Epigenetics and global health

Learning outcomes

At the end of this case study, you should be able to:

  • Explain the key concepts behind epigenetics including what epigenetics is, types of epigenetic modifications, the importance of epigenetics and how it can be related to disease;
  • Explain how epigenetics could potentially influence decisions relating to global health;
  • Discuss how diet and nutrition can have an impact on health and disease through epigenetics; 
  • Critically analyse and evaluate resources given which are related to the field of epigenetics;
  • Develop well-structured and logical arguments relevant to the field of epigenetics and the social, ethical, legal and economic issues (where appropriate) which arise from the case study.


Epigenetics and global health: Issues, Task, Resources

Introduction

What is epigenetics?

Epigenetics is the study of heritable changes in gene expression caused by mechanisms distinct from the underlying DNA sequence i.e. it is caused my modifications to the genome that do not involve a change to the nucleotide sequence. This is most commonly achieved through DNA methylation although histone modifications such as acetylation, methylation and phosphorylation also play a role.

Epigenome and disease progression

Figure 1:  Modification of the epigenome can be achieved through a number of environmental factors which can directly contribute to disease initiation and progression. Everyday stresses such as pollution, alcohol and poor diet modify the epigenome, which in turn alters gene expression patterns by altering a gene's activity; this is normally a tightly regulated process so alteration of gene activity can contribute to pathogenesis of diseases.

 

Unlike the genome which is largely static, the epigenome is dynamic and frequently responds to environmental cues and stresses such as exposure to chemicals, smoking, stress, diet and alcohol (Figure 1). Accumulating evidence suggests that there are epigenetic transgenerational effects meaning that environmental factors experienced by our ancestors may affect us decades later thus what someone does in their lifetime may have an impact on future generations.

Global health issues

One of the key issues in developing countries is food insecurity (ensured access to essential nutrition), which commonly results from poverty, recurrent drought, civil war and soil and land degradation; as such, vast numbers of people worldwide suffer from chronic hunger and malnutrition, a condition characterised by the variety or quality of food being insufficient to support proper health and development (Figure 2; Save the Children, 2012). 

In recent years, global aid programmes and budgets are being downscaled due to the downturn in global economies which can have devastating consequences on the populations which are heavily reliant on them; for example, in 2009, emergency food aid funding fell by 12 percent and the total tonnage of food aid was the lowest since 1961 (World Food Program, 2009).

Malnutrition

Figure 2: Malnutrition is an underling cause of the death of 2.6 million children each year- around one-third of the global total of children’s deaths (Save the Children, 2012).


Aid programmes take on a number of forms that are tailored specifically to each situation with a range of multilateral agencies worldwide being involved in the development and implementation of such programmes, ranging from general food distribution, supplementary feeding or therapeutic feeding. Supplementary feeding is used to correct moderate malnutrition and prevent deterioration of nutritional status among those who are deemed most at risk such as young children and pregnant or lactating women whereas therapeutic feeding is used as treatment for severely malnourished individuals (WHO, 2013). In both cases, the aim of the food programmes is to alleviate micronutrient deficiency, stunting and wasting whilst other interventions aim to encourage changes in behaviour to improve nutrition such as promoting breast feeding.

 

Bibliography

Save the Children, 2012. A life free from hunger: Tackling child malnutrition

World Food Programme, 2009. Food aid flows.

World Health Organisation, 2013. Drought- Technical hazard sheet- natural disaster profiles.

 

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