Hominins, sedges, and termites: new carbon isotope data from the Sterkfontein valley and Kruger National Park

Stable carbon isotope analyses have shown that South African australopiths did not have exclusively frugivorous diets, but also consumed significant quantities of C4 foods such as grasses, sedges, or animals that ate these foods. Yet, these studies have had significant limitations. For example, hominin sample sizes were relatively small, leading some to question the veracity of the claim for australopith C4 consumption. In addition, it has been difficult to determine which C4 resources were actually utilized, which is at least partially due to a lack of stable isotope data on some purported australopith foods. Here we begin to address these lacunae by presenting carbon isotope data for 14 new hominin specimens, as well as for two potential C4 foods (termites and sedges). The new data confirm that non-C3 foods were heavily utilized by australopiths, making up about 40% and 35% of Australopithecus and Paranthropus diets respectively. Most termites in the savanna-woodland biome of the Kruger National Park, South Africa, have intermediate carbon isotope compositions indicating mixed C3/C4 diets. Only 28% of the sedges in Kruger were C4, and few if any had well-developed rhizomes and tubers that make some sedges attractive foods. We conclude that although termites and sedges might have contributed to the C4 signal in South African australopiths, other C4 foods were also important. Lastly, we suggest that the consumption of C4 foods is a fundamental hominin trait that, along with bipedalism, allowed australopiths to pioneer increasingly open and seasonal environments.     

What to eat now? Shifts in polar bear diet during the ice-free season in western Hudson Bay

Under current climate trends, spring ice breakup in Hudson Bay is advancing rapidly, leaving polar bears (Ursus maritimus) less time to hunt seals during the spring when they accumulate the majority of their annual fat reserves. For this reason, foods that polar bears consume during the ice‐free season may become increasingly important in alleviating nutritional stress from lost seal hunting opportunities. Defining how the terrestrial diet might have changed since the onset of rapid climate change is an important step in understanding how polar bears may be reacting to climate change. We characterized the current terrestrial diet of polar bears in western Hudson Bay by evaluating the contents of passively sampled scat and comparing it to a similar study conducted 40 years ago. While the two terrestrial diets broadly overlap, polar bears currently appear to be exploiting increasingly abundant resources such as caribou (Rangifer tarandus) and snow geese (Chen caerulescens caerulescens) and newly available resources such as eggs. This opportunistic shift is similar to the diet mixing strategy common among other Arctic predators and bear species. We discuss whether the observed diet shift is solely a response to a nutritional stress or is an expression of plastic foraging behavior.     

Review: Dietary fiber utilization and its effects on physiological functions and gut health of swine

Although dietary fiber (DF) negatively affects energy and nutrient digestibility, there is growing interest for the inclusion of its fermentable fraction in pig diets due to their functional properties and potential health benefits beyond supplying energy to the animals. This paper reviews some of the relevant information available on the role of different types of DF on digestion of nutrients in different sections of the gut, the fermentation process and its influence on gut environment, especially production and utilization of metabolites, microbial community and gut health of swine. Focus has been given on DF from feed ingredients (grains and coproducts) commonly used in pig diets. Some information on the role DF in purified form in comparison with DF in whole matrix of feed ingredients is also presented. First, composition and fractions of DF in different feed ingredients are briefly reviewed. Then, roles of different fractions of DF on digestion characteristics and physiological functions in the gastrointestinal tract (GIT) are presented. Specific roles of different fractions of DF on fermentation characteristics and their effects on production and utilization of metabolites in the GIT have been discussed. In addition, roles of DF fermentation on metabolic activity and microbial community in the intestine and their effects on intestinal health are reviewed and discussed. Evidence presented in this review indicates that there is wide variation in the composition and content of DF among feed ingredients, thereby their physico-chemical properties in the GIT of swine. These variations, in turn, affect the digestion and fermentation characteristics in the GIT of swine. Digestibility of DF from different feed ingredients is more variable and lower than that of other nutrients like starch, sugars, fat and CP. Soluble fractions of DF are fermented faster, produce higher amounts of volatile fatty acid than insoluble fractions, and favors growth of beneficial microbiota. Thus, selective inclusion of DF in diets can be used as a nutritional strategy to optimize the intestinal health of pigs, despite its lower digestibility and consequential negative effect on digestibility of other nutrients.     

