Healthy Living
Deadly Poisonous: Hidden Risks in Fish and Shellfish      
Next I will talk about the tropical sea fish toxin. It is found in fish in the tropical, subtropical, and temperate zones. Eating these fish, even if caught alive, and cooked immediately, could lead to food poisoning.

Welcome veg-embracing viewers to another episode of Healthy Living. Today we present part one in our two-part series on seafood poisoning which is caused by consuming fish or shellfish tainted with toxins. In the USA it is the primary cause of foodborne illness.

Typical symptoms of seafood poisoning include nausea, vomiting, gastroenteritis, muscle aches, and in the most serious cases, death. With globalization making it possible for contaminated marine life to be sold in markets worldwide, no one who consumes seafood is free from this dangerous threat.

There are eight main types of fish and shellfish poisoning. The most well-known involving fish are:

The most common varieties of shellfish poisoning include:


We start with ciguatera which is caused by ciguatoxins, a poison produced by algae called dinoflagellates, which are found across the world. During summer months, the dinoflagellates proliferate in coastal waters creating what are known as algal blooms. Their population size may become so great that the waters appear red in color because of the pigment in the algae, a phenomenon known as “red tides.”

Ciguatera comes from microscopic algae which grow upon the surface of coral and other larger algae. And that gets consumed by herbivorous fish and it goes up through the food chain. The toxin accumulates within the flesh of the larger fish. That’s what people tend to consume and they become poisoned after eating that.

Ciguatera, the most common type of fish poisoning worldwide, may be contracted from eating tropical reef fish, such as grouper, snapper, sea bass, and parrotfish as well as farmed salmon. Each year an estimated 50,000 cases occur globally. A total of 400 marine species are known to bioaccumulate ciguatoxins, which are 1,000 times more lethal than arsenic.

The illness is marked by such symptoms as severe gastrointestinal distress, nausea, abnormally low heart rate, convulsions, and blurred vision to name just a few. Relapses can occur by consuming seafood, chicken, pork, coffee or alcohol and may happen for years after eating the tainted fish.

Ciguatoxins are resistant to heat and cold, so cooking, smoking, refrigerating, freezing and/or curing the poisoned fish cannot protect a consumer from becoming sickened. It is also undetectable as the toxin is odorless and tasteless.

When a person eats a ciguateric fish and gets ciguatera, the symptoms come on after about one to six, even up to 24 hours and then you can get up to 30 or even more different symptoms from this one poisoning event.

And these range from your common food poisoning symptoms like vomiting and diarrhea, as well as nausea and gut pains to non-specific effects; you get fatigue, you get muscle aches, joint aches and then a wide range of neurological symptoms including bizarre temperature reversal that causes pain on contact with cold objects, but also you get numbness and tingling in the extremities.

You get a whole range of things like itching that jumps around the body. Ciguatera is one of the worst food poisonings, because the symptoms last for weeks, months and sometimes even years. So this very long, protracted illness makes people wonder, and often they don’t even get diagnosed properly.


Scombroid, the second most widespread type of fish poisoning after ciguatera, is the result of ingesting decayed fish, with symptoms sometimes appearing within minutes of consuming the flesh. Fish that may carry scombroid include Sardine, Anchovy, Herring, and Amberjack.

Among all the marine toxin poisoning, the most common one in Formosa (Taiwan) is scombrotoxin fish poisoning, also known as histamine fish poisoning, resulting from consuming dark meat fish, such as Mackerel, Marlin, Bonito, and Tuna. This kind of fish contains histidine, so if they are not properly stored, the bacteria will turn histidine into histamine.

When it’s combined with other amines such as putrescin, or cadaverine, it will cause symptoms similar to histamine poisoning, including rash, fever, dizziness, headache, upset stomach, vomiting and hives. Such cases have happened every year in Formosa (Taiwan) in the past few years.

Some other possible consequences of scombroid poisoning include burning sensations around the mouth, facial flushing, and abnormal heartbeat. Cooking or freezing a fish will not neutralize the toxin.


