High levels of protein could increase risk of heart failure in men, study finds

31 May 2018 --- Eating higher amounts of protein was associated with a slightly elevated risk for heart failure in middle-aged men when compared to those who ate less protein, a study has found. The study, published in Circulation: Heart Failure, an American Heart Association (AHA) journal, adds to the little-researched area of how protein may impact heart failure risk. Researchers also suggest that the type of protein source may be significant, with processed meat being a less healthy protein source than fish, nuts or plant sources.

“There is rather little research data on how protein intake affects the risk of developing heart failure. Therefore, more research on this topic is definitely needed before any strong conclusions can be made. However, our findings indicate the high protein intake may have some adverse effects on health, especially if the protein is coming from animal sources,” Jyrki Virtanen P.hD, Adjunct Professor of Nutritional Epidemiology and study author tells NutritionInsight.

High protein diets are popular and often seen as healthy, but the long-term effects are not always considered. Virtanen explains further, “hard-training athletes, the elderly and the critically ill may benefit from higher protein intakes. But for the general population, it may not be as necessary or health-promoting as it has been recently hyped. One can also get enough protein from food, so protein supplements are not necessary for most people.”

“Earlier studies had linked diets high in protein – especially from animal sources – with increased risks of Type 2 diabetes and even death,” she adds.

The American Heart Association estimates that one in five Americans aged over 40 will develop heart failure. Meaning, when the body is unable to pump enough blood and oxygen to remain healthy. Heart failure can shorten life expectancy. And with no cure, preventing heart failure through diet, lifestyle and more is vital.

The study
Researchers studied 2,441 men, age 42 to 60, at the study’s start and followed them for an average 22 years. Overall, researchers found 334 cases of diagnosed heart failure during the study.

During the 22 years, 70 percent of the protein consumed came from animal sources, while 27.7 percent came from plant sources. A high intake of protein was generally found to be associated with slightly higher risk of heart failure. Only proteins from fish and eggs were not associated with heart failure risk, according to researchers.

The study divided the men into four groups based on their daily protein consumption. When they compared men who ate the most protein to those who ate the least, they found their risk of heart failure was:

• 33 percent higher for all sources of protein;
• 43 percent higher for animal protein;
• 49 percent higher for dairy protein;
• 17 percent higher for plant protein.

“As this is one of the first studies reporting on the association between dietary protein and heart failure risk, more research is needed before we know whether moderating protein intake may be beneficial in the prevention of heart failure,” says Virtanen.

“Long-term interventions comparing diets with differential protein compositions and emphasizing differential protein sources would be important to reveal possible effects of protein intake on risk factors of heart failure. More research is also needed in other study populations.”

Furthermore, the Virtanen cites that the study had some further drawbacks that future studies could address: 

“One potential limitation could be that we had information on dietary intakes only from the study baseline in 1984-1989 and the mean follow-up was about 22 years. The diets of the men may have changed during the follow-up. However, we assessed this possibility by repeating the analyses with 10 years shorter follow-up. The results were quite similar also in these analyses, so the single baseline dietary assessment may not be a major limitation in our study. Of course, one limitation is that we had only men as participants, so we cannot say whether the findings would be similar also in women.”

Concerning a healthy diet, The American Heart Association officially recommends a dietary pattern that includes a variety of fruits and vegetables, whole grains, low-fat dairy products, poultry, fish, beans, non-tropical vegetable oils and nuts; and limits intake of sweets, sugar-sweetened beverages and red meats.

“The findings are interesting as they showed that increased protein intake may have a trend to heart failure risk in men. Most of the dietary studies we have look at diet to lower risk factors such as improving blood sugar and blood pressure and lowering cholesterol and lowering overall risk for cardiovascular risk-risk for heart attack and stroke. This study looked at the role of a high protein diet and heart failure risk and only showed a trend to high protein intake and risk for heart failure,” Nieca Goldberg, M.D., Director, NYU Center for Women's Health and spokesperson for AHA, tells NutritionInsight.

The 13th Annual Food and Health Survey conducted by the International Food Information Council (IFIC), found that cardiovascular health was the top health concern for Americans. However, there was a clear discrepancy visible between the desire for a healthy heart, and how to actually achieve it through diet.

By Laxmi Haigh