By Dr. Charuni Kohombange
Public fear was aroused during the last week with the detection of aflatoxin contamination in several consignments of imported coconut oil. In the dawn of the Sinhala/Hindu New Year, this gloomy news invariably brings distress upon the public, since this is the season that coconut oil is used in massive amounts to prepare numerous sweetmeats for the festival.
How toxic is this substance? How harmful is it if consumed unknowingly? How do you identify safe products? These are some of the burning issues being discussed by the public. This article is aimed at finding answers to these questions, excerpting the discussions with consultant in sustainable innovation and former BASF scientist Dr. Piyal Ariyananda, General Hospital Chilaw Consultant Oncologist Dr. Nuradh Joseph, and Sri Lanka Medical Association (SLMA) Immediate Past President Prof. Indika Karunathilake.
[caption id="attachment_129711" align="alignleft" width="285"]
"A healthy nation is an asset to a country. If the citizens are unhealthy, it leads to low productivity as well as high healthcare costs. It’s a double whammy for a country like us, which is considered as a developing nation since our independence" Dr. Piyal Ariyananda[/caption]
Aflatoxins
Aflatoxins are poisonous substances produced by certain kinds of fungi (moulds) that are found naturally all over the world. They can contaminate food crops and result in serious health threats. Aflatoxins pose a significant economic burden, causing an estimated 25% or more of the world’s food crops to be destroyed annually.
Two closely related species of fungi, Aspergillus flavus and Aspergillus parasiticus, are mainly responsible for producing the aflatoxins of health significance. Under favourable conditions, typically found in tropical and subtropical regions, including high temperatures and high humidity, these moulds, normally found on dead and decaying vegetation, can invade food crops. Drought, insect damage, and poor storage can also contribute to their higher occurrence.
Several types of aflatoxins (14 or more) occur in nature. However, four – aflatoxins B1, B2, G1, and G2 – are considered particularly dangerous to humans and animals, as they have been found in all major food crops. Most human exposure comes from contaminated nuts, grains, and their derived products. Additionally, aflatoxin M1 (AFM1), a product of aflatoxin B1 (AFB1) metabolism, can be found in milk in areas of high aflatoxin exposure.
Harmful effects of aflatoxins
According to the World Health Organisation (WHO), both acute and chronic harmful effects can occur with aflatoxins. Large doses of aflatoxins lead to acute poisoning (aflatoxicosis) that can be life-threatening, usually through damage to the liver. Adults are more tolerant to acute exposure than children. Consequences of long-term exposure to aflatoxins affect many organs and systems leading to several health hazards including cancers. Dr. Nuradh Joseph discussed its cancer-related risks.
“Aflatoxin B1 is one of the most potent carcinogens known to cause liver cancer. Although most liver cancers arise in a background of long-standing liver injury caused by alcohol viral hepatitis B or C as well as non-alcoholic fatty liver disease, there is some evidence to suggest that aflatoxin B1 interacts synergistically with viral hepatitis B in causing liver cancer,” said Dr. Joseph.
Referring to the data from the National Cancer Registry, he said that the incidence of liver cancer is rising in Sri Lanka and the number of new cases registered has risen from 340 in 2015 to nearly 600 in 2019. “However, since there is a general trend of increasing numbers of new cases across all cases, it is not known whether this rise is due to better reporting and recording of data or an actual increase in the number of cases. In addition, some cases of liver cancer are not captured in the Cancer Registry Data, as they are diagnosed with scans alone and sometimes treated with only supportive care. So, the actual number of cases of liver cancer could be much higher than what is reported by the Cancer Registry,” he said.
Emphasising the need for accurate information, Dr. Joseph said that the study on causes and outcomes of liver cancer in Sri Lanka is urgently needed. “It is important to note that alcohol, chronic viral hepatitis, and non-alcoholic fatty liver disease are the main causes for liver cancers. Alfatoxins are well-recognised carcinogens and it is imperative that all food products conform to safety standards,” Dr. Joseph concluded.
[caption id="attachment_129710" align="alignright" width="376"]
"It is important to strengthen mechanisms for food safety regulations and enforcement" Prof. Indika Karunathilake[/caption]
‘Safe limits’ for aflatoxin contamination
“There’s no such safe limit per se, but since we cannot prevent contamination to the zero level and considering the lethal dose (LD50) values administered to rats, different countries have set different standards to safeguard their citizens depending on the chemicals policy and living standards of the country,” said Dr. Ariyananda. Furthermore, he explained the different maximum limits of aflatoxins around the globe.
