Dietary advice often given to patients with chronic kidney disease (CKD) is to restrict protein intake. But not all sources of protein carry the same risks, and some are better than others — although red meat consumption is most strongly associated with an increased risk for end-stage renal disease (ESRD).
The trial recruited 63,257 Chinese adults, between 45 and 74 years old, from 1993 to 1998. Habitual diet information was collected via a validated food frequency questionnaire, and investigators identified ESRD by linking the patients’ records with a nationwide registry – since this study was based in China, they included both pork and beef as ‘red meat,’ because many participants likely abstained from beef due to religious beliefs.
Overall, 951 cases of ESRD occurred over a mean follow-up of 15.5 years. The findings highlight that while the total amount of protein intake may not be directly linked to ESRD, the consumption of red meat had an escalating, dose-dependent association with an increased risk for ESRD. Participants consuming the highest amounts of red meat (top 25%) were found to have a 40% increased risk of developing ESRD, in comparison with those consuming the lowest amounts (lowest 25%).
Furthermore, the study found there was no such correlation with the consumption of other sources of protein (poultry, fish, seafood, eggs, or dairy products) and that plant-based protein sources, like soy and legumes, even had a slightly protective effect.
In a substitution analysis, where one serving of red meat was replaced with one serving of another protein source, researchers found a significant reduction in the relative risk of ESRD. While these findings may not indicate that eating other types of meat is good for preserving kidney function, they show that they do not increase the risk of ESRD either, and are good substitutes for red meat.
The study also didn’t differentiate between cooking methods — like grilling or baking — and researchers believe that this would not play a significant role in the risk for ESRD. To assess that, further research would be required, they said.
Overall, findings also suggested that people with early stage chronic kidney disease (CKD), as well as others conscious of kidney health, would do best by obtaining dietary protein from plant-based sources. However, if meat is preferred, then it would be better to eat more fish, shellfish, and poultry than beef or pork.
“The message is not to avoid red meat like poison, but to eat red meat in moderation and best not make it the single meat item at every meal or main protein source every day. For a healthy diet, it is best to eat a variety of food sources for dietary protein,” Dr. Koh said in an interview with Medscape, where he discussed the study.
Dr. Koh is an epidemiologist at Duke-NUS Medical School and lectures at Saw Swee Hock School of Public Health at the National University of Singapore. He was site principal investigator in the large National Institutes of Health (NIH)-funded Singapore Chinese Health Study.