 men had much better sex afterwards, more fun in bed and just generally felt better about themselves," the Sueddeutsche Zeitung daily cited Olaf Schroeder from Berlin's Charite hospital as saying. "Their libido was even higher than the control group taking Viagra," he said. The potent cocktail includes tribulus terrestris, a herb already used in alternative medicine, a root vegetable found in the Andes called maca and grape juice extract, newspapers said. The treatment, dubbed "Plantagrar", is due to be launched in early 2010, the Bild daily said. But some of those tested had unwelcome side effects. "Two of the subjects had bad diarrhoea," the Berliner Kurier quoted Schroeder as adding. [Via]
Minggu, 15 Maret 2009
Second-Generation Female Condom Approved (HealthDay)
WEDNESDAY, March 11 (HealthDay News) -- The Female Health Co.'s FC2 Female Condom has been approved by the U.S. Food and Drug Administration, the company said Wednesday. The product helps protect women against pregnancy and sexually transmitted diseases. The second-generation condom is similar in design and performance to the FC1, except that it is made of a synthetic rubber called nitrile and costs about 30 percent less, the company said. The FC1 was approved in 1993. The FDA approval of the FC2 will allow the U.S. Agency for International Development to distribute the condoms via global HIV/AIDS programs, the Associated Press reported. The first-generation FC1 has been distributed by United Nations agencies in 142 countries, the wire service said. More information To learn more about female condoms, visit the U.S. National Library of Medicine. [Via]
Natural Alternative To Hormone Replacement Thereapy (HRT)
Natural Alternative To Hormone Replacement Thereapy (HRT)
Most women experience the onset of the menopause at an average age of about 50, but it can start anytime from the early forties to the late fifties. Symptoms can vary: some women sail through but others suffer the miseries of hot flushes, night sweats, irritability, depression, lack of energy and loss of libido.
Orthodox medical practitioners invariably prescribe hormone replacement therapy (HRT) and often anti-depressants and tranquillisers, which can become addictive. However, there is a natural alternative.
HRT is prescribed to counter balance the reduced production by your body of oestrogen which can lead to increased risk of osteoporosis and weakened bones leading to fractures. However, two large clinical trials have shown that HRT does not, in fact, significantly reduce the incidence of bone fractures, and there is an increased risk of heart disease, gallstones, and breast and endometrial cancer.
Rather than a shortage of hormones, it is said that most menopausal symptoms are more to do with an imbalance. By eating a healthy diet, taking regular exercise and natural supplements, you can boost the health of your bones, and balance sugar levels and your hormones.
It is well known that people in some parts of the world (for example Japan and the Mediterranean countries) rarely suffer from heart disease due to their different national diets. It is less well known that women in the Andes region of Peru do not suffer menopausal symptoms. Peruvian women take Maca, a tuberous plant related to the potato. As well as the beneficial effect on menopausal symptoms, Maca boosts energy and libido. Maca is also known as "Peruvian Ginseng" and "Peruvian Viagra".
Centuries ago, the Incas inhabited this area and, in order to boost their energy, their warriors used to take Maca before going into battle. When the Spanish conquered the area they found that their horses suffered from the high altitude. The locals advised them to feed Maca to the horses and the animals immediately experienced an increase in energy levels. The Spanish found that what was good for their horses would also benefit humans, so payment for the taxes levied on the locals was taken in Maca.
There are three phases of menopause: the peri-menopause or the year or so prior to the onset of the menopause when the your body misses the occasional menstrual period. During this time a low dose of 1500mg is recommended to counteract the slow down in the production by your body of hormones. During the actual menopause, increase the dose to around 4000mg each day for a period of 2-3 months, and then reduce the dose to 2000mg. In the post menopause phase, reduce your daily intake of Maca to 1500mg. The risk of osteoporosis is apparent from the onset of the menopause and thereafter. In addition to your daily intake of maca, you are advised to also take a daily dose of Forever Freedom, a natural health drink that contains aloe vera with added Glucosamine, Chondroitin, MSM, and vitamin C. This will ease stiffness and pain in the joints and promote mobility and good bone health.
