Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Risk/benefit analysis of farmed versus wild salmon

28.12.2005


On the one hand, farmed salmon has more heart-healthy omega-3 fatty acids than wild salmon. On the other hand, it also tends to have much higher levels of chemical contaminants that are known to cause cancer, memory impairment and neurobehavioral changes in children. What’s a consumer to do?



In general, a new study shows that the net benefits of eating wild Pacific salmon outweigh those of eating farmed Atlantic salmon, when the risks of chemical contaminants are considered, although there are important regional differences.

Those are the conclusions of Barbara Knuth, Cornell professor of natural resources who specializes in risk management associated with chemical contaminants in fish, and Steven Schwager, Cornell associate professor of biological statistics and computational biology and an expert in sampling design and statistical analysis of comparative data. The two have co-authored a benefit-risk analysis of eating farmed versus wild salmon in the Journal of Nutrition (November, Vol. 135).


"None of us [study authors] argues that the benefits of salmon are not real. But the dirty little secret is that there are risks," said Schwager, noting that even taking into account the risks, the benefits of salmon may be particularly worthwhile for some groups.

"For a middle-aged guy who has had a coronary and doesn’t want to have another one, the risks from pollutants are minor ones, and the omega-3 benefits him in a way that far outstrips the relatively minor risks of the pollutants," he said. "But for people who are young -- and they’re at risk of lifetime accumulation of pollutants that are carcinogenic -- or pregnant women -- with the risks of birth defects and IQ diminution and other kinds of damage to the fetus -- those risks are great enough that they outweigh the benefits."

Knuth added: "Because we found regional differences in contaminants in farmed salmon, with Chilean salmon showing the lowest levels and European (particularly Scottish) farmed salmon showing the highest levels, careful consumers with a history of heart disease could choose farmed salmon from Chile for their high omega-3 content and relatively lower level of contaminants." She noted that farmed salmon from North America would be a better second choice than European farmed salmon.

The researchers’ benefit-risk analysis showed that consumers should not eat farmed fish from Scotland, Norway and eastern Canada more than three times a year; farmed fish from Maine, western Canada and Washington state no more than three to six times a year; and farmed fish from Chile no more than about six times a year. Wild chum salmon can be consumed safely as often as once a week, pink salmon, Sockeye and Coho about twice a month and Chinook just under once a month.

In a study published last spring (Environmental Health Perspectives, May 2005), the research team reported that the levels of chlorinated pesticides, dioxins, PCBs and other contaminants are up to 10 times greater in farm-raised salmon than in wild Pacific salmon, and that salmon farmed in Europe are more contaminated than salmon from South and North American farms.

The team also published a study this fall (Environmental Science and Technology, Vol. 39:8622) that found that farmed salmon, on average, contain roughly two to three times more beneficial fatty acids than wild salmon, presumably because of the differences in the diet on which the fish are raised.

"Our results also support the need for policy and regulatory efforts to limit pollution of our waters and clean up pollution that has occurred, and thus ultimately reduce the risk side of this equation by reducing the potential for human exposure to these contaminants," said Knuth, adding that the country of origin of fish sold should be clearly labeled so consumers can make informed decisions.

Other co-authors of the risk-benefit study include lead author Jeffrey Foran, University of Illinois-Chicago; David Carpenter, University at Albany; David Good, Indiana University; and Coreen Hamilton, AXYS Analytical Services Ltd., British Columbia, Canada. The study was funded by the Environmental Division of the Pew Charitable Trusts.

Joseph Schwartz | EurekAlert!
Further information:
http://www.cornell.edu

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>