Aluminium – It’s everywhere… but is it safe?

Aluminium – It’s everywhere… but is it safe?

InterClinical eNews April 2018, Issue 79

Aluminium is ubiquitous in the environment. In recent years, it has increasingly been incorporated in consumer products, foodstuffs and drinking water with a presumption of safety. This presumption is based on the belief that as is not overtly toxic in acute low dose ingestion, cumulative consumption must also be benign. This month we review the research to shed light on this assumption.

Aluminium in Water
To date, no physiological requirement for aluminium in human health has been found. (1)  Contrary to the popular assumption of safety, chronic low-level ingestion exceeding 1 g per day has been implicated in several conditions including hypophosphataemia (caused by aluminium forming insoluble compounds with phosphate), hypercalcaemia, bone resorption, osteomalacia and Alzheimer’s disease. Embryotoxic effects have also been shown in preclinical trials.(1,2)  Along with the total limit for ingestion, a ‘safe’ drinking water limit of 0.6 mg/ L or 600 ppm per day has been proposed, based on a 40-day aluminium balance study.(1)

Aluminium in Food
Aluminium is used in cookware, as takeaway containers and as a food foil for baking and food storage. Research has confirmed that it is more likely to leach into acidic foods such as lemons and oranges and some salty proteinaceous foods such as salmon and ham. (2) The leaching effect increases up to 18 fold when food is cooked and/or stored in aluminium foil on a tray made of an alloy with a higher electrical potential than aluminium, for example, stainless steel. (2)

Aluminium in Personal care
However, the most common route of aluminium exposure is through the use of antiperspirants which contribute approximately 2 g of aluminium per day to the skin. This is absorbable, not directly via the skin epidermis but rather via the hair follicles, apocrine and eccrine sweat ducts.(1)  Additionally, certain sunscreen can contribute up to 5 g per day.(1) Aluminium is also commonly found in consumer and personal care products; pharmaceutical products such as antacids, adjuvants and prescription medications and is used to remove sediment from drinking water. The residual aluminium left in the water can range from 1.17 mg/L to 5.35 mg/L.(3)

Aluminium Absorption Rates
Absorption from the intestinal tract is calculated at about 1% of ingested aluminium suggesting those who drink unfiltered water may be absorbing somewhere between 0.07 mg/L and 0.018 mg a day if they ingest around 1.5 litres of water daily. Absorption estimates from cosmetics, sunscreens and environmental exposure are harder to predict. It is unknown how much is absorbed via the skin sweat glands and whether it accumulates in the lymphatics; as not all of it is thought to be excreted via the urinary system. (1) Pharmacy antacids contribute approximately 138 mg aluminium per dose and with an upper limit of 8 per tablets per day providing a possible daily dose of 1.104 g per day – above the recommended daily limit.

The unwitting body burden of aluminium can vary significantly from one person to another depending on food and water sources and consumer products used. Caution needs to be exercised to keep exposure to a minimum to avoid negative cumulative exposure effects.
 
Comment:  Aluminium has become a common-place mineral in the environment which enters the human body through a plethora of pathways. Hair tissue mineral analysis is one of the best ways to easily test for aluminium in your patients. Chronic low level, cumulative aluminium ingestion is not necessarily safe. Individual body burden varies from person to person depending on the level of ingestion of the local water supply, the extent of personal product, pharmaceutical, sunscreen and antacid use, and the methods of food preparation employed. 

References

1. Exley C. Human exposure to aluminium. Environmental Science: Processes & Impacts. 2013;15(10):1807-16. 
2. Ertl K, Goessler W. Aluminium in foodstuff and the influence of aluminium foil used for food preparation or short time storage. Food Additives & Contaminants: Part B. 2018 Feb 19.
3. Alexeeff, George V. Public health goal for aluminium In drinking water. 2001

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