Heart disease, including atheroslcerotic cardiovascular disease, is a leading cause of death worldwide. Its associated inflammation and metabolic dysfunction can be prevented with a diet high in nutrient dense foods such as those commonly found in the Mediterranean diet. Findings of a new report indicate that a high intake of vitamin K - a micronutrient found at high levels in common Mediterranean meals - might reduce the incidence of atherosclerotic disease.

Atherosclerosis refers to the hardening of arteries due to the formation of plaques composed of fats, cellular debris, white blood cells, fibrous connective tissue, and calcium. White blood cells called macrophages deposit calcium in these plaques to stabilize them, but the plaques become stiff and fragile over time, increasing the risk of blood clots, heart attack, and stroke. Vitamin K is needed to produce proteins necessary for blood clotting and controls the concentration of calcium in the bones and other tissues. Vitamin K1, called phylloquinone, is found in photosynthetic plants, such as green leafy vegetables. Vitamin K2, called menaquinone, is found in fermented foods, such as cheese and sauerkraut. The recommended daily intake of vitamin K (K1 and K2 combined) is 120 micrograms per day for adult males and 90 micrograms per day for adult females.

The authors analyzed data from the Danish Diet, Cancer, and Health Study, which included over 50,000 participants between the ages of 52 and 60 years old who did not have atherosclerostic cardiovascular disease. At baseline, participants completed questionnaires to assess habitual food intake, which allowed the researchers to estimate their total vitamin K intake. Medical records were then used to measure the number of hospital admissions for cardiovascular diseases that these participants endured over an average of 21 years.

At baseline, intake of vitamin K1 ranged from 80 to 151 micrograms per day and intake of vitamin K2 ranged from 31 to 61 micrograms per day. Margarine, lettuce, broccoli, whole-brain bread, and spinach were the main sources of vitamin K1, while eggs, butter, and hard cheeses were the main sources of vitamin K2. Participants in the bottom 20 percent of consumption were considered to have low intake, while participants in the top 20 percent of consumption were considered to have high intake.

Participants with high vitamin K1 intake had a 21 percent lower risk of hospitalization due to atherosclerotic cardiovascular disease than participants with the lowest intakes. Participants with high vitamin K2 intake had a 14 percent lower risk of hospitalization due to atherosclerotic cardiovascular disease than participants with the lowest intakes. These risk reductions also took into account factors such as physical activity, education, smoking, and overall diet quality.

The authors concluded that high intake of both vitamin K1 and vitamin K2 are protective against atherosclerotic cardiovascular disease. For a great way to add more vitamin K to your diet, check out this micronutrient smoothie from Dr. Rhonda Patrick

• Link to full report.