In 1945, Dr. Weston Price, the pioneer of nutritional epidemiology, published a revised edition of his masterwork, Nutrition and Physical Degeneration, including a new chapter called 'A New Vitamin-Like Activator.' Price described his experiments with a fat-soluble substance vital to healthy bones and teeth found in the butter of cows raised on grass. The grass-fed butter was remarkably effective in curing a number of chronic conditions, including tooth decay, rickets, and seizures. It was even more powerful when combined with cod liver oil. Price called the magic ingredient Activator X.
Some 60 years later, researchers have identified Activator X. It is vitamin K2, a fat-soluble vitamin essential for optimal dental, skeletal, and cardiovascular health. Vitamin K2 has an interesting role: it puts calcium where it belongs (in the bones and teeth) and keeps it away from the places it doesn't belong, such as the arteries, where plaques calcify. Vitamin K2 is essential for healthy development and growth in children. Its effects are subtle: though K2 makes bones dense and strong, it also prevents premature calcification of the cartilaginous parts of bones, the soft parts which allow your baby's bones to grow.
Vitamin K2 can be made in the body from vitamin K1, which is found in green vegetables, but ideally your diet will contain ample sources of K2 itself. Animals who eat grass use K1 to make K2 and thus they are the best dietary source. Get your K2 from the butter, organ meats, and fat of animals raised on grass. A reliable sign of K2 is the rich yellow color of butter from cows on grass; K2's precursor is related to beta carotene. (If you prefer a supplement, you can also buy K2-rich butter oil. Some bacteria also make K2, and you'll find that kind of K2 in fermented foods such as natto, a Japanese soy food.)
Now we know what Price could only surmise: why traditional people went to so much trouble to get fatty meats, organ meats, and grass-fed butter - the 'high vitamin' foods, as Price called them.
K2 is an interesting fellow among vitamins. K2 is made in your reproductive organs. Sperm contains a protein that relies on K2. There is a lot of K2 in your pancreas, brain, and saliva, where it builds healthy enamel and protects you from tooth decay. K2 deficiency (good name for a band) causes fatigue and lethargy in lab animals. K2 prevents heart disease by inhibiting inflammation and calcification of the arteries.
Do you need more K2? If you're vegan or vegetarian or trying to conceive, you probably do. Foods rich in K2 were the heart of fertility diets Price studied. Recall that Price found the combination of cod liver oil and K2 butter powerfully effective. That's because cod liver oil is rich in vitamins A and D, which have several synergetic relationships with K2. In plain language, that means A, D, and K2 work together to build bones, among other vital tasks. A and D are less effective without K2 and vice versa.
If it's bone health you're after, consider one more virtue of traditional diets: saturated fat. You need saturated fat to lay down minerals (such as calcium) in your bones. Studies show that polyunsaturated fats (soybean oil) depress mineralization while saturated fats (butter and palm oil) stimulate bone density. That's why I don't drink skim milk and cannot recommend it, especially for women who are concerned about osteoporosis.
If you're worried about the effects of natural saturated fats on your heart, fear not. The net effect of these traditional fats, such as butter, is to raise HDL. On the virtues of HDL, the National Cholesterol Education Program is clear: 'the higher, the better.' New evidence suggests that LDL is not the villain either, but a repair molecule sent to damaged arteries to fix them.
You might instead choose to avoid the new, 'trans fat-free' non-butter, vegetable-oil based 'buttery' spreads. (I grimace as I type the hype, consoling myself that imitation of traditional foods is the sincerest form of flattery.) Now that trans-fats are known killers, Big Food brings you a new process for making industrial soy bean oil spreadable, because they know how much you want your butter.
How do they do it? By scrambling the fatty acids in a process called interesterification. It appears we won't have to wait 60 years to discover that these fats are not good for you, either. In a recent study by K.C. Hayes, interesterified fats lowered HDL (that's bad), depressed insulin (that's bad), and raised blood sugar (also bad). Compared to what? Good question. Compared to palm oil - yes, the highly saturated tropical fat they taught you to fear.
Remember the rule: if your great-grandmother ate it, it's probably OK.
A highball sits on a bar. Researchers find that men who had two or more alcoholic beverages daily were 33 per cent less likely to develop BPH than teetotalers. Richard Arless Jr/Montreal Gazette 
