Pica is far more than an odd behavioral quirk. In sheep production systems it manifests as the persistent ingestion of non-feed substances: geophagia, trichophagia, urine drinking, fence licking, and even plastic chewing. Beyond disrupting normal feeding, it raises the risk of gastrointestinal injury, impaired nutrient absorption, parasitic infection, and lost productivity. Although the full etiology remains unresolved, researchers have long considered pica a multifactorial disorder rooted in nutritional imbalance, metabolic disturbance, and environmental stress, with mineral deficiency or imbalance widely recognized as a major driver. Shortages of elements such as phosphorus, copper, iron, zinc, and selenium can undermine antioxidant defenses and metabolic homeostasis, potentially pushing animals into the abnormal oral behaviors that define the syndrome.

Simple mineral supplementation has shown promise before—earlier work on wool-eating lambs found that dosing with iron, copper, and zinc sulfate salts raised blood mineral levels and produced complete recovery within eight weeks. But the picture is complicated by the fact that pica may also involve oxidative stress, endocrine dysregulation, and metabolic dysfunction. Moreover, whether supplemented minerals actually reach the bloodstream depends on their chemical form, antagonistic interactions among minerals, the rumen environment, and the intricacies of gastrointestinal absorption. This is where the new study departs from convention: instead of relying on minerals alone, the researchers combined them with Shariga-5, a traditional Mongolian multi-herb formula derived from local ethnoveterinary practice and rich in bioactive flavonoids and phenolic acids.

The Mongolian herbal–mineral supplement, or MHMS, was manufactured into solid 5-kilogram lick blocks containing target concentrations of calcium, phosphorus, copper, iron, manganese, zinc, selenium, and cobalt, along with vitamins D3 and E. Embedded within the mineral matrix were five medicinal herbs of the Mongolian Plateau: turmeric rhizome (Shariga), forsythia fruit (Saolong-Jimusi), clove flower buds (Gaoletu-Baori), chebulic myrobalan fruit (Arula), and gardenia fruit (Zhurula). Widely targeted metabolomic profiling of the individual herbs identified 1,427 metabolite annotation records, with phenolic acids accounting for nearly 39 percent and flavonoids another 32 percent—two chemical classes renowned for free-radical scavenging, metal-ion chelation, and anti-inflammatory activity. The design logic was synergy: trace elements supply the cofactors for antioxidant enzymes, while plant secondary metabolites provide complementary redox support.

To test the formula, the team screened East Friesian rams over seven consecutive days, enrolling only animals that showed five to ten instances of pica behaviors per observation day. Twenty rams, averaging about 1.5 years of age and 42.6 kilograms, were randomly split into two groups of ten, each housed in its own pen. The control group received only a basal diet of corn silage, oat hay, alfalfa, and Leymus chinensis hay; the treatment group received the same diet plus continuous free-choice access to an MHMS lick block. After a 14-day adaptation and a 60-day experimental period, blood was drawn before morning feeding, and serum from six animals per group underwent mineral, biochemical, antioxidant, hormonal, and untargeted metabolomic analyses.

The mineral results were strikingly selective. Serum copper roughly doubled, rising from 4.86 to 9.55 micromoles per liter, while zinc climbed from 10.62 to 15.29 and selenium from 0.43 to 0.59 micromoles per liter. Yet calcium, phosphorus, magnesium, sodium, potassium, iron, and manganese remained unchanged. This selectivity, the authors argue, suggests the supplement primarily restored the trace elements most closely tied to redox defense, metalloenzyme activity, immune regulation, and metabolic homeostasis. Copper underpins mitochondrial respiration and iron metabolism, zinc is a structural and catalytic factor for countless enzymes and supports epithelial barriers, and selenium is an essential component of glutathione peroxidase, a key peroxide-removing selenoprotein. The pattern also echoes previous work showing that mineral responses in ruminants are shaped not just by dose but by body reserves, absorption efficiency, and antagonistic interactions among elements.

The downstream physiological shifts extended well beyond minerals. Total antioxidant capacity in serum rose significantly, even though the individual enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase did not change—an indication that the improvement came from the composite, largely non-enzymatic antioxidant pool, plausibly driven by the herbal polyphenols. Biochemical markers told a similar story of de-escalation: serum glucose fell from 4.44 millimoles per liter, sitting at the upper edge of the ovine reference range, to 3.60, a healthier mid-range value, and aspartate aminotransferase activity dropped from 160.70 to 125.35 units per liter, returning from above the normal range to within it. Because AST reflects hepatic metabolic burden and tissue injury—and pica-affected calves have previously shown elevated transaminases linked to copper deficiency—this normalization suggests the supplement eased tissue metabolic stress in the treated animals.

Perhaps the most dramatic changes appeared in the endocrine panel. Serum triiodothyronine, thyroxine, insulin-like growth factor 1, and growth hormone all rose significantly, signaling enhanced metabolic rate and activated anabolic growth signaling, while cortisol—the primary stress hormone of the hypothalamic–pituitary–adrenal axis—fell markedly, from 943 to 746 picograms per milliliter. The authors note that the supplement’s selenium, copper, zinc, and vitamin E all carry antioxidant functions that could plausibly dampen the HPA axis burden imposed by chronic nutritional stress and oxidative pressure. Previous studies lend support to the mechanism: curcumin supplementation has raised thyroid hormones and lowered cortisol in goats, and vitamin E and selenium combinations have reduced cortisol in transportation-stressed dairy heifers.

