aluminium

see also:

• foods that may be toxic or bad for you

• aluminium is the most common metal in the Earth’s crust and it finds its way into the plants via the soil and high levels of ingestion may have adverse effects
• aluminum exposure occurs through some plant foods, food packaging, medications, water, and industrial sources.
• aluminum toxicity was previously common in dialysis patients due to elevated levels in dialysate, but it has become rare with improvements in the dialysate composition and concentrations now recommended to be below 10 μg/L
• patients with end-stage renal disease are particularly susceptible, as aluminum relies on renal clearance and was historically present in some phosphate binders
• neonates on TPN are also high risk
• acute aluminum toxicity is rare due to the low levels of exposure encountered in everyday life
• 90% of plasma aluminium binds to transferrin and competes with iron for binding
• aluminium is widely distributed throughout the body, with about 60% stored in bones, 25% in the lungs, 10% in muscles, 3% in the liver, and 1% in the brain
  • bones act as a long-term reservoir for various metals, including aluminium
• 99% is renally excreted
  • healthy adults with normal renal function can tolerate daily aluminum intakes of 3500 to 7200 mg without experiencing apparent adverse effects¹⁾
• the European Food Safety Authority (EFSA) has derived a tolerable weekly intake (TWI) quantity of 1mg per kilogram (kg) body weight.

• health concerns are primarily from chronic accumulation, as it has no known biological role in humans and can disrupt cellular processes via:
  • disrupting or inhibiting enzymatic activity
    • eg. reduced activity of glutathione, glutathione peroxidase, glutathione S-transferase, and catalase
  • altering protein synthesis and nucleic acid function
  • modifying cell membrane permeability
• neurotoxicity is the major concern
  • aluminium crosses the blood-brain barrier and is thought to promote oxidative stress, inflammation, amyloid plaque formation, and tau protein tangles linked to Alzheimer's disease and dementia
  • occurs through several mechanisms, including:²⁾
    • neuronal oxidative stress
    • apoptosis
      • corticoneuronal apoptosis occurs via the SAPK/JNK pathway, NF-kB activation, increased p53 and BAX expression, and reduced expression of neurofilaments, tubulins, transferrin receptors, amyloid precursor proteins, and neuron-specific enolase
    • neuroinflammation
    • neurotransmitter disruption
    • cytoskeletal dysregulation
    • lipid peroxidation
    • inhibition of mitochondrial membrane potential
    • reduced ATP levels
    • decreased DNA and RNA strand formation
    • inhibition of DNA repair
    • inhibits protein phosphatase 2A, leading to hyperphosphorylation of tau and neurofilament proteins
    • alter the expression of RNA polymerase I and beta-amyloid precursor protein secretase, resulting in amyloid beta accumulation
    • increases the biosynthesis of transferrin receptors, prevents ferritin production, and raises free iron levels, which further contribute to oxidative stress
• anaemia
  • anemia with anisocytosis and poikilocytosis
  • can result in the formation of leptocytes, acanthocytes, echinocytes, stomatocytes, and target cells
• pulmonary fibrosis
• potroom asthma
  • characterized by a decrease in peak expiratory flow rates due to aluminum exposure, resulting in mild-to-moderate bronchial hyperresponsiveness that is reversible upon removal from aluminum fumes
• osteoporosis
  • accumulation of aluminum in bones can lead to osteoporosis by decreasing osteoblast-mediated bone formation and altering osteoclast function³⁾
• elevated levels of aluminum are associated with a higher incidence of cardiovascular diseases, including hypertension, coronary artery disease, and dyslipidemia⁴⁾
• gastro-intestinal
  • can impact the the GIT microbiome, intestinal permeability, immune responses, and inflammatory reaction
• renal:
  • can reduce glomerular filtration, leading to elevated serum uric acid levels⁵⁾
  • may result in nephrotic syndrome and acute renal glomerulonephritis ⁶⁾
  • disrupts renal tubular transport of p-amino hippuric acid, phosphate reabsorption, and sodium or water balance
  • can also affect sodium-potassium ATPase activity, while elevated intracellular free iron exacerbates oxidative stress
• fertility⁷⁾
  • patients with oligozoospermia exhibit significantly higher aluminum concentrations in their semen, indicating a potential link between aluminum toxicity and fertility issues
  • aluminum exposure in rats over 60 days was associated with decreased sperm count, reduced daily sperm production, impaired sperm motility, lower production of normally shaped sperm, and altered testicular histology

• personal hygiene and cosmetic products are very unlikely to be an issue as there is no significant evidence to suggest that aluminum applied to the skin can enter the bloodstream
  • antiperspirants
  • cosmetics
• medical:
  • older dialysate in dialysis patients
  • aluminium containing phosphate binders (aluminum hydroxide) for end stage renal patients
  • buffered aspirin
  • total parenteral nutrition (TPN)
  • vaccines (although minute quantities)
• industrial
  • inhalational
    • aluminum found in inhaled dust can potentially stay in lung tissue indefinitely
    • contaminated or high aluminium containing soils or dusts
    • cigarette smoke
    • particulate matter from vehicle emissions
    • coal combustion
    • metal refineries
      • workers in aluminium plants, particularly those involved in the electrolysis process, where aluminum fumes are generated
    • other industrial activities

• daily aluminum intake from food is estimated to range from 3.4 to 9 mg — a level that may increase with the presence of lactate, citrate, maltol, or fluoride, intestinal absorption varies between 0.04% and 1.0%, depending on the chemical form ingested⁸⁾
• aluminium can beverages
• aluminium foil cooking
• aluminium cookware - esp. when stewing acidic foods
• pesticides
• drinking water
  • concentrations can be seasonal
  • some natural spring waters can have higher amounts
  • tap water: 0.001–0.2 mg/L median (often 0.05–0.112 mg/L post-treatment); can reach 1 mg/L untreated or in corrosive/acidic systems
  • bottled spring water: usually <0.05 mg/L (often <0.01 mg/L, rarely > 0.1mg/L)
• matcha
  • matcha contains notably higher aluminium levels than green or black tea infusions due to consuming the whole leaf powder**, which absorbs soil aluminium during shaded growth. Studies report matcha samples ranging 1,743–2,350 mg/kg, potentially exceeding EFSA's TWI (1 mg/kg body weight/week) with 2–3.6g daily intake (e.g., 1–2 portions), even as a sole source. Green and black teas, steeped as leaves, leach far less (<500 mg/kg or <13 µg/mL or < 3mg per 250mL cup in infusions), keeping exposure low⁹⁾
• western bakery items made with aluminium baking powder eg. pancakes, waffles (160 mg/kg, occasionally up to ~700 mg/kg)
• steamed breads/buns/cakes using aluminium‑based raising agents (100–320 mg/kg)
• jellyfish (ready‑to‑eat, treated with alum): averages around 1,200 mg/kg
• some seaweeds >20 mg/kg
• vegetables and cereals often in the 5–10 mg/kg range