Diets high in animal protein, such as red meat, can cause kidney damage. In fact, a high-protein diet may cause or exacerbate existing kidney problems. Protein metabolism puts a heavy load on the kidneys, making it more difficult to eliminate waste products. Animal protein metabolism even leaves an acidic residue in the body.
A study published in 2016 in the Journal of the American Society of Nephrology reports that red meat intake was strongly associated with an increased risk of kidney failure among Chinese adults in Singapore who were followed for an average of 15.5 years.
A little alcohol—one or two drinks now and then—usually has no serious effects. But drinking too much can be bad for your kidneys and even worsen kidney disease.
According to the National Kidney Foundation, high alcohol intake can cause changes in the function of the kidneys and make them less able to filter the blood. In addition, alcohol dehydrates the body, which can affect the normal functioning of cells and organs, including the kidneys.
A 2009 study published in Nephrology Dialysis Transplantation reports that alcohol consumption, particularly heavy drinking, is likely to be a significant modifiable risk factor for the development of albuminuria, which is a sign of kidney disease.
A recent 2015 study published in the International Journal of Clinical Biochemistry and Research also suggests that chronic alcohol consumption is associated with renal dysfunction.
High alcohol intake has profound negative effects on the kidneys and their role in maintaining the body’s fluid, electrolyte and acid-base balance. This in turn can increase the risk of a host of kidney-related problems.
If you need to drink, moderate drinking is fine, which means one drink a day for women and older people and two drinks a day for men. However, it’s best to first check with your doctor.
Your body needs a little bit of sodium in order to maintain a proper fluid balance, but an excess can be damaging for your kidneys. When you eat more salt, your kidneys respond by retaining water in order to dilute this electrolyte in your bloodstream to help your heart function properly. This places a load on the kidneys.
High salt intake also increases the amount of protein excreted in the urine, which in turn increases the rate of deterioration of renal function.
A 2009 study published in the American Society of Nephrology reports that people who consume a diet high in sodium are more likely to experience a decline in kidney function.
Along with the kidneys, high salt intake can also be damaging to your heart and aorta.
The recommended amount of salt is no more than 5 grams a day (1 teaspoon of salt is about 6 grams). More than this amount is harmful for your kidneys as well as your overall health.
If you must add salt, use just a pinch of high-quality Celtic or Himalayan sea salt.
Caffeine found in coffee as well as tea, soda and other foods also puts a strain on your kidneys. Being a stimulant, caffeine accelerates blood flow, increasing the blood pressure and stress on the kidneys.
A 2002 study published in Kidney International reports that long-term caffeine consumption exacerbated chronic kidney failure in obese and diabetic rats. Caffeine intake, especially on an empty stomach, is also linked to kidney stone formation.
Another study published in 2004 in the Journal of Urology also reports that caffeine intake may modestly increase risk of calcium-oxalate stone formation.
On top of that, caffeine has a diuretic effect, which means it can lead to dehydration, a risk factor for kidney stones.
Caffeine in moderate amounts will not cause health problems for most people. Drink no more than one to two cups of coffee, or up to three cups of tea, per day. Also, limit your intake of other sources of caffeine like soft drinks, energy drinks, chocolate, cocoa and some medications.