A proinflammatory diet is associated with systemic inflammation and reduced kidney function in elderly adults

Area of Science:

• Gerontology
• Nutritional Science
• Nephrology

Background:

• Diet significantly impacts kidney health, primarily through its influence on inflammation.
• Chronic low-grade inflammation is a growing concern in aging populations.
• Understanding dietary patterns' role in inflammation and kidney function is crucial for public health.

Purpose of the Study:

• To investigate the association between the Adapted Dietary Inflammatory Index (ADII) and kidney function in elderly individuals.
• To determine if chronic low-grade inflammation mediates the relationship between dietary patterns and kidney function.

Main Methods:

• Observational analysis of 1942 elderly participants from two independent cohorts.
• Calculation of the ADII based on 7-day food records, assessing proinflammatory and anti-inflammatory nutrient effects.
• Assessment of kidney function using estimated glomerular filtration rate (eGFR) calculated from serum cystatin C and creatinine.
• Validation of ADII against serum C-reactive protein (CRP) concentrations as a marker of inflammation.

Main Results:

• A higher ADII was significantly associated with elevated CRP levels, indicating increased systemic inflammation.
• Increased ADII was also linked to reduced kidney function, as measured by lower eGFR.
• Mediation analyses revealed that CRP accounted for 15-17% of the association between the ADII and kidney function.

Conclusions:

• A proinflammatory dietary pattern is associated with both systemic inflammation and diminished kidney function in older adults.
• Systemic inflammation serves as a potential mechanistic pathway linking proinflammatory diets to impaired kidney function.
• These findings highlight the importance of dietary choices in maintaining kidney health among the elderly.