CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 5, June 2012
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AFRICA
has been largely confined to patients with lipid disorders, obesity,
diabetes and/renal failure.
18
If, however, nutritional education
and promotion of good nutrition could be better understood and
recognised to be inclusive of behavioural change, then it will be
viewed as a necessary component within contemporary cardiac
rehabilitation and self-management programmes.
18
One cornerstone of HF management particularly relevant
to urban Africans affected by HF is dietary modification. For
example, sodium restriction (2–3 g/day) is standard therapy in the
management of symptomatic chronic HF, and black individuals
are particularly responsive to this strategy.
19,20
However, lack of
adherence and poor self-care behaviours persist, with dietary
indiscretions contributing to a substantial portion (up to 20%)
of hospital readmissions.
21
Specific dietary interventions play an
important role in improving health outcomes.
21,22
Three major studies addressing food choices and dietary
patterns in adult black South Africans were identified from the
literature. However, given the historical rarity of the syndrome,
there are very little data to describe the dietary habits of
specifically urban African patients with HF. The Dikgale study
23
examined food choices, nutrient intake and weight status of
black adults. The Transition, Health and Urbanisation study
(THUSA)
24
examined the food choices, health status and the
effect of urbanisation on a black population. The Black Risk
Factor study (BRISK)
25
examined the risk factors for developing
CVD in urban black Africans. Data from these studies show that
rural black adults have a very low consumption of fat and a high
consumption of carbohydrates, typical of the traditional rural
African diet.
23,25
Urbanisation is associated with markedly increased intake
of fat, sugar, meat and beverages.
23-25
Although a decrease
in the consumption of maize porridge with urbanisation was
found, it is still consumed in high amounts by these black
population groups.
23
As the traditional diet is abandoned in
favour of a Western diet, food choices shift away from complex
carbohydrates and higher fibre to foods high in fat, bringing an
increased risk for chronic diseases of lifestyle.
26
According to
Stewart
et al
., data on the population of Soweto have shown
a low prevalence for CVD and the underlying risk factors.
8
This situation however may be changing, as urbanisation and
the nutritional transition in South Africa is accompanied by an
increase in the CVD risk factors in black Africans.
27
The overall study aim was therefore to provide a detailed
description of the dietary habits and potential nutritional
deficiencies in a subgroup of urban black African patients
diagnosed with HF, living in Soweto, South Africa, and managed
via the Cardiology Unit of the Chris Hani Baragwanath Hospital.
It focused on the impact of varied dietary patterns, the poor
socio-economic status of many patients and probable lack of
awareness of the contribution of poor nutrition to cardiovascular
disease. Ultimately, these data will be used to identify key
targets for more culturally sensitive support and to argue for a
greater role for dieticians in the management of an increasing
number of urban black South Africans affected by HF.
12
Methods
As part of the previously described Heart of Soweto study,
8
detailed demographic and clinical data are captured from
all individuals with heart disease presenting to the Chris
Hani Baragwanath Hospital, Soweto, via a prospective clinical
registry. In 2006, this included 1 960 patients presenting with
a primary or secondary diagnosis of HF (an average of 162
patients per month). All were diagnosed by echocardiography
and specialist cardiological review. This was a prospectively
planned study of 50 consecutively consenting black Africans (28
females, 22 males), referred to the Heart Failure Clinic in 2006/7
with a documented diagnosis of HF.
The study was approved by the Human Research Ethics
Committee (Medical), University of the Witwatersrand,
Johannesburg, M050550. All participants provided written
informed consent. The study fully conformed to the principles
outlined in the Declaration of Helsinki.
Dietary instrument, data and nutrient analyses and
recommendations
In addition to the detailed clinical and demographic data collected
as part of the Heart of Soweto Clinical Registry, an interviewer-
administered quantitative food frequency questionnaire (QFFQ)
was collected at a point in time when patients had received either
limited, or no instructions for a low-sodium, low-fat therapeutic
diet for HF.
28,29
A quantitative food frequency questionnaire
is a validated questionnaire to determine food choices and
consumption. The previously validated QFFQ used in this study
was developed by a researcher at Northwest University. This
QFFQ has previously been used to evaluate the food choices of
the African population living in the North West Province, South
Africa, as part of the THUSA study.
30,31
The quantitative QFFQ has been validated via statistical
methods in an African population.
30
It includes 139 types of
food and records how often a given type of food is consumed as:
time/s per day, per week, per month. It also records preparation
methods. Quantities of food eaten were determined in relation
to pictures of standardised portions of the most commonly
consumed foods (e.g. maize meal porridge, rice, meat, etc.). The
researcher also used standardised cups, teaspoons etc. to estimate
portion sizes. The patients were also asked to name foods eaten
that were not included in the questionnaire and to point out
questions that were unclear or difficult to understand.
The QFFQ was administered through interview by the
researcher, SP, who is a registered dietician in the Heart Failure
Outpatient Clinic, Chris Hani Baragwanath Hospital, and trained
in administering the QFFQ.
Food data were translated into nutrient data using the Medical
Research Council (MRC) Food Finder 3, 2007, which is based
on South African food composition tables. Total dietary starch
was calculated from the total amount of carbohydrates minus
the sum of total dietary fibre plus added sugars. To assess the
consumption of high-sodium foods, data were aggregated to
provide percentages of high-sodium foods consumed both daily
and weekly.
Collated dietary patterns and nutritional intake data were
compared to the South African Food-Based Dietary Guidelines.
Importantly, one guideline advises that unrefined or minimally
processed starchy foods, such as maize, wheat, sorghum, oats,
rice in the form of porridges, breads, pastas, samp, breakfast
cereals and other products should be the main food around which
the rest of the meal is planned.
32
Promotion of carbohydrate-
rich foods contributes to optimal nutrient intake, particularly
