The main results of this study are that: (1) 38% of South Africans report that their households are food-insufficient; (2) after controlling for conventional socioeconomic and sociodemographic variables, food insufficiency was associated with an increased risk of having a 12-month and lifetime DSM-IV diagnosis of anxiety disorder; and (3) respondents who reported that their household ‘often’ did not have enough food were also more likely to have a 12-month and lifetime substance use disorder than those who were food-sufficient.
High rates of food insecurity and food insufficiency have been reported in Tanzania17,19,36
For example, a recent study conducted in rural Ethiopia with 902 participants found that 33% of respondents were food-insecure.27
However, these studies were not national in scope and, to our knowledge, this is the first nationally representative study to document household food insufficiency in sub-Saharan Africa. The finding that 38% of South Africans reported household food insufficiency indicates a significant public health burden. To place this finding in perspective, nationally representative studies in the developed world estimated that only 2.3% of Canadians reported food insecurity with any type of hunger,38
while 4.1% of American households had ‘very low food security’ (conceptually similar to food insufficiency) in 2007.39
Second, data from this population-based representative sample revealed that food insufficiency was associated with having a 12-month DSM-IV diagnosis. Therefore, the 38% of South Africans who experience household food insufficiency not only face the risk of physical health problems associated with an inadequate diet and nutritional deficiencies, but also the risk of having a mental illness. This finding is consistent with results of previous community-based studies18,20,23,40
and the nationally representative studies conducted in the developed world.16,28
Of note, the pattern of results for the association between lifetime DSM-IV diagnosis and food insufficiency was almost identical with the findings for the 12-month DSM-IV outcome.
Respondents who reported food insufficiency were more likely to have a 12-month DSM-IV disorder—and specifically an anxiety disorder—than those who were food-sufficient. This analysis did not observe a significant increase in risk for major depressive disorder, which is inconsistent with previous research reporting an association between food insecurity and depression.19,27
As anxiety disorders are more common than depressive disorders in our sample, it is possible that the finding of an association of food insecurity with anxiety but not with depressive disorders simply reflects a false negative in the latter case. An alternative explanation might be that, in an African setting where food insecurity is widespread, there is more resilience to associated depression than in other contexts. Nevertheless, given that anxiety and depressive disorders are so often comorbid, and given that previous literature has shown that food insecurity is linked with both of these groups of disorders, the former explanation seems more persuasive.
Finally, respondents who reported that they ‘often’ did not have enough food were more likely to have a 12-month and lifetime substance use disorder than those who were food secure. Similar findings were reported in a study conducted in Canada assessing food insecurity among 1213 HIV-positive patients, where participants who reported ever having used recreational injection drugs and ever having had alcohol or drug treatment were more likely to be food insecure.24
Another study conducted in the USA compared food insecurity among 41 low-income Puerto Rican female out-of-treatment drug users and 41 matched controls. The results indicated that drug users were more likely than the controls to experience food insecurity according to the Radimer/Cornell scale.41
It could be that drug users prefer purchasing drugs than food when funds are available.
The relationship between food insufficiency and mental health has implications for reducing the burden of common mental disorders in South Africa. Mental disorders and their associated psychosocial disabilities are a source of considerable morbidity and impose a significant drain on national resources.42
If food insufficiency is a contributing or causal factor in mental illness, preventing it might reduce the risk of onset or recurrence of these costly and disabling illnesses. Many of the major risk factors for mental illness that have been identified in the literature such as low socioeconomic status and genetic factors cannot be readily modified. However, food insufficiency is relatively amenable to intervention. Nutrition education programmes could include mental health screening and mental healthcare providers could screen for food insecurity as part of the psychosocial evaluation. Non-governmental organisations and governmental programmes presently active in South Africa providing food assistance, including the distribution of food parcels, could be used more effectively.
Several limitations of this study must be considered when interpreting these findings. First, although our theoretical perspective suggests the hypothesis that food insufficiency leads to psychiatric disorder, it must be emphasised that the cross-sectional design of our study and many other studies on this topic18,22,43
does not provide information about the causal direction of associations. Although it might be argued that household food insufficiency predisposes individuals to poor mental health, the reverse could also be true. Prospective research in the USA provides support for a bidirectional relationship, where food insecurity predicted depression and depression predicted food insecurity.29
Second, despite the evidence suggesting that food insufficiency increases HIV risk transmission behaviours and susceptibility to HIV once exposed,44
and that people living with HIV/AIDS (PLWHA) are twice as likely to suffer from a psychiatric disorder than the general population,45
an analysis of the association between HIV and food insufficiency was not conducted owing to low self-reported prevalence rates. However, the covariate for self-reported health status should capture some of the variation that may be related to HIV status. Finally, since data were not collected from non-respondents, we know very little about the 15% who refused to participate in the SASH study.
Nevertheless, these data are the first to describe the association between food insufficiency and diagnostic mental health outcomes in a nationally representative population in a low or middle income country. These findings suggest that secure access to food may have health impacts that extend beyond nutritional outcomes to mental health status. These findings also demonstrate the necessity to continue efforts to prevent food insecurity in order to improve the health of South Africans. Our findings highlight the need for more research to better delineate the mechanisms and to test the effects of nutritional interventions.