The double burdens of disease and malnutrition in Africa

Africa is experiencing a sharp rise in NCD related to rapid globalisation and urbanisation⁽Reference Melaku, Temesgen and Deribew^{10, 23–26)}. According to 2018 WHO data, 41·8 % of Africans now live in urban areas and 29·8 % of the population is aged between 30 and 70 years⁽²⁴⁾. Improved prevention and treatment of infectious diseases means that relatively more Africans are living longer than before⁽Reference Steyn and McHiza^27–Reference Bosu³⁵⁾. All these factors have led to shifts in dietary and lifestyle patterns^(26, Reference Abrahams, McHiza and Steyn³²⁾ with a sharp increase in energy intake and physical inactivity. The African diet, like elsewhere in the world, has shifted from largely fibrous to more refined, energy-dense foods coupled with increased consumption of alcohol and sweetened beverages⁽Reference Kearney^33–Reference Bosu³⁵⁾. However, unlike more resource-endowed regions, Africa has a double burden of disease: NCD co-exist with infectious diseases including lower respiratory tract infections, HIV/AIDS and diarrhoeal diseases⁽Reference Benziger, Roth and Moran¹⁾. Africa also has a double burden of malnutrition where stunting, wasting and overweight and obesity co-exist, especially among children and women⁽Reference Prentice^{6, 23,} Reference Vorster, Kruger and Margetts^34–Reference Yaya, Ekholuenetale and Bishwajit⁴⁰⁾. According to WHO malnutrition report for the African region, most countries have high stunting rates of more than 30 %, and the rates are rising. Thirty out of the forty-seven countries have wasting rates greater than 5 %⁽³⁶⁾. Poor intrauterine growth leading to low birth weight, and iron deficiency anaemia among mothers and children are still rampant and are exacerbated by the co-existence of infections including malaria, HIV/AIDS, tuberculosis and others⁽Reference Benziger, Roth and Moran^1, Reference Prentice^{6, 23,} Reference Steyn and McHiza^{27, 36)}. Twenty-six African countries have low birth weight rates more than 10 %⁽³⁶⁾. The African economy is also relatively weaker than elsewhere, making it difficult to cope with this burden and financing is still heavily tilted towards addressing infectious diseases⁽Reference Marquez and Farrington^28, Reference de-Graft Aikins, Unwin and Agyemang^29, Reference Allotey, Davey and Reidpath^31, Reference Yaya, Ekholuenetale and Bishwajit⁴⁰⁾. It is postulated that NCD, specifically, IHD and stroke, will soon overtake infectious diseases as the number one cause of death in the African region^{(4, 23,} Reference Kushitor and Boatemaa^30, Reference Allotey, Davey and Reidpath³¹⁾. NCD account for 37·1 % of all deaths with the probability of dying from at least one of four major NCD estimated to be 20·5 %⁽²³⁾. Diet-related risk factors are among key drivers of the NCD pandemic in Africa⁽Reference Afshin, Micha, Webb, Prabhakaran, Anand and Gaziano^8–Reference Melaku, Temesgen and Deribew^10, Reference Allotey, Davey and Reidpath^31, Reference Abrahams, McHiza and Steyn³²⁾. The double burdens of disease and malnutrition ravaging Africa will certainly undermine the grand march towards Agenda 2063 if nothing is done urgently. So where does Africa begin? The best point is to use existing challenges and convert them into opportunities for action. A few key actions that may have wide impact are considered.

Confront the misconceptions about NCD: it has been done before for HIV

The recognition of NCD as diseases and obesity as a related risk factor is poor in Africa, compounded by stigma associated with wasting in HIV/AIDS. Despite rising knowledge on obesity as risk factor for NCD, it is still largely perceived as a sign of wealth, achievement and marital harmony⁽Reference Ferris and Crowther^41–Reference Simfukwe, Van Wyk and Swart⁴⁴⁾. Healthcare workers have no better perceptions on overweight and obesity⁽Reference Simfukwe, Van Wyk and Swart⁴⁴⁾ and this may compromise care provision to affected populations. Cultural perceptions on body size and shape are as important as other factors including globalisation, urbanisation, occupations and built environment, and must be considered in strategies to address NCD⁽Reference Scott, Ejikeme and Clottey⁴⁵⁾. Well-designed behaviour change communication strategies that are culture sensitive, are needed to challenge these misconceptions and to mitigate stigma associated with NCD.

