Food Toxins. How Safe Are Our Foods?

 

  A friend of ours yesterday sent us this message in pink below through WhatsApp:

 

“China CCTV finally admitted it!  Cancer is increasing because...

The GMO grown food is shocking!

 Every Chinese person should have the right to know.

 The truth is finally out.

Large-scale tumour outbreaks are related to genetically modified foods!

 This is a decisive change: Everyone must read carefully when going to the supermarket: 

Barcodes starting with "8" are genetically modified products!

No matter how much experts advocate that genetically modified foods are harmless, we must remember the following ten points:

1. Americans don’t eat it.

2. The EU absolutely prohibits it.

3. The system of specially providing such food for Chinese officials is strictly prohibited.

4. GMO grown foods are strictly prohibited at the World Expo.

5. They are also strictly prohibited in the Asian Games

6. Africans will not import GMOs even if they starve to death.

7. They are strictly prohibited in the Universities.

8. Russia confirmed that genetically modified food has caused the extinction of animals for three generations.

9. They are prohibited in Kindergartens of the Ministry of Agriculture.

10. They are prohibited in the canteen of the Ministry of Finance.

 "Read labels clearly when buying imported fruits: 

5-digit codes starting with 8 are genetically modified products. Do not buy them." 

The labels on imported fruits are called PLU codes. The four-digit codes used generally start with "3" and "4", indicating that the crop is grown using traditional methods. 

if it is five digits and begins with "9", it is organic; 

if it begins with "8", it is genetically modified. 

 Please note that for your own good you have to educate yourself on food hygiene knowledge and do not rely on the government or enterprises!

I never ask others to forward anything, but for this article, I ask everyone to forward it, and forward it quickly!

 Show it to your family and friends. One more person will see it and one less person will be harmed. 

This relay of love should not be delayed in your hands” (End of quote)

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Allow me now to explain what I know about genetically modified foods.

The relationship between genetically modified (GM) foods and diseases, including cancer, is a topic of ongoing research and debate. First, we have regulation and safety assessments on GM foods.

GM foods undergo rigorous safety assessments by regulatory bodies such as the FDA (U.S.), EFSA (European Union), and WHO.

These assessments evaluate potential health risks, including toxicity, allergenicity, and nutritional effects.

As far as I know and have heard, currently, there is no scientific evidence directly linking the consumption of GM foods to cancer in humans. Major health organizations, including the National Academy of Sciences and the American Medical Association, have stated that GM foods are as safe to eat as their non-GM counterparts.

Long-term studies on GM foods are limited, but available research has not shown adverse health effects related to cancer.

Some studies that have claimed a link between GMOs and cancer have been criticized for methodological flaws and have not been widely accepted by the scientific community. Other health concerns about GM foods also include potential impacts on allergies and antibiotic resistance. However, these concerns are also monitored and regulated.

Public concern about GM foods often arises from misinformation or distrust in scientific institutions. Transparent communication and continued research are essential to address these concerns.

I was told in seminar presentations, GM foods are extensively tested for safety, there is currently no credible scientific evidence linking them to cancer or other diseases. Nonetheless, ongoing research and monitoring are crucial to ensure their long-term safety.
 

Food Additives:

 

Areas in food safety and food toxicology I am more interested and familiar are about all types of food additives, food preservatives, food flavours, food colours, food stabilisers, and other contaminants are added, purposely or accidentally introduced. Questions usually the public ask are what their long-term effects on health, and how do they damage our health

 

Let me try to answer this as a trained and a qualified (MSc in Food Quality Control) and a former Food and Medical Toxicologist.

 Food additives, preservatives, flavours, colours, stabilizers, and contaminants can have varying long-term health effects. We shall very briefly give an overview of potential impacts and concerns. First, we look at Food Additives and Preservatives. Their purpose is to enhance flavour, appearance, texture, and shelf life by food manufacturers to the chagrin of the nutritionist who are always at loggerheads with them

The common types of food additives added by food manufacturers are nitrates and nitrites, sulphites, benzoates, and BHA/BHT. The potential health effects are
allergic reactions to some individuals who may have allergies or sensitivities to specific additives. Certain preservatives, like nitrates and nitrites added to luncheon meat, corned beef, sausages can form carcinogenic compounds under certain conditions.

Some studies suggest a link between artificial colours and hyperactivity in children.

