- Aluminum is naturally present in almost all foods; tea is particularly prone to accumulating it.
- A 2019 study caused alarm, but many people confused content per kilo with the amount actually ingested.
- The dose absorbed per cup of matcha remains low compared to reference health thresholds.
- Origin and soil quality matter: organic, traceable matcha greatly limits the risk.
Aluminum (Al) is the most abundant metal in the Earth's crust. A highly reactive element, it is never found as a free metal in nature. It is found combined with other elements, most often with oxygen (O), silicon (Si) and fluorine (F). These chemical compounds are generally found in soil, minerals, rocks and clays.
As a metal, it is obtained from minerals containing aluminum, mainly bauxite. Aluminum metal is lightweight and silver-white in appearance.
Naturally present in soil, water and air, elevated levels in the environment can be caused by the extraction and processing of aluminum ores or the production of metallic aluminum, alloys and compounds.
Thus, small quantities of aluminum are released into the environment by coal-fired power plants and incinerators, and the effects on nature as a whole and on humans are not without consequence.
In the diet, unprocessed foods such as fresh fruits, vegetables, plants (the tea plant, etc.) and meat generally contain very little or moderate amounts of aluminum. Overall, most traces of aluminum in food, water and medications are quickly eliminated from the body in feces (stools), and much of what enters the bloodstream will quickly leave the body through the micturition reflex (in urine).
However, in addition to being used to make certain food packaging and cookware (saucepans, frying pans, etc.), aluminum compounds may be added, intentionally or not, in varying quantities during food processing — such as in flours, yeasts, colorings, anti-caking agents, or in plant-based beverages such as tea and/or coffee.
What are the effects of aluminum on health?
According to Anses, "in humans, the main routes of chronic exposure to aluminum are oral (food, water, oral medications), dermal (cosmetics and antiperspirants) and respiratory (inhalation of dust). As for the oral route, the general population is essentially exposed to aluminum through food, with intake via water contributing to less than 5% of total intake."
In this way, a very small amount of the aluminum we breathe enters the body through the lungs. A very small amount of aluminum in food or water enters the body through the digestive tract. A very small amount of aluminum from medications with high aluminum content, such as antacids (products based on aluminum and magnesium salts), will be absorbed; and a very small amount can penetrate through the skin when we come into contact with aluminum.
According to a synthesis by the association Santé Environnement France (ASEF), "the toxicity of aluminum depends on the quantity ingested but also on the chemical form in which it is absorbed. The different forms of aluminum depend on the acidity of the medium. Aluminum is more harmful in its soluble form, that is, when the medium is acidic. More concretely, if lemon juice is added to water, the absorption of aluminum will increase considerably, as will its toxicity".
Thus, aluminum is one of the main heavy metals we ingest, along with lead, arsenic, cadmium, chromium, copper, or mercury. The health consequences of the accumulation of heavy metals such as aluminum in the body raise many questions. As current research shows, the harmful effects of high aluminum levels would be particularly linked to the onset of certain neurodegenerative diseases.
Indeed, a study, published in February 2020 in the scientific journal Journal of Alzheimer's Disease, reaffirms and confirms the undoubtedly unique association between high aluminum content in the brain and amyloid-β, and "allows us to postulate that the genetic predispositions defining Alzheimer's disease underlie this relationship". On this subject, it is worth noting that tea polyphenols (EGCG, etc.) are known to induce the expression of various antioxidant enzymes and hinder oxidative damage to DNA.
More and more scientific evidence suggests that green tea may also be used as a potential agent to help treat neurodegenerative diseases, including Alzheimer's disease. The benefits would be partly due to EGCG (epigallocatechin gallate), a catechin (from the flavonoid family) abundant in tea, and in particular in green tea and matcha green tea powder.
Diet and aluminum
Small quantities of aluminum are present in almost all foods to varying degrees. In fact, aluminum is naturally present in most foods, including fruits, vegetables, meat, fish, cereals and dairy products.
Some foods, such as the leaves of the tea plant or Camellia sinensis (the scientific name of the shrubs of the Theaceae family), mushrooms, spinach and radishes, are also more likely to absorb and accumulate aluminum than other foods, as highlighted by an official report from the European Food Safety Authority published in 2008.
