Updated 01 August 2017

Five foods that could kill you

Find out which foods you should avoid if you want to stay alive.


A famous Japanese actor died in 1975, shortly after enjoying a meal of pufferfish. More recently, a 15-year-old girl died after kissing her boyfriend, who had just snacked on peanuts. And in 2003, nine students from Botswana died after consuming methanol-spiked drinks.

Eating forms an integral part of our lives – food nourishes the body and eating is also extremely enjoyable. But the foods we eat can pose health risks. And when we make the wrong choices, it can be lethal.

Be aware of the following poisonous "treats":

1. Pufferfish
Pufferfish, or "fugu", is a popular Eastern delicacy with a twist: if handled incorrectly during preparation, one bite could kill you. In fact, it's estimated that the poison contained in pufferfish, called tetrodotoxin, is 1 200 times deadlier than cyanide.

Yet millions of diners around the globe gamble with their lives every year. For many, there seems to be a thrill in eating a dish that's both delicious and possibly life-threatening. Fortunately, strict control with regards to harvesting and preparation has lowered the incidence of deaths related to fugu.

There are more than a hundred different types of pufferfish, which can be found in waters worldwide. The poison is contained in the internal organs – particularly the liver and ovaries – of the pufferfish.

Only specially licenced chefs, who know exactly how to process the fish so that the edible parts don't contain any poison, are allowed to serve the delicacy. The fish is popular in Japan and Korea, and is gaining acceptance in other parts of the world, such as the United States.

2. Poisonous mushrooms
Most types of mushrooms are harmless. If you buy your mushrooms at a reputable grocer, you don't have to give their safety a second thought.

But picking your own mushrooms can be dangerous – especially since poisonous mushrooms are often difficult to recognise. Some of the poisonous varieties can affect the nervous and cardiovascular system and may even cause death.

Note that poisonous mushrooms readily occur in South Africa. For example, "death cap" (Amanita phalloides) – probably the most lethal mushroom – can be found in the Western Cape, Gauteng and KwaZulu-Natal. It's often found in forests and under trees.

Worldwide, this mushroom causes approximately 90% of deaths related to fungal poisoning.

The problem is that, for the first few hours after ingestion, no symptoms of poisoning are apparent. By the time the symptoms are recognised, major organ damage may already have occurred.

3. Shellfish affected by red tides
Red tides (dinoflagellate blooms) are regular seasonal phenomena that occur on the west coast of South Africa. These blooms, a type of algae that serve as food for shellfish, may discolour the sea to various shades of brown, orange, purple, yellow or red.

According to Cape Town toxicologist Dr Gerbus Müller, the majority of blooms are non-toxic, but toxin-producing species, such as Alexandrium catenella and Dinophysis acuminate occur locally. Mussels, oysters and other bivalve shellfish strain these from the water, digest them, and accumulate their poison.

The shellfish themselves do not seem to be harmed by the poison, but are toxic when eaten. Shellfish affected by red tides can be extremely poisonous. It may cause paralysis and has been known to kill humans.

4. Peanuts
People who are allergic to peanuts know that ingesting even minute quantities of these nuts could be dangerous. But unfortunately, it's not just a question of steering clear of these tasty snacks.

There are three problems:

  • Many foods, which don't obviously contain peanuts, do contain traces of the nuts simply because they've been manufactured in factories where nuts are processed.
  • Labels often don't clearly state whether products have been produced in factories where nuts are processed. The fact that food labels aren't properly regulated in South Africa contributes to the problem.
  • Anyone who hasn't been previously allergic to peanuts can develop such an allergy at any point in his or her lifetime. Over time, this allergy can also become life-threatening.

So, no one can really rest assured.

The most common symptom of peanut allergy is acute hives. However, some patients may rapidly develop a more severe form of hives, swelling of the face, breathing problems, heart failure and even death.

5. Drinks spiked with methanol
In recent years, there have been reports of students who spiked each other's drinks with methanol – a dangerous form of alcohol. This chemical can cause blindness and lead to death.

Although the substance isn't readily available to the average consumer, it can be found in chemical laboratories and in industrial settings or farm storage rooms. For this reason, methanol poisoning is mostly associated with break-ins, where illegal access to methanol is gained.

Methanol initially has the same effect on the body as ethanol, the alcohol found in alcoholic drinks. The problem with methanol is that the body tries to break it down in the same way as ethanol is broken down. Unfortunately, in the case of methanol, the metabolic byproducts are highly toxic.

As little as 4ml (less than a teaspoon) of pure methanol can cause blindness. Larger amounts – in the range of 10-30ml – can be fatal.


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