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:
CIGUATERA SCOMBROID TETRODOTOXIN and MERCURY

The most common varieties of shellfish poisoning include:
PARALYTIC, DIARRHEAL AMNESIC and NEUROTOXIC

CIGUATERA POISONING

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 POISONING

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.

TETRODOTOXIN POISONING

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.

MERCURY POISONING

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.

PARALYTIC SHELLFISH POISONING

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.

NEUROTOXIC SHELLFISH POISONING

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.

AMNESIC SHELLFISH POISONING

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.

DIARRHEAL SHELLFISH POISONING

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 AIMS.gov.au
Professor Richard Lewis www.IMB.UQ.edu.au
Dr. Hwang Deng-Fwu www.Toxin.NTOU.edu.tw
Dr. Yang Chen-Chang www.VGHTPE.gov.tw

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.