Seafood

Ocean to the Plate

Shingo Hamada, Richard Wilk

• Editore: Routledge
• Anno: 2018
• ISBN:
  9781317276456
• Edizione: 1
• Argomento: Sciences sociales
• Categoria: Sociologie

Seafood draws on controversial themes in the interdisciplinary field of food studies, with case studies from different eras and geographic regions. Using familiar commodities, this accessible book will help students understand cutting-edge issues in sustainability and ask readers to think about the future of an industry that has lain waste to its own resources. Examining the practical aspects of fisheries and seafood leads the reader through discussions of the core elements of anthropological method and theory, and the book concludes with discussions of sustainable seafood and current efforts to save what is left of marine ecosystems. Students will be encouraged to think about their own seafood consumption through project assignments that challenge them to trace the commodity chains of the seafood on their own plates.

Seafood is an ideal book for courses on food and culture, economic anthropology, and the environment.

1
Fish as Food

Health and Danger

Is seafood good for you? Most people have heard that countries where they eat a lot of fish, like Japan, have much lower rates of heart disease, and many of us have heard that seafood is rich in omega-3 fatty acids, which promotes health. Hamada and his family usually eat slow-cooked sardines once a week because of their health benefits and their reasonable price. The health benefits of seafood are well-known, but on the other hand, we also hear health warnings about the dangers of consuming too much tuna or other fish that can contain dangerous amounts of mercury or other pollutants. In some parts of the world, but particularly the tropics, some species of fish and shellfish can accumulate natural toxins and become dangerously poisonous.

In Indiana, where Wilk lives, when you buy a fishing license you also get a pamphlet that lists polluted rivers and lakes, the species that have unsafe levels of polychlorinated biphenyls (PCBs) and/or mercury, and suggested limits on how many fish can be eaten safely each month by children, pregnant women, and other adults. This hardly inspires confidence, and it begs the question of whether the benefits of eating fish are outweighed by the hazards. The fear inspired by health warnings like this explain why so many people seem to prefer taking fish oil capsules instead of eating more fish.

Scientifically speaking, each fish species has a different set of nutritional values: some are high in fat, others provide more trace elements like iodine and selenium, and they vary widely in their caloric value. In general, filter feeders and small fish low on the food chain—those that eat algae and tiny plankton—have less fat containing pollutants. Larger, predatory fish are more likely to contain pollutants that they accumulate from the many smaller fish they eat. However, the actual nutrient and pollutant content of any particular fish depends on its age and specific life history, the environments it lives in and moves between, the season, and how the fish is treated after it is caught and before it is eaten.

Regardless of benefits or dangers, billions of people rely on fish and other seafood as an essential part of their daily diet, and for many of them, catching and selling seafood is their livelihood. Fish accounts for approximately 17 percent of animal protein intake globally (Thilsted et al. 2014), and it is a regular part of the diet of more than one billion people (Tacon and Metian 2009). The importance of fish as a vital source of nutrition tends to be higher in developing countries than in industrialized nations.

The Good News

In the 1970s, Danish scientists found that the Greenlandic Inuit, who consumed large amounts of seal, whale, and fish, had extremely low rates of death from heart diseases (Bang et al. 1980). Similar studies of countries with high levels of seafood consumption followed, affecting scientists and policymakers in the US and other countries where heart disease had become the number one cause of death among adults. The 1977 McGovern Report recommended that US citizens decrease their consumption of meat, particularly fatty red meats, and increase their consumption of poultry and fish. Seafood consumption supplies us with animal proteins, essential fats, minerals, and vitamins.

Indigenous people who have lived in the same environment for thousands of years have developed techniques to maximize the nutrition they get from their catch. The Ainu, the indigenous people of northern Japan, use every part of a salmon from head to tail. Citatap, one of their traditional foods, is a chopped mixture of the head, intestines, gills, and milt (sperm), seasoned and preserved with salt (Iwasaki-Goodman et al. 2009). The head, skin, bones, viscera, and even scales of fish, although they are considered waste and thrown away in much of the developed world, are actually the parts that are highest in micronutrients such as iodine, selenium, zinc, calcium, potassium, and vitamins (FAO 2011). Some kinds of cooking, fermentation, and pickling can make these nutrients more available and digestible, or reduce the content dramatically.

