What is the real cost of our food? Implications for the environment, society and public health nutrition

The current, globalised food system supplies 'cheap' food to a large proportion of the world's population, but with significant social, environmental and health costs that are poorly understood. The present paper examines the nature and extent of these costs for both rural and urban communities, by illustrating the financial pressures on food producers and manufacturers to produce cheap food, the disconnection people experience with how and where their food is produced, and the rise in obesity levels that plague the globe. The paper then proposes that community food systems may play an important role in mitigating the adverse environmental, economic and social effects of the dominant food system, by the use of more sustainable food production methods, the development of local economies and enabling closer connections between farmers and consumers. There are many opportunities for public health nutritionists to contribute to the local food system literature to ascertain whether these systems improve inequities, provide better access to healthy food and help stem the tide of rising global obesity levels. Public health nutritionists can play a key role in supporting people to become food citizens and to advocate for democratic and sustainable food systems.     

Are the Dutch acquainted with and willing to try healthful food products? The role of food neophobia

OBJECTIVES: To assess participants' acquaintance with and willingness to try healthful food alternatives, and to test the psychometric properties of an adapted Dutch version of the Food Neophobia Scale (FNS) in order to study the role of food neophobia in this context. DESIGN: A cross-sectional study incorporating two web-based questionnaires, including a retest of the FNS one week later. Measures included acquaintance with and willingness to try 15 healthful food alternatives, level of food neophobia, level of education, gender and age. Multiple linear regression analyses were used to study associations between demographics and level of food neophobia as well as associations between level of food neophobia and acquaintance with and willingness to try the healthful alternatives. SETTING: The study was conducted in The Netherlands using a representative Internet panel. PARTICIPANTS: A total of 326 participants aged 18-50 years participated. RESULTS: Internal consistency and test-retest reliability of the FNS version used were sufficient. On average participants were acquainted with 7.9 of the products and modestly willing to try the products. Lowly educated participants had significantly higher FNS scores than highly educated participants (beta = -0.23, P < 0.01). FNS score was significantly associated with acquaintance with (beta = -0.21, P < 0.001) and willingness to try the healthful alternatives (beta = -0.26, P < 0.001).CONCLUSION: Further research into the role of food neophobia is warranted when wanting to stimulate the integration of healthful alternative products in the daily diet, especially among persons with low education.     

Traditional food diversity predicts dietary quality for the Awajún in the Peruvian Amazon

OBJECTIVE: Our goal was to assess the potential for evaluating strengths of the Awajún traditional food system using dietary assessment, a traditional food diversity score and ranking of local foods. DESIGN: The method was used for dietary data obtained from mothers and children in the Awajún culture of the Peruvian Amazon where >90% of the dietary energy is derived from local, traditional food. Traditional food diversity scores were calculated from repeat 24-hour recalls. Group mean intakes of energy, fat, protein, iron, vitamin A and vitamin C from each food item were used to rank foods by nutrient contribution. SETTING: The study took place in six remote communities along the lower Cenepa River in the Amazonas District of Peru, South America. SUBJECTS: Dietary data were collected from 49 Awajún mothers and 34 children aged 3-6 years, representative of the six communities. RESULTS: Higher traditional food diversity was associated with greater protein, fibre, vitamin and mineral intakes when controlling for energy (partial correlations = 0.37 to 0.64). Unique sources for iron, total vitamin A and vitamin C were found in the Awajún traditional food system. CONCLUSIONS: A traditional food diversity score was a useful tool for predicting nutrient adequacy for the Awajún. Promotion of the Awajún traditional food system should focus on dietary diversity and unique nutrient-dense local foods.     

Can wood ants distinguish between good and bad food patches on the forest floor?

