Nothing is as easy as opening a can of tuna or any other canned fish to eat a portion of this type of food without further preparation. But is it healthy to consume canned fish? And do it often? What happens to methylmercury? Is there a danger from lead?
Canned fish is an understandable choice in homes because you save what fresh fish requires to preserve it well and cook it. However, doubts may arise about whether it affects our health in any way. And here we analyze this question, which one is healthier, what the differences between its different types, and how much we can eat per week?
Canned fish, are they good or bad?
The first thing we must be clear about is that the food controls to which products such as canned fish are subjected, in compliance with the legislation, are very strict, which should give us sufficient confidence; Whether we’re talking about mackerel, sardines, anchovies, bonito, tuna or whatever.
Before being stored in airtight aluminum, tin and glass containers, they are cleaned and sterilized at 100°C, which destroys any possible germs and cancels the enzymes that can degrade them. And they remain without problems in their packaging for between 3 and 5 long years.
In this way, its nutritional and organoleptic qualities do not disappear, which is why canned sardines are as good as those that are usually roasted on a spit, and provide us with the same excellent proteins and appropriate amounts of vitamins and minerals. But we must take into account some considerations.
Which canned fish is healthier
In principle, since canned fish do not differ nutritionally from fresh fish in any significant way, they will be healthy to a greater or lesser extent on their own. For example, if you are looking for the highest quality proteins, sardines, hake, cod, and tuna are a convenient choice.
If you are interested in those that provide more omega-3 fatty acids, mackerel, anchovies, trout, salmon, and, again, tuna stand out in this regard. And sardines, again, mussels and mackerel themselves, due to their smaller size, accumulate less mercury. But how they are preserved also influences.
Natural, pickled or in oil: differences
Canned fish is usually packaged in three ways: naturally, with water only; pickled, with vinegar, salt, and, perhaps, seasonings such as onion or garlic and aromatic herbs; or in olive and sunflower oil. Choosing one or the other depends on what is needed.
Natural fish
Naturally, of course, it is free of fat and caloric intake in the case of those preserved in oil because it is limited to introducing the food into the crystalline liquid. But never the corresponding percentage of salt.
Fish in oil
Apart from the aforementioned salting, very common as a preservative method, we must not forget the lipids and calories provided by both olive and sunflower oil; and with tuna, commonly consumed like this, they even double.
Pickled fish
The acidity of vinegar, which is made precisely with the acid fermentation of wine and is sour and astringent with its acute dryness and bitterness, is what is relevant about pickle, on the other hand. But this procedure does not lack the blessed salt either.
Canned fish oil
The most common recommendation is to choose naturally packaged fish to get rid of the added calories. But, if you still decide to choose the one preserved in oil, it is best to opt for olive oil, extra virgin if possible, because it promotes the health of the cardiovascular system.
Both olive and sunflower oil are vegetable oils. In one, monounsaturated fatty acids are abundant, and in the other, polyunsaturated fatty acids. But, as such, they benefit us. What does not happen with coconut and palm oils and blended oils due to their saturated and trans fatty acids?
Advantages of canned fish compared to fresh fish
The consumption of canned fish provides advantages in terms of duration, price, availability, versatility in cooking or environmental impact in its production.
Time
The great advantage of canned fish is that it can be stored for a much longer time, up to 5 years. With fresh food, after more than two days in the refrigerator, there is a danger of poisoning. Even the frozen one lasts between 3 and 6 months compared to the five years it can achieve in a can.
Price
More or less fresh fish, fresh from river, marine, and oceanic networks or preserved with ice and salting, forces you to spend a greater amount of money for it if we compare it with the one you take out of your wallet to buy in cans or Glass jars. Canned fish is cheaper.
Availability
Canned fish, unlike the different fresh specimens that the seas and rivers provide us with, is available without interruption in supermarkets and grocery stores outside of fishing seasons.
Versatile in the kitchen
Since, due to the treatment of the meat itself in its packaging system, it is very accommodating and can be manipulated and distributed in homemade dishes without any obstacles, its grateful versatility is far superior when it comes to cooking.