Pufferfish naturally have tetrodotoxin in their bodies and poisoning may occur after one eats “Fugu” or a Japanese dish made of Pufferfish. Tetrodotoxin is one of nature’s most fatal poisons and is 10,000 times more potent than cyanide. If an adult consumes just 0.001 milligram of the substance, the outcome could be deadly.

The mortality rate for tetrodotoxin-sickened individuals is estimated to be up to 50%, and no antidote is known to exist. Cooking or freezing the fish does not remove its toxic properties and the amount of poison in just one Pufferfish could kill 30 adults. Besides Pufferfish, Ocean Sunfish, Triggerfish, and Porcupine Fish contain tetrodotoxin. These species can be found in tropical and semi-tropical waters across the globe.

Cases of Pufferfish poisoning have also been found in Formosa (Taiwan) and occasionally in other countries in the world. It’s not very common, but it happens occasionally. The Pufferfish is actually very toxic. It has a kind of neurotoxin element.

Pufferfish poisoning happens when people catch Pufferfish and eat it. The symptoms caused by Pufferfish poisoning include numbness in the mouth and in the tongue. In the more serious cases, the numbness might extend to the limbs and cause respiratory failure and death.

Tetrodotoxin can kill. At the moment, there’s no real way of treating them apart from some form of first aid, or trying to get the toxin out of the person’s stomach so no more of it can get taken up. Some cases you can consume activated charcoal which can be used to try and absorb the toxin and prevent it being taken up through your stomach and the rest of your gut. But if you get a significant dose of those toxins it is fatal.

The tetrodotoxin blocks a protein in our nerves called the sodium channel. This is a protein that allows sodium ions to go across the nerve membrane and that is how we create biological electricity in our bodies. So of course if you close that sodium channel and prevent your biological electricity from working, basically your nervous system and other tissues like your muscles just literally shut down. And so because of that, you’ll die.

Tetrodotoxin is not just found in fish. Some gastropods, a type of mollusk, also produce this poison.

Regarding the tiny gastropods smaller than a thumb, not only is their meat poisonous, but also their intestines. Lots of poisoning cases have occurred in Formosa (Taiwan), such as in Pingtung. Eating more than ten of these tiny gastropods could cost you your life. It also happened in Dongshan Island. Depending on the intensity of the toxin, sometimes eating two is enough to be fatal. You see, the gastropods are only that big, yet two of them can get you killed.


Methylmercury is a neurotoxin and is the most lethal form of mercury, an element which occurs naturally, but can also enter the environment though industrial emissions from sources like coal-burning plants. A joint Harvard University, USA and US Geological Survey study published in 2009 concluded that mercury-laden emissions from industrial activity get into the oceans, are changed into methylmercury by bacteria and then bioaccumulate in different ocean species.

A mother who consumes mercury-contaminated fish or other seafood puts their fetus at high risk of birth defects including mental retardation, cerebral palsy, blindness and deafness. In adults, mercury poisoning from seafood can cause memory loss, tremors, vision loss, heart disease, and death. Like other toxins, mercury is undetectable in fish as it is odorless and tasteless.


Saxitoxin causes paralytic shellfish poisoning and is produced by dinoflagellates. The toxins in these algae become accumulated in the bodies of filter feeders like clams, oysters, and scallops. Saxitoxin-tainted shellfish are found globally, but most often in temperate waters.

There is another kind of marine toxin poisoning, paralytic shellfish poisoning, which is not common but has happened in many countries. We know from its name that it’s resulted from eating shellfish, such as Coelomactra antiquate. The toxin of shellfish is about the same as tetrodotoxin. After eating it, it will poison our nervous system. It can also cause numbness in the mouth, the tongue and the limbs.

In the most serious poisoning cases, muscle paralysis and respiratory failure may occur followed by death within two to 25 hours.


Brevetoxins are responsible for neurotoxic shellfish poisoning and come from dinoflagellates. Consuming contaminated oysters, clams, or mussels can lead to gastrointestinal upset, tingling in the mouth, arms and legs, incoordination, and even temperature reversal like with ciguatera.


