The complex metabolic, vascular and inflammatory perturbations that characterize
diabetes mellitus often lead to progressive
albuminuria, renal injury and dysfunction (
diabetic nephropathy [DN]), and diabetes is the leading cause of
end-stage renal disease in the US and Europe. Diet has an important role in cardiometabolic disorders and its potential influence on DN is of interest.
Fatty acids are a major source of energy, but in excess,
fatty acids (particularly
saturated fatty acids) can induce lipotoxicity. Omega-3
polyunsaturated fatty acids (PUFAs) confer protection against
cardiovascular disease-the major cause of death in patients with DN-by virtue of their
antihyperlipidemic,
antihypertensive, anti-inflammatory and other properties. Omega-6 PUFAs are also cardioprotective. However, a significant proportion of adults consume insufficient quantities of these essential nutrients. This Review describes the role of omega-3 and omega-6 PUFAs in nutrition and metabolism, with a focus on experimental, epidemiologic and clinical studies that have investigated their renoprotective effect in patients with diabetes. Results from a number of studies suggest, but do not firmly establish, that long-chain omega-3 PUFAs (found in
fish oil) reduce
albuminuria in the setting of DN. Intake of
omega-6 fatty acids is associated with reduced
albuminuria in experimental settings and in epidemiologic studies of DN. Although PUFAs do not seem to attenuate glomerular dysfunction, insufficient evidence exists to rule out such an effect. We feel that further research is needed into the potential of PUFA consumption and supplementation in DN.