Cod Cod health

Cod Cod

The white, mild flavored flesh of cod is available throughout the year and is a wonderful substitute for meat protein with its versatility making it easily adaptable to all methods of cooking.

Cod belong to the same family (Gadidae) along with both haddock and pollock. It's not surprising that the words "cod" and "cold" are so similar since cod need the cold, deep, Arctic waters to grow, reproduce and survive.

Food Chart
This chart graphically details the %DV that a serving of Cod provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Cod can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Cod, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Health Benefits
Description
History
How to Select and Store
How to Enjoy
Individual Concerns
Nutritional Profile
References

Health Benefits

Besides being an excellent low-calorie source of protein (a four-ounce serving of cod provides 52.1% of the daily need for protein for only 119 calories), cod contains a variety of very important nutrients and has also been shown to be useful in a number of different health conditions.

Cardiovascular Benefits

Fish, particularly cold water fish like cod, have been shown to be very beneficial for people with atherosclerosis and diabetic heart disease. Studies show that people who eat fish regularly have a much lower risk of heart disease and heart attack than people who don't consume fish. Cod, specifically, promotes cardiovascular health because it is a good source of blood-thinning omega-3 fatty acids, but is also a good source of vitamin B12 and a very good source of vitamin B6, both of which are needed to keep homocysteine levels low. This is important because homocysteine is a dangerous molecule that is directly damaging to blood vessel walls, and high homocysteine levels are associated with a greatly increased risk of heart attack and stroke(homocysteine is also associated with osteoporosis, and a recent study found that osteoporosis occurred more frequently among women whose vitamin B12 status was deficient or marginal compared with those who had normal B12 status.) Cod is also a very good source of niacin, another B vitamin that is often used to lower high cholesterol levels, something else that can lead to heart disease.

Increases Heart Rate Variabilityâ€"A Measure of Heart Muscle Function

One of the ways in which consuming fish rich in omega-3 fats, such as salmon, promotes cardiovascular health is by increasing heart rate variability (HRV), a measure of cardiac function, in as little as three weeks, according to a study published in the April 2005 issue of Chest.

By providing greater variability between beats, the marine omega 3 fatty acids, EPA and DHA, reduce the risk of arrhythmia and/or sudden death.

Researchers from Atlanta, GA, Boston, MA, and Cuernavaca, Mexico, took the HRV of 58 elderly patients every other day for two months to establish an HRV baseline for each participant. For the next 11 weeks, half of the study participants took a daily 2 gram supplement of fish oil and the other half took a daily 2 gram supplement of soy oil.

Patients in both groups experienced a significant increase in HRV, with those who took fish oil achieving a greater increase in a shorter time period. Patients who received fish oil experienced increased HRV within the first 2.7 weeks, whereas it took 8.1 weeks for a significant increase in HRV to be seen in the group taking soy oil.

On the other hand, while none of the study participants experienced significant negative side effects, 41% of participants in the fish oil group reported belching, compared to 16% in the soy oil group.

"Our findings contradict the current belief in the medical community that increasing the intake of omega-3 fatty acids produces only long-term cardiac benefits," said the study's lead author, Fernando Holguin, MD, Emory University School of Medicine, Atlanta, GA. "In fact, our study group showed improvements in heart function in as little as two weeks."

"Studies like this demonstrate that there are additional approaches we can take to protect ourselves from heart attacks," said Paul A. Kvale, MD, FCCP, President of the American College of Chest Physicians. "It's exciting to see the potential for omega-3 fatty acids in improving heart function when it complements a healthy lifestyle of exercising, maintaining a healthy weight, and getting eight hours of sleep."

We'd add eating healthful foods to this proactive list. Rather than pop a daily pill, we'd rather enjoy a daily "dose" of delicious cod, soyfoods, or tuna. For recipes certain to not only increase your heart rate variability but also your delight in eating, click Recipes.

Protection against Fatal Heart Arrhythmia

A healthy way of eating that includes at least 10 ounces of omega-3-rich fish each week improves the electrical properties of heart cells, protecting against fatal abnormal heart rhythms, suggests a study from Greece.

"Long-term consumption of fish is associated with lower QT interval in free-eating people without any evidence of cardiovascular disease. Thus, fish intake seems to provide anti-arrhythmic protection at a population level," wrote the authors in the American Journal of Clinical Nutrition. (Chrysohoou C, et al.)

