Link Between Meat and Fat in Preventing Heart Disease

UCSF Adjunct Professor Ronald Krauss, MD
UCSF Adjunct Professor Ronald Krauss, MD

By Kate Rauch

Fans of ice cream, thick steaks, and sizzling bacon celebrated when in 2011 UCSF adjunct professor Ronald Krauss, MD, and his team revealed research findings indicating that diets high in saturated fats were not linked to a greater risk of heart disease. 

But now there’s a new layer of complexity in efforts to identify a diet that prevents heart disease.  A new study by Krauss and co-authors published in the Journal of Nutrition suggests that lovers of fat may not have it so easy.

We’re taking what we learn in the lab into the clinic and the public health arena...this research is completely translational.
Ronald Krauss, MD

Building on his previous research which identified carbohydrates as a worrisome cholesterol culprit, Krauss wanted to see what happens to cardiovascular risk if people cut carbs, but replace these calories with fats and meat.

The new research compares two diets high in red meat without weight loss or changes in exercise. One was also high in saturated fats from other sources such as milk, cheese, and butter. Both were relatively low in carbohydrates. 

Krauss was surprised to see that in this study, saturated fats weren’t so innocent. 

The diet high in red meat and saturated fat resulted in a more worrisome cholesterol profile than the diet high in red meat, but low in saturated fat, Krauss found.  

Researchers compared a detailed cholesterol analysis, looking at plasma total, LDL (“bad” cholesterol), non-HDL cholesterol (total cholesterol minus “good” cholesterol), and apoB (apolipoprotein B) concentrations.  

The results suggest that the combinations of specific proteins and fats play a significant role in the overall cholesterol profile, Krauss said. “There seems to be a difference between eating a hamburger and a cheeseburger with its added fat.” 

Conclusions & Recommendations

  • Consume white meat in moderation, and limit red meat to special occasions.
  • Eat fish, especially fatty fish (e.g. salmon) twice a week.
  • Use oils high in polyunsaturated fat (e.g., safflower, corn oil) and avoid foods with trans fats from partially hydrogenated oils (read the label).
  • Unless you have a tendency for high cholesterol, you can occasionally eat cheese and butter.
  • Choose whole kernel grains (e.g., dark rye bread, high fiber cereal), and watch out for “whole grain” products with added sugars.

The source of protein could also be key, he added. The earlier, less-incriminating research on saturated fats didn’t focus exclusively on diets high in red meat. Aficionados of bread, pasta, and pastry should stay on notice: the benefits of lowering carbohydrates were reinforced in this study. 

“We’re taking what we learn in the lab into the clinic and the public health arena,” Krauss said. “This research is completely translational.” 

“The main point is that rather than focusing on saturated fat as a top priority for heart disease risk, one really needs to look at the overall diet in which saturated fat is eaten,” said Krauss, who is also an endocrinologist and Director of Atherosclerosis Research at Children’s Hospital Oakland Research Institute.

Research of this type is “not an easy thing,” he said, and resources such as the Clinical Research Services’ Bionutrition Unit, managed by UCSF’s Clinical and Translational Science Institute (CTSI), were integral. The Unit prepared all of the special diets used in the studies, ensuring that they not only meet very specific nutritional criteria, but are also flavorful and easy to prepare. In most cases, study participants received frozen meals to reheat at home.

Intrigued by his latest findings, Krauss is now embarking on a five-year, NIH-funded study to directly test if red meat consumed with foods high saturated fat is a particularly bad combination for heart disease risk, compared to diets with the same amount of saturated fat combined with white meat or non-meat protein sources. 

CTSI at UCSF is a member of the National Institutes of Health-funded Clinical and Translational Science Awards network focusing on accelerating research to improve health. The Institute provides services for researchers at every stage, and promotes online collaboration and networking through UCSF Profiles.