International variability in diet and requirements of manganese: Causes and consequences

Manganese (Mn) is an essential trace element that is critical for human health and development. At the turn of the century when diets were based on whole grains, cereals and other traditional foods, Mn intakes (8–9 mg/d) were much greater than that prevalent today (2 mg/d). As societies have developed, diets have shifted as part of a nutrition transition, to those that are high in processed foods, fat, and sugar. These foods are virtually devoid of Mn. Thus, dietary Mn has declined substantially throughout the world, as confirmed by several wide-scale, total diet studies.International variability in dietary Mn is considerable, due to tremendous diversity in food and culture. In countries where fruit and vegetable intake may be limited, i.e. the United Kingdom, populations may ingest much lower levels of Mn (1.4 mg/d) as compared to Asian cultures (4 mg/d) which have an abundance of plant foods in their food supply and cuisine. The bioavailability of Mn must be considered, including chemical form, oxidation state, mineral-mineral interactions, presence of dietary components and traditional food processing techniques (milling, germination, malting, fermentation). Manganese toxicity is a public health problem that results from exposure to a naturally high water source or contaminated environment of the soil and/or drinking water. In contrast, inadequate intake is associated with adverse health effects such as diabetes, metabolic syndrome, poor birth outcomes and possibly, cancer. Future studies are recommended to set dietary standards for this mineral in countries that lack recommendations to help achieve optimal health.     

Current microalgal health food R & D activities in China

The major microalgal genera presently cultivated in China are Spirulina and Chlorella. They are initially manufactured in the form of algal biomass or extracts by the food industry. The biomass is then used for producing a variety of health products such as tablets, capsules, powder or for extracting bioactive ingredients such as beta-carotene, and phycocyanin. The algal biomass is supplemented to noodles, breads, biscuits, candies, ice cream, bean curd and other common foods as food additives so as to enhance their nutritive and health values. The extracts are mainly used to enrich liquid foods such as health drink, soft drink, tea, beer or spirits.     

Sustainable Consumption of Food: A Framework for Analyzing Scenarios about Changes in Diets

This article describes the integration of life-cycle assessment methods with a new input-output model of the world economy to analyze the environmental and economic implications of alternative future diets. The article reviews findings by industrial ecologists about the energy and land required for the production and consumption of alternative foods and diets in several European countries. It also reviews attributes of foods and diets identified by nutritionists as reducing the risks of obesity and major chronic diseases related to the diets of the affluent. The predominantly plant-based Mediterranean-type diet emerges as a dietary scenario that could satisfy both sets of concerns. The likely implications for agriculture and for farm policies of a shift toward this diet from the current average diet in the United States are discussed and shown to be substantial. The one-country studies reviewed in the article provide substantial insights into the potential ramifications of dietary change. Many of the limitations of these studies could be overcome by conducting the analysis in a global framework that represented the relationships among consumption, production, and trade and the physical constraints within which they operate. Analysis of the environmental and economic implications of alternative scenarios describing healthy diets can help stimulate more intensive dialogue, debate, and action among the interested parties; such analysis can both benefit from and contribute to initiatives such as the World Health Organization's global strategy on diet and health, which intends to enlist the support of governments, corporations, and civil society.     

DESI-MSI and METASPACE indicates lipid abnormalities and altered mitochondrial membrane components in diabetic renal proximal tubules

Metabolomics - Food and dietary ingredients have significant effects on metabolism and health. To evaluate whether and how different diets affected the serum lipidomic profile of dogs. Sixteen...     

Food technology: challenge for health promotion

The food technology has brought countless benefits to today's food supply. Despite its many positive contributions, it has also brought unintended negative consequences. It is the time to mobilize the food technology to help the food supply more secure, safer and healthier, and here three possible approaches are foreseeable: First, we should continue to improve the conventional technologies. Many wholesome foods have been prepared and preserved using natural materials simply by fermentation. Second, we have to enhance the minimal processing as much as applicable. Third, new ingredients, intelligent packaging and functional foods should be explored to improve food supply and health. Today, consumer interest in the functional foods has been increased tremendously, and the future of food lies in the functional foods. However, the situations in the developing world are different from this. As food resource is limited in this region, food technology has to be emphasized to increase food supply. To help solve such complex problems, not only new technologies, but also conventional technologies have to be mobilized. Simultaneously, even higher technical capabilities have to be built up by applying new findings from the related disciplines to allow the food technology to play its vital role.     

