Healthy Food - Salmon

Healthy Food - Salmon. Salmon /ˈsæmən/ is the common name for several species of fish in the family Salmonidae. Other fish in the same family include trout, char, grayling and whitefish. Various species of salmon display anadromous life strategies while others display freshwater resident life strategies. Salmon are native to tributaries of the North Atlantic (genus Salmo) and Pacific Ocean (genus Oncorhynchus). Many species of salmon have been introduced into non-native environments such as the Great Lakes of North America and Patagonia in South America. Salmon are intensively produced in aquaculture in many parts of the world.


Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, populations of several species are restricted to fresh water through their lives. Folklore has it that the fish return to the exact spot where they were born to spawn; tracking studies have shown this to be true, and this homing behavior has been shown to depend on olfactory memory.

Description

With exceptional nutritional value due to their rich concentration of omega-3 fatty acids, salmon is a favorite among fish lovers and enjoyed even by those who are not always fond of fish. Salmon are incredible fish sometimes traveling thousands of miles throughout their life cycle and within two to five years returning to the very location where they were born to spawn and die. The specific characteristics and life cycles of salmon vary with each species. (For example, king salmon has a life cycle of approximately 4-6 years, sockeye, 4-6 years, and silver 3-4 years.)

A good portion of salmon can be classified either as Pacific (Oncorhynchus genus) or Atlantic (Salmo genus) salmon, according to the ocean in which they are found. There is just one native species of Atlantic salmon (Salmo salar), while there are many species of Pacific salmon including chinook (or king), sockeye (or red), coho (or silver), pink, and chum. Norwegian salmon, a popular type of salmon often offered on restaurant menus, is actually Atlantic salmon that is farm-raised in Norway. The flesh of salmon ranges in color from pink to red to orange with some varieties richer in important omega-3 fatty acids than others. For example, chinook and sockeye are fattier fish than pink and chum and contain great amounts of healthy omega-3 fatty acids.

The native habitats of Atlantic and Pacific salmon as described above no longer characterize most of salmon consumed in the United States or in many other countries. Because farmed salmon now accounts for about 80% of all salmon consumed worldwide, it is becoming harder and harder to find wild-caught salmon that live in their native habitat.

History

People have been enjoying salmon as a food ever since this beautiful fish appeared in the Earth's waters. Like other fish, in addition to being consumed in fresh form, preservation techniques such as smoking or salting were used to preserve the salmon. Smoked salmon is still considered traditional fare in many cuisines throughout the world. Healthy Food - Salmon.

Since 1980, global salmon production has increased over 400% in volume, with over 2,400,000 metric tons of salmon being produced in 2004 compared with less than 600,000 metric tons in 1980. Most of this increase has come from production of farmed salmon. (The amount of farmed salmon in today's marketplace is more than 1,000,000 metric tons greater than it was in 1980.) Farmed salmon now accounts for more than 80% of the world's salmon supply. Within this changing salmon marketplace, North American wild salmon, which used to account for about half of the world's wild salmon supply, now only accounts for about 15%. The farming of salmon has increased dramatically in Europe, and Japan and Russia each currently farm about 500,000 tons of salmon.

The trend toward greatly increased salmon farming has been an ongoing concern to many researchers who study the ecological impact of farmed salmon, including the impact on wild salmon populations. Salmon farming has also concerned many researchers from a health standpoint. Farmed salmon—when raised in a non-sustainable way and without regard for the organic standards that exist in some countries outside the U.S. have repeatedly been found to have measurable and undesirable amounts of numerous contaminants. Some researchers have raised the question of whether sustainable salmon farming is even possible, given the natural habits of salmon and the unique habitats that have historically supported their vitality.

