Animal source foods are advantageous for populations with elevated needs
This subsection addresses the following five questions:
- What is the global food security challenge and how do animal source foods fit in?
- Which vulnerable populations benefit from animal source foods, and how?
- How are animal source foods associated with nutritional adequacy?
- What is the relationship between animal source foods and mental health?
- What do intervention studies tell us about the nutritional contributions of animal source foods?
What is the global food security challenge and how do animal source foods fit in?
Many populations, including in high-income countries, struggle to meet recommendations for several priority nutrients. Animal source foods contribute to the solution by enhancing nutrient sufficiency beyond staple foods and biofortification. Eggs and milk are accessible options for low-resource populations and contribute to healthy growth. Despite an increase in ASF intake among children and adolescents globally, Sub-Saharan Africa still faces disproportional deficiencies in key nutrients that are particularly bioavailable in ASFs, such as iron, zinc, iodine, and vitamin B12.
Which vulnerable populations benefit from animal source foods, and how?
Special attention is needed for pregnant and lactating women, infants, children, adolescents, and older adults due to their susceptibility to suboptimal micronutrient levels. Strict vegetarian diets can lead to severe consequences, as evidenced by clinical case reports for both young individuals and adults. Proper nutrition during early childhood is crucial for lifelong health, and complementary foods should include nutrient-rich options like meat, poultry, fish, or eggs. In older adults, animal source foods play a vital role in healthy aging, addressing undernutrition, cognitive decline, functional impairment, and sarcopenia. People with metabolic health issues also benefit from sufficient intake of animal source foods. Given the associated health care costs, the societal impact of addressing these nutritional needs is substantial.
How are animal source foods associated with nutritional adequacy?
Very low intake of animal source foods among vulnerable populations is often linked to decreased nutrient intake and compromised health. In contrast, various studies highlight the associations between the consumption of animal source foods and improved nutrient intake and health outcomes in different groups with elevated needs. Higher meat consumption can be linked to reduced anaemia among elderly, as well as decreased stunting in young children. Dairy consumption is, for instance, associated with an improved status of B-vitamin and vitamin-D biomarkers in older adults. Intake of fish is linked to improved nutritional outcomes, including a better vitamin D status in maternal diets and children's diets. Egg consumption is associated with higher intake of various nutrients, including choline. It is important to underline, however, that such associational data is not necessarily proof of causal relationships.
What is the relationship between animal source foods and mental health?
Many studies have indicated an inverse association between meat intake and mental health issues, although the causal direction is uncertain. Two potential explanations arise: 1) vegetarianism might serve as a cover for underlying mental disorders and eating pathologies, 2) poor mental health could result from nutrient deficiencies or low cholesterol levels. For example, low prenatal meat consumption has been linked to an increased risk of substance abuse in adolescence, potentially linked to vitamin B12 malnutrition. Some studies have found higher rates of depressive episodes among vegetarians compared to meat consumers. While (semi-)vegetarian women might demonstrate positive factors like physical activity and lower body mass indices, they could also report more menstrual problems and poorer mental health. The complex nature of the relationship is underscored by findings that semi-vegetarians with strong orthorexic tendencies tend to exhibit more depressive symptoms than both omnivores and vegetarians. In the elderly population, very low meat consumption has been connected to a higher incidence of dementia and Alzheimer's disease. Overall, the intricate interplay between meat consumption, vegetarianism, and mental health necessitates further comprehensive investigation to elucidate the underlying mechanisms and relationships.
What do intervention studies tell us about the nutritional contributions of animal source foods?
Intervention trials have shown that the incorporation of animal source foods in the diet can enhance nutritional resilience across different life stages, especially when the baseline intake is low. Their administration can help to improve the physical, behavioural, and cognitive outcomes of children, mitigate deficiencies in young females, enhance muscle synthesis in young men, and tackle poor bone health and sarcopenia in older adults. In Kenia, the administration of meat improved the performance of school children. Seafood, rich in long-chain omega-3 fatty acids, protein, and many other nutrients, contributes to improved responses in risk factors for chronic disease and has potential to reduce inflammation. Dairy products have demonstrated various health benefits, including improved vitamin K2 status, enhanced cognitive outcomes in school children in Ghana, and better bone health in various young and adult population groups. In rural Ecuador, it has been shown that eggs contribute to a reduction in stunting and improved plasma levels of essential nutrients like choline and DHA in infants.