Development and validation of a dietary assessment tool to determine dietary intake of people living in oesophageal cancer risk areas in the rural Eastern Cape of South Africa

Rural areas in the Eastern Cape (EC) Province of South Africa have a high incidence of oesophageal cancer (OC). Amongst the known risk factors associated with the cancer is fumonisin exposure (a mycotoxin growing on maize), poor dietary habits and nutrient deficiencies. Little is known about the current dietary habits and nutrient intake of these people, and therefore maize consumption and fumonisins exposure

Application and interpretation of multiple statistical tests to evaluate validity of dietary intake assessment methods

BACKGROUND:Several statistical tests are currently applied to evaluate validity of dietary intake assessment methods. However, they provide information on different facets of validity. There is also no consensus on types and combinations of tests that should be applied to reflect acceptable validity for intakes. We aimed to 1) conduct a review to identify the tests and interpretation criteria used where dietary assessment methods was validated against a reference method and 2) illustrate the value of and challenges that arise in interpretation of outcomes of multiple statistical tests in assessment of validity using a test data set. METHODS: An in-depth literature review was undertaken to identify the range of statistical tests used in the validation of quantitative food frequency questionnaires (QFFQs). Four databases were accessed to search for statistical methods and interpretation criteria used in papers focusing on relative validity. The identified tests and interpretation criteria were applied to a data set obtained using a QFFQ and four repeated 24-hour recalls from 47 adults (18-65 years) residing in rural Eastern Cape, South Africa. RESULTS: 102 studies were screened and 60 were included. Six statistical tests were identified; five with one set of interpretation criteria and one with two sets of criteria, resulting in seven possible validity interpretation outcomes. Twenty-one different combinations of these tests were identified, with the majority including three or less tests. Coefficient of correlation was the most commonly used (as a single test or in combination with one or more tests). Results of our application and interpretation of multiple statistical tests to assess validity of energy, macronutrients and selected micronutrients estimates illustrate that for most of the nutrients considered, some outcomes support validity, while others do not. CONCLUSIONS: One to three statistical tests may not be sufficient to provide comprehensive insights into various facets of validity. Results of our application and interpretation of multiple statistical tests support the value of such an approach in gaining comprehensive insights in different facets of validity. These insights should be considered in the formulation of conclusions regarding validity to answer a particular dietary intake related research question

A food photograph series for identifying portion sizes of culturally specific dishes in rural areas with high incidence of oesophageal cancer

Rural areas of the Eastern Cape (EC) Province, South Africa have a high incidence of squamous cell oesophageal cancer (OC) and exposure to mycotoxin fumonisin has been associated with increased OC risk. However, to assess exposure to fumonisin in Xhosas—having maize as a staple food—it is necessary to determine the amount of maize consumed per day. A maize-specific food frequency questionnaire (M-FFQ) has recently been developed. This study developed a food photograph (FP) series to improve portion size estimation of maize dishes. Two sets of photographs were developed to be used alongside the validated M-FFQ. The photographs were designed to assist quantification of intakes (portion size photographs) and to facilitate estimation of maize amounts in various combined dishes (ratio photographs) using data from 24 h recalls (n = 159), dishing-up sessions (n = 35), focus group discussions (FGD) (n = 56) and published literature. Five villages in two rural isiXhosa-speaking areas of the EC Province, known to have a high incidence of OC, were randomly selected. Women between the ages of 18–55 years were recruited by snowball sampling and invited to participate. The FP series comprised three portion size photographs (S, M, L) of 21 maize dishes and three ratio photographs of nine combined maize-based dishes. A culturally specific FP series was designed to improve portion size estimation when reporting dietary intake using a newly developed M-FFQ

Understanding lactose intolerance and the dietary management thereof

CITATION: Labuschagne, I. & Lombard, M. J. 2012. Understanding lactose intolerance and the dietary management thereof. South African Family Practice, 54(6):496-498.The original publication is available at http://www.safpj.co.zaDiets that exclude dairy may decrease gastrointestinal symptoms in symptomatic individuals who have lactose malabsorption or lactose intolerance. However, most lactose-intolerant adults can consume some lactose without experiencing major symptoms, thereby reducing the need for strict elimination of dairy products from the diet.http://www.safpj.co.za/index.php/safpj/article/view/2932Publisher's versio

A proposed method to determine fumonisin exposure from maize consumption in a rural South African population using a culturally appropriate FFQ

To develop an FFQ for estimating culture-specific maize intake that can distinguish between home-grown and commercial maize. Home-grown maize is more likely to be contaminated with fumonisins, mycotoxins that are associated with increased risk of oesophageal cancer. An existing FFQ developed for use in urban Xhosa populations was used as the initial framework for the maize-specific FFQ (M-FFQ). The existing questionnaire contained 126 food items divided into ten food groups (bread, cereals, vegetables, fruit, meat, dairy, snacks, condiments, beverages and fat). The M-FFQ was developed based on additional data obtained from a literature search, 24 h recalls (n 159), in-depth interviews (n 4), focus group discussions (n 56) and expert consultation. Food items available in local shops (n 3) were compared with information obtained from focus group discussions. Five villages in two rural isiXhosa-speaking areas of the Eastern Cape Province, known to have a high incidence of oesophageal cancer, were randomly selected. Women aged 18-55 years were recruited by snowball sampling and invited to participate. The final M-FFQ comprised twenty-one maize-based food items, including traditional Xhosa dishes and beverages. The questionnaire focused on maize-specific dishes and distinguished between home-grown maize and commercial maize consumption. A culturally specific dietary assessment method was designed to determine maize consumption and therefore fumonisin exposure. The questionnaire will be tested against 24 h recalls and other methods to determine its validity, after which it will be used in various epidemiological studies to determine fumonisin exposure

Acidified infant formula explained

CITATION: Labuschagne, I., Van Niekerk, E. & Lombard, M. J. 2013. Acidified infant formula explained. South African Family Practice, 55(3):354-356.The original publication is available at http://www.safpj.co.zaThe development of effective methods to prevent acute gastroenteritis is an important goal for infant health. Exclusive breastfeeding and postponement of complementary foods until the age of six months is recommended for healthy infants. However, at times, infant formula is required. Various types are commercially available. Acidified cow’s milk formula has been found to prevent the growth of pathogenic bacteria and concurring diarrhoeal disease.http://www.safpj.co.za/index.php/safpj/article/view/3729Publisher's versio