Author Bio
Tony Luck runs a website with advice about maca, a natural alternative to hormone replacement therapy (HRT) and other natural remedies.
Article Source: http://www.ArticleGeek.com - Free Website Content
Paleopathology at the Origins of Agriculture
In April of 1982, archaeologists from around the globe converged on Plattsburgh, New York for a research symposium. Their goal:
There are some major limitations to studying human health by looking at bones. The most obvious is that any soft tissue pathology will have been erased by time. Nevertheless, you can learn a lot from a skeleton. Here are the main health indicators discussed in the book:
There's so much information in this book, the best I can do is quote pieces of the editor's summary and add a few remarks of my own. One of the most interesting things I learned from the book is that the diet of many hunter-gatherer groups changed at the end of the upper Paleolithic, foreshadowing the shift to agriculture. From pages 566-568:
One of the interesting things I learned from the book is that Mesolithic populations, groups that were halfway between farming and hunting-gathering, were generally as healthy as hunter-gatherers:
One pathology that seems to have decreased with the adoption of agriculture is arthritis. The authors speculate that it may have more to do with strenuous activity than other aspects of the lifestyle such as diet. Another interpretation is that the hunter-gatherers appeared to have a higher arthritis rate because of their longer lifespans:
And the final word:
...[to use] data from human skeletal analysis and paleopathology [the study of ancient diseases] to measure the impact on human health of the Neolithic Revolution and antecedent changes in prehistoric hunter-gatherer food economies. The symposium developed out of our perception that many widely debated theories about the origins of agriculture had testable but untested implications concerning human health and nutrition and our belief that recent advances in techniques of skeletal analysis, and the recent explosive increase in data available in this field, permitted valid tests of many of these propositions.In other words, they got together to see what happened to human health as populations adopted agriculture. They were kind enough to publish the data presented at the symposium in the book Paleopathology at the Origins of Agriculture, edited by the erudite Drs. Mark Nathan Cohen and George J. Armelagos. It appears to be out of print, but luckily I have access to an excellent university library.
There are some major limitations to studying human health by looking at bones. The most obvious is that any soft tissue pathology will have been erased by time. Nevertheless, you can learn a lot from a skeleton. Here are the main health indicators discussed in the book:
- Mortality. Archaeologists are able to judge a person's approximate age at death, and if the number of skeletons is large enough, they can paint a rough picture of the life expectancy and infant mortality of a population.
- General growth. Total height, bone thickness, dental crowding, and pelvic and skull shape are all indicators of relative nutrition and health. This is particularly true in a genetically stable population. Pelvic depth is sensitive to nutrition and determines the size of the birth canal in women.
- Episodic stress. Bones and teeth carry markers of temporary "stress", most often due to starvation or malnutrition. Enamel hypoplasia, horizontal bands of thinned enamel on the teeth, is probably the most reliable marker. Harris lines, bands of increased density in long bones that may be caused by temporary growth arrest, are another type.
- Porotic hyperostosis and cribra orbitalia. These are both skull deformities that are caused by iron deficiency anemia, and are rather creepy to look at. They're typically caused by malnutrition, but can also result from parasites.
- Periosteal reactions. These are bone lesions resulting from infections.
- Physical trauma, such as fractures.
- Degenerative bone conditions, such as arthritis.
- Isotopes and trace elements. These can sometimes yield information about the nutritional status, diet composition and diet quality of populations.
- Dental pathology. My favorite! This category includes cavities, periodontal disease, missing teeth, abscesses, tooth wear, and excessive dental plaque.
In Upper Paleolithic times nutritional health was excellent. The evidence consists of extremely tall stature from plentiful calories and protein (and some microevolutionary selection?); maximum skull base height from plentiful protein, vitamin D, and sunlight in early childhood; and very good teeth and large pelvic depth from adequate protein and vitamins in later childhood and adolescence...The level of skeletal (including cranial and pelvic) development Paleolithic groups exhibited has remained unmatched throughout the history of agriculture. There may be exceptions but the trend is clear. Cranial capacity was 11% higher in the upper Paleolithic. You can see the pelvic data in this table taken from Paleopathology at the Origins of Agriculture.
