In 2008 there was a meeting in Mexico City of the representatives of the global dairy industry. They sought to show that saturated fat, the primary fat in dairy and meat products, was not a major health hazard and they adopted a strategy to do this.
First, they funded a researcher to do a study that used a questionable methodology in 2011. The authors controlled for cholesterol level. Since saturated fat reliably raises cholesterol in metabolic ward studies, and since the reason saturated fat causes vascular disease is because it raises cholesterol; they were able to magically make the connection go away.
Time magazine followed with a cover telling you to eat butter. Multiple similar studies have since been published to much media acclaim, all of them part of a concerted food industry effort to exonerate saturated fat. Most of this campaign has progressed unopposed by the scientific establishment that should know better.
But a clear response from the torpid scientific establishment is finally beginning to take shape, almost a decade later. In May 2017 we talked about the European Atherosclerosis Society’s statement that LDL causes heart disease.
Yesterday, the American Heart Association published an extensive and detailed criticism of the effort to put butter and lard back on the American table. If you follow my work, you will already know that the basis of the Heart Association’s argument is one that is simple enough. I’ll quote from the report:
The scientific rationale for decreasing saturated fat in the diet has been and remains based on well-established effects of saturated fat to raise low-density lipoprotein (LDL) cholesterol, a leading cause of atherosclerosis; to cause atherosclerosis in several animal species, especially nonhuman primates; to clear the atherosclerosis in animals when it is reduced in the diet; and likewise to reverse atherosclerosis in humans. … Populations with very low saturated fat intake such as in East Asian and Mediterranean countries have very low rates of CVD, and members of many single populations who have low saturated and high unsaturated fat intake have lower future incidence of CVD compared with those with high saturated and low unsaturated fat intake.
No hand-waving can make these facts go away. Randomized trials are great for drugs, but they aren’t so good for diet. Dietary diseases can take decades to develop and it can be very difficult to afford the total cost of such large scale trials, not to mention free-living people aren’t very likely to follow advice strictly.
That is why no randomized controlled trial has ever shown that telling people to quit smoking benefits them. This is not because quitting smoking doesn’t work. It’s that such a weak nudge to behavior takes so long to have an effect that you can’t really show the benefit in a randomized trial. Yet we all know that quitting smoking is very valuable to your health because we have seen what happens to people who do it.
In the same way, look at the health of the people around you who slather butter on everything, eat cheese and eggs for breakfast, pizza for lunch and burgers for dinner. How are they doing compared to people who eat a plant-centered diet?