Clinical Interventions in Aging (Dec 2012)
Higher estimates of daily dietary net endogenous acid production (NEAP) in the elderly as compared to the young in a healthy, free-living elderly population of Pakistan
Abstract
Iftikhar Alam,1,2 Ibrar Alam,3 Parvez I Paracha,4 Graham Pawelec21Department of Agriculture, Bacha Khan University Charsadda, Khyber Pakhtunkhwa (KPK), Pakistan; 2Tübingen Aging and Tumor Immunology Group, Zentrum für Medizinische Forschung, University of Tübingen, Tübingen, Germany; 3Institute of Bio-technology and Genetics Engineering (IBGE), KPK Agricultural University, Peshawar, Pakistan; 4Department of Human Nutrition, KPK Agricultural University, Peshawar, KPK, PakistanAbstract: Dietary intake has been shown to influence the acid–base balance in human subjects; however, this phenomenon is poorly understood and rarely reported for the least well-studied segment of older people in a developing country. The aims of the present study were to: (1) quantify estimates of daily net endogenous acid production (NEAP) (mEq/d) in a sample of otherwise healthy elderly aged 50 years and above; and (2) compare NEAP between the elderly and young to determine the effects of aging, which could contribute to changes in the acid–base balance. Analyses were carried out among 526 elderly and 131 young participants (aged 50–80 and 23–28 years, respectively), all of whom were free of discernible disease, nonsmokers, and not on any chronic medication. Selected anthropometric factors were measured and 24-hour dietary recall was recorded. We used two measures to characterize dietary acid load: (1) NEAP estimated as the dietary potential renal acid load plus organic acid excretion, the latter as a multiple of estimated body surface area; and (2) estimated NEAP based on protein and K. For the young and elderly, the ranges of NEAP were 12.1–67.8 mEq/d and 2.0–78.3 mEq/d, respectively. Regardless of the method used, the mean dietary acid–base balance (NEAP) was significantly higher for the elderly than the young (P = 0.0035 for NEAP [elderly, 44.1 mEq/d versus young 40.1 mEq/d]; and P = 0.0035 for the protein:potassium ratio [elderly, 1.4 mEq/d versus young 1.1 mEq/d]). A positive and significant correlation was found between NEAP and energy, protein, and phosphorus (P < 0.05 for all trends). The findings from this study provide evidence of the relatively higher production of NEAP in older people, possibly as an effect of higher consumption of certain acid-producing foods by the elderly.Keywords: aging, dietary acid-loads, NEAP, vegetables, fruits