Adult longevity, at 35 years for males and 30 years for females, implies fair to good general health...
There is no clear evidence for any endemic disease.
There's so much information in this book, the best I can do is quote pieces of the editor's summary and add a few remarks of my own. One of the most interesting things I learned from the book is that the diet of many hunter-gatherer groups changed at the end of the upper Paleolithic, foreshadowing the shift to agriculture. From pages 566-568:
During the upper Paleolithic stage, subsistence seems focused on relatively easily available foods of high nutritional value, such as large herd animals and migratory fish. Some plant foods seem to have been eaten, but they appear not to have been quantitatively important in the diet. Storage of foods appears early in many sequences, even during the Paleolithic, apparently to save seasonal surpluses for consumption during seasons of low productivity.Why am I getting the feeling that these archaeologists have a better grasp of human nutrition than the average medical doctor or nutritionist? They have the Price-esque understanding that comes from comparing the diets and multi-generational health of diverse human populations.
As hunting and gathering economies evolve during the Mesolithic [period of transition between hunting/gathering and agriculture], subsistence is expanded by exploitation of increasing numbers of species and by increasingly heavy exploitation of the more abundant and productive plant species. The inclusion of significant amounts of plant food in prehistoric diets seems to correlate with increased use of food processing tools, apparently to improve their taste and digestibility. As [Dr. Mark Nathan] Cohen suggests, there is an increasing focus through time on a few starchy plants of high productivity and storability. This process of subsistence intensification occurs even in regions where native agriculture never developed. In California, for example, as hunting-gathering populations grew, subsistence changed from an early pattern of reliance on game and varied plant resources to to one with increasing emphasis on collection of a few species of starchy seeds and nuts.
...As [Dr. Cohen] predicts, evolutionary change in prehistoric subsistence has moved in the direction of higher carrying capacity foods, not toward foods of higher-quality nutrition or greater reliability. Early nonagricultural diets appear to have been high in minerals, protein, vitamins, and trace nutrients, but relatively low in starch. In the development toward agriculture there is a growing emphasis on starchy, highly caloric food of high productivity and storability, changes that are not favorable to nutritional quality but that would have acted to increase carrying capacity, as Cohen's theory suggests.
One of the interesting things I learned from the book is that Mesolithic populations, groups that were halfway between farming and hunting-gathering, were generally as healthy as hunter-gatherers:
...it seems clear that seasonal and periodic physiological stress regularly affected most prehistoric hunting-gathering populations, as evidenced by the presence of enamel hypoplasias and Harris lines. What also seems clear is that severe and chronic stress, with high frequency of hypoplasias, infectious disease lesions, pathologies related to iron-deficiency anemia, and high mortality rates, is not characteristic of these early populations. There is no evidence of frequent, severe malnutrition, so the diet must have been adequate in calories and other nutrients most of the time. During the Mesolithic, the proportion of starch in the diet rose, to judge from the increased occurrence of certain dental diseases [with exceptions to be noted later], but not enough to create an impoverished diet... There is a possible slight tendency for Paleolithic people to be healthier and taller than Mesolithic people, but there is no apparent trend toward increasing physiological stress during the mesolithic.Cultures that adopted intensive agriculture typically showed a marked decline in health indicators. This is particularly true of dental health, which usually became quite poor.