Distribution

• Atlantic salmon (Salmo salar) reproduces in northern rivers on both coasts of the Atlantic Ocean.
• Chinook salmon (Oncorhynchus tshawytscha) is also known in the US as king salmon or blackmouth salmon, and as spring salmon in British Columbia. Chinook are the largest of all Pacific salmon, frequently exceeding 30 lb (14 kg). The name Tyee is used in British Columbia to refer to Chinook over 30 pounds, and in Columbia River watershed, especially large Chinook were once referred to as June hogs. Chinook salmon are known to range as far north as the Mackenzie River and Kugluktuk in the central Canadian arctic, and as far south as the Central California Coast.
• Chum salmon (Oncorhynchus keta) is known as dog, keta, or calico salmon in some parts of the US. This species has the widest geographic range of the Pacific species: south to the Sacramento River in California in the eastern Pacific and the island of Kyūshū in the Sea of Japan in the western Pacific; north to the Mackenzie River in Canada in the east and to the Lena River in Siberia in the west.
• Coho salmon (Oncorhynchus kisutch) is also known in the US as silver salmon. This species is found throughout the coastal waters of Alaska and British Columbia and as far south as Central California (Monterey Bay). It is also now known to occur, albeit infrequently, in the Mackenzie River.
• Landlocked salmon (Salmo salar m. sebago) live in a number of lakes in eastern North America and in Northern Europe, for instance in lakes Sebago, Onega, Ladoga, Saimaa, Vänern and Winnipesaukee. They are not a different species from the Atlantic salmon, but have independently evolved a non-migratory life cycle, which they maintain even when they could access the ocean.
• Masu salmon or cherry salmon (Oncorhynchus masou) is found only in the western Pacific Ocean in Japan, Korea and Russia. A land-locked subspecies known as the Taiwanese salmon or Formosan salmon (Oncorhynchus masou formosanus) is found in central Taiwan's Chi Chia Wan Stream.
• Pink salmon (Oncorhynchus gorbuscha), known as humpies in southeast and southwest Alaska, are found from northern California and Korea, throughout the northern Pacific, and from the Mackenzie River in Canada to the Lena River in Siberia, usually in shorter coastal streams. It is the smallest of the Pacific species, with an average weight of 3.5 to 4.0 lb (1.6 to 1.8 kg).
• Sockeye salmon (Oncorhynchus nerka) is also known in the US as red salmon. This lake-rearing species is found south as far as the Klamath River in California in the eastern Pacific and northern Hokkaidō island in Japan in the western Pacific and as far north as Bathurst Inlet in the Canadian Arctic in the east and the Anadyr River in Siberia in the west. Although most adult Pacific salmon feed on small fish, shrimp and squid; sockeye feed on plankton they filter through gill rakers. Kokanee salmon is a land-locked form of sockeye salmon.
• The Danube salmon or huchen (Hucho hucho), is the largest permanent fresh water salmonid species.

Ecology

Bears and salmon

In the Pacific Northwest and Alaska, salmon are keystone species, supporting wildlife such as birds, bears and otters. The bodies of salmon represent a transfer of nutrients from the ocean, rich in nitrogen, sulfur, carbon and phosphorus, to the forest ecosystem. Healthy Food - Salmon.

Grizzly bears function as ecosystem engineers, capturing salmon and carrying them into adjacent wooded areas. There they deposit nutrient-rich urine and faeces and partially eaten carcasses. Bears are estimated to leave up to half the salmon they harvest on the forest floor, in densities that can reach 4,000 kilograms per hectare, providing as much as 24% of the total nitrogen available to the riparian woodlands. The foliage of spruce trees up to 500 m (1,600 ft) from a stream where grizzlies fish salmon have been found to contain nitrogen originating from fished salmon.

Beavers and salmon

Beavers also function as ecosystem engineers; in the process of clear-cutting and damming, beavers alter their ecosystems extensively. Beaver ponds can provide critical habitat for juvenile salmon. An example of this was seen in the years following 1818 in the Columbia River Basin. In 1818, the British government made an agreement with the U.S. government to allow U.S. citizens access to the Columbia catchment (see Treaty of 1818). At the time, the Hudson's Bay Company sent word to trappers to extirpate all furbearers from the area in an effort to make the area less attractive to U.S. fur traders. In response to the elimination of beavers from large parts of the river system, salmon runs plummeted, even in the absence of many of the factors usually associated with the demise of salmon runs. Salmon recruitment can be affected by beavers' dams because dams can:

• Create low-energy environments where juvenile salmon put the food they ingest into growth rather than into fighting currents
• Increase productivity through photosynthesis and by enhancing the conversion efficiency of the cellulose-powered detritus cycle
• Increase structural complexity with many physical niches where salmon can avoid predators


• Provide deeper water pools where young salmon can avoid avian predators
• Slow the rate at which nutrients are flushed from the system; nutrients provided by adult salmon dying throughout the fall and winter remain available in the spring to newly hatched juveniles

Beavers' dams are able to nurture salmon juveniles in estuarine tidal marshes where the salinity is less than 10 ppm. Beavers build small dams of generally less than 2 feet (60 cm) high in channels in the myrtle zone. These dams can be overtopped at high tide and hold water at low tide. This provides refuges for juvenile salmon so they do not have to swim into large channels where they are subject to predation.

Parasites

According to Canadian biologist Dorothy Kieser, the myxozoan parasite Henneguya salminicola is commonly found in the flesh of salmonids. It has been recorded in the field samples of salmon returning to the Haida Gwaii Islands. The fish responds by walling off the parasitic infection into a number of cysts that contain milky fluid. This fluid is an accumulation of a large number of parasites.

