David, you write that you would "
like to debate the point that science really is broken in this area", but that is what we have been debating from the start, at least from my perspective. It's one big reason why I pulled you up in the first place. Even more important though in my view is the debate over the outcomes of "high fat low carb" versus "high carb low fat" diets - and I am
not just referring to health. Even more important are the ethical and environmental implications of those diets. A "high fat low carb" diet is essentially one that relies on animal products.
[1] In my view, this diet is bankrupt in all three ways: ethically, environmentally, and health-wise.
Zoë Harcombe argues that the overall weight of evidence against saturated fats was and is lacking, however, other academics disagree, and there nevertheless
is strong evidence to support the current dietary guidelines, which recommend minimising saturated fat. We've covered the Seven Countries Study already to some extent; other supportive analyses are detailed in:
- The 2016 paper, Association of Specific Dietary Fats With Total and Cause-Specific Mortality. "This cohort study investigated 83,349 women from the Nurses' Health Study (July 1, 1980, to June 30, 2012) and 42,884 men from the Health Professionals Follow-up Study (February 1, 1986, to January 31, 2012) who were free of cardiovascular disease, cancer, and types 1 and 2 diabetes at baseline." It found that "Replacing 5% of energy from saturated fats with equivalent energy from PUFA and MUFA was associated with estimated reductions in total mortality of 27% (HR, 0.73; 95% CI, 0.70-0.77) and 13% (HR, 0.87; 95% CI, 0.82-0.93), respectively". The 2017 review report prepared by the Sax Institute for the National Heart Foundation of Australia suggests of this study that "Although this data comes from only two cohorts combined, the updating of dietary information every four years adds a lot of weight to the findings, which are probably more reliable than larger meta-analyses combining weaker studies."
- The 2009 paper, Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies, which, similarly, found that "For a 5% lower energy intake from SFAs and a concomitant higher energy intake from PUFAs, there was a significant inverse association between PUFAs and risk of coronary events (hazard ratio: 0.87; 95% CI: 0.77, 0.97); the hazard ratio for coronary deaths was 0.74 (95% CI: 0.61, 0.89)" and which concludes that "replacing SFAs with PUFAs rather than MUFAs or carbohydrates prevents CHD over a wide range of intakes" (and yes, this is a finding with respect to CVD not all-cause mortality).
- The 2015 Cochrane Systematic Review, Reduction in saturated fat intake for cardiovascular disease the findings of which were "suggestive of a small but potentially important reduction in cardiovascular risk on reduction of saturated fat intake" (and again: yes, this is a finding with respect to CVD not all-cause mortality).
Zoë Harcombe acknowledges the latter paper in the slides for her talk, but I couldn't find mention of the former two - perhaps I simply didn't look hard enough, but more likely, this is not so much an example of dysfunctional science as of a deliberate avoidance of studies that don't support a predetermined view.
David, switching back to butter in the interests of health is not a good idea - but in any case health is the least of the issues.
Far more relevant are
the gross ethical problems with dairy, which, honestly, render the whole debate about any human health (dis)advantages irrelevant. Please do look at that link. We have an obligation to consider the full implications of our consumer choices.
In the meantime, a few comments on recent posts:
Re Dr Greger's manner of speech: perhaps this is simply a matter of taste, because I appreciate his style of verbal presentation. Along similar lines, some people with whom I've shared
Joanna Newsom's music find her voice annoying; I find it delightful and entrancing!
Is Dr Greger selling something? In a way, isn't everybody who advocates for a particular diet, including Zoë Harcombe? When it comes to strictly financial compensation, however, Dr Greger is, it appears to me,
on the up and up. And, for what it's worth, Zoë Harcombe was selling diet books
before conducting the meta-analytic studies to which she refers in her talk, for which
a correction was published...
Re Dr Harcombe's take on Dr Greger ("Greger" with a "G" in the middle, not a "B", by the way): yes, it would have been appropriate for his Daily Mail article to have made clear the need on a vegan diet for B12 supplementation, and the likelihood that supplementing with D and DHA/EPA would be beneficial - but in his other output he makes all of this very clear. Re the apparent deficits in other nutrients: firstly, most of those deficits are due to the energy deficit - Dr Greger didn't say "eat this and only this", but "eat
at least this", which Dr Harcombe at least acknowledges - and, secondly, for those concerned about nutrient deficits, a precautionary multivitamin can allay those concerns anyway.