Stress, however, does not seem to have become common and widespread until after the development of high degrees of sedentism, population density, and reliance on intensive agriculture. At this stage in all regions the incidence of physiological stress increases greatly, and average mortality rates increase appreciably. Most of these agricultural populations have high frequencies of porotic hyperostosis and cribra orbitalia, and there is a substantial increase in the number and severity of enamel hypoplasias and pathologies associated with infectious disease. Stature in many populations appears to have been considerably lower than would be expected if genetically-determined maxima had been reached, which suggests that the growth arrests documented by pathologies were causing stunting... Incidence of carbohydrate-related tooth disease increases, apparently because subsistence by this time is characterized by a heavy emphasis on a few starchy food crops.Infectious disease increased upon agricultural intensification:
Most [studies] conclude that infection was a more common and more serious problem for farmers than for their hunting and gathering forebears; and most suggest that this resulted from some combination of increasing sedentism, larger population aggregates, and the well-established synergism between infection and malnutrition.There are some apparent exceptions to the trend of declining health with the adoption of intensive agriculture. In my observation, they fall into two general categories. In the first, health improves upon the transition to agriculture because the hunter-gatherer population was unhealthy to begin with. This is due to living in a marginal environment or eating a diet with a high proportion of wild plant seeds. In the second category, the culture adopted rice. Rice is associated with less of a decline in health, and in some cases an increase in overall health, than other grains such as wheat and corn. In chapter 21 of the book Ancient Health: Bioarchaeological Interpretations of the Human Past, Drs. Michelle T Douglas and Michael Pietrusewsky state that "rice appears to be less cariogenic [cavity-promoting] than other grains such as maize [corn]."
One pathology that seems to have decreased with the adoption of agriculture is arthritis. The authors speculate that it may have more to do with strenuous activity than other aspects of the lifestyle such as diet. Another interpretation is that the hunter-gatherers appeared to have a higher arthritis rate because of their longer lifespans:
The arthritis data are also complicated by the fact that the hunter-gatherers discussed commonly displayed higher average ages at death than did the farming populations from the same region. The hunter-gatherers would therefore be expected to display more arthritis as a function of age even if their workloads were comparable [to farmers].In any case, it appears arthritis is normal for human beings and not a modern degenerative disease.
And the final word:
Taken as a whole, these indicators fairly clearly suggest an overall decline in the quality-- and probably in the length-- of human life associated with the adoption of agriculture.
Rabu, 11 Maret 2009
Are the MK-4 and MK-7 Forms of Vitamin K2 Equivalent?
The vitamin K found in food can be divided into two categories: phylloquinone
(K1) and menaquinone (K2). K1 is concentrated in leafy greens and other green vegetables. K2 can be further subdivided into menaquinone-4 through -14. The number represents the length of the side chain attached to the napthoquinone ring.
Menaquinone-"X" can be abbreviated MK-"X". MK-4 is the type synthesized by animals for their own use from K1 (and from MK-7 in rats). MK-5 through MK-14 are synthesized by bacteria. MK-7 in particular is made in large amounts by the bacterium Bacillus subtilis that ferments the infamous Japanese condiment natto. It's also sold as a supplement. Animals concentrate MK-4 in a number of organs, with smaller amounts of K1. Certain organs such as the brain, pancreas and salivary gland show an overwhelming preference for MK-4 over K1 in rodents and humans. The liver is a notable exception; in some animals, including humans, it concentrates longer menaquinones to a greater extent than MK-4 if they're present in the diet.
As far as I can tell, MK-4 is capable of performing all the functions of vitamin K. MK-4 can even activate blood clotting factors, which is a role traditionally ascribed to vitamin K1. Babies are often born clotting deficient, which is why we give newborns vitamin K1 injections in the U.S. to prevent hemorrhaging. In Japan, they give children MK-4 to prevent hemorrhage, an intervention that is very effective. Could that have to do with the fact that Japan has half the infant mortality rate of the U.S.?
Certain cultures would have had a predominance of MK-4 over other forms of vitamin K in the diet, which supports the idea that MK-4 can stand nearly alone. These cultures include heavy consumers of dairy like the Masai. Humans go through one of their most critical growth phases-- infancy-- with most of their vitamin K coming from MK-4. Colostrum, the first milk to come out, is particularly rich in MK-4.
Vitamin K is required to activate certain types of proteins, called Gla proteins. Gla stands for gamma-carboxyglutamic acid, a modified amino acid that's synthesized using vitamin K (by a reaction called gamma-carboxylation). Gla proteins are important: the class includes MGP, osteocalcin and blood clotting factors, important for keeping arteries clear, bones strong and blood clotting correctly.
