[문화] 생선을 먹는 것, 건전한 것일까?


(Image credit: Getty Images)

 

 

입력 2020.12.27.

BBC 원문 2020.12.13.

 

[시사뷰타임즈] 우린 생선이라는 것에 대해 건전 식품으로 알고 있지만, 임산부들은 제한적 소비를 하라는 말을 듣는다. 생선 섭취에서 비롯되는 건강을 위한 유익들이 위험보다 비중이 더 클까, 특히 생선 개체수가 갈수록 더욱 격감하고 있는 판에?

 

생선은 우리가 섭취할 수 있는 식품들 중 가장 건전한 것들 중 하나라는 평판이 있다.

 

그러나 채식위주의 대체 식단의 유용성이 커지고 있고, 해산물의 지속가능성 및 탄소 흔적에 대한 우려가 증가일로에 있는 것 등이 일부사람들로 하여금 우리의 식단 차림표 속에 생선이 필요한지의 여부에 대해 의문을 갖게 만든다. 1974년 이래로, 유엔 식량농업기구 (FAO) 는 생물학적으로지속 가능한 수준 안에 있는 생선 재고량이 90%에서 오늘날엔 60% 미만으로 떨어졌다고 보고한다.

 

한편, 수은과 기타 오염물질들에 대한 제반 우려는 예를 들어 임신 상태에 있는 여자들이나 모유 수유를 하는 여자들이 결국엔 일부 어종 소비를 제한하라는 말을 듣게 만든다.

 

생선을 먹는 것은 건강에 유익함을 더욱 제공하는가, 아니면 건강에 위험을 제공하는가?

 

 

중금속

 

 

최근 몇 십년 동안, 생선에 대한 가장 큰 우려들 중 하나는 생선 속의 잠정적으로 해로울 수준의 오염물질 및 금속류이어 왔다.

 

한 가지 걱정은 폴리클로로네이틷 바이페널스 (PSBs: ; C12ClxH10-x의 화학식으로 표시되는 물질의 총칭. 무색 투명한 유상(油狀)으로 산, 알칼리에 침해되지 않고, 절연성이 좋은 것 등 여러 가지 특성이 있음) 이다. 이것은 1980년대에 이르러 금지된 것임에도 불구하고, 이 화학물질들은 전세계적으로 어마어마한 양이 사용됐으며 아직도 우리의 토양과 물에 남아 있다. 이런 화학물질들은 면역체계에서부터 뇌에 이르기까지 모든 것에 끼치는 부정적인 건강 결과와 연관돼 있다. PCBs는 낙농제품에부터 마시는 물에 이르기까지 존재하지만, 생선에서 가장 높은 수치로 발견되는 경향이 있다.

 

생선에서 PCBs 섭취를 제한하기 위한 해법은 일반상식과는 반대되는 개념일 수도 있다고 영국 하트포드셔에 있는 로담스텓 연구소의 조나단 내피어 과학부장이 말한다.

 

유독물질 축적으로 인해 일어날 가능성이 있는 문제는 인간이 직접 소비를 위해 잡은 야생 어종에 대한 우려일 가능성이 더욱 크다.” 고 그는 말한다. 양식되는 생선들이 먹는 해양에서 비롯된 제료들은 씻거나 문질러 유독 성문들이 제거되기 때문에 야생 어종 보다 ᅟᅳᆫ히 더 안전하다는 것이다.

 

하지만, 언제나 그런 것은 아니며 PCB 내용물은 계절적으로 등락을 거듭한다.

 

양식 어종들을 일반적으로 우리의 건강과 환경을 위해 더 나은 것으로 보지만, 대규모 해양 양식은 폐기물로 해양을 오염시키는가 하면 야생 어종 속으로 새 나갈 수도 있는 질병 번식터가 되는 등의 나름대로의 문제가 있다,

 

국민의료보험 (NHS) 측에선 임신녀 및 모유수유녀 들에게 다이악신 (: 제초제 및 소독제 사용에서 나오는 유독성 부산물) 은 물론이고 PCBs를 더욱 많이 갖고 있을 어종 섭취를 일주일에 두 번 정도 먹는 것으로 제한하라고 권고한다. 이러한 생선에는 게와 농어꽈 생선을 비롯한 기름기 없는 것은 물론이고 연어와 정어리처럼 기름기 많은 생선이 포함돼 있다. 1회 먹을 분량은 대략 140g 정도이다.

