An amazing dietary study was launched in Spain in 2003, to look at the effects of a Mediterranean diet on the prevention of cardiovascular disease. Researchers also looked at all cause mortality, diabetes, cancer, dementia and other diseases. 7000 asymptomatic participants ages 55 -80 were selected and followed for 5 years. The subjects were divided into 3 groups – one given extra-virgin olive oil - one liter per week, one given supplemental nuts (walnuts, almonds, and hazelnuts) about 2 tablespoons a day, and one advised to follow a low-fat diet. The first two groups were instructed to follow the Mediterranean diet, high in vegetables and fruits, fish, legumes, grains, and olive oil, and low in meat and dairy products. Wine was permitted, sweets limited. The control group was instructed on a low fat diet. After 5 years, participants following the diets enhanced with olive oil or nuts had a 30% lower risk of dying from cardiovascular disease or having a heart attack or stroke, compared to those on a low fat diet. They also had less cognitive decline. These are impressive results.
Researchers also looked at the Vitamin K intake of participants in this study. People with the highest intake of foods containing Vitamin K were 46% less likely to die of cancer and 36% less likely to die from any cause than those with the lowest intake. Again - impressive results.
Vitamin K – named for the German word for coagulation – helps blood to clot by activating certain proteins made in the liver. It is found in a variety of foods, but mainly in leafy green and cruciferous vegetables. People taking Coumadin to reduce the propensity of blood to form clots are counseled to eat a consistent amount of leafy greens daily to match their dose of Coumadin.
Vitamin K has also been studied for its role in bone metabolism. A Japanese study found that people from regions where vitamin K foods were eaten in abundance had fewer hip fractures. Several other studies from Europe have shown similar results. While supplementation with vitamin K is not considered necessary for most people, eating green vegetables is always a plus.
Sadja Greenwood, MD MPH