I've said before that vitamin K's function is to carboxylate Gla proteins. In fact, that's a gross oversimplification. Research on vitamin K2 is turning up new functions all the time. One of the more exciting things that's been discovered is that it acts like hormone, activating a nuclear receptor called the steroid and xenobiotic receptor (SXR) and thereby influencing the expression of a number of genes. This puts it in the same category as vitamin A and D. It also acts as an antioxidant, a cofactor for sphingolipid synthesis in the brain, and an activator of protein kinase A signaling. These are all functions that have been studied in the context of MK-4, and for most of them, no one knows whether MK-7 has equivalent effects.
I'm always on the lookout for studies that can shed light on the question of whether MK-4 and MK-7 are equivalent. MK-7 is able to activate clotting factors and osteocalcin, so it can clearly function as a cofactor for gamma-carboxylation in some contexts. Osteocalcin is a Gla protein that's important for bone health. MK-7 supposedly hangs out in the blood for longer than MK-4 in humans, which is one of the things MK-7 supplement manufacturers like to mention, but these findings were conducted by MK-7 supplement vendors and the results have not been published. Interestingly, MK-4 and MK-7 have the exact same plasma half-life in rats, so I think the human experiment should be repeated. In any case, a longer plasma half-life is not evidence for superiority of one form over another in my opinion.
Today, I found another difference between MK-4 and MK-7. I was reading a paper about SXR-independent effects of vitamin K2 on gene expression. The investigators found that MK-4 strongly activates transcription of two specific genes in osteoblast cells. Osteoblasts are cells that create bone tissue. The genes are GDF15 and STC2 and they're involved in bone and cartilage formation. They tested K1 and MK-7, and in contrast to MK-4, they did not activate transcription of the genes in the slightest. This shows that MK-4 has effects on gene expression in bone tissue that MK-7 doesn't have.
I tend to think there's a reason why animals synthesize MK-4 rather than other forms of vitamin K2. Vitamin K2 MK-4 seems to be able to perform all the functions of vitamin K, including activating Gla proteins, participating in sphingomyelin synthesis, binding SXR, and activating transcription through protein kinase A. That's what you would expect for an animal that had evolved to use its own form of K2. Investigators haven't tested whether MK-7 is capable of performing all these functions, but apparently there's at least one it cannot perform.
I'd bet my bottom dollar there are other important functions of MK-4 that have not yet been identified, and functions whose full importance has not yet been appreciated. There's no way to know whether MK-7 can fully stand in for MK-4 as long as we don't know all of MK-4's functions. I also think it's worth mentioning that MK-4 is the only form of vitamin K2 that's been shown to reduce fracture risk in clinical trials.
That being said, MK-7 may still have a place in a healthy diet. Just because it can't do everything MK-4 can, doesn't mean it has no role. It may be able to fill in for MK-4 in some functions, or reduce the dietary need for MK-4. But no one really knows at this point. Hunter-gatherers would have had a source of longer menaquinones, including MK-7, from livers. So it's possible that we're adapted to a modest MK-7 intake on top of MK-4.
(K1) and menaquinone (K2). K1 is concentrated in leafy greens and other green vegetables. K2 can be further subdivided into menaquinone-4 through -14. The number represents the length of the side chain attached to the napthoquinone ring.
Menaquinone-"X" can be abbreviated MK-"X". MK-4 is the type synthesized by animals for their own use from K1 (and from MK-7 in rats). MK-5 through MK-14 are synthesized by bacteria. MK-7 in particular is made in large amounts by the bacterium Bacillus subtilis that ferments the infamous Japanese condiment natto. It's also sold as a supplement. Animals concentrate MK-4 in a number of organs, with smaller amounts of K1. Certain organs such as the brain, pancreas and salivary gland show an overwhelming preference for MK-4 over K1 in rodents and humans. The liver is a notable exception; in some animals, including humans, it concentrates longer menaquinones to a greater extent than MK-4 if they're present in the diet.As far as I can tell, MK-4 is capable of performing all the functions of vitamin K. MK-4 can even activate blood clotting factors, which is a role traditionally ascribed to vitamin K1. Babies are often born clotting deficient, which is why we give newborns vitamin K1 injections in the U.S. to prevent hemorrhaging. In Japan, they give children MK-4 to prevent hemorrhage, an intervention that is very effective. Could that have to do with the fact that Japan has half the infant mortality rate of the U.S.?