Henneguya and other parasites in the myxosporean group have complex life cycles, where the salmon is one of two hosts. The fish releases the spores after spawning. In the Henneguya case, the spores enter a second host, most likely an invertebrate, in the spawning stream. When juvenile salmon migrate to the Pacific Ocean, the second host releases a stage infective to salmon. The parasite is then carried in the salmon until the next spawning cycle. The myxosporean parasite that causes whirling disease in trout has a similar life cycle. However, as opposed to whirling disease, the Henneguya infestation does not appear to cause disease in the host salmon even heavily infected fish tend to return to spawn successfully.

According to Dr. Kieser, a lot of work on Henneguya salminicola was done by scientists at the Pacific Biological Station in Nanaimo in the mid-1980s, in particular, an overview report which states, "the fish that have the longest fresh water residence time as juveniles have the most noticeable infections. Hence in order of prevalence coho are most infected followed by sockeye, chinook, chum and pink." As well, the report says, at the time the studies were conducted, stocks from the middle and upper reaches of large river systems in British Columbia such as Fraser, Skeena, Nass and from mainland coastal streams in the southern half of B.C., "are more likely to have a low prevalence of infection." The report also states, "It should be stressed that Henneguya, economically deleterious though it is, is harmless from the view of public health. It is strictly a fish parasite that cannot live in or affect warm blooded animals, including man".

According to Klaus Schallie, Molluscan Shellfish Program Specialist with the Canadian Food Inspection Agency, "Henneguya salminicola is found in southern B.C. also and in all species of salmon. I have previously examined smoked chum salmon sides that were riddled with cysts and some sockeye runs in Barkley Sound (southern B.C., west coast of Vancouver Island) are noted for their high incidence of infestation."

Sea lice, particularly Lepeophtheirus salmonis and various Caligus species, including C. clemensi and C. rogercresseyi, can cause deadly infestations of both farm-grown and wild salmon. Sea lice are ectoparasites which feed on mucus, blood, and skin, and migrate and latch onto the skin of wild salmon during free-swimming, planktonic nauplii and copepodid larval stages, which can persist for several days. Large numbers of highly populated, open-net salmon farms can create exceptionally large concentrations of sea lice; when exposed in river estuaries containing large numbers of open-net farms, many young wild salmon are infected, and do not survive as a result. Adult salmon may survive otherwise critical numbers of sea lice, but small, thin-skinned juvenile salmon migrating to sea are highly vulnerable. On the Pacific coast of Canada, the louse-induced mortality of pink salmon in some regions is commonly over 80%.

What's New and Beneficial about Salmon

• Along with lower risk of contamination from wild-caught Alaskan salmon, we like what experts are saying about the greater sustainability of Alaskan salmon runs. For example, the Monterey Bay Aquarium in Monterey, California has recently determined Alaskan salmon to be the only low-risk salmon in terms of four sustainability criteria: the inherent vulnerability of the fish, the effects of fishing on the overall habitat, the status of wild stocks, and the nature of the by-catch (the other types of fish that are caught unintentionally during salmon fishing).
• Even though contamination with mercury, pesticides, and persistent organic pollutants (POPS) has become a widespread problem in salmon habitats and with the quality of salmon itself, there are still salmon runs that pose relatively low risk in terms of contaminants. Leading this low-risk category for wild-caught salmon are Alaskan salmon. Southeast Alaskan chum, sockeye, coho, pink, and chinook salmon, together with Kodiak coho, pink, and chum salmon have all been evaluated for contaminant consumption risk involving many POPs (including dioxins, dioxin-like compounds, or DLCs, and polychlorinated biphenyls, or PCBs) and have been found to be the lowest risk category of wild-caught salmon for regular consumption. This lower contamination risk amongst all wild-caught salmon is one of the reasons we recommend selection of wild-caught Alaskan salmon as a salmon of choice. (While some salmon runs from British Columbia and the U.S. West Coast also stand out as lower risk in terms of contaminants, we do not feel enthusiastic about recommending them for consumption due to the more precarious sustainability of these salmon runs.)
• Like other seafood, salmon is still not covered under regulations issued by the U.S. National Organics Program (NOP). However, the National Organics Standards Board has officially adopted recommendations for seafood (including salmon) and government officials at the U.S. Department of Agriculture have plans to implement these new regulations by adding them to the National List and issuing rules for compliance. Recommendations from the NOSB currently include:
• allowance of up to 25% fish oil and fish meal from wild-caught fish in the feeding of farmed organic salmon
• no certification of any wild-caught salmon
• organic certification of farmed salmon that meet certain standards
• permitted use of net pens and inland containment facilities
• With so much focus on the amazing omega-3 benefits of salmon, other unique health benefits from salmon may have been inadvertently overlooked. One fascinating new area of health benefits involves the protein and amino acid content of salmon. Several recent studies have found that salmon contains small bioactive protein molecules (called bioactive peptides) that may provide special support for joint cartilage, insulin effectiveness, and control of inflammation in the digestive tract. One particular bioactive peptide called calcitonin (sCT) has been of special interest in these studies. The reason is because a human form of calcitonin is made by the thyroid gland, and we know that it is a key hormone for helping regulate and stabilize the balance of collagen and minerals in the bone and surrounding tissue. As researchers learn more and more about salmon peptides including sCT we expect to see more and more potential health benefits discovered related to inflammation, including inflammation of the joints.

