ABSTRACT
OBJECTIVES: To determine the effects of increasing plant-based foods or dairy products on protein intake in older Americans by performing diet modeling. DESIGN: Data from What We Eat in America (WWEIA), the dietary component of the National Health and Nutrition Examination Survey (NHANES), 2007-2010 for Americans aged 51 years and older (n=5,389), divided as 51-70 years (n=3,513) and 71 years and older (n=1,876) were used. MEASUREMENTS: Usual protein intake was compared among three dietary models that increased intakes by 100%: (1) plant-based foods; (2) higher protein plant-based foods (i.e., legumes, nuts, seeds, soy); and (3) dairy products (milk, cheese, and yogurt). Models (1) and (2) had commensurate reductions in animal-based protein intake. RESULTS: Doubling intake of plant-based foods (as currently consumed) resulted in a drop of protein intake by approximately 22% for males and females aged 51+ years. For older males and females, aged 71+ years, doubling intake of plant-based foods (as currently consumed) resulted in an estimated usual intake of 0.83±0.02 g/kg ideal body weight (iBW))/day and 0.78±0.01 g/kg iBW/day, respectively. In this model, 33% of females aged 71+ years did not meet the estimated average requirement for protein. Doubling dairy product consumption achieved current protein intake recommendations. CONCLUSION: These data illustrate that increasing plant-based foods and reducing animal-based products could have unintended consequences on protein intake of older Americans. Doubling dairy product intake can help older adults get to an intake level of approximately 1.2 g/kg iBW/day, consistent with the growing consensus that older adults need to consume higher levels of protein for health.
Subject(s)
Dairy Products , Diet , Dietary Proteins/administration & dosage , Feeding Behavior , Geriatric Assessment , Nutrition Assessment , Plants, Edible , Aged , Aged, 80 and over , Animals , Female , Humans , Male , Middle Aged , Nutrition Surveys , Nutritional Requirements , United StatesABSTRACT
Delta(5)-Desaturase (D5D) catalyzes the Delta(5,6) desaturation of dietary essential fatty acids of the n-6 and n-3 series. By subtraction hybridization of vitamin A (VA)-deficient and control rat liver cDNA libraries, we isolated a 106-bp cDNA fragment that proved to be homologous to human liver D5D cDNA and used it as a probe to analyze rat D5D mRNA and clone the rat full-length cDNA. Delta(5)-Desaturase mRNA was threefold more abundant in liver from VA-deficient rats than in liver from VA-sufficient rats and was expressed dose dependently when dietary VA was varied (VA marginal > control > VA supplemented). Treatment of VA-deficient rats with all-trans-retinoic acid lowered the level of expression of D5D mRNA toward that of VA-sufficient rats. The 3413-bp full-length D5D cDNA cloned from rat liver contains an open reading frame of 447 amino acid residues sharing 92% similarity with its human counterpart. Expression of this cDNA in HEK293T cells incubated with dihomo-gamma-linolenic acid (20:3, n-6) resulted in a significantly increased ratio of the product, arachidonic acid (20:4, n-6), to substrate in cell lipid extracts. Delta(5)-Desaturase mRNA is expressed in relatively high abundance in rat adrenal gland and mammary tissue and moderately in liver, kidney, lung, spleen, thymus, brain, and eye. The regulation of D5D by VA could be important for growth and development, and reproduction, as well as in the control of inflammation.
