Is Eating Fish Healthy? Make Your Wise Food Decisions
Is Eating Fish Healthy? Make Your Wise Food Decisions
Healthiest Foods?
Salmon
Fish is recognized as one of the healthiest foods for our human beings. However, due to the growing popularity of plant-based alternative foods and growing concerns about the sustainability and carbon footprint of seafood, some people are beginning to question whether our diet requires fish. According to a report by the Food and Agriculture Organization of the United Nations, since 1974, fish catches within the level of sustainable biological production have fallen from 90% to less than 66% today.
Moreover, because of concerns about fish being contaminated by heavy metal mercury and other chemicals, this means that pregnant or breastfeeding women should restrict their consumption of certain fish.
So, is eating fish beneficial or harmful to health?
Heavy Metal
In recent decades, one of the most worries about fish is that fish are polluted. The levels of pollutants and heavy metals in fish may be harmful to humans.
One is the industrial chemicals such as polychlorinated biphenyls (PCBs). Although they were banned from production in the 1980s, they have been widely used worldwide and still remain in our soil and water in large quantities. After the human body absorbs PCBs, a series of health problems may occur, including damage to the immune system and brain. Although PCBs are found in all human foods, from dairy products to drinking water, the highest levels are generally in fish.
Johnathan Napier, the scientific director of the Rothamsted Research in Hertfordshire, UK, said that if you think that you can avoid PCBs by eating less fish, it may not be consistent with common sense.
He said, “The accumulation of toxic compounds in the body of fish may affect human health, but maybe we should pay more attention to the wild fish that is caught for human consumption.” Artificially farmed fish are usually safer than wild fish, because artificially farmed fish The feed has been cleaned or toxic compounds have been removed.
However, this is not absolute. The content of PCBs in fish also varies with the seasons.
Although it is generally believed that large-scale aquaculture is good for human health and the environment, there are also some problems. For example, aquaculture wastewater pollutes the ocean, and farms may also become the source of infectious diseases spreading to the wild.
The British National Medical Service System recommends that pregnant and breastfeeding women should limit the intake of fish that may contain PCBs and other pollutants such as dioxins to two servings per week. These fish include high-fat fish such as salmon and sardines, as well as non-fat fish such as crabs and sea bass. A serving is about 140 grams.
Another worry is that mercury, or mercury, is a neurotoxin that may affect the development of children through the placenta. It has been found that there are many links between mercury intake and cancer, diabetes and heart disease. Although mercury is also present in other foods, such as vegetables, a study found that 78% of study participants’ mercury intake comes from fish and seafood.
Because of the high levels of mercury in fish, the U.S. Food and Drug Administration (FDA) recommends that pregnant women limit the intake of some popular fish, including halibut and tuna, only once a week.
However, Napier said concerns about the accumulation of heavy metals in fish have been overstated. He said that the fish that accumulate high levels of heavy metals in the body are mainly those fish with a particularly long life, such as swordfish, which can live for 15 to 20 years. The mercury concentration in swordfish is 0.995 parts per million (0.995 PPM), while the average life span of salmon is only 4 to 5 years. The mercury concentration is much lower, about 0.014 PPM. Although research on the mercury content of fish is still ongoing, the U.S. Environmental Protection Agency currently states that if pregnant women eat one serving of fish a week, their maximum intake of mercury is only 0.46 PPM.
But this problem is destined to worsen because there is evidence that as the planet warms, the mercury content in the ocean may rise. The study found that as the Arctic permafrost melts, mercury contained in the frozen soil will be released into the waterway.
Napier said that the risk of mercury intake from fish is actually very small, but the benefits are more, especially the omega 3 fatty acids contained in marine organisms are particularly powerful.
Fatty Acid
Eating high-fat fish, including salmon, tuna, sardines and mackerel, can reduce the risk of cardiovascular disease. This is due to the fact that these marine fish contain two types of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA).
Some plants containing omega-3, such as flaxseed and walnuts, their omega-3 fatty acids are mainly the third type of ALA. A 2014 study concluded that the benefits of plant-produced omega-3 on heart health may be comparable to the EPA and DHA of marine fish, but there is no other research to support this conclusion. However, you can find EPA and DHA in seaweed supplements and edible seaweed.
Olive Oil
Napier said, “EPA and DHA both play a very important role in human metabolism, but the human body cannot effectively synthesize these two fatty acids, so it is really important to include these two as part of our diet.”