The untargeted metabolomics added an exploratory molecular layer. Out of 1,062 putatively annotated serum metabolites, 112 differed significantly between groups—51 higher and 61 lower in the supplemented rams. Pathway analysis ranked porphyrin metabolism, the biochemical route for heme synthesis, as the top candidate pathway, with glycine abundance more than doubled and porphobilinogen reduced to less than half of control levels. Because glycine is the starting substrate for heme biosynthesis and also a precursor for glutathione, the body’s master intracellular antioxidant, its rise fits a scenario of improved antioxidant substrate supply. The drop in porphobilinogen, an early heme precursor that can accumulate abnormally when the pathway falters, correlated positively with serum AST, hinting that reduced accumulation of this intermediate accompanied the easing of tissue metabolic pressure. The authors are careful to flag that this pathway enrichment did not survive multiple-testing correction and the metabolites lack validation against authentic standards, so these findings are hypothesis-generating rather than definitive.

The study also candidly acknowledges its limits: individual lick-block intake was not recorded, the composite design cannot separate the effects of minerals from herbs or their synergy, the sample was modest, and rumen fluid and microbiota were not examined. Even so, the overall picture is compelling—a traditional Mongolian herbal formula fused with trace-element nutrition appears to shift pica-affected rams from a stress-laden, oxidatively burdened metabolic state toward physiological balance, with elevated thyroid and growth hormones, subdued cortisol, stronger antioxidant capacity, and a metabolome inching back toward order. For a condition as old as animal husbandry itself, the remedy may lie partly in knowledge herders on the Mongolian Plateau have carried for generations, now given rigorous, molecule-by-molecule confirmation.

Subject of Research: Effects of a Mongolian herbal–mineral supplement on serum minerals, antioxidants, hormones, and metabolomics in rams with pica

Article Title: Free-choice Mongolian herbal-mineral supplementation improves serum mineral, antioxidant, endocrine, and metabolic indices in rams with pica

Article References: Man, D., Chen, L., Ao, X., Zhang, W., & Na, R. (2026). Free-choice Mongolian herbal-mineral supplementation improves serum mineral, antioxidant, endocrine, and metabolic indices in rams with pica. Frontiers in Veterinary Science, 13, Article 1946016. https://doi.org/10.3389/fvets.2026.1946016

Image Credits: AI Generated

DOI: 10.3389/fvets.2026.1946016

Keywords: pica, sheep, herbal-mineral supplement, trace minerals, antioxidant capacity, cortisol, thyroid hormones, serum metabolomics, porphyrin metabolism, Mongolian ethnoveterinary medicine, ruminant nutrition, oxidative stress

The review, led by Gunhild Hodt of Innlandet Hospital Trust and the University of Oslo, together with colleagues from the University of Bergen, Haukeland University Hospital, Sahlgrenska University Hospital and the University of Gothenburg, was conducted in accordance with the PRISMA reporting guidelines, the international standard for systematic reviews in health research. The team searched five major databases — MEDLINE, Embase, the Cochrane Library, CINAHL and PsycINFO — with coverage extending up to January 12, 2026. Their search strategy initially surfaced 8,678 potentially eligible articles, a figure that underscores both the breadth of literature on autism and feeding and, by contrast, how few studies actually address formal eating disorder diagnoses in this population.

The inclusion criteria were deliberately strict. To qualify, studies had to be peer reviewed and published in English, include participants younger than 18 years, involve samples of at least three individuals, and apply recognized diagnostic frameworks — either the DSM-IV or DSM-5, the ICD-9 or ICD-10, or the forthcoming ICD-11. Importantly, the researchers excluded studies that described ARFID-like symptoms or phenotypes without a formal diagnosis, a decision that sharpened the review’s focus on clinically confirmed conditions but also revealed how rarely such diagnoses are formally made in autistic children. After screening, just 23 studies survived: ten examined the combination of autism and ARFID, twelve examined autism and pica, and a single study addressed autism and rumination disorder.

Pica, the most heavily studied of the three conditions in this population, involves the persistent ingestion of non-nutritive, non-food substances such as soil, hair, paper, plastic or metal objects. In typically developing children, the behavior is common in infancy but is considered pathological when it persists beyond a developmental window. In autistic children, particularly those with intellectual disability, pica can persist for years and carries serious medical consequences: lead poisoning from ingested paint chips, gastrointestinal obstruction or perforation, dental damage and parasitic infection. The studies included in the review indicated an increased risk of pica among children with autism, and the authors highlight that potentially severe adverse outcomes appear responsive to early detection and intervention — a point with immediate clinical implications, since a behavior that might be dismissed as a quirk of autism can instead signal a diagnosable, treatable and medically dangerous disorder.