In addition, some of the aluminum we consume comes from processed food additives, such as preservatives, colorings, anti-caking agents and thickeners.
Note that commercially produced foods containing food additives may contain more aluminum than home-cooked foods. Limiting or completely eliminating ultra-processed foods in a balanced diet is therefore a way to reduce exposure to heavy metals — and also to decrease cancer risks, as revealed by a press release published in 2018 by INSERM (French National Institute of Health and Medical Research).
The actual amount of aluminum present in the foods we eat depends largely on 4 factors:
- absorption: how easily a food absorbs and retains aluminum;
- soil: the aluminum content of the soil in which the food was grown;
- packaging: whether the food was packaged and stored in aluminum packaging;
- additives: whether certain additives were added to the food during processing.
In any case, the aluminum content of foods and most medications is not considered a problem (with the exception of aluminum salts), because only a tiny fraction of the aluminum we ingest is actually absorbed. The rest is excreted in the stools. Moreover, in healthy people, absorbed aluminum is subsequently excreted in the urine.
As a general rule, oral exposure to aluminum is usually not harmful. Although over-the-counter oral products containing aluminum are considered safe for healthy people at recommended doses, some adverse effects have been observed after long-term use in certain individuals.
Pour aller plus loin : A Review of Scientific Research on Matcha Tea →: Welcome to our selection of relevant articles and features covering scientific and medical research on tea (green tea, black tea, white tea), with a particular focus on Japanese matcha green tea.
The observed benefits are largely linked to product quality. Feel free to buy exceptional organic matcha online to experience them for yourself.
Tea (Camellia sinensis) is one of the few plants that accumulates aluminum (Al), making tea one of the major dietary sources of aluminum.
Thus, for several years, scientific studies have been reviewing research on the concentrations, speciation and bioavailability of aluminum in tea.
It has been found that, with very rare exceptions, the total concentration of aluminum in tea infusions is between 1 and 6 mg. Probably more than 90% of this aluminum is bound to organic matter, but the nature of the organic species is unclear.
The relative quantity of the different organic aluminum species in tea infusions is unclear, and even the identity of one of them has not been demonstrated with certainty. One possible exception is aluminum trioxalate, which may be an important species.
It seems fairly well established that drinking tea leads to measurable but moderate increases in urinary aluminum excretion. However, the bioavailability of the aluminum present in tea does not seem to be much greater than that of other dietary sources.
Even so, it cannot be dismissed that tea infusions (green tea, black tea, white tea and matcha) may contain particularly "bioavailable" and neurotoxic compounds such as aluminum maltolate, but this is currently speculative.
Research also shows that the total metal content of tea leaves differs depending on the type of tea (green or black) and is probably influenced by many factors, for example the physical and chemical properties of the soil.
Increasing the extraction time showed no effect on aluminum speciation, nor did the addition of sugar. After the addition of lemon juice, speciation changed in one black tea and one green tea sample. The results suggest that lemon juice as an additive can significantly influence aluminum speciation in tea infusions.
In a study published in 2008 in the journal Food and Chemical Toxicology, researchers attempted to estimate the oral bioavailability of aluminum from a tea infusion. The bioavailability of tea averaged 0.37%, which is not significantly different from water (0.3%), or basic sodium aluminum phosphate (SALP) in cheese (0.1 to 0.3%), but higher than that of biscuits (0.1%).
Finally, dietary exposure to trace elements is regularly assessed, along with individual consumption data to estimate dietary exposure in adults and children.
Moreover, a report published in 2012 in the journal Food and Chemical Toxicology shows that in France, exposure is higher for cadmium, aluminum, antimony, nickel and cobalt, and lower for lead, mercury and arsenic.
For aluminum, methylmercury, cadmium, lead and inorganic arsenic, the risk cannot be ruled out for certain consumer groups. In order to minimize nutritional and chemical risks, the French Agency for Food, Environmental and Occupational Health & Safety (Anses) reiterates its recommendation for a diversified diet (food products and origins).
"The EFSA (Food Safety Authority of Ireland) also adopted a Provisional Tolerable Weekly Intake (PTWI) of 1 mg/kg bw/week (a 7-fold decrease from the previous PTWI) in 2008. The JECFA (Joint FAO/WHO Expert Committee on Food Additives), in 2011, revised the value previously established in 2006 upwards, setting the PTWI at 2 mg/kg bw/week. This PTWI applies to all aluminum compounds present in food."
