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

Abstract

Objective: 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. Design: 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. Setting: 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. Subjects: Women aged 18-55 years were recruited by snowball sampling and invited to participate. Results: 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. Conclusions: 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.

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

“…The fact that carbohydrate containing maize based foods are staples of the subjects included in test data sample [12] may have enhanced recall and thus validity outcomes.…”

“…The QFFQ comprised 21 maize-based cultural specific food items and beverages and was accompanied by a portion size food photograph series [11,12]. The recall period of the QFFQ was the past month and response categories included “less than once a month”, “amount per month”, “amount per week” and “amount per day”.…”

A Food Photograph Series for Identifying Portion Sizes of Culturally Specific Dishes in Rural Areas with High Incidence of Oesophageal Cancer

“…Standard portion sizes of maize items, dishes and beverages appearing on the M-FFQ were determined using 24 h recall data ( n = 159) collected in the same areas [7]. Participants provided information on the maize based food items and dishes consumed the previous day, as well as snacks and beverages to provide information on the dietary habits of the people living in these areas.…”

“…Standard ratios of maize to vegetables in nine combined dishes (maize meal + imifino ; maize meal + spinach; maize meal + pumpkin; maize meals + dried beans; maize meal + dried beans; samp + beans; isophi ; mealie rice + spinach; mealie rice + pumpkin) were determined using previously unpublished 24 h recall data from our group ( n = 159) [7], as well as review of previously published data [8,9]. …”

“…Fumonisin contamination of this food source is a major health concern and to date no quantitative assessment of exposure has been conducted [6]. Recently, a culturally specific maize-specific food frequency questionnaire (M-FFQ) was developed [7] to determine fumonisin exposure from maize consumption in rural-dwelling residents of the EC Province.…”