Re the graphs: I'm not really sure from where you sourced them and what you want us to take from them, David.
I don't have much to say re your list of points pertaining to scientific scandals except for three and five. Starting with three:
For example, if it was impossible to pick up the relationship between CVD and fat consumption from dietary studies, why were these ever performed?
A good question, and I asked something similar when sharing Dr Greger's video in the first place. I don't speak for him, but here are a few possibilities:
- The paper to which he referred concludes with this (emphasis mine): "A corollary of the mathematical model here presented is that a correlation close to zero would likely be observed between diet and coronary heart disease incidence. For another disease in which diet is a cause agent, a prospective incidence study following a cross-sectional assessment of diet would presumably be valuable. An appropriate design for demonstrating or refuting diet and coronary heart disease incidence is a dietary change experiment." Thus, according to the paper, cross-sectional dietary studies are presumably valuable in studying health outcomes other than coronary heart disease.
- Perhaps those who conducted these studies were:
- Unaware or otherwise skeptical of this paper, or,
- Aware that a correlation was unlikely to be found, but attempted to find one anyway in the hope that the statistical power just happened to be high enough.
5) Often we see the boundaries between scientific disciplines used to exclude well informed critics. Thus a very prominent physicist is dismissed because he isn't an expert in climatology, or a prominent cardiologist is dismissed because he isn't a nutritionist, or indeed that a professor of Exercise Science and Sports Medicine isn't qualified to speak about nutrition!
I'm genuinely puzzled by this, David: doesn't this totally cut both ways - and worse - and wouldn't you as a highly intelligent person have realised this? I mean, isn't it effectively
by definition the case in supposed "corruptions of consensus" (if I might put it like that) that
far more experts are dismissed by "skeptics" such as yourself than are dismissed by "defenders of the status quo"? Aren't
you in effect dismissing
many very prominent climate scientists who
are experts in climatology?!
Also, I'm not sure whether in your final sentence you're referring to my own take on Professors Yusuf and Noakes, but if you are, I want to make clear (again) that I don't simply "dismiss" them. I've simply questioned the consistency of their claims/findings with those of others - others whom in some cases I believe are much more credible.
And, hey, if we want to refer to the opinions of prominent cardiologists, then how about Dr Joel Kahn, MD (to whom I've referred in an earlier post)? "
Dr Kahn is an Interpreventional Cardiologist, Clinical Professor of Medicine at Wayne State University School of Medicine, Founder of the Kahn Center for Cardiac Longevity in Michigan, and a Summa Cum Laude graduate of the University of Michigan’s prestigious Inteflex program (a 6-year undergraduate / graduate program that developed doctors fresh out of high school). He’s authored hundreds of articles on heart disease, is a frequent lecturer on heart disease and its prevention, has performed thousands of cardiac procedures, and is the owner of GreenSpace Café in Ferndale and Royal Oak Michigan".
Here's Dr Kahn's view on cholesterol:
Why a Low LDL-Cholesterol Still Matters a Lot For Your Health: New Science to Know. Unfortunately, the links in that article are broken, so the original research is - for the moment - inaccessible. In any case, here's how his article starts:
Any debate about the role of controlling abnormal lipid levels in patients at high risk for or with known coronary or vascular disease was resolved when exhaustive analyses on the role of LDL and atherosclerosis were published. These studies examined genetic, epidemiologic, and clinical studies as a consensus statement of the European Atherosclerosis Society.
You should definitely check out the videocast linked to above (at the start of the description of Dr Kahn). Here it is as an embedded video for your convenience. The whole thing is very worth watching / listening to as a contextualisation of the diet wars and the common ground in those wars, but if you're especially interested in the debate about saturated fat, then simply watch/listen between (approximately) 1:12:30 and 1:28:00:
For the animals.
Laird
[1] Although it
is possible to eat a high-fat vegan diet.