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Quiz · 60 sec
Comment bien choisir son matcha ?
4 questions, 60 secondes — testé et validé par 3000+ buveurs.
Commencer le quizzAbout a controversial study on matcha
In July 2019, the publication of a study on the aluminum content present in matcha raised many questions and requests from the Kumiko Matcha community, and within the network of aficionados of this Japanese green tea powder. As usual, Kumiko Matcha is keen to be as transparent as possible in the eyes of all matcha green tea enthusiasts, and to provide maximum insight into the news concerning this delicious beverage.
Since the beginning of the Kumiko Matcha adventure, Valentin, its founder and visionary, has never ceased to bring to light the diversity of quality matcha productions, which are available from a growing number of Japanese artisan-farmers.
The solid and sincere relationship that has developed over the years with these organic and natural tea farmers is a unique and deeply human one. This is what can be felt through their terroir products, to be discovered in photos and videos, and of course at home and among friends.
This close and professional relationship makes it possible to provide, to date, the maximum amount of information on the production process. Whether about the history, origin and composition of each grand cru matcha available at Kumiko Matcha. This is also the same philosophy that underpins and supports all the utensils and fine craft objects (pottery, bamboo whisk, etc.) offered by Kumiko Matcha.
Indeed, in addition to conveying the passion for the world of Japanese matcha, sourced from atypical and rare terroirs, Kumiko Matcha implements everything necessary and required by regulations so that your organic matcha is unique and lives up to its promises.
In addition to the unconditional compliance with regulations related to organic tea farming by our partner artisan-farmers, Kumiko Matcha monitors and regularly has the quality of all matcha available in the Collection tested by independent laboratories. This makes it possible, in particular, to know precisely the different chemical compounds of each matcha, and to enjoy them with complete peace of mind — the only risk being pure pleasure.
To come back to this German study, it is a scientific report on a small-scale study, published in July 2019 by the German Federal Institute for Risk Assessment, the Bundesinstitut für Risikobewertung (BfR).
As matcha has become a very popular product for food and cosmetics consumption, it enjoys many health claims, sometimes without enough evidence to draw hasty conclusions. It is therefore normal that this trendy green tea powder is the subject of regular studies to confirm or refute these claims. This assessment is therefore in line with the trend, as it seeks to meet the requirements of current standards, particularly in the functional food (or superfood) sector, as well as consumer expectations.
The aim of the BfR was to analyze matcha samples selected by them. However, these matcha samples do not represent the intrinsic quality of all the matcha available on the current market.
Although this assessment is a justified approach, it only represents a snapshot of a given moment in time, based on a very small number of matcha samples. Indeed, only 3 matcha samples (of unspecified origin and brand) do not represent reality, and even less so the quality of the matcha offered by Kumiko Matcha.
The BfR examined the health risk for consumers who regularly consume matcha tea. The objective was to determine the levels of aluminum present in matcha to assess the health risks associated with exposure via matcha. The toxicological assessment was conducted on 3 matcha tea samples whose results showed high levels of aluminum.
The three matcha tea samples tested by the Institute revealed that aluminum levels were respectively 1743, 1775 and 2350 milligrams (mg) per kilogram (kg), far exceeding the daily recommendation of the EFSA (European Food Safety Authority) of 1 mg per kg of body weight.
By comparing the analysis of the study and the latest analysis carried out by the GBA Gesellschaft für Bioanalytik mbH laboratory (Hamburg) in March 2020 on the Kumiko Matcha matchas (organic premium, organic ultra-premium, organic hyperpremium), it is clearly apparent that Kumiko Matcha levels are up to three times lower than those of the study.
|
Analysis results Matcha from the BfR study |
Analysis results Matcha from Kumiko Matcha |
||
| Sample 1 |
1743 mg/kg i.e. 1.743 mg/g |
Premium organic matcha |
620 mg/kg i.e. 0.62 mg/g |
| Sample 2 |
1775 mg/kg i.e. 1.775 mg/g |
Ultra-premium organic matcha |
499 mg/kg i.e. 0.499 mg/g |
| Sample 3 |
2350 mg/kg i.e. 2.350 mg/g |
Hyperpremium organic matcha |
544 mg/kg i.e. 0.544 mg/g |
*mg/kg: milligrams (mg) per kilogram (kg); *mg/g: milligrams (mg) per gram (g)
A report that raised many questions
This study raised many questions and also brought to light the difficulty most people have in deciphering the results of a study. Notably, many people confused aluminum content per kilogram with content per gram. One can understand why statistical data processing is one of the most sensitive points of modern science.