Understanding the basic biology underlying the flavor world of children

Health organizations worldwide recommend that adults and children minimize intakes of excess energy and salty, sweet, and fatty foods (all of which are highly preferred tastes) and eat diets richer in whole grains, low- and non- fat dairy products, legumes, fish, lean meat, fruits, and vegetables (many of which taste bitter). Despite such recommendations and the well-established benefits of these foods to human health, adults are not complying, nor are their children. A primary reason for this difficulty is...     

A review of processing of feed ingredients to enhance diet digestibility in finfish

Replacement of fish meal with plant proteins in aquaculture diets presents several problems. Firstly, aquaculture diets, particularly diets for carnivorous fish species, are nutrient dense and may contain up to 450 g crude protein (CP)/kg. Such diets preclude the use of ingredients with only moderate CP content, such as pulses including peas and faba beans or oilseed meals including canola/rapeseed meal and flax. Secondly, virtually all crops contain heat-labile and heat-stable secondary compounds including protease inhibitors, tannins, lectins, phytate, dietary fibre and starch. Removal of heat-labile secondary compounds may be accomplished by extrusion or other heat treatment. However, elimination of heat-stable secondary compounds, and increasing the nutrient concentration of diets, requires fractionation of crops. Fractionation technologies range from low technology processes such as dehulling to medium technologies such as air classification to sophisticated technologies such as aqueous and solvent protein purification. Studies on the nutritional value of processed plant proteins in various fish species have consistently shown improved digestibility and growth compared to feeding unprocessed ingredients. This review examines effects of processing technologies on nutritional properties of soybean meal, canola meal, peas, lupins and flax in aquaculture diets.     

Dietary fiber and the glycemic response

Addition of purified fiber to carbohydrate test meals has been shown to flatten the glycemic response in both normal and diabetic volunteers, reduce the insulin requirement in patients on the artificial pancreas and in the longer term reduce urinary glucose loss and improve diabetes control. In the context of high fiber-high carbohydrate diets these findings have had a major impact in influencing recommendations for the dietary management of diabetes internationally. The mechanism of action appears in part to be due to the effect of fiber in slowing absorption rather than by increasing colonic losses of carbohydrate. Consequently postprandial GIP and insulin levels are reduced and the more viscous purified fibers (e.g., guar and pectin) appear most effective. In addition it has been suggested that colonic fermentation products of fiber may enhance glucose utilization. More recently it has become clear that many aspects of carbohydrate foods (food form, antinutrients, etc.) in addition to fiber may influence the rate of digestion and has led to a classification especially of starchy foods in terms of glycemic index to define the degree to which equicarbohydrate portions of different foods raise the blood glucose. Use of such data may maximize the effectiveness of high carbohydrate and high fiber diets in the management of diabetes and related disorders.     

Comparison of diets fed to southeast Asian colobines in North American and European zoos,with emphasis on temperate browse composition

In May and June 1994 a survey of diets fed to captive southeast Asian colobines in European (n = 12) and North American (n = 9) zoos was conducted. Most diets were very complex, comprising an average of 25 ingredients; 149 different foods were listed in responses. Comparison of diets fed showed that European zoos feed a greater variety of fruits and vegetables, and fewer browse plants, than North American zoos. No standardized diet recommendations, based on ingredient or nutrient composition, are currently available for colobines in captivity. Foods eaten by these primates in nature appear to contain higher amounts of fiber and lower protein and soluble carbohydrates than current zoo diets. Temperate browse plants (n = 11 spp.; leaves plus twigs) sampled in New York in summer and autumn contained higher fiber and lower protein levels than diets fed in this survey, and may approximate the nutrient content of food items selected by free-ranging colobines. Fast-growing roses grown in greenhouses, fed primarily in Europe, contained substantially less fiber and higher protein concentrations than other browses offered, and may not be an appropriate substitute for native foods. © 1996 Wiley-Liss, Inc.     

