Protein-energy malnutrition and chromosome changes

Summary of published research¹

The relationship between proteinenergy malnutrition and genetic damage has been studied in human beings and laboratory animals, but results are still conflicting. A recent study in Argentina set out to assess the structural chromosomal aberrations in peripheral blood lympohcytes of children with protein-energy malnutrition but no infection. A case-control study was performed. Samples were obtained from 25 primary malnourished infants and young children (mean age, 22 months). The control group consisted of 25 healthy children from the same population who were matched 1:1 by age and sex. Anthropometric and clinic evaluations were performed to assess nutritional condition. Before blood collection, parents of each individual were interviewed to complete a semistructural survey specifying age, dietary habits, viral or bacterial diseases, previous exposure to diagnostic x-rays, and use of therapeutic drugs. After 48 hours, 100 cultured lymphocytes were analysed per patient. Statistical analysis was performed using the Epi Dat 3.0 programme.

The chromosomal aberration frequency was nearly seven times higher in malnourished infants than in controls (14.6% versus 2.2%). This difference was statistically significant (P<0.001) and may be explained by the occurrence of achromatic lesions, breaks, and telomeric associations. DNA damage could be attributed to several factors: severe deficiency of essential nutrients (i.e. zinc, iron and vitamin A) required in the synthesis of DNA maintenance factors, deterioration of repair mechanisms, allowing the persistence of an unusually high number of structural chromosomal aberrations and /or the absence of specific factors needed to protect the cell against oxidative DNA damage.

The researchers were aware of the limitations of the study, such as the small sample size and/or the difficulty in addressing the relationship between high levels of DNA damage and specific kinds of infections, drug treatments and severity of malnutrition. Further studies involving a larger number of patients are being planned in Argentina.

¹Padula. G, Salceda. S and Seoane. A (2009). Protein-energy malnutrition contributes to increased structural chromosomal alteration frequencies in Argentinean children. Science Direct. Nutrition Research 29 (2009), pp 35-40. Available online at www.sciencedirect.com