Promote and protect appropriate infant and young child feeding practices: a healthy child is a healthy adult in waiting

There is strong evidence that breast-feeding, if well practiced, has a potential to have double duty impact; enhancing intelligence⁽Reference Rollins, Bhandari and Hajeebhoy^46–Reference Horta, Loret de Mola and Victora⁴⁸⁾ and preventing child mortality, and protecting both mother and child from the risk of NCD⁽Reference Rollins, Bhandari and Hajeebhoy^46–Reference Jacobson, Hade and Collins⁵⁰⁾. Although almost all sub-Saharan African infants are breastfed, challenges remain in the low rates of timely initiation of breast-feeding within the first half hour of delivery and exclusive breast-feeding for the first 6 months of life^(26, Reference Engebretsen, Doherty and Horwood⁵¹⁾. Only a third of African countries have already attained the 50 % exclusive breast-feeding target⁽²⁶⁾. Children who are exclusively breastfed according to WHO recommendations gain more fat-free mass⁽Reference Mulol and Coutsoudis⁵²⁾ and are therefore more likely to have lower risk of overweight and obesity later in life⁽Reference Victora, Bahl and Barros⁴⁷⁾. HIV infection remains a problem to the extent that HIV-infected lactating mothers may not have easy access or adequately adhere to antiretroviral therapy⁽Reference Mulol and Coutsoudis⁵²⁾. Inappropriate infant and young child feeding practices are associated with retarded growth, which increases the risk of later overweight and obesity⁽Reference Symington, Gericke and Nel⁵³⁾.

Do not make policies for the shelf, implement them: where need be, formulate new ones to enable action

Despite some progress, Africa has not kept pace with meeting international commitments in addressing NCD, including the WHO led NCD Global action plan 2013–2020⁽Reference Nyaaba, Stronks and de-Graft Aikins⁵⁴⁾. According to Global Nutrition Report 2017 Africa, like most continents, is not on course to meet global nutrition targets including that of halting the rise in obesity and diabetes by 2025⁽⁵⁵⁾.

Policy formulation and implementation are limited by insufficient political commitment, resource allocation and a dearth of local data for policy making and outcome monitoring⁽Reference Juma, Mohamed and Matanje^56, Reference Juma, Mapa-Tassou and Mohamed⁵⁷⁾. Multi-sectoral action against NCD is also weak due to disjointed coordination, and lack of adequate capacity building and resource mobilisation⁽Reference Juma, Mohamed and Matanje^56, Reference Juma and Wisdom⁵⁸⁾. Involvement of sectors such as trade, academia, media, civil society and agriculture⁽²³⁾ can bring much needed leverage to fight the problem comprehensively. Better regional coordination in NCD-related legislation is needed to foster synergy⁽Reference Siddharthan, Ramaiya and Yonga⁵⁹⁾.

Ensure an environment and foods devoid of contaminants and microbial toxins

Environmental contaminants and microbial toxins have a potential not only to drive undernutrition, but also the risk of obesity and related NCD. Endocrine disrupting compounds such polychlorinated biphenyls, pesticides and mycotoxins may impact child growth and health via modified action of growth hormone, adiposity, DNA methylation and protein synthesis⁽Reference Owino, Cornelius and Loechl¹⁷⁾. Endocrine disruptors negatively impact on hormonal processes associated with growth from in utero and have potential to programme the fetus for later disease⁽Reference DiVall^60–Reference Bornman, Aneck-Hahn and de Jager⁶³⁾. A recent expert consultation on endocrine disruptors in Africa⁽Reference Bornman, Aneck-Hahn and de Jager⁶³⁾ called for urgent action to address this problem and highlighted gaps in resource allocation for research and weak policy implementation. Mycotoxins are fungal secondary metabolites that are linked to adverse health outcomes in both human subjects and livestock⁽Reference Logrieco, Miller and Eskola^64–Reference Stepman⁶⁷⁾. Aflatoxins, a class of mycotoxins produced by Aspergillus flavus, have received the attention of researchers in Africa and beyond. Contamination of food by aflatoxins leads to losses in human health, agriculture and trade⁽Reference Wagacha and Muthomi⁶⁶⁾. Aflatoxins, especially aflatoxins B1, have been linked to cancers of the liver⁽Reference Turner, Moore and Hall⁶⁸⁾ and gallbladder⁽Reference Koshiol, Gao and Dean⁶⁹⁾, acute toxicity⁽Reference Mwanda, Otieno and Omonge^70, Reference Probst, Njapau and Cotty⁷¹⁾, retarded growth in infants⁽Reference Lombard^72, Reference Gong, Cardwell and Hounsa⁷³⁾ and immune function disruption⁽Reference Turner, Moore and Hall^68, Reference Castelino, Routledge and Wilson⁷⁴⁾. Although research has heavily focused on aflatoxin, similar adverse effects on child growth have been observed with other mycotoxins such as Fumonisins⁽Reference Shirima, Kimanya and Routledge⁷⁵⁾ suggesting potential synergy if multiple toxins co-exist.

