Cadmium – Vorkommen in Lebensmitteln, schädliche Auswirkungen auf den menschlichen Körper, Vergiftung

Despite its trace presence in the Earth’s crust, cadmium is ubiquitously detectable in aquatic ecosystems, arable soils, atmospheric particulates, and biological tissues. Its industrial utilization—particularly in agriculture via phosphate-based fertilizers (e.g., superphosphates) and irrigation with contaminated water—facilitates bioaccumulation across the food chain. Cultivated plants, especially root vegetables (potatoes, carrots, beets, celery) and leafy greens (lettuce, spinach), concentrate this heavy metal in their edible tissues, posing a dietary exposure risk. Furthermore, tobacco smoke represents a significant cadmium source: a single cigarette delivers approximately 0.1–0.2 µg of the element to the body, whereas the tolerable weekly intake (TWI) is strictly limited to 2.5 µg/kg of body weight.

Cadmium enters the human body primarily through dietary exposure (chiefly via vegetable consumption), inhalation, and dermal absorption, with epidemiological evidence indicating that approximately 95% of total cadmium intake originates from plant-based foods. This heavy metal exhibits systemic toxicity, accumulating predominantly in detoxification organs—namely the liver and kidneys—while also depositing in bone tissue and male gonads, where it disrupts structural integrity and metabolic function. Chronic exposure may result in irreversible damage to renal tubules (including Fanconi syndrome), proteinuria, and even urological malignancies. Furthermore, cadmium triggers bone demineralization, predisposing individuals to osteoporosis, osteomalacia, and rickets in children. As a divalent element, it competes with essential trace minerals (calcium, iron, zinc, copper) for shared absorption pathways, leading to deficiencies, enzymatic dysfunction, and ultimately multi-organ failure. Cadmium also damages vascular endothelium, accelerating atherosclerotic plaque formation, exacerbates oxidative stress (thereby impairing antioxidant defenses), and induces inflammatory responses that may contribute to obesity. In males, cadmium exposure causes testicular degeneration, necrosis of seminiferous tubules, suppressed testosterone synthesis, impaired spermatogenesis, and prostatic hormonal dysregulation, significantly reducing fertility. Additionally, cadmium is a documented carcinogen: by compromising cell membrane integrity, promoting apoptosis, inhibiting DNA repair mechanisms, and inducing genomic mutations, it contributes to the development of renal, hepatic, testicular, prostate, and lung cancers (the latter via tobacco smoke exposure). The International Agency for Research on Cancer (IARC) classifies Cd²⁺ ions as a Group 1 carcinogenic substance.

Cadmium poisoning presents a significant health hazard, particularly for individuals adhering to plant-based diets, men, pregnant women, infants, and young children. Elevated risk also affects residents of heavily industrialized agricultural regions and occupational groups with direct cadmium exposure—including farmers, metalworkers, and long-term tobacco smokers. Effective protection against cadmium accumulation requires mindful selection of food sources: diversifying suppliers of root vegetables, leafy greens, fruits, cereal products, and fish minimizes the risk of chronic exposure. Purchasing directly from local producers—at farmers' markets or organic farms—provides transparency regarding cultivation practices, fertilizer use, and field locations. Additionally, tobacco consumption (both active and passive) should be substantially reduced, as cigarette smoke constitutes a primary route of cadmium absorption. While ubiquitous in the environment, cadmium exerts multifaceted, detrimental effects on human health; however, essential food groups such as vegetables, fruits, and whole grains—rich in vital nutrients—should not be eliminated from the diet.