Saturated Fat and Your Heart: How to Read Science

The observation that diet and health are related can be traced back at least to Maimonides a 1,000 years ago and Hippocrates over 2,000 years ago. With advances in public health measures and medical care, the average lifespan has been dramatically extended. Unfortunately, many of the extra years are burdened with chronic diseases like heart disease and cancer. More than ever, trying to determine what diet is most related to health is of importance to living a long life without disease. Nutrition science can be difficult, complex, and conflicting at times. What can you do when headlines appear that are in direct conflict with one another? Is the media biased or even bought?

What is the controversy?

In the last year this situation has exploded, and it pertains to the role of whole food plant diets and heart disease. Research on the contribution of foods rich in saturated fats like cheese, butter, meats, eggs, and pastries to heart disease has been ongoing since the 1950’s. In order to evaluate the most current and quality data, a systematic review and meta-analysis of the relationship between saturated fat and heart disease was published by the Cochrane Database of Systematic Reviews (CDSR) on May 19, 2020. The CDSR is widely regarded as the leading and most respected of sources for evaluating topics in health care. The authors analyzed 15 controlled trials involving over 59,000 subjects and concluded that “The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events (21%). Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies.”  It would seem clear that reducing or eliminating meats, cheeses, egg yolks, lard, butter, ghee and baked goods would favor better odds of avoiding heart disease. Of note, major media channels did not report on this research and it was buried in the National Library of Medicine.

What was the backlash?

            The clarity on nutrition advice provided by the esteemed CDSR lasted all of 3-4 weeks as a “State of the Art Review” by 12 authors on the topic of saturated fat and health was published in a major cardiology journal on June 16, 2020. They did not original research but analyzed previously published studies. The 12 authors concluded that “Whole-fat dairy, unprocessed meat, eggs and dark chocolate are SFA-rich foods with a complex matrix that are not associated with increased risk of CVD. The totality of available evidence does not support further limiting the intake of such foods.”  Unlike the esteemed CDSR paper, this review created 100’s of headlines worldwide.

How can we reconcile the diffferences?

           How can we reconcile such conflicting conclusions? It is challenging and leaves many confused, feeling that they can eat whatever they want while nutrition scientists “duke it out”.  One major concern not mentioned in the media regarding the 2^nd paper promoting saturated fat was that 9 of the 12 authors disclosed research funding by dairy or beef foundations. Let’s repeat that, 75% of the authors promoting saturated fat were funded by industry organizations that promote foods rich in saturated fat!

            In a second challenge to the findings of the CDSR, 10 authors published a “hypothesis” that those suffering from a relatively rare genetic disorder causing a high cholesterol, familial hyperlipidemia, would benefit more from a low-carbohydrate diet than a low-fat diet. The authors did not original research. Guess what? Five of the 10 authors revealed financial ties that they benefit from relating to low-carb diets. The other 5 are well known low-carb advocates routinely advocating for dietary approaches in conflict with major medical societies and research findings. Would you be surprised that this paper also got worldwide headlines indicating that a “new paradigm” had been identified?

How to Approach Nutrition Science?

          Are there any ways to approach nutrition research with a system you can “digest” when new data and conflicting reports appear?  I rely on 2 leading research scientists who have proposed such an approach. One is Valter Longo, Ph.D, author of The Longevity Diet, creator of the plant-based Fasting Mimicking Diet, and internationally known leading academic researcher. He describes the “Five Pillars of Longevity” as a format to evaluated nutrition research. These 5 pillars are 1) biochemical research, 2) randomized trials, 3) epidemiology, 4) study of centenarians, and finally, 5) analysis of complex systems (like the environmental impact of a diet). For example, Dr. Longo considers the popular keto diet to be  a “half a pillar at most” as it lacks many of the components of this analytical system. In contrast, Dr. Longo teaches a plant-based diet in his book as it encompasses all 5 pillars.

           The other leading scientist is Nobel Prize Laureate Michael Brown, MD who was awarded this high honor in 1985 for his research on the LDL cholesterol.  Dr. Brown delivered a lecture titled “A Century of Cholesterol and Coronaries” and described a method of evaluating the scientific literature on the relationship between cholesterol and heart disease. He called the method the “Four Lines of Evidence”. These 4 lines were remarkably similar to the Pillars described by Dr. Longo. Together they provide a framework to consider new information in a meaningful and big picture way.

What Do You Do?

          What can be concluded regarding saturated fat and heart disease? Should you add butter to your coffee tomorrow? One study was published by an esteemed organization (CDSR). The other two wer written by authors with the major financial biases including investments in companies dedicated to promoting diets high in saturated fats.

         Using the 5 Pillars or the 4 Lines of Evidence, there exists biochemistry, randomized trials, epidemiology and Centenarian data that indicate that diets lower in saturated fats (reduced or absent meats, cheeses, butter, pastries, lard, ghee) promote health and reduce the risk of heart disease. No single new study can upend 70 years of research even if a new study can get inordinate and inappropriate praise in the media. While nutrition science can be challenging, using the methods here will help you make healthy decisions about your diet, always favoring plant-based selections. Do not believe all media headlines. They can be bought or, at a minimum, influenced by a flow of dollars that generates clickbait headlines.