All aspects of the NOSB recommendations remain controversial. The limitation of organic certification to farmed salmon appears to have been related to the NOSB's desire for certainty about compliance of salmon production with organic regulations as well as its belief that verification of compliance for wild-caught salmon would simply not be possible. However, many advocates of sustainable food argue that farming creates an unnatural habitat for fish and is likely to compromise fish quality. Since organic regulations prohibit the use of animal by-products in the feeding of land animals (like cows or chickens), this area of certification for farmed fish has been equally controversial. When salmon migrate out to sea, many different types of fish are included in their natural diet. From this perspective, it would seem appropriate to allow the feeding of fish oil and fish meal from wild-caught fish to farmed organic salmon. However, at the same time, prohibited feeding of non-organic animal by-products to cows, chickens, and other land animals has played an important role in assuring organic quality. When animals are being raised for organic food, it's obvious that non-organic animal by-products in their diet increase risk of contamination.

While we welcome the idea of certification standards for organic seafood, we aren't convinced that the current NOSB recommendations make good sense. For this reason, if the current recommendations are implemented into law, we will continue to recommend selection of wild-caught Alaskan salmon as a salmon of choice, even over certified organic, farm-raised salmon. However, if changes are made in the current NOSB recommendations, we'll re-evaluate your best chances of getting optimal nourishment from any salmon that you decide to include in your meal plan.

Health Benefits

Benefits Related to Omega-3 Content
Salmon has earned its research reputation as a health-supportive food based largely on its unusual omega-3 fatty acid content. It's very common for 4 ounces of baked or broiled salmon to contain at least 2 grams of omega-3 fats—more than the average U.S. adult gets from all food over the course of several days. (If we consider 4 grams of omega-3 fatty acids to be a daily goal for a person consuming a 2,000 calorie diet—based upon recommendations from the 1999 Workshop on the Essentiality of and Recommended Dietary Intakes (RDI) for Omega-6 and Omega-3 Fatty Acids sponsored by the National Institutes of Health (NIH)—then this would equal about 50% of this goal. For more on this, see our write-up on omega-3s.)

About half of this omega-3 fat is provided in the form of EPA (eicosapentaenoic acid) and a slightly lower amount is provided in the form of DHA (docosahexaenoic acid). The amounts of EPA and DHA contained in salmon are unusual among commonly-eaten foods. In addition to this high concentration of omega-3 fats is the relatively small amount of omega-6 fats in salmon and its outstanding ratio of omega-3 to omega-6. Four ounces of salmon will typically contain less than 1/2 gram of omega-6 fat, for an omega-3 to omega-6 ratio of approximately 5.5 to 1. In the average U.S. diet, this ratio has repeatedly been shown to be lop-sided in the opposite direction, with at least 4-5 times as much omega-6 fat as omega-3 fat, and in some studies, up to 12-20 times more. In our World's Healthiest Foods rating system for food, only two foods provide more omega-3s per standard serving than salmon. Those two foods are walnuts and flaxseeds. Both of these plant foods are outstanding sources of omega-3s! However, they cannot be compared on an equal basis to salmon because their omega-3 fats come in the form of alpha-linolenic acid (ALA) rather than EPA or DHA.

The widely-studied benefits of omega-3 fatty acids are documented in our Omega-3 Fatty Acids profile in the Essential Nutrients section of our website. In general, these benefits involve improved control of the body's inflammatory processes, better overall cell function, improved transfer of information between the body's cells, and better brain function. When researchers look specifically at intake of omega-3-containing fish like salmon, they find health support in all of the above areas. However, some areas of omega-3 support are what we would call "standout" areas. These areas include:

Benefits Related to Protein and Amino Acid Content
The outstanding omega-3 benefits of salmon are not this food's only claim to unique health support. One intriguing new area of health benefits for salmon involves the protein and amino acid content of this fish. Several recent studies have found that salmon contains small bioactive protein molecules (called bioactive peptides) that may provide special support for joint cartilage, insulin effectiveness, and control of inflammation in the digestive tract. We've seen recent studies, for example, on salmon peptides and treatment of ulcerative colitis. We also have to wonder whether intake of salmon peptides may be related to the reduced risk of colorectal cancer that is associated with consumption of this food. One particular bioactive peptide called calcitonin has been of special interest in these salmon and amino acid studies. The human body makes its own human form of calcitonin (through a process which takes place in the thyroid gland), and we know that calcitonin is a key hormone for helping regulate and stabilize the balance of collagen and minerals in the bone and surrounding tissue. As researchers learn more and more about salmon peptides—including calcitonin (sCT), and its relationship to human calcitonin—we expect to see more and more of salmon's potential.

