title: Genetic Variations as Modifying Factors to Dietary Zinc Requirements-A Systematic Review.
abstract: Due to reduced cost and accessibility, the use of genetic testing has appealed to health professionals for personalising nutrition advice. However, translation of the evidence linking polymorphisms, dietary requirements, and pathology risk proves to be challenging for nutrition and dietetic practitioners. Zinc status and polymorphisms of genes coding for zinc-transporters have been associated with chronic diseases. The present study aimed to systematically review the literature to assess whether recommendations for zinc intake could be made according to genotype. Eighteen studies investigating 31 Single Nucleotide Polymorphisms (SNPs) in relation to zinc intake and/or status were identified. Five studies examined type 2 diabetes; zinc intake was found to interact independently with two polymorphisms in the zinc-transporter geneSLC30A8to affect glucose metabolism indicators. While the outcomes were statistically significant, the small size of the effect and lack of replication raises issues regarding translation into nutrition and dietetic practice. Two studies assessed the relationship of polymorphisms and cognitive performance; seven studies assessed the association between a range of outcomes linked to chronic conditions in aging population; two papers described the analysis of the genetic contribution in determining zinc concentration in human milk; and two papers assessed zinc concentration in plasma without linking to clinical outcomes. The data extracted confirmed a connection between genetics and zinc requirements, although the direction and magnitude of the dietary modification for carriers of specific genotypes could not be defined. This study highlights the need to summarise nutrigenetics studies to enable health professionals to translate scientific evidence into dietary recommendations.
authors.affiliation: Department of Nutrition, Dietetics and Food, Monash University, Notting Hill VIC 3168, Australia. kjday1@student.monash.edu.
authors.forename: Kaitlin J
authors.initials: KJ
authors.lastname: Day
authors.affiliation: Department of Nutrition, Dietetics and Food, Monash University, Notting Hill VIC 3168, Australia. melissa.adamski@monash.edu.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Adamski
authors.affiliation: Department of Nutrition, Dietetics and Food, Monash University, Notting Hill VIC 3168, Australia. aimee.dordevic@monash.edu.
authors.forename: Aimee L
authors.initials: AL
authors.lastname: Dordevic
authors.affiliation: Department of Nutrition, Dietetics and Food, Monash University, Notting Hill VIC 3168, Australia. chiara.murgia@monash.edu.
authors.forename: Chiara
authors.initials: C
authors.lastname: Murgia
mesh_terms: D000375:Aging / Q000235:genetics*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D003071:Cognition / Q000187:drug effects; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000235:genetics; D005838:Genotype; D006801:Humans; D008895:Milk, Human / Q000737:chemistry; D065228:Non-Randomized Controlled Trials as Topic; D009751:Nutritional Requirements / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D016032:Randomized Controlled Trials as Topic; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood
chemical_list: D027682:Cation Transport Proteins; C486299:SLC30A2 protein, human; D015032:Zinc
keywords: SNPs; nutrigenetics; nutritional genomics; zinc requirements