Cardiovascular Journal of Africa: Vol 26 No 2 (March/April 2015)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 2, March/April 2015 AFRICA 61
majority (83.9%) reported mainly avoiding adding salt to food
at the table.
As previously reported,28 there is a tendency for individuals
to perceive their dietary quality as good, even in the presence
of results of an objective measure showing opposite results.
Therefore, although it is difficult to know the exact amount
of salt added to food at the table or in cooking, we found that
contrary to the high urinary sodium values found, the majority
of our participants classified their own level of salt consumption
as ‘just right’ or ‘too little’, indicating a misperception of the
amount of salt they were eating. This gap between the self-
perceived and actual quality of a diet has been attributed to
the inability of individuals to perceive their own dietary salt
imbalance,29 therefore leading to an unrecognised high salt intake.
On the other hand, it has also been observed that some
people have a taste preference for high-sodium foods,7 which
leads to an inadequate perception of the amount of salt they are
consuming. Of concern is that although our participants were
medical students and future educators in public health, none of
them reported the habit of reading the labels of processed foods
to see the sodium content before consumption. Although sources
of dietary sodium vary largely worldwide,7 a high amount of
sodium has been found in processed foods,30,31 which are the main
sources of dietary salt.
A high-potassium diet has many benefits for health. As
previously reported,32 an increase of 42 mmol of potassium per
day is associated with a 21% reduced risk of stroke. In our study,
the average potassium intake was lower than the recommended
value of approximately 90 mmol per day.33 Considering that the
potassium excreted in 24-hour urine comes from the diet, the
findings of lower values of urinary potassium in our participants
suggest an unhealthy diet, in particular a poor consumption of
fresh vegetables and fruits.
It has been advised that a healthy diet should provide
enough content of potassium to achieve the molar ratio of
sodium to potassium of approximately one to one.33 We found
a ratio of three to one, confirming a high dietary salt intake
in the majority of our participants. Although the proportion
of subjects classified as having hypertension was low, there is a
potential risk for early blood pressure in this young population
if the current level of salt intake is maintained.
With regard to other classic cardiovascular risk factors,
we found a high prevalence of physical inactivity and 15% of
participants reported alcohol intake, but a low prevalence of
hypertension, diabetes and obesity. The high prevalence of
physical inactivity seen in this study is similar to the findings
of a study that enrolled university students from developed and
developing countries, in which physical inactivity tended to be
higher among students from developing countries.34
A positive finding in our study was that none of our
participants reported smoking. This result may reflect a possible
cultural difference regarding smoking among young people from
different countries.
The unsatisfactory behaviour regarding dietary salt seen in
this study may reflect the fact that because our students were
aware of their current health status, they did not worry about
their salt intake and therefore did not perceive their high risk for
the development of health-related consequences.
The main limitation of the study was that our sample was
not representative of a national student population. Despite the
small sample size, the strength of this study was that a possible
selection bias was minimised by randomly selecting the students
from the overall student body.
The complete 24-hour urine collection provided an estimation
of salt and potassium consumption, reflecting the daily pattern
of nutrient intake by our participants. Beyond the measurement
of the amount of salt consumption, the study also included
a survey on awareness and attitude regarding dietary salt,
including discretionary salt use (i.e. cooking or at the table),
which are important elements in finding the main source of salt
consumed by our participants.
Overall, our findings suggest urgent educational action
is needed to target behavioural change on dietary salt habits
and other health-risk behaviour of the students. This is
required for early prevention of the development of chronic
non-communicable diseases.
Conclusion
The study indicates a high salt intake among medical students,
with a misperception of their level of salt intake, and insufficient
attitude and behaviour regarding control of salt intake. These
results justify urgent nutritional education to upgrade their
knowledge for appropriate behaviour aiming at reducing their
salt intake and preparing them for their future role in community
counselling.
We thank Dr Carlos A Tembua and Mrs Nidia LPA van Dúnem for their
help in sample collection. The study was supported by a special grant from
Fundação para Ciência e Desenvolvimento from Angola.
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