Children and Wild Foods in the Context of Deforestation in Rural Malawi

There is growing recognition of the contribution of wild foods to local diets, nutrition, and culture. Yet disaggregation of understanding of wild food use by gender and age is limited. We used a mixed methods approach to determine the types, frequencies, and perceptions of wild foods used and sold by children in four villages in southern Malawi that have different levels of deforestation. Household and individual dietary diversity scores are low at all sites. All households consume one or more wild foods. Across the four sites, children listed 119 wild foods, with a wider variety at the least deforested sites than the most deforested ones. Older children can name more wild foods than younger ones. More children from poor households sell wild foods than from well-off households. Several reasons were provided for the consumption or avoidance of wild foods (most commonly taste, contribution to health, limited alternatives, hunger, availability, local taboos).     

Small intestinal effects of starchy foods

Recent dietary guidelines advocate increased starch intake, but it is not clear as to how the increased intake of starch should be achieved. Recent data suggest that the quality of starch as well as its quantity is important in determining the biological effects of high carbohydrate diets. The quality of starchy foods can be assessed by their rates of digestion, which in turn are related to their glycaemic responses. Many factors affect the rate of digestion of foods and these are probably related to alterations in the chemical structure or nature of the starch. The incorporation of slowly digested, low glycaemic index foods into the diets of healthy subjects and individuals with diabetes and hyperlipidaemia is associated with the predicted reductions in postprandial glycaemic responses and with reductions in insulin secretion and blood lipids. In the past, the aim of starch processing has been to increase digestibility and improve absorption. However, it is now suggested that the use of more slowly digested starchy foods may have positive health benefits.     

Functional macronutritional generalism in a large omnivore,the brown bear

We combine a recently developed framework for describing dietary generalism with compositional data analysis to examine patterns of omnivory in a large widely distributed mammal. Using the brown bear (Ursus arctos) as a model species, we collected and analyzed data from the literature to estimate the proportions of macronutrients (protein, carbohydrate, and lipid) in the diets of bear populations. Across their range, bears consumed a diversity of foods that resulted in annual population diets that varied in macronutrient proportions, suggesting a wide fundamental macronutrient niche. The variance matrix of pairwise macronutrient log‐ratios indicated that the most variable macronutrient among diets was carbohydrate, while protein and lipid were more proportional or codependent (i.e., relatively more constant log‐ratios). Populations that consumed anthropogenic foods, such agricultural crops and supplementary feed (e.g., corn), had a higher geometric mean proportion of carbohydrate, and lower proportion of protein, in annual diets. Seasonally, mean diets were lower in protein and higher in carbohydrate, during autumn compared to spring. Populations with anthropogenic subsidies, however, had higher mean proportions of carbohydrate and lower protein, across seasons compared to populations with natural diets. Proportions of macronutrients similar to those selected in experiments by captive brown bears, and which optimized primarily fat mass gain, were observed among hyperphagic prehibernation autumn diets. However, the majority of these were from populations consuming anthropogenic foods, while diets of natural populations were more variable and typically higher in protein. Some anthropogenic diets were close to the proportions selected by captive bears during summer. Our results suggest that omnivory in brown bears is a functional adaptation enabling them to occupy a diverse range of habitats and tolerate variation in the nutritional composition and availability of food resources. Furthermore, we show that populations consuming human‐sourced foods have different dietary macronutrient proportions relative to populations with natural diets.     

Biotechnological approaches for the production of prebiotics and their potential applications

Worldwide interest in prebiotics have been increasing extensively both as food ingredients and pharmacological supplements, since they have beneficial properties for human health. Prebiotics not only stimulate the growth of healthy bacteria such as bifidobacteria and lactobacilli in the gut but also increase the resistance towards pathogens. In addition to this, they also act as dietary fiber, an energy source for intestinal cells after converting to short-chain fatty acids, a stimulator of immune systems, sugar replacer etc. Moreover, due to heat resistant properties, they are able to maintain their intact form during the baking process and allow them to be incorporated into every day food products. Thus, they can be interesting and useful ingredients in the development of novel functional foods. This review provides comprehensive information about the different biotechnological techniques employed in the production of prebiotics and their potential applications in different areas.     

