RESEARCH AREAS – CENTRE OF EXCELLENCE FOR NUTRITION

The Nutrition Transition

The relationships between nutritional exposures and health outcomes, as well as modulating and influencing factors, are examined in cross-sectional and prospective epidemiological studies, intervention and clinical trials, and in mechanistic molecular and genetic experimental studies. Problems such as roles of individual nutrients, the impact of urbanisation, obesity, inactivity, undernutrition, HIV/AIDS, poverty, nutrient requirements, and nutrition education of the public are addressed. Results of this work have been used in formulating nutrition policy in South Africa and have focused world attention on the nutritional situation in rural Africa. Projects include nutrition and health relationships in the multi-funded, international “PURE” study, the WHO funded “Food-based dietary guideline” study and the DOH funded nutrient profiling model project.

Body Composition & Health

Obesity is a major public health problem in South Africa and contributes significantly to our overall burden of disease. In this area of study we investigate the determinants of obesity and other patterns of body composition and relate it to risk factors for chronic disease in adults and children in an attempt to understand the drivers and prevent the potential consequences of this pandemic. Together with the focus on childhood malnutrition this forms a strategic focus where cutting edge work is performed with major public health impact. The impact of physical activity and diet on body composition (bone mineral density, fat mass and lean mass) is also examined.

Maternal & Child Nutrition or Malnutrition

Factors affecting the nutritional status and health of South African children are examined in epidemiological, clinical and intervention studies. The role of nutrition and physical activity on body fat distribution, early childhood development, as well as interrelationships between nutrition and treatment of HIV-infected children are examined. In addition, we address the double-burden of nutrition-related diseases in South Africa, focusing not only on underdevelopment and infectious diseases, but also on the link between maternal malnutrition and risk of non-communicable diseases in their offspring. Currently, the NuPED study is assessing dietary intake and nutritional status of urban pregnant women in Johannesburg, and will determine associations thereof with birth outcomes, maternal and offspring health. Important milestones of this programme are participation in national surveys, inputs into fortification policies in South Africa, as well as prize-winning international publications on child health, body composition, and risk of adult-onset non-communicable diseases.

Fatty Acids & Lipids

Health consequences of dietary lipids go well beyond their role as energy sources and should be seen as key nutrients that affect early growth and development, as well as how the body responds to nutrition-related chronic and infectious diseases. Our research focuses on the effects of essential fatty acids on cognition, child behaviour and immune function studied in randomised controlled trials and animal models. Additionally, we are interested in potential interactions with micronutrients on various outcomes. One successful study within this programme was the FeFA- study which investigated the effects of omega-3 fatty acid and iron supplementation, alone and in combination, on cognition and immune function in school aged children. Currently, the TSWAKA- study examines the effect of lipid-based nutrition (essential fatty acids and micronutrients) on growth and cognition of 6 month-old infants. Another focus is the study of potential associations between dietary fatty acids, blood fatty acid composition and several cardiovascular risk markers in longitudinal studies. The research programme includes many international collaborators. (Linda)

Micronutrient Malnutrition

Micronutrient malnutrition remains an important public health concern in South Africa and the Department of Health has set its alleviation as a national priority. Our research in this area focuses on studying the role of micronutrients in early childhood development and immune function, and tests novel interventions to prevent and manage micronutrient deficiencies in randomised controlled trials and animal models. The randomised controlled Beformi-study examined the effects of a fortified drink on child cognition and growth in South African school children. In another study food-based approaches to address micronutrient deficiency were studied using African green leafy vegetables as an acceptable source of various micronutrients. These vegetables also contribute towards dietary diversification in poor communities. A newer focus lies on iodine nutrition. We recently assessed iodine nutrition in South African mothers and their infants during breastfeeding and complementary feeding. We are also part of a multi-centre iodine balance study with the aim to establish the iodine requirements for infants 0-6 months, in collaboration with renowned international iodine experts.

Nutrition & Haemostasis

The influences of nutrition on levels and functions of blood coagulation and fibrinolytic proteins during health and disease are examined using cutting edge technology. We are one of the very few groups in the world focusing on these relationships and are generally regarded as leaders in the field. In addition to our specialised infrastructure developed over the years, access to biological samples obtained in our other programmes offers unique opportunities for in-depth research of the role of nutrition as well as other environmental and genetic exposures on the haemostatic system. Our activities in this field have led to major new understandings of basic molecular effects of amongst others, alcohol on haemostasis and the role of hypercoagulability in diseases such as diabetes and coronary artery disease. Many of our studies currently aim to determine the haemostatic profile and functioning (including genetic regulation), with special focus on fibrinogen and fibrin clot properties of black South Africans, an understudied population in Cardiovascular Disease aetiology. We additionally play a leading role in an international committee tasked with the standardisation of these assays between laboratories world-wide. CEN has international patents in this field.

