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Iron is an essential mineral that supports biological functions like growth, oxygen transport, cellular function, and hormone synthesis. Insufficient dietary iron can lead to anemia and cause fatigue, cognitive impairment, and poor immune function. Animal-based foods provide heme iron, which is more bioavailable to humans, while plant-based foods typically contain less bioavailable non-heme iron. Edible insects vary in their iron content and may have heme or non-heme forms, depending on their diet. Edible insects have been proposed as a protein source that could address issues of food insecurity and malnutrition in low resource contexts; therefore, it is important to understand the bioavailability of iron from insect-based foods. In this study, we used Inductively Coupled Plasma and Mass Spectrometry (IPC-MS) and Caco-2 cell culture models to compare the soluble and bioavailable iron among five different lab-produced tempeh formulations featuring Tenebrio molitor (mealworm) with their non-fermented raw ingredient combinations. Finally, we compared the iron bioavailability of a mealworm tempeh with two sources of conventional beef (ground beef and sirloin steaks) and two commercially available plant-based meat alternatives. The results show that while plant-based meat alternatives had higher amounts of soluble iron, particularly in the Beyond Burger samples, the fermented mealworm-based tempeh had greater amounts of bioavailable iron than the other samples within the set. While all the samples presented varying degrees of iron bioavailability, all products within the sample set would be considered good sources of dietary iron.

Small-scale farming of edible insects could help combat public health challenges such as protein energy malnutrition and anemia, but reliable low-cost feeds for insects are needed. In resource-limited contexts, where grains such as maize are prohibitively costly for use as insect feed, the feasibility of insect farming may depend on finding alternatives. Here, we explore the potential to modify plentiful maize crop residue with edible mushroom mycelium to generate a low-cost feed adjunct for the farmed two-spotted cricket, Gryllus bimaculatus. Mushroom farming, like insect agriculture, is versatile; it can yield nutritious food while increasing system circularity by utilizing lignocellulosic residues from row crops as inputs. Pleurotus ostreatus, is an edible basidiomycete capable of being cultivated on corn stover (Zea mays). Mushroom harvest results in abundant “spent” substrate, which we investigated as a candidate feed ingredient. We created six cricket feeds containing fermented Pleurotus substrate plus an unfermented control, measuring cricket mass, mortality, and maturation weekly to evaluate cricket growth performance impacts of both fungal fermentation duration and mushroom formation. Pasteurized corn stover was inoculated with P. ostreatus mycelium and fermented for 0, 2, 3, 4, or 8 weeks. Some 4 and 8-week substrates were induced to produce mushrooms through manipulations of temperature, humidity, and light conditions. Dried fermented stover (40%) was added to a 1:1 corn/soy grain mix and fed to crickets ad libitum for 44 days. The unfermented control group showed higher survivorship compared to several fermented diets. Control group mass yield was higher for 2 out of 6 fermented diets. Little variation in cricket iron content was observed via ICP-spectrometry across feeds, averaging 2.46 mg/100 g. To determine bioavailability, we conducted in vitro Caco-2 human colon epithelial cell absorption assays, showing that iron in crickets fed fruiting-induced substrates was more bioavailable than in unfruited groups. Despite more bioavailable iron in crickets reared on post-fruiting substrates, we conclude that Pleurotus-fermented stover is an unsuitable feed ingredient for G. bimaculatus due to high mortality, variability in growth responses within treatments, and low mass yield.

Responding effectively to intensifying climate change hazards to protect human health in personal and professional settings is an urgent and pressing challenge. This will require collaboration and subject matter expertise of people across the life course and occupations. In this perspective piece, we build on a previously published compilation of climate and health literacy elements to explore tangible opportunities to strengthen climate and health understanding among individuals spanning educational levels, professional settings, and societal needs. Educational materials addressing climate change and health linkages have historically focused on K-12, college, post-graduate education, and continuing medical education, with less attention devoted to reaching students in trade schools and other professional settings. Here, we outline a flexible blueprint for strengthening climate and health literacy among all people by targeting education in a way that is relevant for each age group or profession. In particular, we discuss the idea of professional adaptability as a way to design practical climate and health training for people currently in the workforce.

