We all know that aluminium – an abundant element on Earth – is bad for us, especially for our brain and liver. Minimal exposure to aluminium is not a problem: the World Health Organisation has established a safe daily intake of about 2mg per kilogram of body weight per day. According to a Joint FAO/WHO Expert Committee on Food Additives, the daily allowable intake of aluminum is 6-14mg/day for teens and adults.
However, most people are exposed to and ingest far more – aluminium is present in food like corn, yellow cheese, salt, herbs, and tea. It’s used in antacids and antiperspirants, as well as in cooking utensils.
The beverage that has the highest amount of aluminium is… tea! Researchers back in the 50s noticed that tea leaves absorbed aluminium from the soil.
Are you taking in too much aluminium from tea?
According to cancer.gov, infusions of green and black tea could range from 14 to 2238 micrograms per litre. (1mg is 1,000 micrograms and 1 litre is equal to 4.23 cups). So a cup of either green or black tea could contain 0.5293mg/cup of aluminum. The older the leaves and the poorer the quality, the higher the aluminium content.
Up to a fifth of aluminum intake may come from beverages, so what we drink probably shouldn’t contribute more than about 4mg a day – that works out to about 5 small cups of tea (green, black, or oolong). This includes bubble tea.
A study in Mexico found the surprising result that adding sugar to tea was found to greatly increase aluminum concentrations in the cup – it’s believed that the chemical structure of sugar may be inducing the polyphenols in tea to release aluminum.
While tea contains a high amount of aluminium, the percentage that we absorb in the intestine may be less than 10%.
This could be because tea also contains reasonably high concentrations of an amino acid called L-Theanine. A recent study reports that L-Theanine has “neuroprotective effects” which could perhaps be the reason it counteracts the potentially negative effects of the aluminum.
So, while it’s unlikely that moderate amounts of tea can have any harmful effects tea may not be a suitable for children with kidney failure, since they can’t get rid of aluminum as efficiently. To make sure you’re not taking int too much aluminium, limiting your intake of tea to less than 5 a day and drinking it without sugar may be a good way to start.
Where else is aluminium found? What else should you look out for?
If you’re worried about absorbing aluminium, you may want to pay more attention to your antiperspirant than your tea bag.
Another source of high aluminium content is, unsurprisingly, in tin foil that’s commonly used to cook food. Wrapping your food in foil and putting it in the oven is problematic, especially if the food is acidic or spicy and prepared at high temperatures. Aluminium is significantly more likely to leach into acidic foods (it sparks a process that dissolves layers of aluminium into food), and leaching levels climb more when spice is added. The solution? Simply line the foil with baking sheet or use other cooking vessels.
Of course, it comes as no surprise that aluminium is highly concentrated in cigarettes, with values ranging from 699 – 1,200μg/g.
Aluminium is naturally-occuring, and is present almost everywhere from the soil to certain foods and industrial processes. This means avoiding all aluminium isn’t possible. If you’re worried about any health effects, simply stick to a healthy diet and lifestyle instead.
Additional info via nutritionfacts.org and California Tea House.