Zinc supplementation in the treatment of anorexia nervosa.

Revista da Associacao Medica Brasileira (1992). 2013;59(4):321-4
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Plain language summary

Anorexia nervosa (AN) is a disorder characterised by significant weight loss, restrictive diets, a search for thinness and a distortion of body image. Zinc is a key micronutrient that plays essential roles in the body including in gene transcription regulation and enzyme reactions.  There is a similarity between symptoms of zinc deficiency and AN; namely weight loss, changes in appetite and sexual dysfunction. This review aims to provide healthcare professionals with insight into the nutritional recommendations for zinc in patients with AN.  The review suggests that there are clinical studies demonstrating a strong association between AN and low levels of serum zinc and low levels of urinary zinc suggesting a micronutrient deficiency in these individuals. The severity of zinc deficiency is associated with greater weight deficits and longer AN duration. It is also associated with higher levels of anxiety and depression in AN individuals. Zinc is key in smell and taste perception and the brain regions associated with interpreting eating as pleasurable. Reduced food intake and practices like purging and low-zinc diets may exacerbate any low levels and impair zinc absorption. A controlled study showed that oral supplementation resulted in a higher rate of body mass index (BMI) increase and an improvement in neurotransmitters.  The review recommends: 1. Check serum levels of zinc in AN patients as it may be low. Zinc status may contribute to eating behaviour including gaining pleasure from eating, smell and taste. 2. Zinc supplementation of 15mg/daily for preventative purposes and 15-20mg/daily if zinc deficiency is identified after testing. The review recommends supplementation for a minimum of 2 months.

Lifestyle medicine

Fundamental Clinical Imbalances : Neurological
Patient Centred Factors : Mediators/Eating disorder
Environmental Inputs : Nutrients ; Mind and spirit
Personal Lifestyle Factors : Nutrition ; Psychological
Functional Laboratory Testing : Imaging
Bioactive Substances : Zinc

Methodological quality

Allocation concealment : Not applicable
Publication Type : Journal Article ; Practice Guideline

Metadata

Nutrition Evidence keywords : Weight loss ; Restrictive diets ; Anorexia nervosa ; Zinc deficiency