Environmental impact
Canned fish guarantees a low environmental impact because it does not require refrigeration and, thus, the supply chain to market it, which includes transportation, pollutes less. And we need to combat the pollution and destruction caused to the planet by anthropogenic climate change.
Calcium content and energy contribution
In addition and sterilization at 100 °C, the calcium from the sardine skins is transmitted to the meat and it contains three times more of it. And fats and carbohydrates are transformed into energy more easily by the acetic acid in the vinegar in the pickle.
Contraindications of canned fish
The potentially harmful nature of canned fish is linked to the particularities of each person’s health, which may constitute excessive consumption for this specific reason. Someone with hypertension should not eat too much-canned tuna because the salt it contains raises blood pressure, for example.
Those who suffer from a certain degree of overweight would not be wise to eat these foods packed in oil, to avoid their fat. And a diagnosis of gastroesophageal reflux or hyperkalemia is not compatible with pickled vinegar, which also partially denatures optimal proteins or the purine of oily fish.
How many cans of fish can you eat a week?
Between the virtues of this preserved delicacy, its drawbacks, and the wisdom of following a rich, varied and balanced diet, there is no choice but to opt for moderation. A couple of cans a week seems reasonable. Above all, knowing that three or four servings of fish are generally recommended, also fresh.
Plumbosis, methylmercury, and other canned fears
Despite what has been warned, that the fish goes through strict controls, the truth is that most and least people have heard of dangers lurking between the walls of cans. Thus, lead or methylmercury are two agents that predict the worst for our health, but are present in tiny quantities. Only the high consumption of these products, says the legend, can guarantee us dangerous and lethal contamination. Is this true?
In the case of lead, which causes heavy metal contamination called plumbosis, we can say that it is an evil of the past. This no longer happens because lead is not used in any case to make cans. A little over a century ago, however, lead was used to seal cans and this passed into food. There are many horror stories, never better said, associated with canned plumbosis.
Methylmercury, however, is a different story. This is a heavy metal that fish ingest in their livelihood and accumulates especially in large, carnivorous and long-lived species such as tuna. It occurs to a greater or lesser extent in all fish. The case raised alarm, especially in the United States, where many young people who consumed canned tuna daily had mercury concentrations above the safety threshold. The case was so famous that it has even been fictionalized in several medical series.
After several decades of study, however, the scientific consensus has tried to put the fear of methylmercury in its right place. This, although it is still there, cannot be valued without rigor and without understanding the benefits of consuming fish. Thus, for example, following the request of the European Commission to carry out a risk-benefit analysis in relation to human health, the EFSA Scientific Committee attempted to capture different scenarios based on typical fish consumption patterns of population groups at risk (which are a representation of the worst case scenario, so to speak).
The Scientific Committee determined that to protect against methylmercury toxicity and obtain the benefits of fish consumption, it is recommended to limit consumption of high-mercury fish/shellfish species to a few servings (<1-2) per day. week. Among the species with the greatest presence of this substance, we find:
- Swordfish (Emperor)
- Bluefin tuna (bluefin tuna)
- Shark
- Pike (pike fish)
- Mero fish
- king mackerel
- Goldfish (dorado, dolphinfish)
- Snapper fish (red snapper)
- Whiting fish
- mako fish
These species are typically at the top of the food chain and can accumulate higher levels of methylmercury compared to other fish species. However, it is important to note that methylmercury levels can vary depending on the geographic location and specific water conditions in which the fish is caught. Furthermore, not all of them are usually sold canned.
In any case, currently, the scientific consensus, represented by the EFSA, has established that the consumption of around 1-2 servings of fish or seafood per week and up to 3-4 servings per week during pregnancy has been associated with better outcomes. functional neurodevelopment in children compared to no use. These amounts have also been associated with a lower risk of mortality from coronary heart disease (CHD) in adults and are consistent with current intakes and recommendations in most European countries considered.
To make these recommendations, EFSA has taken into account both the beneficial and adverse effects of nutrients and non-nutrients in fish and seafood, that is, it has also taken into account the presence of contaminants such as methylmercury. Therefore, and ultimately, rational consumption, without abuse, should be more than enough to ensure the benefits without falling into fear of the harms of methylmercury.