Develop capacity to collect non-communicable disease-sensitive data for evidence-based policy formulation and action

There is also a dearth of data on overweight and obesity in the continent⁽Reference Vorster, Kruger and Margetts³⁴⁾ and little knowledge that infant feeding practices, such as breast-feeding, are linked to reduced risk of NCD in both children and mothers. Policy formulation and design of interventions to tackle NCD depends on the availability of appropriate data. In terms of diet-related risk factors (food intake and physical activity), adiposity is the most sensitive indicator of the risk of obesity and related NCD. Being obese heightens the risk of death from major NCD: metabolic syndrome, diabetes, CVD and some cancers⁽Reference Banjare and Bhalerao^76–Reference Nyberg, Batty and Pentti⁷⁸⁾. For example, strong correlations have been demonstrated between high BMI and increased risk of hypertension⁽Reference Choukem, Kengne and Nguefack⁷⁹⁾ and diabetes⁽⁸⁰⁾. While BMI is a useful screening tool that allows for categorising individuals as overweight or obese, it does not measure adiposity, the most important component of metabolic load⁽Reference Wells and Shirley⁸¹⁾. Individuals with the same BMI may not necessarily have the same amount and distribution of body fat⁽Reference Yajnik, Fall and Coyaji^82, Reference D'Angelo, Yajnik and Kumaran⁸³⁾. Knowledge of the amount of body fat, how it is distributed throughout the body and the composition of lean mass is important⁽Reference Wells and Shirley^81, Reference Wells and Fewtrell^84, Reference Mazzoccoli⁸⁵⁾. Techniques to measure body composition include bioelectrical impedance, dual-energy X-ray absorptiometry, densitometry including air displacement plethysmography and isotope dilution techniques⁽Reference Duren, Sherwood and Czerwinski⁸⁶⁾. Isotope dilution including deuterium oxide and doubly labelled water techniques are based on the estimation of total body water⁽Reference Lee and Gallagher^87, Reference Owino, Slater and Loechl⁸⁸⁾. Isotope dilution has been used as a reference method to validate other methods of body composition assessment⁽Reference Essa'a, Dimodi and Ntsama^89, Reference Fields, Wilson and Gladden⁹⁰⁾.

Where does Africa go from here?

While complex multi-sectoral approaches to address this NCD menace are needed, Africa may benefit from taking simple initial steps to address NCD risk factors. As Lloyd-Williams and colleagues⁽Reference Lloyd-Williams, Bromley and Orton⁹¹⁾ rightly argue, there is a plethora of policies and interventions proposed but trying to do them all at the same time may be counterproductive. Africa may benefit from the law of the vital few⁽Reference Dunford, Su and Tamang^92, Reference Nisonger⁹³⁾ and start only with what is doable and most impactful. Actions that enable simultaneous addressing of both infectious and NCD will be most desirable⁽Reference Steyn and McHiza²⁷⁾. Such actions may include: (1) Promote behaviour change communication to challenge perceptions on NCD. Such approaches can be based on lessons learnt from tackling infectious diseases such as HIV and tuberculosis. Health-care systems already in place to respond to these infections can be used as platforms to for dedicated response to NCD⁽⁹⁴⁾; (2) Formulate and implement policies and regulations limiting wide availability of unhealthy foods while promoting healthy lifestyle; (3) Mainstream nutrition education in school curricula. Holistic school-based interventions that involve parents and the community may be most effective⁽Reference Ickes, McMullen and Haider^95–97) and may simultaneously address food insecurity in a double duty format; (4) Implement policies to regulate food and environmental contaminants; (5) Collection of accurate data based on indicators that can reflect the double burdens of disease and malnutrition. Body composition is influenced by multiple adverse exposures; body fat accumulation and distribution are key predictors of the risk of obesity and related NCD⁽Reference Owino, Cornelius and Loechl^17, Reference Wells and Shirley⁸¹⁾. Including accurate body fat and lean mass measurement in NCD surveillance may add value on interpretation of risk and design of interventions.