Heavy metals in food: can they be avoided? I will answer at once: it is impossible. But you need to, as they say, know the enemy and eat wisely.
Most often, the term “heavy metals” is a common name for the metals cadmium, mercury, lead, arsenic and tin in the environment. They are released into the environment, for example, through the extraction and storage of metals, the production of paint and the combustion of coal and waste. Heavy metals can also be found in fertilizers. Lead can come from lead pipes in old buildings and tin comes from tinned foods. (The coating on the inner surface of the can ensures that the tin does not seep into the food, so it is only in case of damage that tin can leak into the food).
Why heavy metals occur in food
Heavy metals bind to clay. This pollutes rivers, oceans and finally fish. Plants absorb heavy metals from soil, air and water. Animals get heavy metals through water and food. Therefore, meat and other animal products contain heavy metals. It is inevitable.
The following products may have elevated levels of heavy metals:
- Seafood like lobsters, crabs, mussels, squid;
- Predatory fish such as swordfish, shark, tuna, king mackerel, eel;
- Animal organs, especially kidneys and liver;
- Vegetables that grow on open grounds: cabbage, carrots, leafy vegetables, roots;
- Other foods of plant origin from the open ground: potatoes, legumes, cereals;
- Rice and rice products;
- Mineral supplements.
Health effects of heavy metals
Prolonged excessive consumption of heavy metals can damage the human kidneys, liver, brain and nervous system.
Heavy metals can bind to cells in the human body that actually need to bind to iron and calcium. As a result, the amount of iron and calcium in the blood decreases, which can end in anaemia or osteoporosis.
As for arsenic and cadmium, it is well known that long-term excessive consumption increases the risk of skin and lung cancer.
In the Netherlands, where I live, specific measures are being taken to reduce heavy metal pollution. These measures include the introduction of unleaded gasoline, the replacement of lead pipes, a ban on dyes (yellow) that contain cadmium. And, of course, there is strict food control. In this way, the state ensures that the risk of excessive consumption of heavy metals is very small.
The European Food Safety Authority (EFSA) has established a tolerable daily intake (TDI) for the heavy metals cadmium and mercury. Recently, the TDI for uranium has been established too. Particularly, mineral water can be a source of uranium. Lead and arsenic are so toxic that no tolerable intake can be established. Lead and arsenic exposure should be as low as possible. Tin is not very toxic, so no TDI has been established for it.
Children can ingest somewhat higher amounts of heavy metals due to their lower body weight, but what matters is what people ingest during the course of their lives.
In the EU the maximum permissible content of heavy metals in foods is regulated. These figures are indicated separately for various foods such as fish, seafood, meat, rice, other cereals, vegetables. The content of heavy metals in drinking water is also regulated.
So, how to eat now???
I wrote this article not to scare you, but to make you eat a variety of foods. After all, the most important advice on how to protect yourself from heavy metals is to eat a variety of foods. This approach prevents you from getting the same heavy metal every day by accident.
Next, do not eat canned food if the coating of the tin is damaged. A small scratch on the tin is not harmful.
Eat garlic regularly. Its regular consumption can help the detoxification of heavy metals in the body. A 4-week study involving 117 car battery plant workers (who were over-exposed to lead by the nature of their work) found that garlic reduced lead levels in the blood by 19%. It also reduced the number and frequency of clinical signs of toxicity, including irritability, headache, and blood pressure. The drug D-penicillamine, used in the control group, failed to reduce these symptoms. Garlic also had far fewer side effects than D-penicillamine. Thus, garlic was much more effective in cleansing the human body of lead than a pharmaceutical drug.
If you are pregnant or wish to become pregnant, then you are better off not consuming predatory fish such as swordfish, pike, perch, shark, eel, tuna and king mackerel. These fish have too much mercury. This applies to both fresh and canned predatory fish.
In general, it is advised not to eat more than four servings of fish per week. It is also recommended to consume different varieties of fish.