Dean Pomerleau Posted October 14, 2015 Report Share Posted October 14, 2015 [Another one for the "non-CR diet and health" forum. If such a forum ever gets created, I promise I'll use my moderator super-powers to move all these threads to the new forum!] Dr. Greger's latest video titled Everything in Moderation? Even Heart Disease? has this interesting graph from  of cardiovascular disease and heart attacks as a function of total serum cholesterol level (click to enlarge): It shows that 35 percent of heart attacks occur in people with total serum cholesterol between 150 and 200 mg/dL. I had no idea it was that high. And virtually no heart attacks occur in people with cholesterol below 150 mg/dL, which is why many people (including me) have said it makes you virtually "heart attack proof". But then I started thinking, wait a minute. Couldn't this simply be a reflection of population statistics, and not reflect a causal relationship between cholesterol level and heart attacks? To understand this possibility, consider a similar plot of height vs. # of heart attacks. Assuming heart attacks are totally independent of height, you'd still see a similar bell curve of the number of heart attacks plotted against height, for the simple reason that height is distributed along a bell curve. So 50% of heart attacks would occur in men below the median height of 5'10" in the US, and furthermore only a tiny fraction of heart attacks (~3%) would occur in men shorter than 5'2", which is two standard deviations below the median. Does that mean that having a very short stature makes you heart attack proof? Of course not, it just means that there aren't many men shorter than 5'2" to contribute to the heart attack statistics. As an admirer of both Dr. Greger's work, I am sometimes disappointed when he uses potentially misleading statistics like this one to advance his perspective on diet and health (i.e. the value of following a plant-based diet - which I very much agree with). So what is the more accurate picture of the relationship between cholesterol and heart attack risk? Here is a graph, from , which BTW has a very good overview of various blood markers, including cholesterol sub-components and their association with CHD: As you can see from the graph on the right, CHD mortality rate (as opposed to total # of heart attacks) appears to be pretty asymptotic below 200 mg/dL. It's only when you get up to a total cholesterol of about 225 mg/dL that you see CHD mortality rate rising significantly, above which it goes through the roof. This is what's called evidence-based medicine, and it is why the American Heart Association and European equivalent (the European Societies for Cardiology, Hypertension and Diabetes) recommend keeping total cholesterol below 190-200, rather than necessarily trying to push it below 150 using diet or statins. With the latter, you might end up like this guy : So despite what Dr. Greger suggests, keeping one's total cholesterol below 150 mg/dL, as opposed to somewhere in the range of 150-200 mg/dL, doesn't appear to provide a dramatic benefit in terms of heart attack risk. To be fair, Dr. Greger has another video on the optimal cholesterol level for heart health that does seem to get the science better. It ignores total cholesterol level, and instead looks at all the randomized control trials of cholesterol lowering drugs, which suggest that an LDL level below 70 mg/dL (about 1/2 the average LDL level in US adults, 130 mg/dL) does make one virtually "heart attack proof". But then again, the relevance of results from people who are taking statins, not to mention the relevance for us of statin-induced LDL reduction or other positive effects of statins, make it far from certain that these results apply to people keeping LDL cholesterol low through diet and lifestyle choices. --Dean ---------------  Atherosclerosis. 1996 Jul;124 Suppl:S1-9. Lipids, risk factors and ischaemic heart disease.Castelli WP(1).Author information:(1)Framingham Cardiovascular Institute, MA 01701-9167, USA.Over 200 risk factors for cardiovascular disease (CVD) have now been identified.Among these, the three most important are (1) abnormal lipids, including the factthat there are more than 15 types of cholesterol-containing lipoproteins and fourdifferent types of triglyceride-rich particles, some of which are veryatherogenic, (2) high blood pressure, and (3) cigarette smoking. In addition,many other factors including diabetes, haemostatic factors such as fibrinogen,factor VII, plasminogen activator inhibitors, and new factors such asapolipoprotein E4 and homocysteine, are known to increase the risk of developingclinical CVD. A low risk for CVD requires that these various factors are presentin the circulation in the correct proportions. Two simple tests for determiningplasma lipid levels can be used to identify those individuals with an atherogeniclipid profile and who are, therefore, at increased risk for CVD. Firstly, theratio of total cholesterol to high density cholesterol (HDL cholesterol) shouldbe determined, followed by measurement of plasma triglyceride concentrations.This will allow differentiation of whether the low density lipoproteins (LDL),HDL cholesterol or triglyceride-rich particles such as the small dense beta-verylow density lipoproteins (VLDL) are the major cause for concern. Once identified,those individuals with a high lipid risk profile should be treated before, ratherthan after, experiencing coronary heart disease (CHD).PMID: 8831910 -------------------  The Journal of the International Federation of Clinical Chemistry and Laboratory Medicine Vol 13:2 (2003) THE ROLE OF LIPIDS IN THE DEVELOPMENT OF ATHEROSCLEROSIS AND CORONARY HEART DISEASE: GUIDELINES FOR DIAGNOSIS AND TREATMENT Victor Blaton Department of Clinical Chemistry, Hospital AZ Sint-Jan AV, Brugge, Belgium pdf: http://www.ifcc.org/ifccfiles/docs/140206200306.pdf Link to comment Share on other sites More sharing options...
This topic is now archived and is closed to further replies.