Benefits Related to Selenium
Another nutrient concentrated in salmon worthy of special mention is selenium. In terms of absolute selenium amount, salmon ranks in our WHFoods top 10, and four ounces provide about 62% of the Daily Value (DV) for this mineral. Strong selenium intake is associated with decreased risk of joint inflammation, and also with prevention of certain types of cancer, including colorectal cancer. As an antioxidant nutrient, selenium has also been shown to be especially important in cardiovascular protection through maintenance of the molecule glutathione. Each of these selenium-related benefits overlaps with other spotlight areas for salmon as a health-supportive food.

Cardiovascular Benefits
Intake of fish rich in omega-3 fat (including salmon) is associated with decreased risk of numerous cardiovascular problems, including: heart attack, stroke, heart arrhythmia, high blood pressure, and high triglycerides in the blood. Intake of omega-3-containing fish is also associated with improved metabolic markers for cardiovascular disease. Some cardiovascular benefits from omega-3 fat in fish like salmon start with only one omega-3 fish meal per week. Most of the benefits, however, start to show up in research studies with somewhat higher fish intake, along the lines of 2-3 times per week. In most studies, one serving of fish is approximately 6 ounces. Studies of fish intake and cardiovascular risk sometimes measure benefits against total grams of omega-3 fats obtained in the daily diet. In many of these studies, a daily minimum of 2 grams of omega-3s is required for measurable cardiovascular protection. (Remember that this 2-gram amount is the amount contained in approximately 4 ounces of cooked salmon.)

Decreased Cancer Risk
Intake of fish rich in omega-3 fat is also associated with decreased risk for several types of cancer. These cancer types include colorectal cancer, prostate cancer, and breast cancer. Some of the strongest findings for decreased cancer risk following regular intake of omega-3 fish involve the blood cell or lymph cell-related cancers including leukemia, multiple myeloma, and non-Hodgkins lymphoma. Similar to cardiovascular studies, cancer risk studies typically begin to show measurable benefits when omega-3 fish are consumed at least once per week.

Eye Benefits
Omega-3 intake and consumption of omega-3 fish has been associated with decreased risk of two eye-related problems: macular degeneration and chronic dry eye. In the case of macular degeneration (a chronic eye problem in which material in the center of the retina on the back of the eyeball begins to deteriorate and cause loss of vision), two fish servings per week is the amount that has been shown to significantly decrease risk. For decreased risk of chronic dry eye, a somewhat higher amount of omega-3 fish intake (2-4 servings per week) was the minimum amount needed, with 5-6 weekly servings showing even greater reduction of risk.

Like brain studies on omega-3 fish intake, dry eye studies have started to look specifically at neuroprotectins made from DHA in salmon and other omega-3 fish. These omega-3 derived molecules may help prevent chronic dry eye by lowering background levels of inflammation in the eye.

Improved Mood and Cognition
Many researchers consider DHA to be the most important fat found in the human brain, and the unusual concentration of this omega-3 fatty acid in salmon helps explain the research-documented benefits of salmon and omega-3 fish intake for thinking and the decreased risk of certain brain-related problems that accompanies omega-3 fish consumption. Intake of omega-3s and omega-3 containing fish is associated with decreased risk of depression, decreased risk of hostility in some studies of teenagers, and decreased risk of cognitive decline in older persons. Some studies have shown an association between IQ and omega-3 intake, and also between IQ and intake of omega-3 fish.

Especially interesting in this area of fish intake, DHA, and brain function is the relatively recent discovery of protectins. Protectins are special compounds made from DHA and preliminary research studies have shown them to have a potentially important role as anti-inflammatory regulatory molecules, especially when produced by nerve tissue. (When protectins are produced by nerve tissue, they are typically called "neuroprotectins.") Researchers have speculated that at least some of the brain-related benefits from omega-3 fish intake may be due to conversion of the DHA in these fish to protectins that can help prevent excessive inflammation.

