title: [NUTRIENTS AND RADIOTHERAPY; REVIEW OF THE LITERATURE].
abstract: BACKGROUND
  nutrition is an important influence on treatments and quality of life of cancer patients. The relationship between different nutritional components and radiotherapy is today a topic of growing interest.
  
  
  OBJECTIVE
  to evaluate the influence of macro and micronutrients on tolerance and effectiveness of radiotherapy and their role in modulating chronic toxicity.
  
  
  METHODS
  we performed a research of the published literature by consulting the MEDLINE database and Cochrane Library online between 1995 and 2015, relevant publications based on impact factor were selected. Data from the analyzed studies were exposed in sections by type of nutrient.
  
  
  RESULTS
  most of the studies showed common features: small sample sizes, high heterogeneity, underpowered results and few prospective randomized studies. In the section of fiber, its use in prophylaxis and treatment of radiation enteritis has been successfully evaluated in some studies, although evidence of its recommendation is still weak. Omega 3 and omega 6 fatty acids have a high metabolic potential, however the evidence regarding this benefit is limited to observational studies in certain tumors. Among the amino acids, glutamine is the most studied, and controversial results of its effect on mucositis, esophagitis and radiation enteritis were found. Vitamins and minerals are a heterogeneous group of substances that showed potential benefit due to their antioxidant activity and their supposed protector effect against toxicity secondary to radiotherapy. Ketogenic diets are beginning to be clinically studied after promising preclinical results.
  
  
  CONCLUSIONS
  the analyzed studies show controversial or inconclusive results regarding the influence of nutrients in the radiotherapy. It has been not found Sorong evidence about their role in patients receiving ionizing radiation. Well-designed, prospective and randomized studies are needed to establish recommendations.
authors.affiliation: Hospital Universitario Fundación Jiménez Díaz Quirón Salud, Madrid.. jluna@fjd.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Luna
authors.affiliation: Hospital Universitario Rey Juan Carlos, Móstoles.. jluna@fjd.es.
authors.forename: Enrique
authors.initials: E
authors.lastname: Amaya
authors.affiliation: Hospital Universitario Fuenlabrada.. jluna@fjd.es.
authors.forename: M Victoria
authors.initials: MV
authors.lastname: de Torres
authors.affiliation: Hospital Universitario 12 de Octubre, Madrid. España.. jluna@fjd.es.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Peña
authors.affiliation: Hospital Universitario Fundación Jiménez Díaz Quirón Salud, Madrid.. jluna@fjd.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: Prieto
mesh_terms: D004751:Enteritis / Q000209:etiology / Q000628:therapy; D006801:Humans; D044623:Nutrition Therapy; D018529:Nutritional Support; D011878:Radiotherapy / Q000009:adverse effects* / Q000379:methods*