Natural flavours come from natural sources, while artificial flavours are synthesized.
The potential health effects are generally recognized as safe (GRAS) by regulatory bodies, though long-term effects of some artificial flavours are less well-studied.
Some artificial flavours may cause allergic reactions in sensitive individuals.

Food colours added by food manufacturers can be in the form of synthetic dyes commonly used to make foods more appealing. Their potential health effects are allergic reactions in some individuals who may react to certain synthetic dyes.
Some studies suggest a link to hyperactivity in children. More seriously is that some artificial dyes have been linked to cancer in animal studies, leading to bans or restrictions in certain countries.

As far as food stabilizers and emulsifiers are concerned, their purpose is to improve texture and consistency. Common types are carrageenan, lecithin, xanthan gum.
Generally considered safe, though high consumption of some, like carrageenan, has been linked to gastrointestinal inflammation in some studies.

Then we also encounter contaminants as such pesticides, heavy metals, plasticizers, and accidental contamination. Their potential health effects through chronic long-term exposure to contaminants like heavy metals (lead, mercury) can cause neurological damage, kidney damage, and other health issues.

They can also cause endocrine disruptors.  Some contaminants, such as certain plasticizers (BPA), can disrupt hormone function and are linked to various health issues, including reproductive problems and cancer. The long-term health effects are the risk of cancers. Some additives and contaminants have been linked to cancer in animal studies. However, regulatory bodies ensure that exposure levels in humans are far below those that cause harm in animals. Long-term exposure to certain contaminants like heavy metals can lead to neurological damage and cognitive decline.

Then we also have reproductive issues where some additives and contaminants can affect reproductive health and development besides metabolic and endocrine effects.  Some substances, particularly endocrine disruptors, can interfere with hormone function and metabolism, potentially leading to obesity, diabetes, and other metabolic disorders. Certain additives and contaminants can cause gastrointestinal inflammation and other digestive problems.

However, most countries have Regulatory Measures and Food Regulation and Monitoring. 

Here in Malaysia, we have the Food Act 1983 & Food Regulations 1985 to ensure food safety.

Food safety authorities set permissible levels for additives and contaminants to minimize health risks. In order to reduce exposure, consumers can choose whole, minimally processed foods and read labels to avoid specific additives and contaminants.

Hence permitted food additives within permissible limits can be considered safe. 

 Continuous research and reassessment of food additives and contaminants help ensure food safety.

Many food additives and contaminants are regulated to minimize health risks, potential long-term effects can vary. Ongoing research and prudent consumer choices are crucial for maintaining health.

 

Toxins in Food Preparations:

What about foods that are BBQ over open fires such as our popular satays Don’t they cause cancers or other diseases? Let’s have a look.

Grilling or barbecuing food over an open flame can produce several compounds that are considered harmful and potentially carcinogenic. The main concern revolves around the formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs). Here's a breakdown of the chemistry and toxicology of these compounds:

The chemistry is the formation of polycyclic aromatic hydrocarbons (PAHs).

PAHs are formed when fat and juices from meat grilled directly over an open flame drip onto the fire, causing flames and smoke. The smoke that results contains PAHs, which then adhere to the surface of the meat. Common PAHs include benzo[a]pyrene and dibenzo[a,h]anthracene.

Then we also have to deal with heterocyclic amines (HCAs). HCAs are formed when amino acids (the building blocks of proteins), sugars, and creatine (a substance found in muscle) react at high temperatures, typically during grilling, frying, or broiling.

 Some examples of HCAs include amino-imidazo-quinoline (IQ), amino-imidazo-quinoxaline (IQx), and amino-imidazo-pyridine (PhIP).

Foods grilled over an open fire as in BBQ meat have carcinogenic potential. PAHs compounds can bind to DNA, causing mutations that may lead to cancer. Studies have linked high levels of PAH exposure to lung, skin, and bladder cancers. An example of foods cooked under an open fire is satay, made worse when the satay is eaten with contaiminated peanut sauce made from mouldy Aspergillus flavus peanuts. 

However, an occasional consumption of satay as I have done once in a blue moon is safe, provided we do not make this as our regular dietary lifestyle. The risk of hepatocelluar carcinoma (liver cancer) is always there. 

 Similar to PAHs, HCAs can also bind to DNA and induce mutations. Epidemiological studies have suggested a link between high intake of well-done, fried, or barbecued meats and an increased risk of colorectal, pancreatic, and prostate cancers.

