Dementia Prevalence and Impact in Low Income Areas in South Africa

Images courtesy of Dementia SA

This project examines the nutritional status of older, low-income South Africans in relation to depression and dementia prevalence. Southern Africa has one of the lowest life expectancy rates in the world for both men (53 years) and women (54 years). This decline in longevity in SA is not only a result of communicable diseases (e.g. AIDS), but also a range of non-communicable diseases (NCDs). Due to the adoption of aspects of the Western diet—including high sugar and fat content—NCDs are on the rise, with cardiovascular disease accounting for 17% of all deaths in SA in 2000 (Bradshaw, 2003).

Mental illness is an understudied field in low and middle-income countries, despite the fact that it is predicted to be the largest contributor to the burden of disease in these countries by 2050. At present, access to management and care, including care for dementia sufferers, is not at an acceptable standard. International research shows that risk factors for both depression and dementia include elevated levels of an amino acid (homocysteine) in the bloodstream, which may be toxic to the brain. Homocysteine is a by-product of a metabolic cycle in protein digestion, specifically reliant on vitamins B12 and folic acid to reduce its concentration. Treatment with B vitamins, including folic acid and B12, has been shown in some studies to delay cognitive decline in the elderly (Durga, 2008; de Jager 2012). There have also been studies showing a decrease in depressive symptoms with folic acid. Depression has been shown to increase the rate of cognitive decline in those with preclinical Alzheimer's disease.

Thus, a study to determine a) the nutritional and homocysteine status and b) the prevalence of cognitive impairment and dementia with and without depressive symptoms would be valuable in South Africa. The study would indicate if there is a similar chance of intervention with simple nutrients to delay cognitive decline and alleviate symptoms of depression in older people in low and middle-income countries, as in the Western world where previous trials have been done (Smith et al, 2010). If the risk factors are as prevalent as in the Western World, then it would help to motivate the health services to increase spending on nutrient supplements as a cheap and effective intervention.

  • Dr Celeste de Jager, University of Cape Town
  • Professor Marc Combrick, University of Cape Town
  • Associate Professor John Joska, University of Cape Town
  • Emeritus Professor Margaret Hoffman, University of Cape Town
  • Associate Professor Marjanne Senekal, University of Cape Town
  • Dr Janetta Harbron, University of Cape Town
  • Mrs Catherine Day, University of Cape Town
  • Mrs Zarina Ebrahim, University of Cape Town
  • Professor Louise Dye, University of Leeds
  • Professor Janet Cade, University of Leeds
  • Professor Hilary Powers, University of Sheffield

Public Health (Non-communicable Disease)