Compared to most meats and poultry, fish is much lower in total fat and saturated fat, is a source of very high-quality protein, supplies lots of vitamins and minerals and contains high levels of omega-3 fatty acids. By adding one or two fish meals to your family’s diet each week, you can net some very hefty health benefits. Salmon should not be raised in farms if you are relying on this fish as your Omega-3 oil source. Caution must also be exercised with regard to the mercury content of larger predatory fish. Some doctors have been known to take a capsule of DMSA each time they consume fish containing mercury as a precautionary measure.
The seafood lowest in methylmercury include: catfish (farmed), blue crab (mid-Atlantic), croaker, fish sticks, flounder (summer), haddock, trout (farmed), salmon (wild pacific) and shrimp.
The important omega-3 fatty acids, EPA and DHA, are better absorbed when eating the fish, such as wild salmon, compared to just taking fish oil supplements. Please see the Treatment “Fish Oils” for further details.
Increased Fish Consumption can help with the following
Multiple Sclerosis / Risk
The Swank diet includes eating fish at least 3 times per week. Alternately, fish oils could be substituted at 1500mg three or more times per week.
Increased Risk of Stroke
Eating fish, one or more times per month, was associated with a reduced risk of ischemic stroke in a study of 43,671 men aged 40 to 75 years followed for 12 years. No associations were found between fish or long-chain omega-3 polyunsaturated fatty acid intake and risk of hemorrhagic stroke.
The use of fish oil or increased consumption of omega-3 fatty acids should have the same effect. [JAMA 2002;288(24): pp.3130-6]
Mercury Toxicity / Amalgam Illness
There is increasing concern over fish which are being found to contain significant levels of mercury. These potentially dangerous levels are coming from fish eating smaller fish – methyl mercury bio-accumulates over time. The large predator fish, such as swordfish/marlin, ahi (yellow fin tuna), king mackerel, shark (often sold as imitation crab), and tilefish have the highest accumulations because they are at the top of the food chain (well, almost!). Many people who consume significant amounts of these fish are showing very elevated levels of mercury in their hair. The FDA is currently recommending most other fish as safe for consumption at amounts of 1kg per week or less.
Mercury enters the environment naturally and through industrial pollution. Cutting back on seafood is a way of cutting down on blood mercury levels, but the benefits of seafood, including omega-3 fatty acids and selenium, should be balanced against the mercury risk.
The U.S. Environmental Protection Agency’s recommended reference dose, or level below which exposures are considered harmless, of mercury in the blood is 5.8 micrograms per liter. The average level of mercury in the women’s blood in this particular study, was about one microgram per liter, well below the reference dose.
However, about 8% of the women had levels that above the reference dose. Further, women who ate at least three servings of fish during the 30 days prior to the study had mercury levels of close to two micrograms per liter – four times higher than those of women who did not eat fish.
Adult women had three times higher blood mercury levels than children, partly because adults tend to eat more fish than children, according to researchers.
Fish such as haddock, tilapia, salmon, cod, pollock and sole, as well as most shellfish tend to be relatively low in methylmercury, according to researchers. [JAMA April 2, 2003;289: pp.1667-1674]
Diabetes Type II
Eating fish twice a week may help diabetes patients. By Mary Brophy Marcus, USA TODAY November 3, 2008
Centering supper around a fish dish at least twice a week might help people with diabetes lower their risk of kidney disease, a study suggests. In the November issue of the American Journal of Kidney Diseases, British researchers analyzed the records of more than 22,300 middle-aged and older English men and women who were part of a large European cancer study. They wanted to examine the effect of eating fish on kidney disease.
The study subjects had answered questionnaires about their diet habits, including how much fish they ate a week, and had provided urine samples, which were analyzed for the presence of a protein called albumin, an indicator of kidney damage.
The researchers reported that of the 517 study subjects who had diabetes (most of whom had type 2), those who on average ate less than one serving of fish each week were four times more likely to have albumin in their urine than people with diabetes who ate fish twice a week. “Protein in the urine is one of the earliest signs of kidney disease, a serious complication of diabetes,” says study co-author Amanda Adler, an epidemiologist with the Medical Research Council Epidemiology Unit at Addenbrooke’s Hospital in Cambridge.
Adler speculates that the nutrient content of fish may affect kidney function and improve blood glucose control. But what kind of fish makes the biggest health splash wasn’t determined.
“We didn’t ask about the type of fish people ate, but in this bit of England people eat cod, plaice, haddock, canned tuna. Even fish and chips would have been included,” she says.
Susan Spratt, assistant professor of medicine in the division of endocrinology at Duke University Medical Center, says it’s too early to recommend diet changes based on the findings, noting that cause and effect are hard to determine in this type of epidemiological study. “People who eat fish might have other healthier habits,” she says.
To prove fish could be a kidney disease-fighting factor in diabetes, clinical trials would be required in which people with diabetes ate fish and others did not, she says. “But it wouldn’t hurt patients to eat more fish,” says Spratt, who recommends fish oil to lower triglycerides in her diabetes patients who do not respond to or tolerate other therapies.