The mechanisms of action of these compounds lead to DNA damage.  Both PAHs and HCAs can form DNA adducts, where the chemicals bind directly to DNA. This can cause errors in DNA replication, leading to mutations and potentially cancer.

We also have to deal with oxidative stress leading to cellular damage and inflammation, both of which are associated with cancer development.

The mitigation strategies lie in cooking methods. We should avoid direct exposure of meat to an open flame or hot metal surface and avoid prolonged cooking times at high temperatures.

Pre-cook meat in the microwave or oven to reduce grilling time.

Use lower heat settings and avoid burning or charring the meat. Marinating meat before cooking can reduce the formation of HCAs. Ingredients like vinegar, lemon juice, and herbs (rosemary, thyme, oregano) are particularly effective.

Cutting and trimming excess fat to reduce drippings that cause flare-ups and smoke.

Cut meat into smaller pieces to reduce cooking time.

We can also consider alternative cooking methods such as baking, steaming, or using slow cookers to prepare meat, as these methods do not typically produce PAHs and HCAs.

Understanding the chemistry and toxicology of BBQ foods highlights the importance of cooking methods and food preparation in reducing exposure to potentially harmful compounds. By adopting safer cooking practices, one can enjoy BBQ foods while minimizing health risks.

 Microbial Food Poisoning:

While manufactured foods sold in supermarkets within their shelf lives are normally safe.

As a nutritionist-cum-clinician, microbiologist and food quality control specialist myself, we also consider problems of food poisoning known as foodborne illness  caused by consuming contaminated food mainly sold by street food vendors or even improperly cooked at home. Various bacteria, viruses, parasites, and fungi are responsible for these illnesses. Here are the main sources, microorganisms involved, and the diseases they cause:

First, we have the bacteria, the Salmonella spp. The sources of poisoning are undercooked poultry, eggs, meat, dairy products, and contaminated produce. The disease they cause is salmonellosis. The symptoms are diarrhoea, fever, abdominal cramps, vomiting. The second is Escherichia coli (E. coli) O157. The sources are undercooked beef (especially ground beef), contaminated water, raw milk, and produce. The disease they cause are haemorrhagic colitis, haemolytic uremic syndrome (HUS). The symptoms are severe diarrhoea (often bloody), abdominal pain, vomiting, and in severe cases, kidney failure.

Next, comes Listeria monocytogenes. The sources of infection are from ready-to-eat deli meats, unpasteurized dairy products, soft cheeses, and contaminated produce. The disease they cause is Listeriosis where the symptoms are fever, muscle aches, nausea, diarrhoea, and in severe cases, meningitis, septicaemia, and complications in pregnant women (miscarriage, stillbirth). Then comes the Campylobacter jejuni infection where the sources come from undercooked poultry, unpasteurized milk, and contaminated water. The infection they cause is Campylobacteriosis where the symptoms are diarrhoea (sometimes bloody), fever, abdominal cramps, nausea, vomiting.

Consider also food poisoning caused by Clostridium perfringens where the sources come from meat, poultry, gravy, and dishes left at room temperature. The disease for this is Clostridium perfringens food poisoning where the symptoms are diarrhoea and abdominal cramps. Staphylococcus aureus comes next where the sources come from improperly stored meat, dairy products, and salads (e.g., egg, tuna, chicken). The disease is Staphylococcal food poisoning. The clinical presentations are nausea, vomiting, stomach cramps, diarrhoea. Others are Bacillus cereus arising from rice, pasta, and other starchy foods that have been left out at room temperature. This causes Bacillus cereus food poisoning where the symptomatic presentations are vomiting (emetic form) or diarrhoea (diarrheal form).

Clostridium botulinum is another food poisoning. This is caused improperly canned foods, fermented fish, and other anaerobically packaged foods. This causes botulism with serious muscle paralysis, difficulty breathing, double vision, difficulty swallowing.

That’s not all. We also have viruses that cause food poisoning. First there is this Norovirus where the sources come from contaminated water, raw or undercooked shellfish, and infected food handlers. The disease it causes is viral gastroenteritis where the clinical presentations are nausea, vomiting, diarrhoea, and stomach pain.

