Maretha Opperman

Bio: Maretha Opperman is an academic researcher from Cape Peninsula University of Technology. The author has contributed to research in topics: Fatty acid & Medicine. The author has an hindex of 5, co-authored 8 publications receiving 198 citations.

Nutritional contribution of street foods to the diet of people in developing countries: a systematic review

Abstract: Human Sciences Research Council, Medical Research Council, Cape Peninsula University of Technology and the National Research Foundation

Analysis of omega-3 fatty acid content of South African fish oil supplements

Abstract: Introduction : Substantial evidence describes the protective effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFA) on cardiovascular diseases as well as many other conditions. Numerous fatty acid preparations are marketed for supplementing the Western diet, which is low in n-3 fats. Since these preparations may vary in their n-3 PUFA content, we tested 45 commercially available products on the South African market for their fatty acid composition. Method : Forty-five commercially available n-3 fatty acid supplements were analysed using gas-liquid chromatography to determine their fatty acid content. Results : More than half of the n-3 supplements available on the South African market contained ≤ 89% of the claimed content of EPA and/or DHA as stated on the product labels. To meet ISSFAL's recommendation of 500 mg EPA + DHA/day can cost consumers between R2 and R5 per person per day (R60 to R150 p/p/month). Regarding rancidity, the majority of capsules contained conjugated diene (CD) levels higher than that of vegetable oil obtained from opened containers (three months) used for domestic cooking purposes, despite the addition of vitamin E as antioxidant. Conclusion : Since no formal regulatory structure for dietary supplements currently exists in South Africa, consumers depend on self-regulation within the nutraceutical industry for assurance of product quality, consistency, potency and purity. Our results indicate that more than half of the n-3 fatty acid supplements on the South African market do not contain the claimed EPA and/or DHA contents as stated on product labels, and they contained CD levels higher than that in unused vegetable oils obtained from opened containers used for domestic cooking purposes.

Analysis of the omega-3 fatty acid content of South African fish oil supplements: a follow-up study.

Abstract: Introduction: Globally the omega-3 (n-3) fatty acid supplement industry is expanding rapidly while consumers are becoming more aware of the health benefits of n-3 fatty acids. Our group conducted a survey in 2009 on 45 commercially available fish oil supplements on the South African market. The aim of the study was to determine the fatty acid composition and content of supplements for comparison with the claimed contents on the product label. The survey was repeated in 2012 on 63 supplements. Methods: Sixty-three commercially available n-3 fatty acid supplements were analysed using gas–liquid chromatography to determine their fatty acid composition and content. Results: This analysis has shown an improvement in the accuracy of EPA content (44% in 2009) declared on supplement labels compared to the 2012 (52%) survey. It was also evident that a higher percentage of supplements (13% in 2009 vs 35% in 2012) contained DHA levels higher than declared. In 2009, 64% of supplements cost R2.01 to R5.00 or more to achieve a daily intake of 500 mg EPA + DHA, compared to 81% in 2012. Forty-four per cent of supplements were found to be in the early stages of rancidity [conjugated diene (CD) levels] compared to 73% in 2009. More than 80% of supplements had peroxide levels higher than the recommended content as specified by the Global Organisation for EPA and DHA Omega-3 (GOED). The majority (81%; n = 51) of the supplements under study in 2012 had a 1.1–1.5:1 EPA-toDHA ratio or less, compared to 56% in 2009. Almost a third (32%) of the supplements in the 2012 survey contained ethyl esters (EE) or a combination of ethyl esters and triglycerides. Conclusion: Although the results of the 2012 versus the 2009 analysis were encouraging in terms of the accuracy of EPA declared on the supplement labels, the high peroxide levels found in the supplement oils are of concern. High peroxide levels are associated with potential health implications. EE were present in some of the supplements, even though the safety of EE has not been confirmed in vulnerable groups such as pregnant women and children.

South African seed oils are safe for human consumption

Abstract: Objectives: A diet that is high in fat and low in carbohydrates is advocated in the recently published The Real Meal Revolution. A suggestion was made in this publication that seed oils are toxic. The authors stated that available seed oils on the South African market were high in trans-fatty acid (TFA), as well as being genetically modified, and thus should be avoided. We compared three oils, i.e. canola, sunflower and olive oil, against internationally accepted standards, to determine the quality of these oils using gaschromatographic analysis, to determine whether or not there was any foundation to the statement pertaining to the toxicity of South African seed oils. Reported parameters included the fatty acid profile, TFA content, peroxide level and conjugated diene (CD) content. Design: Samples were purchased from local retail stores. Two independent researchers de-identified the oils, and stored them in numbered containers under nitrogen until commencement of the analysis. Hence, a blind sample of oils was received. Outcome measures: Twelve (n = 12) olive oil, 15 (n = 15) canola oil and 7 (n = 7) sunflower oil samples were subjected to analysis. CD and peroxide levels were conducted spectrophotometrically, and fatty acid content determined by gas liquid chromatography. Results: The total TFA content of the three types of sampled oils was below 0.5%, and the peroxide (meq O 2 /kg) and CD levels (μmol/g) were within allowable limits, as described in the Codex Standard for Named Vegetable Oils, as well as previous publications. Conclusion: The results demonstrated that the South African seed oils included in this analysis contained a negligible amount of TFA, adhered to international recommendations with respect to fatty acid content, and were well within the safe range for oxidation products. Therefore, the statement that South African seed oils are toxic is inaccurate, unscientific and without merit.