Regulation of aflatoxin contamination in food involves formulation and enforcement of the maximum limits (MLs) tolerated in the food. Although most countries formulate their own MLs for aflatoxins in food, many of them rely on limits formulated by regional or international bodies. The US has a guideline level of 20 µg/kg, that equals to 20 part per billion (ppb) aflatoxins and the European Commission (EU), a more stringent ML of 4 µg/kg for total aflatoxins in food. In developing countries, MLs for total aflatoxins range from 10 to 20 µg/kg, with 10 µg/kg being the most frequently set level. Similarly, East African countries have set standards to 10 μg/kg (10 ppb) body weight. As of the 2018 published levels, Sri Lankan standards are also set to total AF level as 10 ppb and AFB1 as 5 ppb.
As per the global data, the existence of MLs for aflatoxins in foods cannot be effective in the absence of effective and efficient compliance by the private sector, coupled with enforcement by governments. Developed countries have very effective food control systems, such as the US Food and Drug Administration (FDA), which regulates across both the public and private sectors. However, developing countries have very weak enforcement by regulatory agencies and largely uncontrolled food marketing and processing systems.
Aflatoxin contamination of coconut oil: Is there significant harm?
The public is concerned and worried about whether the contaminated coconut oil that is released to the market and can cause serious health hazards if consumed unknowingly. Dr. Ariyananda stated that according to the reports, the current stock contains about 30 ppb total aflatoxin in the coconut oil (which is three times the permitted/standard level). The oral LD50 range of aflatoxin B1 is estimated to be 0.3-17.9 mg/kg body weight for most animal species and for total aflatoxin 10-20 mg/kg acute level. Considering these calculations, in order to ingest this much aflatoxin, one needs to consume 10 litres of coconut oil at once (30ug x 10 = 300ug = 0.3 mg).
However, in any meal, even if we add uncooked coconut oil to certain dishes, we don’t even add 10 ml of coconut oil to the whole portion that can be sufficient for a family of four. Sharing the dish among five people equally, you could say that one person will consume less than 2 ml of coconut oil. When it comes to frying, the total estimated amount of coconut oil consumption would be less than 1 ml.
“Therefore, it is safe to conclude that there will be no significant impact, if one has unknowingly ingested aflatoxin contaminated coconut oil. However, prolonged exposure in high levels can lead to serious health hazards,” said Dr. Ariyananda, who is also a member of the Royal Society of Chemistry, UK.
[caption id="attachment_129713" align="alignleft" width="367"]
"Chronic low-level exposure to aflatoxins, particularly aflatoxin B1, is associated with increased risk of developing liver cancer" Dr. Nuradh Joseph[/caption]
Coconut oil: Homemade vs. imported
There are certain opinions that homemade coconut oil is safer than imported coconut oil. Dr. Ariyananda revealed his opinion on this as well.
“Aflatoxin contamination of coconut oil simply depends upon the manufacturing method. Coconut oil produced via copra is the most susceptible to the aflatoxin contamination. When copra is dried over a long period of time under substandard conditions, it could grow the fungi Aspergillus with exposure to the high humidity and low heat, facilitating the formation of aflatoxin in the copra. Once the oil is extracted by pressing, dissolved aflatoxin could contaminate the oil. Whether it’s locally produced or imported, if the manufacturer does not follow good manufacturing practices, it could lead to contamination,” said Dr. Ariyananda.
However, if the coconut oil is produced via other methods, i.e., using boiled coconut milk or freezing of coconut milk, the possibility of contamination is minimal, unless it is mistakenly exposed to water. Unlike the commercially prepared coconut oils, homemade oils are not subjected to quality testing. Hence, the quality of the product cannot be assured scientifically.
Testing for aflatoxins before releasing to consumers
The Sri Lanka Standards Institute (SLSI) and Ministry of Health have strict guidelines on testing 102 food items imported to Sri Lanka, and the list is growing as new standards are added to the list. The detection of aflatoxin in food, such as corn, maize, peanuts, other grains, and spices has been done since the 1970s by Sri Lankan researchers, and the ITI (Industrial technology Institute). The standards were set to limit contaminated food reaching consumers and review it periodically, ensuring the highest possible quality.
However, there are many local producers without a proper brand name that don’t follow the good manufacturing practices or testing standards, and they do not even know if their food items are contaminated. Therefore, it is recommended to bring those small-scale manufacturers and producers under regulation to ensure they follow the proper protocols.