According to the US National Institutes of Health (NIH), “seafood consumption is associated with potential health benefits, including neurologic development during gestation and infancy and reduced risk of heart disease” (Iwamoto et al. 2010). The United Nations Food and Agriculture Organization (FAO 2016b) calls fish “nature’s super food” for its nutritional components. In the 1950s Ralph T. Holman, a researcher at the Hormel Institute, a research division of the Hormel Food Corporation, coined the terms omega-3s and omega-6s for the essential fatty acids in foods(Holman 1998). Fish oil is widely available in many forms as a dietary supplement. Long-chain omega-3 fatty acids— docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)—are particularly valued as nutrients essential for optimal neurodevelopment in infants and young children. Fatty dark-fleshed fish like herring and mackerel have much higher content of omega-3 fatty acids, while lean white-fleshed fish like mahi-mahi or barracuda have much less. Paradoxically however, fish with a lot of body fat are also the most likely to accumulate toxins and heavy metals, and diners are often warned to remove all the fat from fish caught in polluted waters. Dietary guidelines from the US Food and Drug Administration (FDA) suggest eating two or three fish meals per week, preferably fatty fish, to improve cardiovascular health and reduce the risk of coronary heart disease (Gebauer et al. 2006).

It is worth remembering the limits of nutritional science. Traditional folklore in Europe recommended fish as “brain food”, and similar recommendations can be found in many other cultures. Over the last few decades, nutritionists and public health advocates have claimed to find many different positive effects of fish consumption in human diets, creating a long list of diseases and ailments that can be prevented by eating more fish, including Alzheimer’s disease and other dementias, strokes, metabolic syndrome, obesity, diabetes, asthma, and deteriorating vision. Some even claim that eating more fish can cure your acne, help you avoid arthritis, lower the risk of cancer, speed up your metabolism, increase your concentration and attention span, improve your sleep, keep you from getting depressed, and make you a generally happier person (Morris et al. 2003; Baik et al. 2010).

We should remember, however, that most of the studies that these recommendations are based upon are weak and are at best indicative rather than conclusive. They generally measure the fish consumption of a sample of people, and then compare this with the incidence of different diseases. This is the standard method in nutritional epidemiology, and it is full of potential flaws, so it can be very misleading.

First, they rarely directly measure how much fish or seafood a person is eating; instead they depend on self-reporting, which can be very unreliable. Most people cannot recall everything they ate during the past week or even month with any accuracy, and they are notoriously unreliable in reporting how much they eat.

Second, the actual group of people being studied is often small and/or biased. A study may enroll people who are quite unusual and atypical, and they are rarely representative of the ethnic and gender diversity of an entire population.

Third, most nutritional studies report only correlations, meaning that when you see one thing you also tend to see something else more often than you would find by chance. One of the most basic flaws in all social science research is confusing correlation and causation; just because two things co-occur does not mean that one causes the other. For example, people who live near the ocean could be richer than average, and while they eat more fish than people living inland, they may be healthier because they have better access to medical care, less strenuous work, or any number of other factors. They eat more fish, but they probably also drink more red wine and fresh fruits and vegetables and have time to go to the gym and exercise.

While this science about nutrition and seafood is complicated, the actual claims in reliable studies are modest, and the results are carefully stated and qualified, but when those scientific results make their way into the popular press they are often distorted and exaggerated to a ridiculous degree. For example, the US Agency for Healthcare Research and Quality (AHRQ) put together a panel of scientists to review many studies of the effects of ingesting omega-3 fatty acids on diseases of the eyes (Hodge et al. 2005). They conclude that there is no clear evidence one way or the other, because while some studies showed positive effects, others were neutral or negative, and all the studies had flaws that made their results questionable.

Yet, the “Eat This, Not That” website, in an article...