SINGAPORE — Taking one serving of red meat a day — regardless of how it is cooked — increases one’s risk of developing kidney failure by as much as 40 per cent, a study that tracked participants for 15 years has found.

The finding was derived from a long-term Singapore Chinese Health Study, which followed more than 63,000 individuals aged 45 to 74 years from between 1993 and 1998, looking at their lifestyle and diet and any links to major chronic diseases in Singapore such as cancer, cardiovascular disease and osteoporosis.

Among the cohort, the top 25 per cent in terms of red meat consumption were 40 per cent more likely to develop kidney failure than the bottom 25 per cent, including vegetarians. Kidney failure usually requires patients to go for dialysis or a kidney transplant.

Taking into account factors such as gender, smoking status and pre-existing conditions like diabetes, the study found that there was no clear relationship between total protein intake and the risk of kidney failure. In fact, the researchers from the Saw Swee Hock School of Public Health at National University of Singapore (NUS) and Duke-NUS Medical School found that substituting red meat with other sources of protein lowers one risk by up to 62 per cent.

“We embarked on our study to see what advice should be given to chronic kidney disease patients or to the general population worried about their kidney health regarding types or sources of protein intake,” said Professor Koh Woon Puay, who teaches at both institutions, and was the principal investigator.

Poultry, fish, eggs and dairy were not found to affect the risk of kidney failure. But the study indicated that soy and legumes could possibly lower one’s risk, although Prof Koh said more detailed studies would be needed to confirm the relationship.

For instance, substituting one daily serving of red meat with poultry could reduce the risk of kidney failure by about 62.4 per cent. For fish, eggs, and soy and legumes, the risk was reduced by 48.6 per cent, 44.9 per cent and 50.4 per cent respectively.

They conducted the study by altering a food questionnaire based on Western diets of steak and pork chops to local favourites including bak kut teh, Hainanese chicken rice and steamed fish. Participants’ eating habits were studied in detail for more than a year, covering 165 dishes and beverages. A detailed study involving 1,000 participants from the same study cohort found that 97 per cent of the red meat consumed was pork.

Noting an almost 50 per cent increase in the number of patients needing dialysis in Singapore, Prof Koh said the research was part of efforts to better prevent the onset of kidney failure. According to latest figures from The Singapore Renal Registry’s interim report for 1999 to 2014, the number of people receiving dialysis increased from 2,466 to 5,912 people.

The number of new cases each year jumped from 680 cases in 1999 to 1,730 in 2014.

Stopping short of prescribing how much red meat to consume, Prof Koh recommended that consumers avoid eating red meat daily or in every dish, and instead look at substituting it with other sources of protein.

Asked whether the study findings would apply to other ethnic groups in Singapore, Prof Koh said: “I do not see any biological reason why it will not apply.” As for whether how the red meat is prepared makes a difference, Prof Koh said cooking methods and how the body metabolises the meat are some of the other factors that she and her team intends to study in future.