 

또 다른 우려는 태반을 통과하여 어린이 발달에 영향을 미칠 수 있는 신경독인 수은이다. 수은 섭취는 암, 당뇨병 그리고 심장질환 등과의 사이에 수도 없는 연결고리들이 있다. 야채 등에서도 수은이 발견될 수도 있긴 하지만, 한 연구에서는 조사 참여자 중 78%가 생선과 해산물에서 수은을 섭취했음을 알게 됐다.

 

생선 속에 있는 수은의 수치는 미국 식품의약국 (FDA) 가 큰 넙치와 참치 등 일부 인기있는 생선류 섭취를 임산부들이 제한해야할 것이라고 -1주일에 1회로- 권고하기에 이를 정도로 높다.

 

그러나, 생선 속에 중금속류가 축적되는 것에 대한 우려는 지나치게 과장돼 온것이라고 내피어는 말한다. 그는 그런 건 15년에서 20년을 살 수 있는 황새치처럼 특히 징수 어종일 경우에나 해당되는 문제라고 말한다. 황새치의 수은 집중 농도는 0.995 PPM안 번면, 평균 4~5년은 사는 연어는 대략 0.014이다. 연구가 아직은 진행 중에 있는 것이긴 하지만, 미국 환경보호국은 현재 임신부가 일주일에 1회만 먹을 경우, 한 번 먹을 때 허용되는 평균 수은 농도는 가장 높이 잡아도 0.16 PPM이라고 말한다.

 

그러나 이 문제는 더욱 악화되도록 설정된 것이, 해양에서 최초로 발견된 수은 수치는 지구가 더워짐에 따라 오르고 있을 수도 있음을 시사하는 증거가 있기 때문이다. 연구에선 북극의 영구동토층이 녹으면서, 얼어붙은 땅 속에 갇혀있던 수은을 수로를 통해 방출하고 있음을 알게 됐다.

 

수은은 작은 위험을 주긴 하지만, 내피어는 생선에선 더 많은 것을 -특히 해양 오미거 (오메가) 3(: 오미거 3은 주로 생선 기름에서 추출한 건강보조식품)- 얻는 것이 있다고 말한다.




Is eating fish healthy?

 

(Image credit: Getty Images)

 

By Jessica Brown

13th December 2020

 

We know of fish as a healthy food, but pregnant women are told to limit consumption. Do the health benefits of eating fish outweigh the risks, particularly as stocks grow more depleted?

 

Fish has a reputation for being one of the healthiest foods we can eat.

 

But the rising availability of plant-based alternatives, and increasing concerns about seafood’s sustainability and carbon footprint, have led some to question whether we need it in our diets. Since 1974, the UN's Food and Agricultural Organization reports, fish stocks within biologically sustainable levels have declined from 90% to just under 66% today.

 

Meanwhile, concerns over mercury and other pollutants mean women who are pregnant or breastfeeding, for example, are told to limit their consumption of some species.

 

Does eating fish provide more health benefits or health risks?

 

Heavy metal

 

In recent decades, one of the biggest concerns about fish has been its potentially harmful levels of pollutants and metals.

 

One concern is polychlorinated biphenyls (PCBs). Although they were banned by the 1980s, these industrial chemicals were used worldwide in huge quantities and still linger in our soil and our water. They’ve been associated with a range of negative health effects on everything from the immune system to the brain. While PCBs are present in everything from dairy products to drinking water, the highest levels tend to be found in fish.

 

One of the biggest concerns about fish has been its potentially harmful levels of pollutants and metals (Credit: Getty Images)

 

The solution for limiting your intake of PCBs from fish may be counterintuitive, says Johnathan Napier, science director at Rothamsted Research in Hertfordshire, England.

 

“The possible problem of the accumulation of toxic compounds is likely to be more of concern for wild species that are caught for direct human consumption,” he says. Because the marine-derived ingredients that farmed fish are fed are cleaned or scrubbed to remove toxins, farmed fish is often safer than wild.

 

That isn't always the case, however, and PCB content also fluctuates seasonally.

 

While they are generally viewed as better for our health and the environment, large-scale aquaculture has its own problems, such as polluting the oceans with waste and becoming breeding grounds for diseases that can spill over into the wild.