Common in tropical countries like in Malaysia is the hepatitis A virus caused by contaminated water, raw or undercooked shellfish, and food handled by infected persons example, from hawkers.  This causes hepatitis A where the clinical presentations are fever, fatigue, nausea, abdominal pain, jaundice.

Ah, I almost forgot the parasites. Let me give you some examples of food poisoning caused by parasites. First, we have this condition called Toxoplasma gondii. This is caused by undercooked meat (especially pork, lamb, and venison), contaminated water, and produce. The disease or food poisoning is toxoplasmosis where the patient is presented with flu-like symptoms, with severe complications in immunocompromised individuals and pregnant women (miscarriage, congenital defects). Then not forgetting, as I sometimes do, we have this disease called Giardia lamblia. The sources come from contaminated water, raw produce. This parasite in foods causes Giardiasis where the symptoms are diarrhoea, gas, stomach cramps, and nausea. 

Next, comes the Cryptosporidium spp. caused by contaminated water, raw produce. The condition it causes is Cryptosporidiosis where the patients complain of watery diarrhoea, stomach cramps, nausea, vomiting.

Ah, I must also not forget the fungi (Molds). I shall mention about the Aspergillus spp. (producing aflatoxins) under Natural Toxins shortly.  

Contaminated nuts, grains, and spices caused by Aspergillus flavus causes aflatoxicosis. This is a serious disease where there is liver damage, cancer (with long-term exposure).

Ensuring proper food handling, cooking, and storage practices can significantly reduce the risk of foodborne illnesses.

Natural Toxins in Foods:

 Perhaps we should be worried about natural toxins such as aflatoxins and other mould-producing mycotoxins present in foods.  Do they cause cancers and in what ways?

These may accidentally enter into our food supply. We may have to consider their risks

Let us look at a few examples as I am familiar in this area on nutrition and medicine and when I was working as a food and a medical toxicologist with a specialist team at the Massachusetts Institute of Technology (MIT) before I joined the Institute for Medical Research in Malaysia in other areas of studies in the late 1960’s.  

Let me very briefly explain about mycotoxins, particularly aflatoxins, that are indeed potent natural toxins that pose significant health risks, including cancer. Aflatoxins are produced by certain species of Aspergillus fungi, commonly found in crops such as peanuts, maize, and tree nuts. Here is a detailed overview of aflatoxins, other mycotoxins, and various natural toxins that can enter the food supply, their risks, and their health effects, along with relevant studies:

Aflatoxins are primarily produced by Aspergillus flavus and Aspergillus parasiticus.  The most common types are aflatoxin B1, B2, G1, and G2, with aflatoxin B1 being the most toxic and prevalent. They are present especially in mouldy peanuts especially when peanuts are stored in hot humid climates like Africa and tropical countries including in Malaysia, Singapore and SE Asian countries where peanut products including peanut sauces are made. The health effects of aflatoxins are due to its carcinogenicity, especially aflatoxin B1 that is a potent liver carcinogen. It is classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC).

The mechanism of aflatoxin carcinogenicity is, it can form DNA adducts, leading to mutations. They also induce oxidative stress and disrupt cellular processes. High doses can cause aflatoxicosis, characterized by liver damage, haemorrhage, and even death.

Studies have shown a strong correlation between aflatoxin exposure and liver cancer, particularly in regions with high hepatitis B virus prevalence, which synergistically increases cancer risk. A study in China demonstrated a significant reduction in liver cancer rates following interventions to reduce aflatoxin exposure.

There are other mycotoxins also, not just aflatoxins. An example is ochratoxin A. This is produced by Aspergillus and Penicillium species, found in cereals, coffee, dried fruit, and wine. Ochratoxin A is linked to kidney damage and is a potential human carcinogen (Group 2B by IARC). There is also evidence from animal studies that show nephrotoxicity and carcinogenicity.

We also encounter fumonisins produced by Fusarium species, commonly found in maize. Its health effects are associated with oesophageal cancer and neural tube defects. Epidemiological studies in South Africa and China have linked fumonisin-contaminated maize to high rates of oesophageal cancer.

Consider also the mycotoxin zearalenone which is produced by the Fusarium species, found in maize and other cereals. This has estrogenic effects causing reproductive disorders. Animal studies show reproductive toxicity and potential links to endocrine disruption.

Another example is deoxynivalenol (DON) produced by Fusarium species, found in cereals. Its health effects cause immunotoxicity, gastrointestinal issues, and reduced growth in animals.  Studies indicate immunosuppressive effects and potential impacts on human health, particularly in children.

