Nuclear Techniques in Nutrition
Stable isotopes have been used as tracers in human nutritional studies for many years. A number of isotopes have been used frequently to assess body composition, energy expenditure, protein turnover and metabolic studies in general, such as deuterium (2Hydrogen), 18Oxygen, 13Carbon and 15Nitrogen. Nevertheless, there is still occasional confusion and concern over their safety, which can hinder the appropriate use of these isotopes in human studies. This mini review aims, therefore, to consider the safety of the four stable isotopes mentioned above, and to reiterate and reaffirm their safety once again. It is hoped that these data will be of use to new researchers in the field, as well as those considering the ethical or other implications of using these stable isotopes in nutritional research. Undoubtedly some of the confusion arises as deuterium, especially, is associated with the nuclear industry. However, as their name implies, of course, none of these stable isotopes are radioactive, and no adverse biological or physiological effects have been reported at the very low levels of enrichment that are used in human studies. There are ample data to reaffirm the safety of stable isotopes at the levels used in nutritional research, and unnecessary concerns and/or confusion should not be a block to continued use of these important tracers.
The IAEA’s work complements the work of other UN agencies, NGO’s and other major players in nutrition and health by encouraging use of nuclear techniques to develop and evaluate interventions to combat malnutrition in all its forms. These nuclear techniques, in particular stable (non-radioactive) isotope techniques, add value by improving the specificity and sensitivity of nutritional evaluations such as the assessment of body composition, bone mineral density, total daily energy expenditure, intake of human milk in breastfed infants, vitamin A status, and bioavailability of micronutrients from foods (see IAEA Nutrition Factsheet). These nuclear techniques are also used to assess the health effects of environmental factors such as environmental enteric dysfunction (EED); and the influence of changes in dietary and physical activity patterns on risk of overweight and obesity. Although stable isotope techniques have been used as research tools in nutrition for many years, the application of these techniques in programme development and evaluation is a relatively new approach where the IAEA has a unique opportunity to contribute technical expertise. The IAEA has fostered the more widespread use of these techniques in Member States through support to national and regional nutrition projects via the Technical Cooperation Programme and through Coordinated Research Projects addressing priority areas in nutrition over many years.
Nutrition activities at the IAEA are aligned with the Sustainable Development Goals (specifically, but not limited to #2.1, 2.2, and 3.4); i.e., access to safe and nutritious foods for all, reduction in stunting by 40%, reducing and maintaining wasting at below 5%, and reduction of mortality from non-communicable diseases by one-third. These activities cover the entire life course with specific focus on: infant and young child nutrition, childhood obesity, adolescent and maternal nutrition, healthy ageing, in addition to diet quality and econutrition. Work in these areas is done in close collaboration with relevant partners to create synergies and complement ongoing research and evaluation activities with the use of stable isotope techniques that will add valuable information.
In 2016, St John’s Research Institute, Bangalore, India was redesignated as an IAEA Collaborating Centre for Nutrition. The Institute´s research focuses on nutrition as well as on infectious and lifestyle-related diseases, and is an excellent example of a centre where stable isotope technique is being used for nutrition-related research and programme evaluation.
This website provides easy access to IAEA documents on nuclear techniques in nutrition and will be updated as additional documents as well as e-learning modules become available.
Additional links:IAEA Coordinated Research Projects in nutrition
IAEA Technical Cooperation