The toxin associated with amnesic shellfish poisoning is from a type of red-brown algae that is found in the oceans surrounding Europe, North America, East Asia and Southeast Asia. The less severe effects of poisoning include dizziness, headache, and disorientation, but amnesia and death may also occur.

Other toxins are things like domoic acid, which is the cause of amnesic shellfish poisoning, which is a rare occurrence. But as you can tell from the name what it does is it affects the human brain and people actually forget about what’s happened.


Another syndrome is something called diarrhetic shellfish poisoning. Obviously again from the name, it causes very bad diarrhea and that’s caused by a toxin called okadaic acid. And again, that comes from a microscopic algae that can form these blooms that people see as part of red tides.

It has a very difficult to treat diarrhea problem in that it causes the epithelium of people’s gut linings to actually slough off, so it’s not like something you can rush down to the chemist and get an anti-diarrhetic to try and deal with it. It’s quite a severe form of diarrhea.

As we have seen today, the risks associated with consuming fish and shellfish are extremely high and the possible devastating results include death. Doctors Lyndon Llewellyn, Hwang Deng-Fwu and Yang Chen-Chang, and Professor Richard Lewis, we thank you for taking time from your busy schedules to discuss the issue of seafood poisoning and the toxins hidden in marine life. May humankind soon stop eating all animal products and instead adopt the safe, nutritious and delicious organic vegan diet.

For more details on the experts featured on today’s program, please visit the following websites
Dr. Lyndon Llewellyn
Professor Richard Lewis
Dr. Hwang Deng-Fwu
Dr. Yang Chen-Chang

Treasured viewers, please join us again next Monday on Healthy Living for part two of our program on the hazards of eating fish and shellfish. Coming up next is Science and Spirituality after Noteworthy News. May Heaven bless you with everlasting vitality and well-being.
Halo concerned viewers and welcome to Healthy Living. Today we present part two in our two-part series on seafood poisoning, which is caused by consuming fish or shellfish tainted with toxins.

In the US seafood poisoning is the primary cause of foodborne illness. Typical symptoms of the condition include nausea, vomiting, gastroenteritis, muscle aches, and in the most serious cases, death. With globalization making it possible for contaminated marine life to be sold in markets around the world, no one who consumes seafood is free from this dangerous threat.

Last week we covered a number of well-known types of seafood poisoning, including ciguatera, the most common form of fish poisoning in the world.

Ciguatoxins are resistant to heat and cold, so cooking, smoking, refrigerating, freezing and/or curing the contaminated fish cannot protect a consumer from becoming sickened. It is also undetectable as the toxin is odorless and tasteless.

With something like ciguatera, one of the things that people do need to understand is that it’s a mobile toxin. It’s taken up by fish; those fish can travel long distances and they can travel long distances by swimming or being put on a ship or a plane and being transported elsewhere. The barriers are breaking down and seafood is being moved around the world at an extraordinary rate.

In the last 200 years, scientists worldwide have identified five or six types of ciguatoxin, which accounts for only half of the various types of ciguatoxin. The constituents of the rest still can’t be analyzed by modern technology. From this you know that ciguatoxins are very mysterious and complex. There are still some toxins that we do not know about.

Some of these toxins are water-soluble, and some fat-soluble. They are mainly found in the coral reefs. The toxins may originate from bacteria, algae, or plankton algae in the coral reefs. The macroalgae residing in the coral reefs are eaten by the fish and the toxins thus stay inside the bodies of herbivore and carnivore fish and are subsequently consumed by humans.

Ciguatera poisoning cases that occur in China or Hong Kong are always very serious, because the fish are usually the bigger ones weighing about 100 kilograms each. In Hong Kong, the restaurants usually buy the whole fish and serve it all at the same time to about 50 to 100 people. So, all these people would suffer from the poisoning at once.