Certain cultures would have had a predominance of MK-4 over other forms of vitamin K in the diet, which supports the idea that MK-4 can stand nearly alone. These cultures include heavy consumers of dairy like the Masai. Humans go through one of their most critical growth phases-- infancy-- with most of their vitamin K coming from MK-4. Colostrum, the first milk to come out, is particularly rich in MK-4.
Vitamin K is required to activate certain types of proteins, called Gla proteins. Gla stands for gamma-carboxyglutamic acid, a modified amino acid that's synthesized using vitamin K (by a reaction called gamma-carboxylation). Gla proteins are important: the class includes MGP, osteocalcin and blood clotting factors, important for keeping arteries clear, bones strong and blood clotting correctly.
I've said before that vitamin K's function is to carboxylate Gla proteins. In fact, that's a gross oversimplification. Research on vitamin K2 is turning up new functions all the time. One of the more exciting things that's been discovered is that it acts like hormone, activating a nuclear receptor called the steroid and xenobiotic receptor (SXR) and thereby influencing the expression of a number of genes. This puts it in the same category as vitamin A and D. It also acts as an antioxidant, a cofactor for sphingolipid synthesis in the brain, and an activator of protein kinase A signaling. These are all functions that have been studied in the context of MK-4, and for most of them, no one knows whether MK-7 has equivalent effects.
I'm always on the lookout for studies that can shed light on the question of whether MK-4 and MK-7 are equivalent. MK-7 is able to activate clotting factors and osteocalcin, so it can clearly function as a cofactor for gamma-carboxylation in some contexts. Osteocalcin is a Gla protein that's important for bone health. MK-7 supposedly hangs out in the blood for longer than MK-4 in humans, which is one of the things MK-7 supplement manufacturers like to mention, but these findings were conducted by MK-7 supplement vendors and the results have not been published. Interestingly, MK-4 and MK-7 have the exact same plasma half-life in rats, so I think the human experiment should be repeated. In any case, a longer plasma half-life is not evidence for superiority of one form over another in my opinion.
Today, I found another difference between MK-4 and MK-7. I was reading a paper about SXR-independent effects of vitamin K2 on gene expression. The investigators found that MK-4 strongly activates transcription of two specific genes in osteoblast cells. Osteoblasts are cells that create bone tissue. The genes are GDF15 and STC2 and they're involved in bone and cartilage formation. They tested K1 and MK-7, and in contrast to MK-4, they did not activate transcription of the genes in the slightest. This shows that MK-4 has effects on gene expression in bone tissue that MK-7 doesn't have.
I tend to think there's a reason why animals synthesize MK-4 rather than other forms of vitamin K2. Vitamin K2 MK-4 seems to be able to perform all the functions of vitamin K, including activating Gla proteins, participating in sphingomyelin synthesis, binding SXR, and activating transcription through protein kinase A. That's what you would expect for an animal that had evolved to use its own form of K2. Investigators haven't tested whether MK-7 is capable of performing all these functions, but apparently there's at least one it cannot perform.
I'd bet my bottom dollar there are other important functions of MK-4 that have not yet been identified, and functions whose full importance has not yet been appreciated. There's no way to know whether MK-7 can fully stand in for MK-4 as long as we don't know all of MK-4's functions. I also think it's worth mentioning that MK-4 is the only form of vitamin K2 that's been shown to reduce fracture risk in clinical trials.
That being said, MK-7 may still have a place in a healthy diet. Just because it can't do everything MK-4 can, doesn't mean it has no role. It may be able to fill in for MK-4 in some functions, or reduce the dietary need for MK-4. But no one really knows at this point. Hunter-gatherers would have had a source of longer menaquinones, including MK-7, from livers. So it's possible that we're adapted to a modest MK-7 intake on top of MK-4.
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