Using Nutrition-related Biomarkers to Improve Health
Yesterday TalkingNutrition wrote about the confusion created when we are presented with competing messages regarding the best diet for long-term health. A lack of objective measurements of nutritional status contributes to the confusion. Because it is cheaper and more convenient than collecting blood or tissue samples for analysis, researchers often rely upon estimates of habitual food intake to assess nutritional status. Measuring food intake is fraught with errors: selective dietary recall, underreporting of the amount of food consumed, inaccurate food compositional data, etc. The name of one commonly used tool, the semiquantitative food frequency questionnaire (FFQ), is indicative of the challenge.
Researchers need better insights into nutritional status than best estimates of dietary intakes to understand nutrient-disease relationships (other than deficiency diseases like beriberi, pellagra, scurvy, rickets, goiter, etc). Resonance Raman light scattering spectroscopy (RRS), a type of laser spectroscopy, has been proposed as it can be used to detect carotenoids because of their linear structure with altering carbon double and single bonds. Using this technique, Mayne and colleagues reported that skin carotenoid levels accurately reflect carotenoid intake. The highest carotenoid levels were found in the palm of the hand. In a new study with RSS, Scarmo and colleagues measured skin carotenoid status, six times, in the palm of the hand of 74 volunteers over 6 months. They report that a single measurement of skin carotenoid is a reasonable estimate of carotenoid status providing season of measurement and sun exposure are taken into consideration.
Applications of new nutrition-related biomarkers like RSS will increase understanding of nutrient-disease relationships. These tools will help researchers better assess the role of nutrients, in this case carotenoid status, and genetics, i.e, polymorphisms in carotenoid metabolizing genes, on physiological function in the eye (age-related macular degeneration) and brain (autism).
Scarmo S, Cartmel B, Lin H, Leffel DJ, Ermakov IV, Gellerman W, Bernstein PS, Mayne ST. Single v. multiple measures of skin carotenoids by resonance Raman spectroscopy as a biomarker of usual carotenoid status. 2013 Br J Nutr doi:10.1017/S000711451200582X
Thompson FE, Subar AF, Loria CM, Reedy JL, Baranowski T. Need for technological innovation in dietary assessment. 2010 J Am Diet Assoc doi:10.1016/j.jada.2009.10.008
Willett WC, Sampson L, Stampfer MJ, Rosner B, Bain C, Witschi J, Hennekens CH, Speizer FE. Reproducibility and validity of a semiquantitative food frequency questionnaire. 1985 Am J Epidemiol 122:51-65
Mayne ST, Cartmel B, Scarmo S, Lin H, leffell DJ, Welch E, Ermakov I, Bhosale P, Bernstein PS, Gellerman W. Noninvasive assessment of dermal carotenoids as a biomarker of fruit and vegetable intake. 2012 Am J Clin Nutr doi:10.3945/ajcn.2010.29707