What health professionals should know about omega-3 fatty acid supplements

Abstract: Omega-3 (n-3) fatty acids are essential to maintain satisfactory human health and need to be consumed in the diet. Western diets are often deficient in n-3 fatty acids because of an insufficient intake of cold water oily fish. The main n-3 fatty acids in fatty fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). To date, no formally accepted dietary reference intakes for EPA and DHA exist, while international intake recommendations differ widely. Supplementation is an easy and convenient way of increasing dietary n-3 fatty acid intake, but very little information is available to health professionals when advising consumers on choosing a supplement to suit their lifestyle. Reliable nutrition information on product labels is vital since misleading information may lead to erroneous dosages with concomitant adverse effects. Since no formal regulatory structure for dietary supplements currently exists in South Africa, consumers depend on self-regulation within the industry for assurance...

Slum Health: Arresting COVID-19 and Improving Well-Being in Urban Informal Settlements.

Abstract: The informal settlements of the Global South are the least prepared for the pandemic of COVID-19 since basic needs such as water, toilets, sewers, drainage, waste collection, and secure and adequate housing are already in short supply or non-existent. Further, space constraints, violence, and overcrowding in slums make physical distancing and self-quarantine impractical, and the rapid spread of an infection highly likely. Residents of informal settlements are also economically vulnerable during any COVID-19 responses. Any responses to COVID-19 that do not recognize these realities will further jeopardize the survival of large segments of the urban population globally. Most top-down strategies to arrest an infectious disease will likely ignore the often-robust social groups and knowledge that already exist in many slums. Here, we offer a set of practice and policy suggestions that aim to (1) dampen the spread of COVID-19 based on the latest available science, (2) improve the likelihood of medical care for the urban poor whether or not they get infected, and (3) provide economic, social, and physical improvements and protections to the urban poor, including migrants, slum communities, and their residents, that can improve their long-term well-being. Immediate measures to protect residents of urban informal settlements, the homeless, those living in precarious settlements, and the entire population from COVID-19 include the following: (1) institute informal settlements/slum emergency planning committees in every urban informal settlement; (2) apply an immediate moratorium on evictions; (3) provide an immediate guarantee of payments to the poor; (4) immediately train and deploy community health workers; (5) immediately meet Sphere Humanitarian standards for water, sanitation, and hygiene; (6) provide immediate food assistance; (7) develop and implement a solid waste collection strategy; and (8) implement immediately a plan for mobility and health care. Lessons have been learned from earlier pandemics such as HIV and epidemics such as Ebola. They can be applied here. At the same time, the opportunity exists for public health, public administration, international aid, NGOs, and community groups to innovate beyond disaster response and move toward long-term plans.

Fish oil supplements in New Zealand are highly oxidised and do not meet label content of n-3 PUFA

Abstract: We evaluated the quality and content of fish oil supplements in New Zealand. All encapsulated fish oil supplements marketed in New Zealand were eligible for inclusion. Fatty acid content was measured by gas chromatography. Peroxide values (PV) and anisidine values (AV) were measured, and total oxidation values (Totox) calculated. Only 3 of 32 fish oil supplements contained quantities of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that were equal or higher than labelled content, with most products tested (69%) containing <67%. The vast majority of supplements exceeded recommended levels of oxidation markers. 83% products exceeded the recommended PV levels, 25% exceeded AV thresholds, and 50% exceeded recommended Totox levels. Only 8% met the international recommendations, not exceeding any of these indices. Almost all fish oil supplements available in the New Zealand market contain concentrations of EPA and DHA considerably lower than claimed by labels. Importantly, the majority of supplements tested exceeded the recommended indices of oxidative markers. Surprisingly, best-before date, cost, country of origin, and exclusivity were all poor markers of supplement quality.

Street vendors and cities

Abstract: This paper synthesizes recent research and evidence on urban policies and local government practices as they relate to street vending, one of the most visible occupations in the informal economy. It presents the latest available evidence on the size, composition and contribution of street vending, and reviews the rich literature on street vending as well as media coverage reflecting the extent of exclusionary policies and practices. While many analyses explore the reasons behind evictions and relocations through case studies, this paper draws on participatory methods and surveys to examine the more “everyday” challenges that street vendors face, even when licensed. The data demonstrate the livelihood impacts of generalized workplace insecurity, harassment and confiscation of merchandise on street vendors’ earnings, assets and time. We briefly explore the models of organizing and policy approaches in Ahmedabad, India and Lima, Peru, where collective action among vendors has resulted in more innovative poli...

The Safe Food Imperative: Accelerating Progress in Low- and Middle-Income Countries

Abstract: Food safety is linked in direct and indirect ways to achieving many of the Sustainable Development Goals, especially those on ending hunger and poverty, and promoting good health and well-being. Food and nutritional security are realized only when the essential elements of a healthy diet are safe to eat, and when consumers recognize this. The safety of food is vital for the growth and transformation of agriculture, which are needed to feed a growing and more prosperous world population, for the modernization of national food systems, and for a country's efficient integration into regional and international markets. The safety of food is the result of the actions or inactions of many stakeholders operating under diverse environmental, infrastructure, and socio-political conditions. These stakeholders include farmers, food handlers and distributors, food manufacturers, food service operators, consumers, regulators, scientists, educators, and the media. Their behavior can be shaped by their awareness of food safety hazards; their technical, financial, and other capabilities to apply effective mitigating practices; and prevailing rules, incentives, and other motivators. Food safety outcomes can be strongly influenced by policies, investments, and other interventions. These alter the awareness, capabilities, and practices of stakeholders, from farm to fork. Well-functioning markets can provide incentives for farmers and food business operators to supply products that match the safety characteristics consumers demand. Even so, there are many circumstances stemming from problems of information and costs where pure market signals fail and additional measures are needed. Problems of information include the actual attributes of food products, and the location and origins of food safety hazards.