What is cadmium and what foods have it?

Cadmium is a heavy metal found in the environment due to its release as a by-product derived from industrial activities. It is also used in fertilizers so it can pollute agricultural crops and it can accumulate in terrestrial and marine animals, especially in shellfish and crustaceans, as well as in the viscera of other animals (liver, kidneys, etc.).

The main danger of excessive consumption of cadmium is its toxicity in our body since it is a metal that tends to accumulate in organs such as liver and kidney, affecting their functions and causing serious long-term illnesses.

Therefore it is necessary know which foods of our habitual consumption contain large doses of this metal to minimize its consumption and avoid high exposure in order to

Risks of consuming cadmium for our health

The highest percentage of cadmium present in the body accumulates in the kidneys, lungs and liver for an estimated time of 10-30 years.

The people most vulnerable to its effects are considered to be those who suffer diabetes and / or kidney dysfunction. In addition, its absorption capacity is higher in infants and children, being also a metal that is easily transmitted during pregnancy and lactation.

Kidneys and liver

The kidneys are the main target organ since the toxicity of this metal affects the proximal tubules causing, indirectly, disturbances in calcium metabolism (demineralization of bones, osteoporosis and spontaneous bone fractures).

In the case of a prolonged and high exposure to cadmium, tubular damage, nephropathy and kidney dysfunction can also occur that can evolve into kidney failure and cancer. In fact, according to the International Agency for Research on cancer (IARC) cadmium has been classified as a Category 1 carcinogen (It can induce the development of bladder, endometrial and breast cancer) in addition to being considered an endocrine disruptor.

Digestive problems

Acute toxicity can cause symptoms after a high intake of this metal such as acute abdominal pain, nausea, vomiting, diarrhea, headache and / or vertigo.

What foods contain the most cadmium?

Viscera of animals, crustaceans and shellfish

The animal entrails are the organs with the highest content of this metal, being the kidney the organ that accumulates the most cadmium followed by liver and other offal. Regarding the Marine animals, we found high levels of this metal in crustaceans and shellfish such as prawns, spider crabs, prawns or crabs.

The risk of consuming this type of food in excess lies in the fact that we usually consume almost all of this food, including viscera, heads and the meat inside the shell of crabs.

Vegetable products and cereals

On the other hand, the cadmium contained in certain plant-based products such as seaweed, especially wakame, and nori seaweed (used to make sushi), cocoa, wild mushrooms, cereals, and oilseeds.

In general, these foods contain lower cadmium content than shellfish. In the case of cereals, because it is a food whose intake is much higher in our diet, it can lead to a increased exposure to this metal so it is considered the food group that contributes the most cadmium in the total of our daily intake.

Even so, its usual intake does not carry the same cadmium intake as that which would occur with sporadic consumption of shellfish and crustaceans, so it is not necessary to specify a limit on its consumption.

How to minimize its consumption?

According to the EFSA (European Food Safety Authority) a Tolerable Weekly Intake limit of Cadmium is established 2.5µg per kilo of body weight in healthy people. This limit, therefore, could be 0.187 mg for an adult weighing 75 kg, while for a child weighing 35 kg it would be 0.084 mg.

Hence the importance of the population limiting, as much as possible, the habitual consumption of foods with a higher content of this metal:

• Heads of prawns, prawns, crayfish and the body of crustaceans such as crab, spider crab or crab.
• Viscera (kidney, liver and other offal) of veal, pork and other meats commonly consumed.

As for the rest of foods that may contain a lower cadmium content, it is not necessary to reduce their intake since there are laws to establish maximum limits of cadmium for their commercialization (as is the case of cereals).

Likewise, human exposure to cadmium can be minimized by other actions such as:

• The reduction of global emissions of environmental cadmium from industrial activities (mining, metallurgy, etc.)
• (washed and peeled) of fruits, vegetables and tubers that have been exposed to this mineral. In this sense, it would be convenient to prioritize the consumption of organic vegetables and fruits since their production does not involve the use of cadmium fertilizers.
• The elimination of the use of cadmium in products such as toys, jewelry and plastics.
• Avoid active and passive inhalation of tobacco smoke as it is considered the prevalent source of exposure in smokers.

• The main danger of an excessive consumption of cadmium is its toxicity in our organism since it is a metal that tends to accumulate in organs such as the liver and kidney.
• The foods with the highest content of this metal are: prawn heads, prawns, crayfish and the body of crustaceans such as crab, spider crab or crab. As well as, offal (kidney, liver and other offal) of veal, pork and other meats commonly consumed.
• Hence the importance of the general population and, especially the child population, limiting, as far as possible, the consumption of these foods.

Judith Torrell

Diploma in Human Nutrition

Clinical Nutrition Specialist