Selecting reliable coconut oil products
During the year 2020, the Ministry of Health with the SLMA Expert Committee on non-communicable diseases (NCDs), provided expertise to the Coconut Development Authority on developing an official certificate displaying a “certified” label on the sealed bottled coconut oils produced by local manufacturers. This was for the consumer to identify good-quality and safe coconut oil.
According to Prof. Indika Karunathilake, the Ministry of Health and CDA have jointly identified the following five criteria for eligibility to give a certificate of good quality.
"A healthy nation is an asset to a country. If the citizens are unhealthy, it leads to low productivity as well as high healthcare costs. It’s a double whammy for a country like us, which is considered as a developing nation since our independence" Dr. Piyal Ariyananda[/caption]
Aflatoxins
Aflatoxins are poisonous substances produced by certain kinds of fungi (moulds) that are found naturally all over the world. They can contaminate food crops and result in serious health threats. Aflatoxins pose a significant economic burden, causing an estimated 25% or more of the world’s food crops to be destroyed annually.
Two closely related species of fungi, Aspergillus flavus and Aspergillus parasiticus, are mainly responsible for producing the aflatoxins of health significance. Under favourable conditions, typically found in tropical and subtropical regions, including high temperatures and high humidity, these moulds, normally found on dead and decaying vegetation, can invade food crops. Drought, insect damage, and poor storage can also contribute to their higher occurrence.
Several types of aflatoxins (14 or more) occur in nature. However, four – aflatoxins B1, B2, G1, and G2 – are considered particularly dangerous to humans and animals, as they have been found in all major food crops. Most human exposure comes from contaminated nuts, grains, and their derived products. Additionally, aflatoxin M1 (AFM1), a product of aflatoxin B1 (AFB1) metabolism, can be found in milk in areas of high aflatoxin exposure.
Harmful effects of aflatoxins
According to the World Health Organisation (WHO), both acute and chronic harmful effects can occur with aflatoxins. Large doses of aflatoxins lead to acute poisoning (aflatoxicosis) that can be life-threatening, usually through damage to the liver. Adults are more tolerant to acute exposure than children. Consequences of long-term exposure to aflatoxins affect many organs and systems leading to several health hazards including cancers. Dr. Nuradh Joseph discussed its cancer-related risks.
“Aflatoxin B1 is one of the most potent carcinogens known to cause liver cancer. Although most liver cancers arise in a background of long-standing liver injury caused by alcohol viral hepatitis B or C as well as non-alcoholic fatty liver disease, there is some evidence to suggest that aflatoxin B1 interacts synergistically with viral hepatitis B in causing liver cancer,” said Dr. Joseph.
Referring to the data from the National Cancer Registry, he said that the incidence of liver cancer is rising in Sri Lanka and the number of new cases registered has risen from 340 in 2015 to nearly 600 in 2019. “However, since there is a general trend of increasing numbers of new cases across all cases, it is not known whether this rise is due to better reporting and recording of data or an actual increase in the number of cases. In addition, some cases of liver cancer are not captured in the Cancer Registry Data, as they are diagnosed with scans alone and sometimes treated with only supportive care. So, the actual number of cases of liver cancer could be much higher than what is reported by the Cancer Registry,” he said.
Emphasising the need for accurate information, Dr. Joseph said that the study on causes and outcomes of liver cancer in Sri Lanka is urgently needed. “It is important to note that alcohol, chronic viral hepatitis, and non-alcoholic fatty liver disease are the main causes for liver cancers. Alfatoxins are well-recognised carcinogens and it is imperative that all food products conform to safety standards,” Dr. Joseph concluded.
[caption id="attachment_129710" align="alignright" width="376"] "It is important to strengthen mechanisms for food safety regulations and enforcement" Prof. Indika Karunathilake[/caption]
‘Safe limits’ for aflatoxin contamination
“There’s no such safe limit per se, but since we cannot prevent contamination to the zero level and considering the lethal dose (LD50) values administered to rats, different countries have set different standards to safeguard their citizens depending on the chemicals policy and living standards of the country,” said Dr. Ariyananda. Furthermore, he explained the different maximum limits of aflatoxins around the globe.
Regulation of aflatoxin contamination in food involves formulation and enforcement of the maximum limits (MLs) tolerated in the food. Although most countries formulate their own MLs for aflatoxins in food, many of them rely on limits formulated by regional or international bodies. The US has a guideline level of 20 µg/kg, that equals to 20 part per billion (ppb) aflatoxins and the European Commission (EU), a more stringent ML of 4 µg/kg for total aflatoxins in food. In developing countries, MLs for total aflatoxins range from 10 to 20 µg/kg, with 10 µg/kg being the most frequently set level. Similarly, East African countries have set standards to 10 μg/kg (10 ppb) body weight. As of the 2018 published levels, Sri Lankan standards are also set to total AF level as 10 ppb and AFB1 as 5 ppb.
