Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fish is good – fish is bad. Balancing health risks and benefits

19.10.2005


Harvard Center for Risk Analysis explores this issue



Fish has been a staple of human nutrition in many cultures, but there has been some controversy recently about the benefits and risks of fish consumption. For example, fish supplies polyunsaturated fatty acids (PUFAs), substances that might protect against coronary heart disease (CHD) and stroke. On the other hand, fish supplies methyl mercury (MeHg), a compound implicated in impairment of cognitive development and IQ. How can the consumer decide whether to increase or decrease consumption? What steps should governments, public health authorities and commercial fishing industries take in response to these conflicting facts?

Joshua T. Cohen, PhD, of the Harvard School of Public Health, writes, "Because fish consumption confers both benefits and risks, the advisories issued by the U.S. federal government raise the possibility of a classic risk–risk trade-off: by avoiding one risk (exposure to MeHg), consumers who follow these advisories may be incurring another (adverse health consequences associated with lower n-3 PUFA intake). Likewise, individuals who increase their consumption of fish because of this food’s nutritional benefits may incur risks associated with MeHg exposure."


In a series of articles published in the current issue of the American Journal of Preventive Medicine, the results of detailed analyses of the available literature sheds some light on this quandary. The Harvard Center for Risk Analysis undertook a project to create a decision model to evaluate policies that influence population fish consumption. Although much of this work was supported by grants from the National Food Processors Association Research Fund and the Fisheries Scholarship Fund, neither organization controlled the research findings or interpretations of the results.

The Harvard Center convened an expert panel to help guide the process and advise on evaluation of the scientific literature. The overall decision-analytic approach was to identify the important health effects, assess the dose–response relationships between fish consumption (or a constituent) and each health outcome, and then to synthesize these dose–response relationships into an overall model of health effects.

An introductory article "Health Trade-offs from Policies to Alter Fish Consumption" by Steven M. Teutsch, MD, MPH, Merck & Co., Inc., West Point, Pennsylvania; and Joshua T. Cohen, PhD, Harvard Center for Risk Analysis, Boston, Massachusetts, discusses the overall rationale for the project and why the decision analytic approach it illustrates is critical. They point out that although there is a substantial literature on the risks and benefits of fish consumption, important gaps remain. Despite these gaps, decisions about how to deal with tradeoffs must be made based on what we know now. The authors explain that "Decision analysis is an important tool that can quantitatively synthesize disparate information and assess the impact of uncertainty on our conclusions."

In "A Quantitative Analysis of Fish Consumption and Stroke Risk" by Colleen Bouzan, MS, Joshua T. Cohen, PhD, William E. Connor, MD, Penny M. Kris-Etherton, PhD, George M. Gray, PhD, Ariane König, PhD, Robert S. Lawrence, MD, David A. Savitz, PhD, and Steven M. Teutsch, MD, the authors conclude that "any fish consumption confers substantial relative risk reduction compared to no fish consumption, with the possibility that additional consumption confers incremental benefits."

Turning attention to coronary heart disease, the article "A Quantitative Analysis of Fish Consumption and Coronary Heart Disease Mortality" by Ariane König, PhD, Colleen Bouzan, MS, Joshua T. Cohen, PhD, William E. Connor, MD, Penny M. Kris-Etherton, PhD, George M. Gray, PhD, Robert S. Lawrence, MD, David A. Savitz, PhD, and Steven M. Teutsch, MD, shows "that consuming small quantities of fish is associated with a 17% reduction in CHD mortality risk, with each additional serving per week associated with a further reduction in this risk of 3.9%."

In some cultures, fish is known as "brain food." In the article, "A Quantitative Analysis of Prenatal Methyl Mercury Exposure and Cognitive Development" by Joshua T. Cohen, PhD, David C. Bellinger, PhD, and Bennett A. Shaywitz, MD, the authors examine the negative cognitive effect of MeHg exposure. Although the effects they observed were small on an individual level, they suggest that "Ultimately, the importance of a shift in IQ due to MeHg exposure lies in its aggregate impact on the population. While not noticeable in an individual, subclinical effects can be large when summed over the population. Our purpose in estimating the magnitude of this effect is to compare its aggregate impact to the aggregate impact of other subtle effects associated with changes in fish consumption."

Some positive cognitive effects of fish consumption can be found in a study, "A Quantitative Analysis of Prenatal Intake of n-3 Polyunsaturated Fatty Acids and Cognitive Development" by Joshua T. Cohen, PhD, David C. Bellinger, PhD, William E. Connor, MD, and Bennett A. Shaywitz, MD. Although the effects, like those of MeHg, were small on the individual level, the authors conclude, "Nonetheless, the estimates developed here serve as a useful starting point for the purpose of quantitatively evaluating the cognitive benefits of maternal fish consumption, so that these benefits can be compared to the attendant risks resulting from prenatal exposure to mercury."

"A Quantitative Risk–Benefit Analysis of Changes in Population Fish Consumption" by Joshua T. Cohen, PhD, David C. Bellinger, PhD, William E. Connor, MD, Penny M. Kris-Etherton, PhD, Robert S. Lawrence, MD, David A. Savitz, PhD, Bennett A. Shaywitz, MD, Steven M. Teutsch, MD, and George M. Gray, PhD, synthesizes the results of these four contributions, weighs the positive and negative effects, and discusses a range of appropriate public health recommendations.

In addition, two commentaries take a somewhat broader view of the issues. "Fish, Health, and Sustainability," by Anthony J. McMichael and Colin D. Butler, of the National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia, looks at potential consequences of changes in diet on a global scale. They caution, "The well-informed fish consumer of the future may wish to consider not only the likely MeHg and PUFA concentration of her meal, but its ecologic impact and – perhaps – whether his/her use of market power could unintentionally harm the health of others."

Charlotte Seidman | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Health and Medicine:

nachricht Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin

nachricht Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>