A higher protein diet may increase risk of heart failure
The high-protein, low-carbohydrate diet fad still seems to be going strong. While such diets do help people lose weight (largely because they stop eating junk), we already know that diets that are high in animal protein and animal fats put people at greater risk of type 2 diabetes. They also appear to have some negative effect on your cognitive ability. On the other hand, there's some older research to suggest that a low-carbohydrate diet may not affect your risk of heart disease, at least for women.
A study just published in Circulation: Heart Failure (2018;11:e004531) (a publication of the American Heart Association) is an observational study of nearly 2,500 Finnish men who were between the ages of 42 and 60 at the start of the study's recruitment period between 1984 and 1989.
The participants provided medical and family history, along with their smoking status and level of physical activity and alcohol consumption, and were weighed and measured to determine their Body Mass Index. Further, with the help of a nutritionist they filled out a detailed Finland-specific dietary questionnaire for the previous 4 days, which included a weekend day. Finally, their blood pressures were measured and blood drawn for cholesterol scores.
After an average of over 22 years of follow-up, the authors accessed Finland's national health service database(s) to see which of the participants had been diagnosed with heart failure. The reported diets of those who were diagnosed with heart failure were then compared with those who were not.
For their analysis the authors took into account the participant's family and personal health history, BMI, smoking status (length and amount), alcohol intake and physical activity, their health status at the start of the study (did they have heart disease or take heart medications?), their overall intake of the different types of fat and fiber, and education.
When they broke out the overall intake of different types of proteins into four increasing levels of intake, the authors found that compared to those who consumed the least protein - from any source - those who consumed the most protein were 33% more likely to be diagnosed with heart failure. Those who consumed the most land animal protein were 43% more likely to be diagnosed with heart failure, and those who consumed the most protein from red meat (including beef, pork, and organ meats, but not processed meat) were only 14% more likely to be diagnosed with heart disease.
On the other hand, those who consumed the most protein from fish were no more likely to be diagnosed with heart failure than those who consumed the least protein from fish, with similar results for protein from eggs. Oddly, consuming the highest amounts of protein from fermented dairy were associated with an even higher risk of heart failure: 70% greater than those who consumed the least dairy.
What this means for you
In the case of all protein sources, except for processed red meat, consuming moderate amounts of protein (more than those in the lowest levels of intake but less than those in the highest levels of intake) had no statistically significant effect on the risk of heart failure. While more research is clearly needed to find out if higher protein intake actually has some causal effect on heart failure, your take-home here is that a moderate-protein diet that saves processed meats like bologna or bacon for an occasional treat is safer for your heart.
First posted: August 15, 2018