Invited Review Free Radicals in Foods

During the last decade increasing attention has been given to the role of free radicals in biological oxidations. The subject has been of increasing interest to both the food scientist and the physiologist. Free radical scavengers in the form of both indigenous and added antioxidants are necessary for the successful preservation of food; free radicals are increasingly being implicated in the onset of, among others, ischaemic heart disease and for protection against these diseases it is suggested that the dietary intake of the antioxidant vitamins should be increased especially for diets high in polyunsaturated fats. ^1,2 Convenience and snack foods which absorb substantial amounts of frying oils are being increasingly consumed. Since poly-unsaturated fatty acids are particularly susceptible to oxidation by free radicals during the storage, cooking and frying of foods, the potential risk of exposure to lipid degradation products' is likely to have increased. In foods the non-enzymic and lipoxygenase catalysed oxidation of polyunsaturated fatty acids, β-carotene and vitamin A can result in the loss of essential nutrients and the development of off-flavours.     

Machos and Sluts: Gender, Sexuality, and Violence among a Cohort of Puerto Rican Adolescents

During the past decade, interpersonal violence increasingly has become a public health concern. As a result, prevention programs now aim to decrease violence among diverse populations. This article describes the beliefs and rationale for gender-based violence among a cohort of low-income, predominantly second-generation, mainland Puerto Rican adolescents. Based on a three-year (1989-91) ethnographic study, the findings describe how these young people, through the use of gender-based social constructs such as "machos" and "sluts," justify violence by linking it to beliefs about gender roles, sexuality, and biology, and thus perpetuate gender-role conformity, particularly heterosexual male dominance. The findings suggest that if the public health community is going to reduce gender-based violence among Puerto Rican youth, it needs to acknowledge that gender and sexuality are important ingredients that support violence and avoid a simplified and stereotypical model of culture that ignores other social factors and changes in traditional Latino gender roles.     

Evaluating gull diets: a comparison of conventional methods and stable isotope analysis

ABSTRACT Samples such as regurgitated pellets and food remains have traditionally been used in studies of bird diets, but these can produce biased estimates depending on the digestibility of different foods. Stable isotope analysis has been developed as a method for assessing bird diets that is not biased by digestibility. These two methods may provide complementary or conflicting information on diets of birds, but are rarely compared directly. We analyzed carbon and nitrogen stable isotope ratios of feathers of Glaucous Gull (Larus hyperboreus) chicks from eight breeding colonies in northern Alaska, and used a Bayesian mixing model to generate a probability distribution for the contribution of each food group to diets. We compared these model results with probability distributions from conventional diet samples (pellets and food remains) from the same colonies and time periods. Relative to the stable isotope estimates, conventional analysis often overestimated the contributions of birds and small mammals to gull diets and often underestimated the contributions of fish and zooplankton. Both methods gave similar estimates for the contributions of scavenged caribou, miscellaneous marine foods, and garbage to diets. Pellets and food remains therefore may be useful for assessing the importance of garbage relative to certain other foods in diets of gulls and similar birds, but are clearly inappropriate for estimating the potential impact of gulls on birds, small mammals, or fish. However, conventional samples provide more species‐level information than stable isotope analysis, so a combined approach would be most useful for diet analysis and assessing a predator's impact on particular prey groups.     

Immunoglobulin E mediated food allergy.Modelling and application of diagnostic and predictive tests for existing and novel foods

It is known that some foods cause an allergenic response in certain individuals. Clinical and immunological tests are available for the diagnosis of food allergy and identification of food allergens. However, there are no valid tests for the prediction of the allergenic potential of foods not normally recognized as allergenic. Such foods include: food products developed from foods which may not be recognizable as allergenic in their modified forms; foods produced using novel processes (novel foods), for example genetically modified foods; and foods not normally consumed but that are being used increasingly as alternatives to more traditional foods. Both the risks associated with food allergy and the fact that foods such as the ones described above will become available to the consumer, highlight the need for methods to screen for potential food allergens. This review provides a general overview of food allergy including mechanism, development and prevalence, but focuses on and discusses: 1) the possible risks (with specific reference to food allergy) associated with new and novel foods; and 2) the development/use of food allergy models (in vivo and in vitro) to assess the allergenic potential of new and novel foods.