The QT interval is a measure of the heart's electrical cycle, from the beginning of ventricular depolarization, the Q wave, to the end of the T wave, at which point cardiac repolarization is complete.

A lower QT score indicates a lower resting heart rate. As a higher resting heart rate has been linked to an increased risk of sudden death, the result of approximately 50% of heart attacks, lowering the resting heart rate provides significant health benefit.

Researchers at the University of Athens enrolled 3,042 people (1,514 men, aged 18-87, and 1,528 women, aged 18-89), who used a validated food frequency questionnaire to record their food intake of 156 different foods. Along with alcohol consumption and physical activity were also recorded, and electrocardiography was used to measure several indexes of study participants' heart rate.

After the raw data scan, those who ate more than 10 ounces (300 grams) of fish per week were found to have QT scores 13.6% lower than people who did not eat fish.

After adjusting the results for potentially confounding factors such as age, sex, physical activity status, BMI, smoking habits and intake of nuts, the reduction in QT scores in those eating 10 or more ounces of fish each week rose to 29.2%, compared to those who did not eat fish.

In an earlier study, Harvard researchers reported that among those consuming the most fish, heart rate was 2.3 beats per minute lower and likelihood of prolonged QT was 46% lower. Similar results were found in study participants taking 1 gram of omega-3s daily. The mechanism behind these benefits is thought to be omega-3 fats' effects on the flow of sodium and calcium in the ion channels, which are involved with electrical signaling in cells.

Practical Tip: A typical serving of fish is 4 ounces, so just 3 servings of omega-3-rich fish, such as cod, each week would provide 2 ounces more than the 10 ounces this research indicates confers significant protection against sudden death from a heart attack. For great, quick and easy recipe ideas, take a look at our Recipe Assistant.

Eating fish, such as cod, as little as 1 to 3 times per month may protect against ischemic stroke (a stroke caused by lack of blood supply to the brain, for example, as a result of a blood clot), suggests a meta-analysis of 8 studies published in the July 2004 issue of Stroke.

Data on nine independent groups participating in eight different studies found that, compared to those who never consumed fish or ate fish less than once per month, risk of ischemic stroke dropped:

9% in those eating fish 1 to 3 times per month
13% in those eating fish once per week
18% in those eating fish 2 to 4 times per week
31% in those eating fish 5 or more times each week

Just Two Servings of Omega-3-rich Fish a Week Can Lower Triglycerides

Triglycerides are a form in which fat is carried in your bloodstream. In normal amounts, triglycerides are important for good health because they serve as a major source of energy. High levels of triglycerides, however, are associated with high total cholesterol, high LDL (bad) cholesterol and low HDL (good) cholesterol), and therefore, with an increased risk of cardiovascular disease.

In addition, high triglycerides are often found along with a group of other disease risk factors that has been labeled metabolic syndrome, a condition known to increase risk of not only heart disease, but diabetes and stroke. (Metabolic syndrome is the combined presence of high triglycerides, increased blood pressure, high blood sugar, excess weight, and low HDL (good) cholesterol.)
Triglyceride Levels
Less than 150 mg/dL Normal
150-199 mg/dL Borderline-high
200-499 mg/dL High
500 mg/dL Very High

*Note: Triglycerides are most accurately measured after an 8-12 hour fast.

In this 6-month study involving 142 overweight men and women with high triglycerides, subjects were divided into 5 groups, one of which served as a control group, 2 of which ate 2 servings of fish high in omega-3s while also replacing their normal household fats with fat high in sunflower (Group 1) or canola oil made from rapeseed (Group 2), and 2 of which ate 2 weekly servings of white fish while also replacing their normal household fats with ones high in sunflower (Group 3) or canola oil made from rapeseed (Group 4).

Canola oil also provides some omega-3 fats, with an omega-6:omega-3 ratio of 2:1, while sunflower oil contains omega-6, but no omega-3 fats.

At the end of the study, triglyceride levels had dropped 6.6% in the omega-3-rich fish groups combined. Triglycerides dropped mostâ€"10.4%â€"in those consuming omega-3-rich fish and canola oil. In those eating omega-3-rich fish and sunflower oil, triglycerides dropped 2.8%.