 

The NHS recommends that pregnant and breastfeeding women limit their intake of fish species more likely to contain PCBs, as well as other pollutants like dioxins, to two portions per week. These fish include oily fish like salmon and sardines, as well as non-oily fish including crab and sea bass. A portion is around 140g.

 

Because oily fish like sprats have a relatively high level of toxins known as PCBs, pregnant women should not have more than two portions per week (Credit: Getty Images)

 

Another worry is mercury, a neurotoxin that could pass through the placenta and affect child development. There are numerous links between mercury ingestion and cancer, diabetes and heart disease. While mercury can be found in other foods, such as vegetables, one study found that 78% of participants' mercury intake came from fish and seafood.

 

In fish, mercury levels are high enough for the US Food and Drug Administration (FDA) to recommend that pregnant people limit their intake of some popular fish, including halibut and tuna, to one serving a week.

 

But concerns around the accumulation of heavy metals in fish has been overexaggerated, says Napier. He says it’s only a problem when it comes to species that live a particularly long time like swordfish, which can live for 15 to 20 years. Swordfish has a mercury concentration of 0.995 PPM, while salmon, which lives on average for four to five years, has around 0.014. While research is still ongoing, the US's Environmental Protection Agency currently states that for pregnant women, the highest allowable average mercury concentration per serving, if eating one serving a week, is 0.46 PPM.

 

But the issue is set to worsen, as there’s evidence to suggest that levels of mercury found in the ocean may rise as the planet warms. Research has found that as Arctic permafrost melts, it releases mercury that was trapped in frozen ground into waterways. (Read more about the poisons being released by melting Arctic ice.)

 

While mercury poses a small risk, Napier says there stands to be much more to gain from fish particularly marine omega 3.

 

Fatty acids

 

Consumption of oily fish, including salmon, tuna, sardines and mackerel, has been linked to a lower risk of cardiovascular disease, thanks to its marine omega 3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

 

Some plant-based sources of omega 3, such as flax seeds and walnuts, are rich in a third type ALA. A 2014 study concludes that the heart health benefits of plant-based omega 3 may be comparable to EPA and DHA, but there isn't research to back it up yet. However, you can find both EPA and DHA in algae supplements and in edible seaweed.

 

“Both EPA and DHA play a plethora of important roles in human metabolism, but we can’t make them very effectively in our bodies, so it’s really important to have them as part of our diet,” Napier says.

 

DHA is abundant in our brains, retinas and other specialised tissues. Along with EPA, it helps to fight off inflammation in the body, which is linked to higher risk of heart disease, cancer and diabetes.

 

“Population data looking at the effects of marine omega 3 on health is consistent and strong, and shows that people with a higher intake of EPA and DHA have a lower risk of developing common diseases, particularly heart disease, and dying from them,” says Philip Calder, head of human development and health at England’s University of Southampton.

 

One way to avoid potential damage from mercury exposure while still getting omega 3 is to take fish oil supplements. However, research recently carried out on behalf of the World Health Organization (WHO) looking at omega-3 supplements across range of health outcomes found they don’t have the same effect as eating oily fish.

 

While you can get omega 3 from fish oil supplements, they aren’t as effective as eating oily fish itself (Credit: Getty Images)

 

“Our bodies are adapted to metabolising whole foods, rather than a single slug of a particular nutrient or ingredient,” Napier says.

 

“Our findings suggest a very small beneficial effect [in terms of lowering the risk] of dying of coronary heart disease,” adds Lee Hooper, a reader at the University East Anglia and one of the WHO study’s researchers.

 

Around 334 people would have to take omega-3 supplements for four or five years for one person not to die from coronary heart disease, she says.

 

But there’s an issue with population studies like Hooper’s. While some oily fish, such as sardines, aren’t relatively expensive, fish is generally associated with a more expensive diet. It’s widely accepted that socioeconomic status affects health outcomes so it’s possible that families who eat more fish also have higher incomes and healthier lifestyles in general.

 

Normally, researchers will take into account such confounding factors, Calder says, but they might not think of everything that could skew a study’s results. The WHO report was a review of 79 studies, which each will have differed in how they controlled for participants' socioeconomic status.

 

Fish is generally associated with a more expensive diet so could it be that those who eat more fish are higher-income and healthier in general? (Credit: Getty Images)

 

But intervention trials, where people are randomly assigned to a group and an intervention such as taking omega-3 supplements is measured, have problems, too. Analysing potential health impacts of EPA and DHA deficiency, for example, is difficult, Calder says, because people start trials with varying levels of omega-3 in their systems.