Some sea species self-produce toxins for protection. For example, the skin and organs of the Pufferfish are extremely dangerous as they have tetrodotoxin, a substance which is 10,000 times more potent than cyanide. Consequently handling or eating a Pufferfish can be fatal. Fishing is another activity that can lead to death as physical contact with hazardous marine species is a possibility.

The toxins of some marine animals are not only fatal through ingestion, but also by contact. As there are poisonous snakes on land, there are poisonous snakes in the sea and they are just as deadly. In addition to poisonous snakes, lots of animals in the sea are very poisonous.

It is common knowledge in Formosa (Taiwan) that the Stingrays are the most deadly, followed by the Striped Eel Catfish. The third most poisonous is a kind of squid called Rockfish, and the fourth kind is what we call “Stink Belly Fish,” which is in the north and in the south we have the Spotted Scat Fish.

These are the five main kinds of poisonous fish in Formosa (Taiwan). If stung by the first two or three kinds, it could be fatal because their toxins are the same as poisonous snakes. They could kill you by dissolving your hemoglobin, resulting to hemolytic symptoms.

A bacteria called vibrio parahemolyticus is found worldwide in areas with brackish saltwater and is from the same bacterial family that causes cholera. If one eats seafood contaminated with vibrio parahemolyticus, gastroenteritis may occur. These bacteria can enter the body by touching marine life as well.

People who fish for Elops (ladyfish) can get stung by the fish, and their hands would swell terribly. The records of the Mackay Memorial Hospital show that they have treated more than a dozen such victims and five or six of them died. However, their death was not caused by the fish toxin. Scientists discovered that it was due to a kind of bacteria called vibrio parahemolyticus in the sea.

The symptoms of this kind of infection resemble that of tetanus. Together with the fish toxin, the bacteria enter the blood and then the muscles, and then the brain, causing meningitis. The victims would die in two or three days. At present there is no antibiotic available for the treatment of vibrio parahemolyticus. Once infected, the victim would die in two to three days. So we must be very careful. Don’t take a fish sting lightly.

Some take fish liver oil supplements, thinking it is good for the eyes. This is an incorrect notion, as the supposed vision-improving properties of the oil have not been scientifically proven.

About fish liver oil, at our clinic, many parents ask us if they should feed their children fish liver oil to help improve the health of their eyes, as fish liver oil contains vitamin A. Why don’t we recommend eating fish? It’s because our entire ocean is polluted now, including our fresh waterways.

The pollution is very severe. There is a lot of mercury and environmental hormones in the water, so all the fish have accumulated a lot of heavy metal pollutants and environmental hormones.

In fact the belief that eating fish is good for our eyes has no scientific basis.

If we want our children or ourselves to have good eyes, we can get the necessary nutrients from plants. These food sources are safer because they have less contaminants. This is what we recommend for eye care.

Usually, the most poisonous fish are the bigger ones, weighing more than three or five kilograms. The toxin is usually in the liver. They could also be carrying a concentrated amount of vitamin A, such as in the case of tuna or muraeninae fish, and thus capable of causing vitamin A poisoning.

Actually, plants are very rich in vitamin A. The vitamin A in veggies is in the form of beta carotene, which can be transformed to vitamin A by our body. So, if we eat veggies that contain beta-carotene and let the body transform it into vitamin A, this is a safer way to get this vitamin. Why so? If we get vitamin A directly from foods, the excessive amount will accumulate in our bodies, because vitamin A is a fat-soluble vitamin. When we accumulate too much, it will cause symptoms of poisoning.

Most consumers are not aware that they have been poisoned, so they don’t go to see a doctor. The symptoms are similar to influenza, so doctors often misjudge and treat it as influenza. Usually it takes a week for doctors and patients to figure out that it is vitamin A poisoning caused by eating fish liver when rashes appear and the skin starts to peel.

Some consume fish oil supplements, which are derived from the tissues of oily fish, in the mistaken belief that they are beneficial to the heart as the oil contains omega-3 fatty acids.