Bottomline: A healthy way of eating that incorporates at least 2 weekly servings of fish and other food sources of omega-3 fats, such as flaxseed or canola oil, may significantly lower triglyceride levels. Replacing normal household fats with flaxseed oil, in which the ratio of omega-6:omega:3 fats is 1:4, might result in an even larger drop in triglyceride levels.

Eating Fish Daily Provides Substantially More Protection against Heart Attack

While as little as a weekly serving of fish lowers risk of ischemic stroke, enjoying a daily serving omega-3-rich fish, such as cod, provides significantly greater reduction in the risk of coronary heart disease than eating fish even as frequently as a couple of times a week, show the findings of a study published in the January 17, 2006 issue of Circulation, the journal of the American Heart Association.

Researchers in Japan followed 41,578 men and women aged 40 to 59, none of whom had cardiovascular disease or cancer when the study began, from 1990-1992 to 2001. Food frequency questionnaires completed at the beginning of the study and in 1995, provided information on weekly fish intake, which was analyzed for omega-3 content.

When individuals whose fish consumption was in the top one-fifth of participants at 8 times per week were compared to those whose intake was in the lowest fifth at once per week, they were found to have a 37% lower risk of developing coronary heart disease and a 56% percent lower risk of heart attack.

When the effect of omega-3 fatty acid intake on cardiovascular risk was analyzed, coronary heart disease risk was lowered by 42% among those whose intake was the highest at 2.1 grams per day or more compared to those whose intake was the lowest at 300 milligrams per day. Those whose intake of omega 3s was in the top fifth received a 65% reduction in the risk of heart attack compared to those whose omega 3 intake was lowest.

The authors theorize that daily fish consumption is highly protective largely due to the resulting daily supply of omega-3 fatty acids, which not only reduce platelet aggregation, but also decrease the production of pro-inflammatory compounds called leukotrienes. Lowering leukotrienes reduces damage to the endothelium (the lining of the blood vessels), a key factor in the development of atherosclerosis. "Our results suggest that a high fish intake may add a further beneficial effect for the prevention of coronary heart disease among middle-aged persons," note the study's authors.

Choose Broiled or Baked, but Not Fried Cod

Eating cod that's broiled or baked, but not fried, may reduce risk of atrial fibrillation, the most common type of heart arrhythmia, especially in the elderly, according to a Harvard study published in the July 2004 issue of Circulation. In the 12-year study of 4,815 people 65 years of age or older, eating canned tuna or other broiled or baked fish 1 to 4 times a week correlated with increased blood levels of omega-3 fatty acids and a 28% lower risk of atrial fibrillation. Eating broiled or baked fish 5 times a week lowered risk even moreâ€"a drop in atrial fibrillation risk of 31%.

Eating fried fish, however, provided no similar protection. Not only is fried fish typically made from lean fish like cod and Pollack that provide fewer omega-3 fatty acids, but in addition, frying results in the production of damaged, free-radical-laden fats in the fish as well as the frying oil.

In further research to determine if the omega-3 fats found in fish oil were responsible for fish's beneficial effects on the heart's electrical circuitry, Dariush Mozaffarian and colleagues from Harvard Medical School analyzed data on fish intake and electrocardiogram results from 5096 adults, aged 65 or older, who were enrolled in the Cardiovascular Health Study from 1989-1990.

Eating tuna or other broiled or baked fish at least once a week was associated with lower heart rate (-3.2 beats/minute) and a 50% lower likelihood of prolonged ventricular repolarisation (the period of time it takes the heart to recharge after it beats, so it can beat again), compared to those consuming fish less than once a month.

Consuming 1 gram/day of omega-3 fatty acids from fish was associated with 2.3 beats/minutes lower heart rate and a 46% lower risk of prolonged ventricular repolarisation.

Eating fish at least 5 times per week was associated with an even healthier heart rhythm.

However, eating fried fish (typically sold in the U.S. as fish burgers or fish sticks) was not associated with increased blood levels of omega 3 fats or any beneficial electrocardiogram results.

In fact, a previous study led by the same researcher (Mozaffarian, Am J Cardiol 2006 Jan) found that while eating baked or broiled fish was linked to a slower but more powerful heart beat and lower blood pressure, eating fried fish was associated with heart muscle motion abnormalities, a reduced ejection fraction, lower cardiac output, and higher blood pressure.

Since irregular heart beats are a major precipitating factor in sudden death due to cardiac arrest, promoting a healthy heart rhythm by eating baked or broiledâ€"