Wood ants (Formica rufa group) normally feed on secretions of aphids to obtain carbohydrates, and on free-living invertebrates to obtain proteins. The availability of protein resources is usually unpredictable, and the demand for proteins is high during the period when ant larvae are developing. Thus, ants should select high quality food patches, i.e. patches with plenty of prey, when these are available. Foraging on the forest floor is seldom observed, but should be an alternative behaviour during periods of scarce food supply in the trees. To study the hunting behaviour of wood ants on soil invertebrates, ants were offered fly larvae (maggots) in two different quantities (six or two per pah) at two distances from an ant trail. Maggots exposed on the forest floor were found by randomly patrolling ant scouts regardless of bait quality. However, scouts that found the baits with six larvae recruited workers faster and, on average, four times as many workers were recruited to the six-larvae bait than to the bait with only two larvae. This indicates that ants can distinguish between poor and rich patches and that they are able to use this information to recruit more workers. Also, more workers were recruited and more maggots were carried away from patches nearby trails than from those far away. The results indicate that, during the warm season, ants explore and exhibit adaptive ‘foraging behaviour’ on the forest floor in the whole territory, not only close to trails. Consequently, wood ant feeding on soil invertebrates may be a common way for obtaining a large amounts of protein.     

‘David and Goliath’ of the soil food web – Flagellates that kill nematodes

Nematodes and flagellates are important bacterial predators in soil and sediments. Generally, these organisms are considered to be competitors for bacterial food. We studied the interaction among flagellates and nematodes using axenic liquid cultures amended with heat-killed bacteria as food and showed for the first time that a small and common soil flagellate (Cercomonas sp.) is able to attack and kill the much larger nematode Caenorhabditis elegans. The killing process is not caused by soluble metabolites but requires direct contact between the flagellate cells and the nematode surface and occurs rapidly (within a few hours) at high flagellate density. At lower flagellate density, adult nematodes sometimes avoid attachment of flagellates, feed on them and become the dominant bacterial predator. Considering that bacterial feeders affect bacterial communities differently, and that one bacterial feeder can control the abundance of another, suggests a new perspective on how bacterial diversity and trophic interactions are linked in the soil food web.     

Feed or food responsible for the presence of low-level thiouracil in urine of livestock and humans?

In recent years, questions have been raised on the possible semi-endogenous status of the alleged xenobiotic thyreostatic drug thiouracil; thiouracil has been detected in the urine of various animals (livestock and domesticated) at concentrations between 1 and 10 μg L(-1) and also in human urine. Although several studies suggest Brassicaceae-derived feed as potential origin, no traces of thiouracil have been detected in feed so far. Therefore, the aim of this study was to elucidate the origin of thiouracil in the urine of livestock and humans. To this purpose various Brassicaceae feed and food sources (e.g., rapeseed, rapeseed coarse meal, cabbage, cauliflower, broccoli) were investigated for the presence of thiouracil. In addition, the impact of the Brassicaceae-related β-thioglucosidase enzyme was evaluated. This myrosinase enzyme appeared to be crucial, because without its catalyzed hydrolysis no thiouracil could be detected in the various Brassicaceae-derived samples. Therefore, a sample pretreatment with incorporated enzymatic hydrolysis was developed after ensuring the quality performance of the extracted myrosinase mixture with a single-point glucose assay. Upon enzymatic hydrolysis and LC-MS(2) analysis, thiouracil was successfully detected in samples of traditional rapeseed, rapeseed-'00' variety coarse meal (values of erucic acid <2% and glucosinolates <25 μmol g(-1)), and rapeseed cake at 1.5, 1.6, and 0.4 μg kg(-1), respectively. As for the food samples, broccoli and cauliflower displayed thiouracil concentrations of 6.0 and <1.0 μg kg(-1), respectively. To the best of the authors' knowledge this study is the first to report the presence of naturally occurring thiouracil in feed and food samples. Future research should investigate the pathway of thiouracil formation and identify its possible precursors.     

The impact of earthworms on the abundance of Collembola: improvement of food resources or of habitat?

I assessed the direct influence of earthworm excretions, and the impact of earthworms through their action on the soil structure (increased macroporosity), on the population dynamics of the collembolan species Heteromurus nitidus. The intestinal content of Collembola arising from cultures on different soil types was observed, and two experimental cultures of H. nitidus were run: (1) a culture performed on an inert substrate supplied either with earthworm casts or with soil as food resource, (2) an experiment using microcosms with cores of two humus forms (moder and calcic mull), in the presence or absence of earthworms. The observation of gut contents revealed that H. nitidus feeds on excrements, the composition of which (ratio organic matter/mineral matter) varies according to the humus form where it lived. Slightly aged (10–15 days) organo-mineral casts of earthworms appeared to be a better food than calcic mull aggregates or organic material from moder. Densities of H. nitidus cultured in cores of calcic mull were higher than in moder, except when cores of moder were inhabited by an anecic earthworm for 2 months. The humus form strongly influenced populations of H. nitidus, firstly because densities of predators were higher in moder than in calcic mull, and probably also because of soil macroporosity. It was concluded that earthworms would affect predation on H. nitidus by creating a network of interconnected macropores in which Collembola can move and find shelter.     