Without denouncing the methodology, what is the validity of this scientific study? Where did the samples come from? Was it organic matcha? How was it stored and handled? How can one denounce the presence of a high aluminum level in a product by analyzing only 3 samples out of hundreds of existing products?
So many questions, sometimes without answers, which do not allow the results of this report to be taken at face value and turned into a generality.
While the assessment may be based on measured results that showed aluminum levels, the report does not provide sufficient data here to consider that all matcha are at that same level.
Generally, before sounding the alarm, note that scientists are careful to avoid media hype without first conducting large-scale studies and objective meta-analyses, in order to guarantee as much as possible the accuracy of a conclusion.
Let us remember that science is not a coldly neutral process. Science is above all a human activity, carried out by men and women, with their strengths but also their weaknesses.
In reality, there is currently no distinct data on matcha tea or powdered tea consumption for any population type that would allow us to say that all matcha teas contain high levels of aluminum.
Thus, this report is only an estimate and an assumption about the long-term intake of aluminum via matcha tea. It does not reflect the reality of the matcha available from the majority of respectful artisan entrepreneurs like Kumiko Matcha.
In this way, a more in-depth examination of the evidence of causality and clinical relevance is the only possible path to obtaining better data.
Kumiko Matcha regularly monitors the quantities of heavy metals in all its products and is always within the low limits of current food safety laws.
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How to guarantee the quality of the matcha tea you consume?
The analysis of the various results of scientific studies on a multitude of infusions such as tea (matcha, green tea, black tea, white tea) shows that the location factor influences heavy metal content.
The geographical origin (terroir) of the cultivar of each tea consumed is a crucial factor in aluminum content, since soils differ from one country and region to another.
To this major factor, it is important to emphasize that teas from organic farming considerably reduce the chances of drinking tea containing a high level of aluminum.
Therefore, when someone wishes to consume quality tea, it can be worthwhile to find out about its aluminum content — either by reading the detailed information available or by asking the manufacturers or matcha suppliers of professional matcha.
Thus, with the aim of highlighting the quality work of the Japanese artisan farmers who collaborate specifically with Kumiko Matcha, and of being as close as possible to everyone's expectations regarding the effects of matcha green tea on health, Kumiko Matcha provides a wealth of substantiated, precise information, delivered by independent and competent organizations and laboratories.
In this way, each matcha (premium organic matcha, ultra-premium organic matcha, hyperpremium organic matcha) comes with a detailed and clear description, and a certificate of analysis to allow everyone to buy organic matcha from Japan with complete confidence.
For the record, the latest analysis results obtained from a German laboratory, the GBA (Gesellschaft für Bioanalytik mbH), reveal the precise levels of three matcha green teas available at Kumiko Matcha. The analysis results show that they comply with the admissible doses that the body can naturally eliminate.
Aluminum content of Kumiko Matcha's matcha green teas:
- Premium organic matcha tea: 620 mg/kg, i.e. 0.62 mg/g (view the analysis PDF)
- Ultra-premium organic matcha tea: 499 mg/kg, i.e. 0.499 mg/g (view the analysis PDF)
- Hyperpremium organic matcha tea: 544 mg/kg, i.e. 0.544 mg/g (view the analysis PDF)
In addition to the inimitable flavors of quality matcha, the scientifically proven benefits of matcha are numerous: regulating mood, relaxing the mind, helping to eliminate heavy metals and chemical toxins from the body, increasing physical performance and endurance, etc.
Thus, Kumiko Matcha — together with its partner artisan farmers — wants to offer you the best possible guidance for buying and enjoying a quality organic matcha green tea.
Jimmy Braun/BlogNutritionSanté - December 2020
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