As per the global data, the existence of MLs for aflatoxins in foods cannot be effective in the absence of effective and efficient compliance by the private sector, coupled with enforcement by governments. Developed countries have very effective food control systems, such as the US Food and Drug Administration (FDA), which regulates across both the public and private sectors. However, developing countries have very weak enforcement by regulatory agencies and largely uncontrolled food marketing and processing systems.
Aflatoxin contamination of coconut oil: Is there significant harm?
The public is concerned and worried about whether the contaminated coconut oil that is released to the market and can cause serious health hazards if consumed unknowingly. Dr. Ariyananda stated that according to the reports, the current stock contains about 30 ppb total aflatoxin in the coconut oil (which is three times the permitted/standard level). The oral LD50 range of aflatoxin B1 is estimated to be 0.3-17.9 mg/kg body weight for most animal species and for total aflatoxin 10-20 mg/kg acute level. Considering these calculations, in order to ingest this much aflatoxin, one needs to consume 10 litres of coconut oil at once (30ug x 10 = 300ug = 0.3 mg).
However, in any meal, even if we add uncooked coconut oil to certain dishes, we don’t even add 10 ml of coconut oil to the whole portion that can be sufficient for a family of four. Sharing the dish among five people equally, you could say that one person will consume less than 2 ml of coconut oil. When it comes to frying, the total estimated amount of coconut oil consumption would be less than 1 ml.
“Therefore, it is safe to conclude that there will be no significant impact, if one has unknowingly ingested aflatoxin contaminated coconut oil. However, prolonged exposure in high levels can lead to serious health hazards,” said Dr. Ariyananda, who is also a member of the Royal Society of Chemistry, UK.
[caption id="attachment_129713" align="alignleft" width="367"] "Chronic low-level exposure to aflatoxins, particularly aflatoxin B1, is associated with increased risk of developing liver cancer" Dr. Nuradh Joseph[/caption]
Coconut oil: Homemade vs. imported
There are certain opinions that homemade coconut oil is safer than imported coconut oil. Dr. Ariyananda revealed his opinion on this as well.
“Aflatoxin contamination of coconut oil simply depends upon the manufacturing method. Coconut oil produced via copra is the most susceptible to the aflatoxin contamination. When copra is dried over a long period of time under substandard conditions, it could grow the fungi Aspergillus with exposure to the high humidity and low heat, facilitating the formation of aflatoxin in the copra. Once the oil is extracted by pressing, dissolved aflatoxin could contaminate the oil. Whether it’s locally produced or imported, if the manufacturer does not follow good manufacturing practices, it could lead to contamination,” said Dr. Ariyananda.
However, if the coconut oil is produced via other methods, i.e., using boiled coconut milk or freezing of coconut milk, the possibility of contamination is minimal, unless it is mistakenly exposed to water. Unlike the commercially prepared coconut oils, homemade oils are not subjected to quality testing. Hence, the quality of the product cannot be assured scientifically.
Testing for aflatoxins before releasing to consumers
The Sri Lanka Standards Institute (SLSI) and Ministry of Health have strict guidelines on testing 102 food items imported to Sri Lanka, and the list is growing as new standards are added to the list. The detection of aflatoxin in food, such as corn, maize, peanuts, other grains, and spices has been done since the 1970s by Sri Lankan researchers, and the ITI (Industrial technology Institute). The standards were set to limit contaminated food reaching consumers and review it periodically, ensuring the highest possible quality.
However, there are many local producers without a proper brand name that don’t follow the good manufacturing practices or testing standards, and they do not even know if their food items are contaminated. Therefore, it is recommended to bring those small-scale manufacturers and producers under regulation to ensure they follow the proper protocols.
Selecting reliable coconut oil products
During the year 2020, the Ministry of Health with the SLMA Expert Committee on non-communicable diseases (NCDs), provided expertise to the Coconut Development Authority on developing an official certificate displaying a “certified” label on the sealed bottled coconut oils produced by local manufacturers. This was for the consumer to identify good-quality and safe coconut oil.
According to Prof. Indika Karunathilake, the Ministry of Health and CDA have jointly identified the following five criteria for eligibility to give a certificate of good quality.
- Whether the oil is adulterated
- Whether the oil is rancid
- Whether the oil has aflatoxins
- Check the factory standards
- SLS/ISO (International Organisation for Standardisation) standards