Nutrigenetics

The major focus of the Nutrigenetics team is to unravel the genetic underpinnings of cardiovascular disease in the South African population. The core group of four staff members each focus on elucidating the different molecular pathways involved in the regulation of various risk factors specific to CVD development i.e. unfavourable lipid profiles, type 2 diabetes mellitus, hypertension and haemostasis. In the past year, we have improved on our research capacity in terms of working with medium-throughput genotyping analyses, which has allowed us to increase our genetic screening capabilities in analysing large cohorts. Concurrent with this improved analytical capacity we have also improved our bioinformatics capacity by learning to work with programmes such as GenomeStudio which allows for the quality control and effective handling of such datasets. (Lizelle)

Nutrition in Exercise & Sport

This area of study is developing rapidly and focuses on the importance of the diet and lifestyle behaviour on health outcomes. Specific foci include physical activity, body composition, disordered eating, reproductive function and bone health in women. Recently factors affecting the nutritional status and health of South African University athletes and non-athletes, especially female students, were investigated in a cross-sectional, study, focusing on the female athlete triad. This study ran parallel with an American study and focused on the relationship between energy availability, bone health, and menstrual function; the impact of physical activity and diet on body composition (bone mineral density, fat mass and lean mass) was also examined. (Lize)

Therapeutic Nutrition

This is an emerging area of research in CEN where the focus is on the therapeutic nutritional management of various diseases. The research in this area is currently focused on the management of malnutrition in both the paediatric and adult hospital populations in South Africa and various other African countries.

Special Projects

Prospective Urban and Rural Epidemiology study

The PURE study is the first prospective African study investigating the determinants of non-communicable disease in Africa. The final data collection for this 10-year study was completed in 2015 and will be a landmark study once all the prospective data have been analysed. The cross-sectional analysis has already delivered many papers and post graduate students and is generating international interest and collaboration.

Evidence-Informed Decision-Making for public health nutrition

In 2012, the SUNRAY project found that while a great deal of research was published, there was a substantial amount of duplication in research effort and a focus on researching “treatment” rather than on preventive actions to address causes. The research portfolio was also found to be driven by donors rather than the needs of the population or views of local stakeholders. Moreover, SUNRAY highlighted the need for a large network to enhance evidence-informed decision-making and policy-driven research in health and nutrition in Africa

EVIDENT (Evidence-informed Decision-making in Health and Nutrition) was created to address all of these concerns, in particular in Africa. EVIDENT is an Afro-centric hub that enhances evidence-informed decision-making and policy-driven research in health and nutrition with a focus on Africa. More than half of its partners come from African countries, including Ghana (University of Ghana), Tanzania (Sokoine University of Agriculture), Uganda (Makarere University), Benin (University of Abomey-Calavi), Ethiopia (Ethiopian Institute of Public Health), South Africa (North-West University), Belgium (Institute of Tropical Medicine), UK (NICE international; Sheffield University, ScHARR) and the Netherlands (Royal Institute of Tropical Medicine). A case study was recently conducted to document whether South Africa is using evidence-informed decision-making processes in public health nutrition programming.

The South African Breast Cancer study

Breast cancer (BC) in women of African ethnicity is a disease that appears in younger women with a higher proportion of ER- cases. Influences of diet, body fatness and physical activity on BC need to be investigated in African women in Africa because of the uniqueness of this population in rapid lifestyle transition, where BC has now become one of the most common incident cancers in women. Large differences between urban and rural populations have been shown in South Africa, and prevalence of overweight and obesity is high.

Through the setting-up a population based case-control study of BC in the largest public breast clinic in South Africa, the study aims to clarify the role of body size, diet and physical activity in an African population, according to hormone-receptor status, and whether it differs from that in Caucasians. The findings will provide evidence to help from the public health strategies to reduce BC risk in African women. Primary prevention, if possible, is particularly important in African settings as tumours are aggressive, diagnosed at a late-stage and treatment is often unaffordable. Study partners include the  International Agency for Research on Cancer, Lyon, France; MRC/Wits Developmental Pathways for Health Research Unit, University of the Witwatersrand, Johannesburg, South Africa;  Batho Pele Breast Unit, Chris Hani Baragwanath Academic Hospital, Soweto, South Africa and the Centre of Excellence for Nutrition, North-West University (Potchefstroom Campus), Potchefstroom, South Africa