Studies and real-life observations have shown no toxicity of açaí berries nor manganese toxicity from dietary sources in general. And to give the all-clear: eating açaí every day is common in Brazil and is considered safe and healthy, even in more significant amounts. Everything discussed in this article points toward the answer: eating a bowl of açaí daily is safe.
Açaí, the special berry from the Amazonian forest
Have you just discovered that your açaí bowl is a manganese bomb and wondered if you have overdosed on the trace mineral by eating a bowl every day? If so, you are not alone! Let’s see what is going on with the exotic berry and if it is healthy to eat it daily.
Açaí makes for a full nutritious meal!
Tropical fruits generally are more nutritious and richer in fats than temperate fruits and thus are an essential part of a raw diet. On a raw, high-fruit diet getting nutritionally rich, tropical fruits is crucial (read here why humans need tropical fruits for best health).
Açaí berry, the fruits of the amazonian palm tree Euterpe oleracea, is long-known in Brazil for its high nutrient density and is actively being researched for its health benefits. Açaí is often consumed to substitute for one “normal” meal and thus is an exciting source of nutrition for raw vegans.
Açai is relatively high in fats, which partly consist of similar fatty acids as those found in avocados and olives. 100 grams of açaí pulp contains 5gram fat (this is around one-third of the fat in 100g avocado), of which over 60 % are unsaturated (of which 11 % are polyunsaturated fatty acids). Also, the berry is a good source of Omega-3s compared to other fatty fruits like avocados or coconuts.
Because of its flavor and health-promoting properties, açaí has gained enormous popularity as a health food in Europe and the US. The tropical berry is not just a newer trend food appreciated by the health community. It’s also is a traditional food in the Amazonian Region of Brazil!
Açaí consumption in Brazil
Brazil has an impressive natural botanical wealth, including medicinal plants and tropical fruits. When you live in Brazil, you are basically in fruit heaven, as you can buy fruits, fruit juices, and smoothies at almost every corner indexed from A-Z!
One of Brazil’s famous fruits is the açaí berry, primarily sold in pulp and served as a semi-frozen smoothie or bowl with a unique, full flavor. It is one of the most popular fruits in Brazil: the “tigela de açaí” comes in many variations as mixtures with other fruits or toppings such as slices of bananas, mangoes, honey, nuts and granola variations.
For example, in Amapa, 26 liters of açaí is consumed per person per year, which is around half a cup (0.7 dl) daily. Keep in mind that this is the average number, meaning that some people consume more than that, while others don’t eat açai at all. Daily consumption of one bowl of açaí is practiced in Brazil and even advised on local health sites.
How much açaí per day is recommended?
Adults and children over three years old can consume 180 ml of açaí daily, and children under the age of threes years old 100 ml, according to a Brazilian nutritionist. That means one acai bowl per day is recommended in the regions where the berry grows and is traditionally consumed.
However, in some Amazonian communities, the daily açaí intake reaches up to 2 liters a day. In conclusion, the high consumption of açaí does not lead to health issues or manganese toxicity in Brazil.
Getting to know the people’s dietary habits in the country of the açaí berry already gives us a good indication of the safety of daily consumption. However, maybe local people are genetically adapted to the high manganese consumption and thus do not experience toxicity? Not likely in the evolutionary timeline, given that Brazil’s non-native population has not inhabited the area long enough to see adaptive traits.
Manganese content in açaí
Açaí is one in a million when it comes to manganese: the berry is a league of its own with a whooping manganese content of up to 120 mg per 100 g pulp. This is extraordinary to the point that the NIH does not have any other food with similarly high manganese content listed in its factsheet.
Does the manganese content in açaí exceed recommendations?
Theoretically, yes, manganese in açai berry exceeds recommendations, but there is more to the story! So, how much of the mineral is actually recommended and how much is in the berries?