Joint Protection
One fascinating area of omega-3 and omega-3 fish research has involved the joints. Research on fish intake and joint protection has shown that EPA from fish like salmon can be converted by the body into three types of closely-related compounds that work to prevent unwanted inflammation. One group of compounds are the series 3 prostaglandins. A second type are the series 3 thromboxanes. A third and more recently discovered type are the resolvins. All of these omega-3 fat derivatives are able to help prevent excessive and unwanted inflammation. What's especially interesting about salmon, however, is that it combines these anti-inflammatory benefits that are related to omega-3 content with anti-inflammatory benefits that are related not to fat but to protein. Recent studies demonstrate the presence of small bioactive protein molecules (called bioactive peptides) in salmon that may provide special support for joint cartilage (as well as other types of tissue). One particular bioactive peptide called calcitonin has been of special interest in these studies, because a human form of calcitonin is made in the human body by the thyroid gland, and we know that it is a key hormone for helping regulate and stabilize the balance of collagen and minerals in the bone and surrounding tissue. Salmon peptides—including calcitonin (sCT)—may join forces with salmon's omega-3 molecules to provide unique anti-inflammatory benefits for the joints

How to Select and Store
Salmon is sold in many different forms. Fresh salmon is available whole or in steak or fillet form. Salmon is also available frozen, canned, dried or smoked. Based on a combination of sustainability and potential contamination concerns, we recommend that you select wild-caught Alaskan salmon above all other forms of salmon currently available in the marketplace. If you cannot find wild-caught Alaskan salmon in your local grocery in fresh or frozen form, we recommend that you select wild-caught Alaskan salmon in canned form as a next best alternative.

With respect to potential contamination, we base our Alaskan salmon recommendation on recent research placing these salmon at the top of the low-risk list for potential contaminants, including pesticides, and persistent organic pollutants (POPS). Southeast Alaskan chum, sockeye, coho, pink, and chinook salmon, together with Kodiak coho, pink and chum salmon have all been evaluated for contaminant consumption risk involving many POPs (including dioxins, dioxin-like compounds (DLCs) and polychlorinated biphenyls, or PCBs) and have been found to be the lowest risk category of wild-caught salmon for regular consumption.

With respect to sustainability, we have been impressed with the work of the Monterey Bay Aquarium in Monterey, California and its establishment of Alaskan salmon as the only low-risk salmon in terms of four sustainability criteria: the inherent vulnerability of the fish, the effects of fishing on the overall habitat, the status of wild stocks, and the nature of the by-catch (fish other than salmon that are caught unintentionally during salmon fishing). There is one exception to this higher sustainability profile of Alaskan salmon, however, and that exception involves the by-catch related to wild-caught Alaskan chinook. With respect to by-catch, the Monterey Bay Aquarium has placed Alaskan chinook salmon in a moderate versus low-risk category in terms of sustainability. For this reason, you may want to choose other species of Alaskan salmon (like chum or coho or sockeye or pink) for the lowest sustainability risk.

Sustainability issues related to the selection of non-Alaskan salmon have become more and more apparent, especially with respect to U.S. West Coast salmon. In 2008 and for the first time in its history, the National Marine Fisheries Service shut down the U.S. West Coast ocean salmon fishing season due to the large drop in numbers of chinook salmon that were returning to the Sacramento River in California. Whereas 775,000 salmon had returned to this river to spawn in 2002, by 2008 the number of salmon expected to return had dropped dramatically. The Fisheries Service had set a target spawning goal of 122,000-180,000 for the Sacramento River chinook. However, at the time when the fishing season was shut down in 2008, only 54,000 had actually returned. Scientists believe that the loss of natural habitat in the San Francisco Delta is playing a role in the jeopardized sustainability of the Sacramento River chinook salmon run and point to a need for habitat restoration in this context.

Just as with any seafood, it is best to purchase salmon from a store that has a good reputation for having a fresh supply of fish. Get to know a fishmonger (person who sells the fish) at your grocery store, so you can have a trusted resource from whom you can purchase your fish.

Fresh whole salmon should be displayed buried in ice, while fillets and steaks should be placed on top of the ice. If you are purchasing a whole fish and want to eat the skin, have the salmon scaled. Healthy Food - Salmon.

Smell is a good indicator of freshness. Since a slightly "off" smell cannot be detected through plastic, if you have the option, purchase displayed fish as opposed to pieces that are prepackaged. Once the fishmonger wraps and hands you the fish that you have selected, smell it through the paper wrapping and return it if it does not smell right.

While smoked salmon is popular, we don't believe it to be as healthful as fresh or canned salmon. That's because in addition to having less omega-3s than non-smoked fish, smoked fish may contain toxic substances called polycyclic aromatic hydrocarbons (PAHs). For more on this subject, please see this Q+A.

When storing all types of seafood, including salmon, it is important to keep it cold since fish is very sensitive to temperature. Therefore, after purchasing salmon or other fish, make sure to return it to a refrigerator as soon as possible. If the fish is going to accompany you during a day full of errands, keep a cooler in the car where you can place the salmon to make sure it stays cold and does not spoil.

