A study published in the Journal of the American Society of Nephrology (JASN) revealed that red meat could increase the risk of kidney failure in great populations.
“Our study shows that red meat intake may increase the risk of ESRD in the general population and substituting alternative sources of protein may reduce the incidence of ESRD,” reads the publication.
The risk of kidney failure compared to the ideal amount of protein ingestion is still being analyzed but randomized tests have shown that eating less protein from red meat slows the development of chronic kidney disease (CKD) towards eventually presenting end-stage renal disease (ESRD).
The link between beef and kidneys
The research was carried out in Singapore through the Chinese Health Study over the course of five years. 63,257 Chinese adults from the ages of 45 to 74 were reviewed, starting in 1993. The researchers noted their eating habits through questionnaires and their relation to ESRD was linked to Singapore’s records of kidney failure.
Among the participants, 951 of them suffered from ESRD at some point in the study. Three-quarters of the 951 afflicted patients have had ingested a significant amount of red meat. On the other hand, eating dairy, fish, eggs or poultry was not linked to an increased risk of suffering from ESRD.
It has been proven that red meat increases the risk of cancer, mainly because its ingestion forces the body to assimilate a sugar molecule that is present in the meat of cows, lamb, and pork. The molecule triggers an immune response that diverts in inflammation, thus increasing the likelihood of developing tumors. When scientists isolated this molecule and exposed mice to it, they saw a 5-times higher risk of developing cancer in the exposed mice when compared to the other specimens. The liver of mice was the organ where tumors most commonly form, while in humans it was the colon.
The molecule is known as Neu5Gc, and it is present in many types of cancerous tissue, although the human body does not produce it. Notably, this molecule is present in large quantities in beef, bison, lamb and pork, while poultry, fish, and vegetables lack the molecule. The body reacts by sending antibodies against the newly ingested sugar. Then, inflammation ensues. This may suggest that the same molecule that renders red meat as a potential carcinogen is also responsible for many cases of kidney failure due to its ingestion.
Diabetes, red meat and kidney failure
According to the American Kidney Fund (AFK), diabetes is the most common cause of kidney failure in the United States. Because diabetes alters how the body processes insulin, a hormone that regulates the assimilation of sugar, perhaps there is a link between ESRD and the sugar molecule native to red meat which has been highlighted as a carcinogen.
When there is an elevated amount of sugar in the bloodstream, the patient suffers from hyperglycemia. Hyperglycemia is especially harmful to people with CKD. Diabetes has been proven to contribute towards kidney malfunction and cardiovascular disease.
The American Diabetes Association says that, as the body processes the proteins that it ingests, the waste product appears and gets accumulated in the kidneys, which serve as filters for the bloodstream. The accumulated waste gets expelled through urine, but even if the kidneys are working at their fullest, proteins and red blood cells do not get filtered most of the time.
Hyperglycemia makes it so the kidneys filter an excessive amount of blood, which leads to overworking the organ. If this goes on for several years, protein can be lost in urine, which is an indicative of CKD where ESRD usually follows. After ESRD, the patient needs to undergo a kidney transplant or its blood must be filtered with a machine, a process known as dialysis.
The sole existence of the Neu5Gc sugar molecule is not an indicative of red meat being a carcinogen, although it most likely helps accelerate the process of developing cancer. Red meat does have some significant nutritional benefits, as it is a reliable source of protein and iron.
Red meat was also linked to an increased risk of heart disease. This time, it comes from the gut microbe reactions as they become exposed to carnitine, a component of red meat. Carnitine has been linked to the narrowing and hardening of the arteries, which may also be related to kidney failure. According to the CDC, at least 20 million Americans are suffering from CKD, where the cases in people aged 65 or older have doubled from 2000 to 2008.
Advocates for red meat, such as Betsy Booren, vice president of scientific affairs of the North American Meat Institute, claim that the study carried out in Singapore does not reflect the impact that the ingestion of red meat has on the lives of Americans. Booren called “inappropriate and premature” to compare and apply the findings to the diet of North Americans. According to the Wall Street Journal, in 2012, the average American consumed 71.2 pounds of red meat and 54.1 pounds of poultry, that’s equivalent to a 3-ounce steak and 2.3 ounces of chicken every day.