For dinner, stick with low-fat broiled and baked recipes, she says.
Cancer / Risk - General Measures
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
The short term (2 week) use of fish oil, late in the course of cancer, provided no noticeable benefits. 1.8gm per day EPA and 1.2gm per day DHA had no effect on appetite, tiredness, nausea, well-being, caloric intake, or nutritional status. [ J Clin Oncol 2003;21(1): pp.129-34]
Increased Risk of Esophageal Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Stomach Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Colon Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30-50% lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30% lower risk), endometrial cancer (20% lower risk), and ovarian cancer (30% lower risk).
Increased Risk of Rectal Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Pancreatic Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Cancer Of The Larynx
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Ovarian Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Increased Risk of Coronary Disease / Heart Attack
A large-scale study in Japan drawing from 24 populations in 16 countries revealed a strong, inverse association between levels of taurine excretion and ischemic heart disease. [Hypertens Res 2001 Jul;24(4): pp.453-7] Fish are high in taurine.
Increased Risk of Endometrial Cancer
Study subjects who ate two or more servings of fish weekly had a much lower risk for esophageal, stomach, colon, rectum, and pancreatic cancers than those who avoided fish. In fact, the rates of these types of cancer were 30 to 50 percent lower among fish eaters. High fish consumption was also associated with lower risks for cancers of the larynx (30 percent lower risk), endometrial cancer (20 percent lower risk), and ovarian cancer (30 percent lower risk).
Motherhood Issues
Based on the recommendations of the Environmental Working Group and the U.S. Public Interest Research Group, it is recommended that shark, swordfish, king mackerel and tilefish, tuna, sea bass, halibut, marlin, pike, Gulf coast oysters and white croaker not be eaten by pregnant women and women of childbearing age who might become pregnant due to mercury contamination. It also recommended that nursing mothers and young children steer clear of these fish. In addition, the report says canned tuna, mahi-mahi, cod and pollack should not be eaten more than once a month.
Possible Pregnancy-Related Issues
Based on the recommendations of the Environmental Working Group and the U.S. Public Interest Research Group, it is recommended that shark, swordfish, king mackerel and tilefish, tuna, sea bass, halibut, marlin, pike, Gulf coast oysters and white croaker not be eaten by pregnant women and women of childbearing age who might become pregnant due to mercury contamination. It also recommended that nursing mothers and young children steer clear of these fish. In addition, the report says canned tuna, mahi-mahi, cod and pollack should not be eaten more than once a month.
“The widespread contamination of fish with mercury has given its reputation as ‘brain food’ a new and disturbing connotation. Mercury is toxic to the developing fetal brain, and exposure in the womb can cause learning deficiencies and delay mental development in children.”
A Center for Disease Control report finds that an estimated 375,000 babies being born each year at risk of neurological problems due to exposure to mercury in the womb. The Mercury Policy Project report indicates that at least 10 percent of women of childbearing age have levels of mercury in their bodies that exceed what the U.S. Environmental Protection Agency considers acceptable and this translates to nearly six million women.
It is a tragedy that the modern way of living has damaged a very healthy food with mercury toxicity as a result of burning coal for electricity, which releases mercury into the atmosphere. Generally the larger the fish, the more mercury it contains. It would be best to avoid fish consumption during pregnancy and strictly limit it thereafter in young children. On the other hand, fish oil, containing essential fatty acids, is usually free of mercury as a result of processing and its use has been shown to reduce the frequency of preterm deliveries.
Key
| May do some good |
| Likely to help |
| May have adverse consequences |
| Reasonably likely to cause problems |
| Avoid absolutely |
Glossary
Saturated Fat
A type of fat that is readily converted to LDL cholesterol and is thought to encourage production of arterial disease. Saturated fats tend to be hard at room temperature. Among saturated fats are animal fats, dairy products, and such vegetable oils as coconut and palm oils.
Protein
Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.
Mineral
Plays a vital role in regulating many body functions. They act as catalysts in nerve response, muscle contraction and the metabolism of nutrients in foods. They regulate electrolyte balance and hormonal production, and they strengthen skeletal structures.
Fatty Acids
Chemical chains of carbon, hydrogen, and oxygen atoms that are part of a fat (lipid) and are the major component of triglycerides. Depending on the number and arrangement of these atoms, fatty acids are classified as either saturated, polyunsaturated, or monounsaturated. They are nutritional substances found in nature which include cholesterol, prostaglandins, and stearic, palmitic, linoleic, linolenic, eicosapentanoic (EPA), and decohexanoic acids. Important nutritional lipids include lecithin, choline, gamma-linoleic acid, and inositol.
EPA
Environmental Protection Agency. Also: Eicosapentanoic Acid. A metabolite of the omega-3 fatty acid alpha-linolenic acid.
DHA
Docosahexanoic Acid. A metabolite of the omega-3 fatty acid alpha-linolenic acid.