Several experiments, including the DART-2 (Diet and Reinfarction Trial) study in the US have shown that those who take such supplements actually fare worse in terms of heart health as compared to those who do not take such products. Dr. Liu Teng-Chieh says that plant-based sources are superior to fish oil for acquiring DHA (docosahexaenoic acid), an omega-3 fatty acid.

We can also get DHA from seaweed. Actually, our bodies can make DHA. For example, if we consume alpha-linolenic acid (ALA), which is an essential fatty acid, our bodies can convert it into DHA. What kinds of food are rich in ALA?

Examples of ALA-rich foods include soybeans and nuts such as cashews and walnuts, etc. Flaxseeds also contain a lot of essential fatty acid ALA, which can be transformed into DHA by our bodies. So, if you want your children to have better eyes and strong and healthy bodies, you can feed them seaweed, nuts, soybeans, etc.

Dioxins are toxic substances that cause reproductive and developmental disorders, cancers and immune-system damage in humans. The World Health Organization says more than 90% of dioxin exposure in humans comes from consuming animal products, including eggs, fish and shellfish.

Dioxin pollution can be found on land and in the ocean and it happens all over the world, not just in Formosa (Taiwan). Similarly, dioxins can contaminate fish through bioaccumulation. Dioxins can stay in our bodies for a long time. They stay in a fish’s body for almost all of its life. So once we humans or fish consume dioxins, they stay in the body.

Dioxins are a primary cancer hazard. They can cause cancer and immune system disorders. One of the most famous cases regarding dioxin contamination happened a few years ago. It was found that farmed salmon contained especially high levels of dioxins. Only a few cases like that have been exposed and there may be others that have not been exposed.

To conclude today’s program, we feature someone who experienced shellfish poisoning who shares how the event totally changed her life.

About 10 years ago I had an allergic reaction to eating oysters and my face became swollen and red. I sought treatment from doctors at various hospitals: China Medical University Hospital, Jen-Ai Hospital, Kuang Tien General Hospital, and Tungs’ Taichung MetroHarbor Hospital… I also tried small clinics but my condition didn’t improve. For more than one year I went to different places, for two or three months each, but nothing helped me.

Finally, after some thinking, I prayed to the Buddha. I said, “From now on, I am not going to take any medicine or apply any ointment. Please help me and let my face recover. I will begin to be a full vegetarian.”

Indeed, after I embarked on the vegetarian diet the redness on my face vanished. I have been a full vegetarian for 10 years now. My skin is fine and my health is good. I feel very light and nice.

We sincerely thank Doctors Lyndon Llewellyn, Hwang Deng-Fwu, Yang Chen-Chang, and Liu Teng-Chieh for sharing their expert opinions on the issue of seafood poisoning and the toxins hidden in marine animals. To avoid the health conditions we’ve covered in our two-part series, please embrace the healthful, organic vegan diet which provides all the necessary nutrients needed for lifelong strength and vitality.

For more details on the experts featured on our program, please visit the following websites
Dr. Hwang Deng-Fwu
Dr. Liu Teng-Chieh
Dr. Lyndon Llewellyn
Dr. Yang Chen-Chang

Thank you for joining us on today’s episode of Healthy Living. Coming up next is Science and Spirituality, after Noteworthy News. May we always enjoy the highest of spirits and everlasting well-being.

  Simple Steps toward Better Global Health: Dr. Juan Garay 
 A Diabetes-Free World 

Most popular
 Dr. Neal Barnard:Eating Right for Cancer Survival
 Dr. T. Colin Campbell's The China Study: Reducing Risk of Disease through a Vegan Diet
 Australia’s Mission X: Finding Health & Happiness
 The Coronary Health Improvement Project: Promoting the Vegan Lifestyle
 Dr. Pam Popper on Corporate Wellness and School Nutrition
 Glow with Gifts from Nature: Living on Raw with David Wolfe
 Functional Foods for Vitality: An Interview with Dr. Vargas of Colombia (In Spanish)
 Dr. Joan Borysenko: Mending Mind and Body
 Vegan Nutrition with Dr. Eric Slywitch
 Dr. Steve Blake - Promoting A Natural Way of Life