The temperature of most refrigerators is slightly warmer than ideal for storing fish. Therefore, to ensure maximum freshness and quality, it is important to use special storage methods to create the optimal temperature for holding the fish. One of the easiest ways to do this is to place salmon, which has been well wrapped, in a baking dish filled with ice. The baking dish and fish should then be placed on the bottom shelf of the refrigerator, which is its coolest area. Replenish ice one or two times per day.

The length of time that salmon can stay fresh stored this way depends upon how fresh it is, i.e. when it was caught. Fish that was caught the day before you purchased it can be stored for about four days, while fish that was caught the week before can only be stored for about one or two days.

You can extend the shelf life of salmon by freezing it. To do so, wrap it well in plastic and place it in the coldest part of the freezer where it will keep for about two to three weeks.

Tips for Preparing and Cooking

Tips for Preparing Salmon
Try to buy a whole salmon side or filet that is from the thickest part of the fish. For taste and texture reasons, many people prefer to remove the skin of the salmon. We definitely recommend skin removal if you are preparing wild-caught salmon other than Alaskan salmon or if you are preparing farmed salmon that is not certified organic. Our reason for skin removal in these circumstances is reduction of contaminant risk. Research has shown the skin of the salmon to contain measurable amounts of persistent organic pollutants (POPs) when salmon swim in contaminated waters. If you are preparing certified organic farmed salmon or wild-caught Alaskan salmon, however, you may want to leave the skin intact since it contains health supportive nutrients, including peptides with anti-inflammatory potential.

The Healthiest Way of Cooking Salmon
The best ways to cook salmon is by using methods that will keep it moist and tender. Salmon can be easily overcooked and become dry, so be sure to watch your cooking times. Healthy Food - Salmon.

One of our favorite ways to prepare salmon is using our "Quick Broil" method. Preheat the broiler on high and place an all stainless steel skillet (be sure the handle is also stainless steel) or cast iron pan under the heat for about 10 minutes to get it very hot. Place salmon on hot pan and broil for 7-10 minutes, depending on thickness. You do not need to turn the salmon. (See our Quick Broiled Salmon with Ginger Mint Salsa recipe for details on how to prepare "Quick Broiled" salmon.) While grilled salmon tastes great, make sure it does not burn. It is best to grill salmon on an area without a direct flame. Extra care should be taken when grilling, as burning can damage nutrients and create free radicals that can be harmful to your health. For more see Are there health risks with char-broiling and gas grilling foods?

As food

Salmon is a popular food. Classified as an oily fish, salmon is considered to be healthy due to the fish's high protein, high omega-3 fatty acids, and high vitamin D content. Salmon is also a source of cholesterol, with a range of 23–214 mg/100 g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon, but still well below levels considered dangerous. Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon still outweigh any risks imposed by contaminants. The type of omega-3 present may not be a factor for other important health functions.

Salmon flesh is generally orange to red, although white-fleshed wild salmon occurs. The natural colour of salmon results from carotenoid pigments, largely astaxanthin, but also canthaxanthin, in the flesh. Wild salmon get these carotenoids from eating krill and other tiny shellfish.

The vast majority of Atlantic salmon available around the world are farmed (almost 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%). Canned salmon in the US is usually wild Pacific catch, though some farmed salmon is available in canned form. Smoked salmon is another popular preparation method, and can either be hot or cold smoked. Lox can refer to either cold-smoked salmon or salmon cured in a brine solution (also called gravlax). Traditional canned salmon includes some skin (which is harmless) and bone (which adds calcium). Skinless and boneless canned salmon is also available.

Raw salmon flesh may contain Anisakis nematodes, marine parasites that cause anisakiasis. Before the availability of refrigeration, the Japanese did not consume raw salmon. Salmon and salmon roe have only recently come into use in making sashimi (raw fish) and sushi.

How to Enjoy

A Few Quick Serving Ideas

• Combine left-over cold salmon with greens and vegetables for a delicious salad.
• Quick Broil salmon and top with a honey mustard sauce.


• Serve seared, or broiled salmon over whole wheat pasta. Top with a sauce made with olive oil, dill weed, lemon peel, scallions and black pepper. Look for our healthy methods of Stovetop Searing and Quick Broiling.

Individual Concerns
Since 1946, the U.S. Department of Commerce, through its National Ocean and Atmospheric Administration (NOAA), operates the National Marine Fisheries Service and its Seafood Inspection Program (SIP). In addition, under the Seafood Hazard Analysis and Critical Control Point (HACCP) Regulation, the U.S. Food and Drug Administration is charged with the responsible of inspecting fish processing facilities in the U.S. However, since participation in SIP is voluntary, many fish are brought into the U.S. from other countries, and the HACCP fish processing inspection service only has the funding and manpower to inspect approximately 1% of fish products imported into the U.S., many consumers have become concerned about the safety of their fish, including their salmon. Given widespread contamination of marine habitats worldwide, this concern makes sense to us. We encourage consumers of fish to take special care in choosing all fish, including salmon. "Special care" might mean asking more questions to a local fish purveyor or taking extra time to locate high-quality fish like wild-caught Alaskan salmon. Some fish are not considered safe for pregnant or nursing mothers or young children to eat. Updated information in this area can be found at the U.S. Food and Drug Administration (FDA) website (http://www.fda.gov/food/foodsafety/). For information on the topic of seafood and mercury contamination, please see our article Should I be concerned about mercury in fish and what fish are safe to eat?