Precipitation as the most affecting factor on soil–plant environment conditions affects the mycorrhizal spore numbers in three different ecological zones in Turkey

Mycorrhizal symbiosis is the one of the most important relationship between microbiota and plants to sustain plant nutrition in relatively unfavourable conditions. Somehow this relation is threatened by time, therefore, definition of the factors effecting mycorrhizal symbiosis has become essential. The aim of this study was to determine the differences in specific mycorrhizal parameters such as sporulation and soil–plant environment conditions in three different regions of Turkey. During 1996?2002, 53 soil series were selected from natural and agricultural plant communities in three different agro-ecological zones of Turkey: Central Anatolia (CA), the Southeastern Anatolian (SA) project area and the Coast of Mediterranean (CM). The arbuscular mycorrhizal fungus (AMF), spore numbers and mycorrhizal root colonization were related to the annual average precipitation, soil characteristics and host plant identity.

In the CM zone (average annual precipitation of 650?mm), soils found under natural vegetation contained a maximum value of 108?spores?g^?1, with bare soils containing a minimum number of 0.1?spores?g^?1. In the CA zone (330?mm annual average precipitation), the maximum number of spores in the soil samples was 46.5?spores?g^?1 with a minimum of 6.8?spores?g^?1 and in the SA soil samples (380?mm annual average precipitation), a maximum of 48.4?spores?g^?1 and a minimum of 14.2?spores?g^?1 were recorded. The overall mean number of mycorrhizal spores g^?1 soil was 15.5?±?14.4, 22.2?±?8.6 and 27.9?±?25.4 for the CA, SA and CM zones, respectively. Mean spore numbers differed in only two of the three zones, with the third zone being intermediate. Precipitation was the most affecting factor on the sporulation of AMF. Also host plant species and certain soil parameters, such as positive correlations with CaCO₃ and N-min and a negative correlation with organic matter, have an influence on sporulation.

The key finding is that the cropping system has a large impact on spore numbers/abundance. Seventeen standing crops as well as bare soil, fallow and natural areas were compared. There are a large number of factors which can affect mycorrhizal development; in the present work, it seems that soil and crop management, and environmental factors (such as precipitation) affect sporulation and root colonization. Covering land surface with mycorrhiza-dependent cover crop, irrigation and less soil till may increase indigenous mycorrhizal spores.     

Is the adapted Radimer/Cornell questionnaire valid to measure food insecurity of urban households in Tehran, Iran?

OBJECTIVE: To assess the validity of the adapted Radimer/Cornell questionnaire to measure food insecurity in low-income urban households in Tehran, the capital of Iran. DESIGN: The Radimer/Cornell questionnaire was modified and used to assess the applicability, validity and reliability of such a measure in a culturally different context of urban households in Tehran. Factor analysis and Cronbach's alpha were used to assess validity and reliability, respectively. Socio-economic characteristics and food consumption frequency of the household were used to assess the criterion validity of the questionnaire. SETTING: District 20 of Tehran. SUBJECTS: A sample of 250 Iranian nuclear households with at least one child aged 1-18 years and a non-pregnant, non-lactating woman of reproductive age, selected through a multistage random sampling method. RESULTS: Three scales, labelled as household, individual and child hunger, were extracted through factor analysis using varimax rotation. Internal consistency of the scales was 0.897, 0.820 and 0.796, respectively. Individual insecurity and child hunger were inversely correlated with monthly per capita income, father's education, mother's education and father's occupational status, and positively correlated with household size, as expected. However, household insecurity did not follow the same pattern. Consumption frequency of fruits, vegetables, dairy, red meat and rice declined as food insecurity status worsened, while bread and potato consumption increased. CONCLUSION: The results show that a modified version of the Radimer/Cornell questionnaire is a valid and reliable instrument to measure household food insecurity in a culturally different context. However, further modifications seem necessary to measure food insecurity at household level. Results lend support to the utility and applicability of experience-based measures in varying cultural communities.