The Big Fat War is Over: Saturated Fat Causes Heart Disease, Says Dr. Joel Kahn

If you have not noticed, it has been a war out there for a decade. Specifically over fat.

After nearly 50 years of science concluding that foods rich in saturated fats–like meats, cheeses, poultry, butter, and lard–cause heart disease, the public has been confused over and over, by stories such as TIME magazine covers, and many online posts celebrating that “Butter is Back.”

Did scientists get it wrong? Even though there are dozens and dozens of studies from metabolic wards of randomized studies of patients' meals, and massive epidemiology studies, all having pointed to the harm of dietary patterns high in saturated fats?

Here is the answer: Sat fat should be off the menu. It does cause heart disease.

In a long-ago TIME magazine cover, published way back in 1961, the role of saturated fats in the diet as a risk for heart disease was emphasized with a picture of Ancel Keys, Ph.D. and a story inside. Dr. Keys was a world-famous researcher on nutrition at the University of Minnesota who proposed in 1953 that not all dietary fats, but specifically saturated fats, lead to elevated cholesterol and an increased risk for heart attacks, strokes, and early deaths.

He was quoted in that article as recommending that we “eat less fat meat, fewer eggs, and dairy products… reasonably low-fat diets can provide infinite variety and aesthetic satisfaction for the most fastidious—if not the most gluttonous—among us”. This is hardly a radical view but was quite ahead of its time. In 1970 Keys and his co-authors published the Seven Countries Study that confirmed that countries with higher intakes of saturated fat-rich foods, like Finland, had the highest heart disease rates. Meanwhile, the island of Crete Greece had the lowest rate of cardiovascular disease, suggesting for the first time that a Mediterranean diet high in vegetables and low in meat was the heart healthiest way to go.

After a famous meeting of the world dairy industry in 2008 planning an attack on saturated fat science, a research paper was published in 2010 that questioned whether saturated fat and heart disease were related. The paper got huge headlines, even though a senior author received funding from the dairy industry. The article was also severely criticized by a senior researcher in nutrition in the same journal.

It took one more similar study of poor quality to lead TIME magazine to place a stick of butter on the cover in June of 2014 with the statement “Eat Butter” making everyone think, "Butter is Back!"

The final blow was the publication of a best-selling book The Big Fat Surprise, promoting the health benefits of meat, dairy, and other sources of saturated fat, and the Food War was officially in full swing. For example, in 2018 I spent nearly 4 hours as a guest on the Joe Rogan Experience (Episode 1175) debating back and forth about the role of saturated fat and heart disease.

Nutrition science can be of variable quality and difficult to parse, but a group that holds nutrition research to the high standards is The Cochrane Reviews. They publish a series of primary research in human health care and health policy online in The Cochrane Library.

This week, The Cochrane Library published an analysis of the relationship between dietary saturated fat and cardiovascular diseases (CVD), such as heart attacks, strokes, and sudden death. They examined 15 high-quality randomized controlled trials involved about 59,000 subjects with data on diet and CVD events.

The Cochrane Review demonstrated unequivocally that reducing dietary saturated fat lowered the risk of combined CVD events by 21%. That may not sound like a lot, but in scientific terms it's huge.

Further analysis showed that the greater the reduction in dietary saturated fat, the greater the drop in the risk of CVD events. This was true both for people who had no prior history of heart events, and those who had. In fact the reduction in sat far was even more powerful for those who did have known heart disease. (Meanwhile, there was no evidence for any harmful effects of reducing saturated fat intake.)

That means giving up butter, meat, and poultry, as well as tropical oils like coconut and palm oil. The less sat fat you eat, the better for your heart. The authors of The Cochrane Review concluded: “reducing saturated fat intake for at least 2 years causes a potentially important reduction in combined CVD events.”

The more you cut out the better. The “greater reduction in saturated fat caused greater reductions in CVD events.” These conclusions are consistent with the vast majority of studies prior to when the dairy industry began to confuse the public in order to promote sales of their high-fat foods.

Dietary saturated fat is found in the greatest amounts in red meat, full-fat dairy like butter, and poultry. It is low or absent in most whole plant foods with the exception of coconut oil and palm oil. (Tropical oils do contain sat fat.) But the study authors also warned that you should avoid saturated fats in foods such as "cakes, biscuits, pies and pastries, butter, ghee, lard, palm oil, sausages and cured meats, hard cheese, cream, ice cream, milkshakes and chocolate (for further details see NHS 2020)."

Overall, The Cochrane Review ends a decade of confusion. The Big Fat Wars are over. You should stick to eating foods that are low in dietary saturated fats to reduce your risk for heart disease. Replacing animal products with whole food plant choices will reduce your risk of developing the number 1 cause of death in the Western world, for both men and women: Cardiovascular disease. 

Dr. Joel Kahn is a Clinical Professor of Medicine at Wayne State University School of Medicine, and author of the bestsellers: The Whole Heart Solution, Dead Execs Don't Get Bonuses, Vegan Sex: Vegans Do It Better, The Plant-Based Solution and owner of GreenSpace & Go.