Near-death experience with nattokinase 16. May 2010 William Davis (22) This is a true story that I personally witnessed. A 60-some year old man heard that nattokinase "thinned the blood." So he had been taking it for the past 6 months. One week before he came to see me, he abruptly became quite breathless. He was unable to walk more than 20 feet or bend over to tie his shoes due to the breathlessness. He came to see me in the office. I was alarmed by how breathless he was without signs of heart failure or other obvious explanation. I sent him for an immediate CT pulmonary angiogram. Within 30 minutes, we had the diagnosis: a large "saddle" pulmonary embolus, meaning a large blood clot that straddled the right and left main pulmonary arteries. One wrong move and . . . bang! He would have been dead within a couple of minutes, since a large clot can completely occlude the large arteries feeding the lung, essentially corking any blood circuiting through the lungs and back to the left side of the heart. (Causing, incidentally, electromechanical dissociation, in which the heart keeps beating for a few minutes but no blood is being pumped. CPR can keep you alive for a few minutes, then it's over.) When I advised the patient of the diagnosis (after initiating the REAL anticoagulants), he said, "But I was taking nattokinase!" Exactly. Blood clots are no laughing matter. They are potentially fatal events. Betting your life on some company's advertisement is nothing short of foolish. Anyone who reads The Heart Scan Blog knows that I am an avid supporter of nutritional supplements. I even write articles and consult for the supplement industry. But I truly despise hearing unfounded marketing claims that some supplement companies will make in the pursuit of a fast buck. There is no doubt that we need better, safer methods to deal with dangerous blood clots, whether in the lung, pelvis, or other areas. But, before anyone takes a leap based on the extravagant marketing claims made by a supplement manufacturer, you want to be damn sure there are real data--not marketing claims, REAL data--before you use something like nattokinase in place of a proven therapy. Don't confuse the very interesting, though unpalatable, natto with nattokinase. Natto contains vitamin K2 and some other interesting compounds, including nattokinase.