 

In addition, research shows that fish might impact everyone’s health to varying degrees, depending on how well they can convert precursor forms of EPA and DHA. This difference could come down to a person’s overall diet and lifestyle, Calder says, but genetic differences could also play a role.

 

Another reason the health benefits of fish may vary is because of how fish are raised.

 

Marine ecosystems are full of omega-3: little fish eat marine plankton, and get eaten by bigger fish, and the whole food chain passes on omega-3 to humans. But the system is different for farmed fish, which is what most of us eat. “In a fish farm, it’s just thousands of fish in a cage. They eat what they’re given by the fish farmer,” Napier says.

 

As they would in the wild, farmed fish normally are fed smaller fish species. In the wild, however, fish would eat a variety of smaller fish. In farms, fish are often fed fish meal made from Peruvian anchovies.

 

But these anchovies are already being fished at the maximum level at which the industry can be sustained, Napier says even as global aquaculture is expected to keep growing. According to the UN’s Food and Agricultural Organization, growing demand for fish oil supplements means that the fish oil contained in the fish meal fed to farmed fish is diminishing. That means the amount of omega-3 in the fish we consume is declining, too.

 

Growing demand for fish oil supplements means that the level of omega 3s in the fish we eat is declining (Credit: Getty Images)

 

“There are finite levels of omega fish oils that come out of the ocean each year that’s all we’ve got,” he says. “If aquaculture is expanding but the most important input you need to put into people’s diets, the fish oil, is completely static, you’re diluting how much is fed to the fish.”

 

Research from 2016 found that levels of EPA and DHA in farmed salmon decreased by half over a decade. Even so farmed salmon still has more omega-3 than wild salmon, Napier says.

 

“Wild salmon swims back forth across the Atlantic; it’s a lean animal. It’s not laying down fat because it’s burning everything it consumes,” he says.

 

Brain food

 

Aside from omega-3, fish has other beneficial nutrients, including selenium, which protects cells from damage and infection; iodine, which supports a healthy metabolism; and protein.

 

Fish has long been hailed as “brain food”. A recent study suggests this isn’t just thanks to its omega-3 content although studies have also found a link between omega-3 and slower cognitive decline.

 

Researchers compared brain volumes in people who consumed fish with those who didn’t, and found that baked or broiled fish is associated with larger grey matter volumes, independent of omega-3 levels.

 

Researchers found that eating baked or broiled fish is associated with larger brain volumes

 

“Our brain volumes change with improved health and disease. The more neurons you have, more brain volume you have,” says Cyrus Raji, assistant professor of radiology and neurology at Washington University School of Medicine.

 

Researchers compared the fish-eating habits and MRI scans of 163 participants who were in their late 70s, on average. They found that, compared to participants who didn’t eat any fish, those who ate fish on a weekly basis had larger brain volumes mostly in their frontal lobe, which is important for focus, and in their temporal lobes, crucial for memory, learning and cognition.

 

The relationship between fish and the brain could be down to fish having an anti-inflammatory effect, Raji says, because when the brain responds to reduce inflammation, it can affect brain cells in the process.

 

“This means you can improve brain health and prevent Alzheimer’s with something as simple as the dietary consumption of fish,” says Raji. To make the brain as resilient as possible to dementia, Raji advises starting to eat fish at least once a week when you’re in your twenties or thirties.

 

Another reason fish can be healthy is because it replaces less healthy foods in our diets. “If we eat more fish, we tend to eat less of other things,” says Hooper.

 

One reason fish and seafood can be healthy is because they replace less healthy foods in our diets (Credit: Getty Images)

 

Still, because there isn’t robust research suggesting major health inadequacies for people who don’t eat fish, Calder says it’s difficult to definitively say that fish is essential to overall human health. However, he adds, it is clear that omega-3 promotes health and reduces the risk of disease.

 

But getting to the bottom of how healthy fish really is may be a moot point after long. “Since fish isn’t a sustainable food source, research now will probably focus on solutions to that such as how to grow algae and harvest omega-3 oil, instead of more studies into fish,” Calder says.

 

Individuals can help by choosing the most sustainable fish species available. Guides like the one by the Marine Conservation Society show which fish are the best, with 50 of the 133 species listed coming up as mostly sustainable, “good” choices including, fortunately, popular favourites like farmed salmon, prawns, cod, mackerel, mussels, oysters and farmed halibut.

