title: Estimates of daily net endogenous acid production in the elderly UK population: analysis of the National Diet and Nutrition Survey (NDNS) of British adults aged 65 years and over.
abstract: Dietary intake has been shown to influence acid-base balance in human subjects under tightly controlled conditions. However, the net effect of food groups on alkali/acid loading in population groups is unclear. The aims of the present study were to: (1) quantify estimates of daily net endogenous acid production (NEAP) (mEq/d) in a representative group of British elderly aged 65 years and older; (2) compare and characterise NEAP by specific nutrients and food groups likely to influence dietary acid loading; (3) determine whether geographical location influenced NEAP. The National Diet and Nutrition Survey dataset, consisting of a 4 d weighed record and anthropometric data, was used to estimate dietary acidity. Dietary under-reporters were excluded by analysing only subjects with energy intakes >/= 1.2 x BMR. NEAP was estimated as the dietary potential renal acid load+organic acid excretion, the latter as a multiple of estimated body surface area. NEAP was lower in women compared with men (P < 0.001), and lower than values reported in a Swedish elderly cohort. Lower dietary acidity was significantly associated with higher consumption of fruit and potatoes and lower consumption of meat, bread and eggs (P < 0.02 to P < 0.001). Lower intakes of fish and cheese were associated with lower NEAP in men only (P < 0.01 to P < 0.001). There were regional differences for NEAP, with higher intakes in Scotland/Northern regions compared with Central/South-Western and London/South-Eastern regions (P = 0.01). These data provide an insight into the acid-generating potential of the diet in the British elderly population, which may have important consequences in this vulnerable group.
authors.affiliation: Division of Nutrition, Dietetics and Food Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK. r.gannon@surrey.ac.uk
authors.forename: Richard H T
authors.initials: RH
authors.lastname: Gannon
authors.forename: D Joe
authors.initials: DJ
authors.lastname: Millward
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Brown
authors.forename: Helen M
authors.initials: HM
authors.lastname: Macdonald
authors.forename: David P
authors.initials: DP
authors.lastname: Lovell
authors.forename: Lynda A
authors.initials: LA
authors.lastname: Frassetto
authors.forename: Thomas
authors.initials: T
authors.lastname: Remer
authors.forename: Susan A
authors.initials: SA
authors.lastname: Lanham-New
mesh_terms: D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000209:etiology*; D000367:Age Factors; D000368:Aged; D000465:Algorithms; D000704:Analysis of Variance; D000886:Anthropometry; D004032:Diet; D015930:Diet Records; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D009749:Nutrition Surveys; D012606:Scotland; D012737:Sex Factors; D018709:Statistics, Nonparametric