While the RDA (Recommended Dietary Allowance) is not established for manganese, the AI (Adequate Intake) is 2 mg/d, and the UL (Tolerable Upper Intake Level) is 11 mg.
|Recommended Dietary Allowance (RDA)||not established|
|Adequate Intake (AI)||ca. 2 mg / day|
|Tolerable Upper Intake Level (UL)||11 mg / day|
Table 1: Manganese recommendations
|Manganese Source||Manganese (Mn) content (in mg)|
|200 g açai (numbers from to chronometer.com)||13|
|200 g açai (numbers from study A)||9.5|
|200 g açai (numbers from study B)||between ca. 29 – 240 (total Mn content)|
|200 g açai (numbers from study B)||ca. between 11 and 132 (bioavailable Mn content)|
Table 2: Manganese content in 200 g açaí pulp
One 200 ml açaí bowl contains around 13 mg of manganese (according to chronometer.com), which is at least six times the “adequate intake”. This is around 2 mg more than the “maximum” we should consume per day. However, there is a great variability in manganese content in the berries: one study (“study A” in table 2) found 200 ml of açaí pulp to contain 9.5 mg of manganese, which is below the UL. The other study (“study B” in table 2) states that 200 ml exceeds the AI by at least 50%.
Now, can we – based on those numer – conclude that 200 ml of açaí exceed the recommended manganese dosage? Let’s dive in a bit deeper:
Can manganese be overdosed from foods?
Mangenese is essential for health, but can cause toxicity in excess, which has been observed in miners and metal workers (occupational overexposure). But can we experience manganese toxicity from our diet? The short answer is that there is no known toxicity resulting from dietary manganese, but only from inorganic manganese inhalation and water and precautions for over-supplementation:
Dietary manganese toxicity has not been observed in humans (see here).
Toxicity data and reported adverse health effects only exist for manganese dust inhalation (i.e., industrial workers) or drinking manganese-rich (contaminated) water, but not for dietary intake. The latter two sources consist of inorganic ionic manganese (water) or inorganic manganese dioxide (dust).
In plants, manganese is a cofactor for hundreds of enzymes and thus is loosely bound to the biochemical matrix of the plant cells. This is an important difference, because the bioavailabilty (how much of a nutrient we actually absorb from a food) of minerals and other compounds depends on its chemical form:
The total concentration of an element in a plant alone does not define its toxicity!
For açaí, the bioavailabilty of manganese lies between 7 and 18% of the total amount. Generally the larger part of manganese from food is quickly excreted and only a small percentage is absorbed due to its poor solubility. Taking a manganese supplement, which comes in inorganic forms like manganese gluconate, manganese sulfate, manganese ascorbate, and amino acid chelates of manganese (see here), is therefore not the same as taking the compound within the plant food. Because overdosing on inorganic manganese is possible, consuming an adequate amount of açaí berry might be a natural alternative to supplements.
How much açaí per day is safe?
No açaí toxicity found
Neither in real life nor in studies has there been shown manganese toxicity due to overconsumption of açaí. A toxicity evaluation of açaí in mice demonstrated no toxicity over 90 days (no acute toxicity and no “mutagenic, clastogenic, cytotoxic, or genotoxic” effects) in high doses up to 40g/kg bodyweight.
Quite to the contrary: Açaí has many health benefits, such as cardiovascular benefits and reducing oxidative stress! And, more impressively, while manganese toxicity leads to neurological, Parkinson-like symptoms, the berry on the other hand is beneficial for neurological functions and has even shown to help with Parkinson disease.
The manganese content in açaí is based on lab values and in-vitro studies. The concerns for manganese toxicity are hypothetical and are based on comparing the manganese levels found in the plant compared to toxicity data established with inhalation exposure. Consuming a mineral (or other compounds) within its natural, complex biochemical matrix can have very different effects than taking the isolated or inorganic form.
Studies and real-life observations have shown no toxicity of açaí berries nor manganese toxicity from food sources in general. And to give the all-clear: eating açaí every day is common in Brazil and is considered safe and healthy, even in more significant amounts. Everything discussed so far points toward the answer: eating a bowl of açaí daily is safe.
If you prefer to rule out any risk of overconsumption, you might want to eat a 100-200 ml açai bowl 3-4 times a week instead of every day.
But let’s not lose sight of the bigger picture: the berry is a fruit, a natural food source for humans, which naturally are adapted to high fruit intake! Our body has sensory and instinctive intelligence! In animals (and humans), foods are commonly rejected and start to “taste not as good” if too much is consumed. In other cases, we react with digestive issues, like diarrhea, if something is consumed in excess. Those are all protection mechanisms that have kept us alive for eons and have warned and protected us from toxicity since before we had scales and sophisticated laboratories to measure the contents of minerals.
So, yes, I will continue to eat my delicious açaí pulp mixed with three bananas, 100 g of mangoes, grass juice powder, and a splash of distilled water almost every day, as long as I find it appealing and tasty.
Read more about the human high-fruit diet here:
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