Our human brain, retina and other special tissues have a large amount of DHA fatty acid. Together with EPA, DHA helps fight inflammation in the body, which is associated with a high risk of heart disease, cancer and diabetes.
Philip Calder, Director of the Human Development and Health Research Program at the University of Southampton in the United Kingdom, said, “The data and conclusions that study the impact of marine fish Omega-3 on human health are consistent and very convincing. People who eat EPA and DHA fish are less likely to suffer from common diseases and die due to diseases, especially heart disease.”
If you don’t want to eat fish with high mercury content to avoid harm to your body, but you want to take omega-3, the alternative is to take fish oil supplements. However, a recent study conducted on behalf of the World Health Organization (WHO) found that the health effects of omega-3 supplements are not as effective as eating high-fat fish.
Napier said, “The evolution of the human body is to metabolize the whole food, not a single nutrient or a certain food ingredient.”
Lee Hooper, a professor at the University of East Anglia in England and one of the researchers of the WHO Omega-3 Health Program, added, “Our results show that (in terms of reducing the probability of death from coronary heart disease, supplements) The beneficial effects are small.”
She said that an average of about 334 people must take omega-3 supplements for 4 to 5 consecutive years before one person will not die of coronary heart disease.
But the research by Hooper et al. has a problem. Although some high-fat fish, such as sardines, are not very expensive, generally speaking, fish and other seafood are still a more expensive diet. It is generally believed that socioeconomic status will affect health. Therefore, in short, families that eat more fish may also have higher incomes and healthier lifestyles.
Calder said that researchers usually take these complex factors into consideration, but they cannot take into account all the factors that will distort the results of the study. This WHO report comprehensively analyzes 79 studies, each of which controls the socio-economic status of the participants in a different way.
Food For Brain
Omega-3 Fatty Acid
Besides Omega-3, fish has other beneficial nutrients, including selenium, a trace element that protects cells from damage and infection, iodine, which supports healthy metabolism, and protein.
Fish has long been known as “brain-building food”. A recent study showed that this is not just because fish contains omega-3 fatty acids, but research has also found an association between omega-3 fatty acids and slowing down cognitive decline.
Researchers compared the brain capacity of people who eat fish and people who do not eat fish, and found that grilled fish is associated with the volume of human brain gray matter, but has nothing to do with the level of omega-3.
Cyrus Raji, assistant professor of radiology and neurology at the University of Washington School of Medicine, said, “Our brain capacity will also change as health and disease improve. The more neurons you have, the more The greater the brain capacity.”
The researchers compared the fish-eating habits and MRI scan results of 163 participants with an average age in their 70s. They found that compared with the participants who did not eat fish, the participants who ate fish each week had a larger brain volume, mainly located in the frontal lobe, which is important for concentration, as well as memory, learning, and cognition. Temporal lobe.
Raj said that eating fish is associated with brain capacity, possibly because fish has anti-inflammatory effects, because when the brain responds to slow down inflammation, it can affect the growth of brain cells.
Raj said, “This means that in order to improve brain health and prevent Alzheimer’s disease, it is very simple, just eat more fish in the diet.” In order to make the brain can prevent dementia as much as possible, Raj suggests 20 I started eating fish at least once a week when I was a few or 30 years old.
Another reason fish is good for health is that fish replace unhealthy foods in our diet. Hooper said, “If we eat more fish, we generally eat less other things.”
However, Calder said that because there is no solid and reliable research showing that people who do not eat fish have major health deficiencies, it is difficult to clearly conclude that fish is indispensable to overall human health. But he added that it is clear that Omega-3 can promote health and reduce the risk of disease.
To figure out how healthy fish are for humans, it may be different for a long time in the future. Calder said, “Because fish is not a sustainable food source, current research may focus on solving this problem, such as how to grow algae to produce omega-3 oil, rather than focusing on fish’s research on human health. ”
As an individual, to help solve the problem of sustainable seafood development, you can choose to buy the most sustainable fish species. For example, the Marine Conservation Association put forward a guide to fine fish species. Among the 133 fish species on the list, 50 are the most sustainable “good” choices. Fortunately, many of them are widely loved fish. Such as artificially cultivated salmon, prawns, cod, mackerel, mussels, oysters and artificially cultivated halibut.
*Follow Facebook