Our kidneys have many important functions; besides filtering waste, they help control blood pressure, help make red blood cells, and more. The eGFR (estimated glomular filtration rate) is a blood lab that is used to assess kidney function, as low eGFR levels can indicate kidney damage or even kidney failure. In a 15 year study following 900 adults (free of stroke and coronary artery disease), researchers analyzed diet and eGFR status. The researchers found that people most closely following the Mediterranean Diet were least likely to have a low eGFR, and least likely to have a high rate of eGFR decline (which would have indicated a worsening of kidney function).
Clinical Journal of the American Society of Nephrology. 2014 Nov 7;9(11). (Khatri M et al.)