For some individuals, a second area of concern related to salmon is genetic engineering. In 2010, the U.S. Food and Drug Administration (FDA) held hearings on the proposed entry of genetically engineered Atlantic farmed salmon into the U.S. marketplace. Propriety, genetically-engineered salmon (proposed for sale under the commercial name AquAdvantage) have been developed using "antifreeze" genes from ocean eelpout (a type of fish) and growth hormone genes from chinook salmon to produce a type of salmon which can grow more quickly and will require less feed for its growth. In a period of several months, the FDA received nearly 400,000 public comments on the proposed allowance of GE salmon into the marketplace. In California, several state legislators have called for mandatory labeling of GE salmon sold in California if the sale of GE salmon is approved by the FDA and the FDA does not require labeling at a federal level. If the sale of GE salmon is allowed by the FDA, individuals wishing to avoid GE salmon intake will need to avoid any farmed salmon products not providing a GE-free label.

Salmon and Purines
Salmon contain naturally-occurring substances called purines. Purines are commonly found in plants, animals, and humans. In some individuals who are susceptible to purine-related problems, excessive intake of these substances can cause health problems. Since purines can be broken down to form uric acid, excess accumulation of purines in the body can lead to excess accumulation of uric acid. The health condition called "gout" and the formation of kidney stones from uric acid are two examples of uric acid-related problems that can be related to excessive intake of purine-containing foods. For this reason, individuals with kidney problems or gout may want to limit or avoid intake of purine-containing foods such as salmon.

Allergic Reactions to Salmon
Although allergic reactions can occur to virtually any food, research studies on food allergy consistently report more problems with some foods than with others. It's important to realize that the frequency of problems varies from country to country and can change significantly along with changes in the food supply or with other manufacturing practices. For example, in several part of the world, including Canada, Japan, and Israel, sesame seed allergy has risen to a level of major concern over the past 10 years.

In the United States, beginning in 2004 with the passage of the Food Allergen Labeling and Consumer Protection Act (FALCPA), food labels have been required to identify the presence of any major food allergens. Since 90% of food allergies in the U.S. have been associated with 8 food types as reported by the U.S. Centers for Disease Control, it is these 8 food types that are considered to be major food allergens in the U.S. and require identification on food labels. The 8 food types classified as major allergens are as follows: (1) wheat, (2) cow's milk, (3) hen's eggs, (4) fish, (5) crustacean shellfish (including shrimp, prawns, lobster and crab); (6) tree nuts (including cashews, almonds, walnuts, pecans, pistachios, Brazil nuts, hazelnuts and chestnuts); (7) peanuts; and (8) soy foods.

These foods do not need to be eaten in their pure, isolated form in order to trigger an adverse reaction. For example, yogurt made from cow's milk is also a common allergenic food, even though the cow's milk has been processed and fermented in order to make the yogurt. Ice cream made from cow's milk would be an equally good example.

Food allergy symptoms may sometimes be immediate and specific, and can include skin rash, hives, itching, and eczema; swelling of the lips, tongue, or throat; tingling in the mouth; wheezing or nasal congestion; trouble breathing; and dizziness or lightheadedness. But food allergy symptoms may also be much more general and delayed, and can include fatigue, depression, chronic headache, chronic bowel problems (such as diarrhea or constipation), and insomnia. Because most food allergy symptoms can be caused by a variety of other health problems, it is good practice to seek the help of a healthcare provider when evaluating the role of food allergies in your health.

Nutritional Profile
The unique protein and amino acid composition of salmon is often overlooked in its nutritional profile. Salmon contains short protein molecules called peptides that have been shown to be bioactive and may have important anti-inflammatory properties. Salmon also provides important amounts of the antioxidant amino acid taurine. The unique protein and amino acid composition of salmon is often overlooked in its nutritional profile. Salmon contains short protein molecules called peptides that have been shown to be bioactive and may have important anti-inflammatory properties. Salmon also provides important amounts of the antioxidant amino acid taurine. Salmon is an excellent source of vitamin B12, vitamin D, and selenium. It is a good source of niacin, omega-3 fatty acids, protein, phosphorus, and vitamin B6. It is also a good source of choline, pantothenic acid, biotin, and potassium.