Other natural toxins in the food supply are the cyanogenic glycosides where the source is found in cassava, bitter almonds, and certain fruit seeds. They can release cyanide when metabolized, leading to acute toxicity, neurological issues, and even death. Chronic exposure to cyanide from improperly processed cassava is linked to neurological diseases such as Konzo and tropical ataxic neuropathy.

 Lectins are another example. These natural toxins are found in legumes such as beans and lentils. Lectins cause gastrointestinal distress and interfere with nutrient absorption. However, proper cooking significantly reduces lectin activity, minimizing health risks.

 Solanine poisoning is found in green potatoes and other nightshade plants. Its health impact is it causes gastrointestinal and neurological symptoms. Fortunately, as far as I know, it is rare in commercial food supplies, but occasional poisoning incidents have been documented. Saponins in foods are fairly common. The sources are found in quinoa, legumes, and some herbs. This can cause gastrointestinal irritation and haemolysis in high doses. Studies have shown saponin is generally considered safe with proper preparation and cooking.

The mitigation strategies are to keep foods under proper storage by keeping foods dry and at appropriate temperatures to prevent fungal growth. We also need food quality control online all the way till the foods are processed, stored and distributed into the market till how they are stored at home.

 

Food Quality and Safety Control:

 

 Food quality control starts from the farm through Good Agricultural Practices, including crop rotation, pest control, and avoiding contaminated feed for animals.

We also consider food processing, such as techniques like fermentation, cooking, and nixtamalization (for maize) can reduce toxin levels.

Last but not least we need regulation and monitoring through food laws by implementing and enforcing maximum allowable limits for mycotoxins in foods.

Understanding the risks associated with these natural toxins highlights the importance of proper food handling, storage, and processing. Awareness and regulatory measures are crucial to minimize exposure and protect public health.

Food scientists, food technologists and food engineers, analytical food chemists, food microbiologists and nutritionists working togrether with statisticians overseeing data on food quality and their control in the food industry are usually employed by all reputable food manufacturers to ensure food safety in compliance with Food Laws and Food Regulations.

Just look at the tens of hundreds if not thousands of manufactured foods sold in supermarkets.  University graduates in all these areas of food science, food technology, food chemists, food quality control, including nutritionists, etc, etc are in tremendous demand by all food manufacturers throughout the world to ensure food safety as required by food laws and regulations of every country.  

There is no escape.

Hope this article helps

 

Juboo Lim

 

Reference:

1. Liu, Y., Wu, F. (2010). Global Burden of Aflatoxin-Induced Hepatocellular Carcinoma: A Risk Assessment. Environmental Health Perspectives, 118(6), 818-824.
2. Reddy, L., Odhav, B. (1998). Mycotoxin: The Toxic Compound Produced by Moulds. Review on Biology, 3(1), 6-10.
3. Sydenham, E. W., Shephard, G. S., Thiel, P. G., Stockenström, S., Snijman, P. W., van Schalkwyk, D. J. (1996). Fumonisin contamination of commercial corn-based human foodstuffs. Journal of Agricultural and Food Chemistry, 44(1), 172-175.
4. Kuiper-Goodman, T., Scott, P. M. (1989). Risk Assessment of the Mycotoxin Zearalenone. Regulatory Toxicology and Pharmacology, 10(3), 244-264.
5. Pestka, J. J. (2007). Deoxynivalenol: Toxicity, mechanisms and animal health risks. Animal Feed Science and Technology, 137(3-4), 283-298.
6. Cliff, J., Nicala, D., Saute, F., Givragy, R., Azalio, F., Gani, A. (1997). Ankle clonus as a neurological sign in drought-affected regions of Mozambique. The Lancet, 349(9058), 1666-1671.
7. Pusztai, A. (1991). Plant Lectins. Cambridge University Press.
8. Friedman, M., McDonald, G. M. (1997). Potato Glycoalkaloids: Chemistry, Analysis, Safety, and Plant Physiology. Critical Reviews in Plant Sciences, 16(1), 55-132.
9. Shi, J., Arunasalam, K., Yeung, D., Kakuda, Y., Mittal, G., Jiang, Y. (2004). Saponins from Edible Legumes: Chemistry, Processing, and Health Benefits. Journal of Medicinal Food, 7(1), 67-78.