Malnutrition and food insecurity remain high in rural Rwanda, where residents consume a low-diversity diet provided through subsistence farming. Agricultural interventions using kitchen gardens may improve diet diversity in some populations. However, little is known about their efficacy when developed using community-based participatory research in combination with nutrition education focused on the empowerment of women. The objective of this study was to develop and implement a kitchen garden and nutrition education intervention using a community-engaged model and examine its impact on household diet diversity and food security. Using a mixed methods community-level design, we assessed a 16-week intervention implemented in Cyanika, Rwanda. Stratified purposeful sampling was used to select women participants representing 42 households. Household diet diversity scores (HHDS) and hunger scores were calculated at the baseline, post-intervention and one-year follow-up. HDDS increased after intervention from a pre-intervention intake of 2.59 [1.3] food groups/day, to 4.85 [1.6] at four months post-intervention and at one year post-intervention, reaching 5.55 [1.3]. There were no significant changes in household hunger scores. Our results indicate that collaborative community-engaged nutrition-sensitive agricultural interventions can increase household diet diversity; however, future work should explore whether this type of intervention strategy can lead to sustained changes and impact nutritional adequacy in this population.

Abstract Edible insects are often considered a nutritious, protein-rich, environmentally sustainable alternative to traditional livestock with growing popularity among North American consumers. While the nutrient composition of several insects is characterized, all potential health impacts have not been evaluated. In addition to high protein levels, crickets contain chitin and other fibers that may influence gut health. In this study, we evaluated the effects of consuming 25 grams/day whole cricket powder on gut microbiota composition, while assessing safety and tolerability. Twenty healthy adults participated in this six-week, double-blind, crossover dietary intervention. Participants were randomized into two study arms and consumed either cricket-containing or control breakfast foods for 14 days, followed by a washout period and assignment to the opposite treatment. Blood and stool samples were collected at baseline and after each treatment period to assess liver function and microbiota changes. Results demonstrate cricket consumption is tolerable and non-toxic at the studied dose. Cricket powder supported growth of the probiotic bacterium, Bifidobacterium animalis, which increased 5.7-fold. Cricket consumption was also associated with reduced plasma TNF-α. These data suggest that eating crickets may improve gut health and reduce systemic inflammation; however, more research is needed to understand these effects and underlying mechanisms.

Some evidence suggests that edible insects could be used to treat malnutrition following protein deficiency. However, additional studies are needed to better assess the potential of edible insects as a therapeutic food supplement and their long-term impact on recovery from malnutrition. The goals of this study were to investigate the effectiveness of a cricket-based diet in recovery from protein-malnutrition in early life, and to compare cricket protein to more traditional sources used for food fortification and supplementation. Protein-malnutrition was induced by administration of an isocaloric hypoprotein diet (5% protein calories) in young male mice for two weeks during puberty, followed by a six-week recovery period using a cricket-, peanut- or milk-based diet. We examined the impact of protein-malnutrition and subsequent recovery on body weight, growth and select biomarkers of inflammation and metabolism. Protein-malnutrition resulted in growth retardation, downregulation of inflammatory markers in spleen tissue, decreased levels of serum triglycerides, and elevated serum levels of leptin and adiponectin. The cricket-based diet performed equally well as the peanut- and milk-based diets in body weight recovery, but there were differences in immune and metabolic markers among the different recovery diets. Results suggest edible crickets may provide an alternative nutrient-dense protein source with relatively low environmental demands for combating the effects of early-life malnutrition compared to more traditional supplementation and fortification sources. Additional investigations are needed to examine the short and long term impacts of different recovery diets on metabolism and immune function.

Most global dietary forecasts predict a reduction in nutritional deficiencies over the next several decades driven by significant increases in environmentally unsustainable livestock and animal source food consumption. Here, we explore a more environmentally sensitive alternative to improve global nutrition, consuming insects. Our study focuses on Africa and Asia, two continents with a history of eating insects and high rates of nutritional deficiency. We model the impact of adding modest amounts (2.5, 5 and 10 g per day, dry weight) of regionally appropriate and farmable species on total nutrient intake and population-wide risk of deficiency for specific nutrients of concern: protein, zinc, folate, and vitamin B12. We also estimate the total potential change in dietary iron. Five grams per day of insect consumption could alleviate a considerable amount of risk of nutritional deficiency: 67 million (95% uncertainty interval: 49–84 million) fewer people at risk of protein deficiency, 166 million (120–220 million) fewer people at risk of zinc deficiency, 237 million (120–439 million) fewer people at risk of folate deficiency, and 251 million (28–2271) fewer people at risk for vitamin B12 deficiency. For iron, per capita supplies could increase by 3% (0.8%–6.0%) with insects, and even more so for vulnerable groups in countries currently suffering severe rates of anemia: 4.2% (0.5%–8.8%) for women of childbearing age and 4.1% (0.4%–10.0%) for children under 5. Doubling or halving insect intake per capita causes the benefits for nutritional deficiency risk to roughly double or halve accordingly. Effects are most pronounced in South and Central Asia, though sub-Saharan Africa, East Asia, and Southeast Asia also see considerable reduction in nutritional risk. These results demonstrate the potential for insects to fill a crucial role in providing nutrition for these populous and rapidly developing regions while safeguarding the global environment.