 

[기사/사진: BBC]

 



Comment



    게시물이 없습니다.

[ 시사 View 社說 ]

트럼프 탄핵심판 … 버먼트 주 연방 상원의원 패트맄 리히 (민주) 이 심판 평결문을 읽는 순간. /... 더보기

[BTI] 베스트 번역·통역

[BTI] 베스트 번역·통역원은 어떤 곳인가? ◇ 영어전문업체 [영작·한역·통역] <시사뷰타임즈> 우측 상단에 베스트 번역·통역 안... 더보기

[ 시사뷰타임즈 영상 ]

바다에 가라앉은 로움 제국의 타락한 도시 [BBC 영상으로 보기: 22분짜리]입력 2021.2.24.BBC 원문 2021.2.23. [시사뷰타임즈] 지상에도 일부 ... 더보기

[지카 바이러스]

유전자 조작 곰팡이, 멀레어리아 모기 99% 신속 박멸: 연구 결과 유전자 조작 곰팡이에 감염된 모기는 녹색을 띈다 Image copyrightBRIAN LOVETT 입력 2019.5.31.BBC 원... 더보기

[SVT 영어회화]

[POP 영어 21] Uriah Heep - Easy Living [공식 동영상으로 들으며 가사 보기] Uriah Heep - Easy Living This is a thing I've never known beforeIt's ca... 더보기

[역사 속의 오늘]

[인사말씀] 그동안 오늘의 역사를 읽어주신 독자 여러분 감사합니다! 2015년 첫눈 풍경. 아직 열린감을 따지도 않았는데 감과 나뭇가지 위에 눈이 쌓여있다 <시... 더보기

[시사뷰 클릭 베스트]

독자분들께 말씀드립니다 ‘시사뷰타임즈 클릭 베스트’는 조횟수가 1천이 넘는 기사 또는 글을 올려놓는 곳입니다... 더보기

[ 세계의 독재자들 ]

안토니우 드 올리베이라 살라자르- 1889.4.28 ~ 1970.7.27(폴츄걸, 산타콩바당) 입력 2017.11.2[시사뷰타임즈] 안토니우 드 올리베이라 살라자르(폴츄걸어: António de Oliveira Sa... 더보기

[건강 Health ]

얼음이 어는 추위 속 운동, 그 놀라운 유익함 [BBC 제공 영상으로 보기] 추위, 지방을 더 많이 연소시키는가 입력 2021.2.25.BBC 원문 2021.2.24 [... 더보기

[ 전국 맛집 기행 ]

[복수한우날고기] 한우우거지국밥, 선지국밥 모두 3,500원? 위치: 대전광역시 중구 태평로 120(테평동 375-8) 입력 2020.6.3. [시사뷰타임즈] 이곳은 이미 ‘... 더보기

[고사성어]

박찬종의 격화소양 (隔靴搔癢) 입력 2019.6.5. [시사뷰타임즈] ‘강적들’이라는 프로그램에 출연한, 박찬종, 이재오는 ‘보... 더보기

[SVT 촛불문화제 보도물]

공공기관을 국민의 품으로! 민영화반대, 민주수호 범국민 촛불 http://wjsfree.tistory.com/75 March 22, 2014 Pan-Citizen Action Day Park Geun-hye who was illegally elected take respons... 더보기

[터져나오는 시국선언!]

[역대 대통령 개관]

박정희-1 한국:새로운 위험 요소들 이란 제목의 타임지 박정희(朴正熙, 1917년 11월 14일(음력 9월 30일)... 더보기

[역대 정당 개관]

민주당의 역사 출처 1987년 대통령선거 직전 김대중의 대통령후보 출마를 위해 창당된 평화민주당(平和民... 더보기

[SVT 컴퓨터문제 해결]

슈퍼마이크로(Supermicro), 시스템 플랫폼 채택 가속화를 위해 곧 출시될 3 세… 슈퍼마이크로, 고객들이 3 세대 인텔 제온 확장 가능 프로세서 (코드명 아이스레이크) 기반... 더보기

[18대 대선 부정선거실체]

'제18대 대선 선거무효소송인단, 부정선거 관련 책 발간 (광고) 『제18대 대통령 부정선거 전자개표기 미분류표 집계 총람』책을 냈습니다! 안녕하... 더보기