Avoidant restrictive food intake disorder, or ARFID, presents a very different clinical picture. Introduced as a formal diagnosis in DSM-5, ARFID describes a restrictive eating pattern driven not by concerns about weight or body shape — the hallmark of anorexia nervosa and bulimia — but by sensory aversion to food textures, tastes and smells, fear of aversive consequences such as choking or vomiting, or a simple lack of interest in eating. The result can be weight loss, nutritional deficiency, dependence on supplements or tube feeding, and profound psychosocial impairment. The ten studies in the review that examined autism and ARFID together support a substantially increased co-occurrence of the two conditions, a finding that aligns with the broader clinical observation that sensory sensitivities and rigid, repetitive behaviors characteristic of autism frequently shape what, how and how much an autistic child will eat.

One of the review’s most important conceptual contributions is its confirmation that the eating disorders co-occurring with autism are fundamentally different in motivation from the classic eating disorders of adolescence. The authors state that the substantial co-occurrence of autism and these eating disorders involves concerns in which weight and body shape are not the primary drivers. This distinction matters enormously for clinical practice. Screening tools and treatment protocols developed for body-image-driven eating disorders may be poorly suited to an autistic child who restricts intake because of texture aversion, or who eats inedible objects because of sensory seeking. Misclassification can delay appropriate care, and the review’s authors emphasize that early detection of these eating disorders may improve clinical outcome.

Rumination disorder, the third condition examined, received by far the least scientific attention. The condition involves the effortless regurgitation of recently eaten food, which may then be re-chewed, re-swallowed or spit out, and it is not explained by gastrointestinal illness or another medical condition. In the entire body of literature screened by the review team, only one study met the criteria for examining rumination disorder in autistic children and adolescents. The authors conclude that rumination disorder may still be underrecognized and understudied in autism, a gap with real consequences: chronic regurgitation can cause dental erosion, esophageal injury, weight loss and malnutrition, and the behavior is frequently mistaken for reflux or vomiting, leading to ineffective medical workups rather than behavioral treatment.

Beyond the headline findings on occurrence, the review delivers a sobering assessment of the methodological quality of the existing evidence. The included studies, the authors report, have small cohorts and lack standardized diagnostic assessment and treatment protocols. In practical terms, this means that estimates of how common pica, ARFID and rumination disorder truly are among autistic children remain imprecise, that comparisons across studies are difficult, and that no evidence-based treatment pathway has been firmly established for any of the three conditions in this population. The abbreviations listed in the article — from the Brief Autism Mealtime Behaviour Inventory to the Food Frequency Questionnaire and the Gastrointestinal Symptom Inventory for ASD — hint at the patchwork of instruments researchers have used, none of which constitutes a gold-standard diagnostic tool for these disorders in autistic youth.

The clinical pathway from recognition to treatment emerged as another weak link. Because pica, ARFID and rumination disorder sit at the intersection of pediatrics, child and adolescent psychiatry, clinical psychology and gastroenterology, autistic children with these conditions may be seen — or missed — in any of several settings. A child with pica may present first to a pediatrician with lead poisoning; a child with ARFID may be referred to an eating disorder clinic built around adolescent anorexia; a child with rumination disorder may undergo repeated gastrointestinal investigations. Without standardized diagnostic criteria applied consistently across these pathways, the review suggests, the same underlying disorder can be interpreted very differently depending on which door the family walks through first.

The research team — which also included Gro Janne Henningsen Wergeland, Ola Skjeldal, Jørn Isaksen, Mads Holten-Andersen, Vesna Bryn and senior author Maj-Britt Posserud — calls implicitly for a new generation of studies: larger cohorts, validated diagnostic instruments adapted for autistic children, and controlled trials of interventions ranging from behavioral treatment for pica and rumination to graded food exposure for ARFID. Published open access in the Journal of Eating Disorders and supported by the Innlandet Hospital Trust, the review arrives at a moment of growing scientific interest in the intersection of autism and eating behavior. Its message to clinicians and researchers alike is clear: eating disorders in autistic children are real, common enough to matter, dangerous when missed, and responsive to early detection — but the field must first build the diagnostic and therapeutic foundations that other areas of eating disorder research have long taken for granted.

Subject of Research: Co-occurring feeding and eating disorders in children and adolescents with autism spectrum disorder

Article Title: Pica, avoidant restrictive food intake disorder and rumination disorder in children and adolescents with autism spectrum disorder: A systematic review

Article References: Hodt, G., Wergeland, G. J. H., Skjeldal, O., Isaksen, J., Holten-Andersen, M., Bryn, V., & Posserud, M.-B. (2026). Pica, avoidant restrictive food intake disorder and rumination disorder in children and adolescents with autism spectrum disorder: A systematic review. Journal of Eating Disorders, 14(1), Article 226. https://doi.org/10.1186/s40337-026-01772-x

Image Credits: AI Generated

DOI: 10.1186/s40337-026-01772-x

Keywords: autism spectrum disorder, pica, ARFID, rumination disorder, eating disorders, systematic review, children, adolescents, feeding behaviour, diagnostic assessment, early intervention, Journal of Eating Disorders