Are Fish Oil Supplements Right For You?

By Joyce M. Vergili, MS, RD, CDN, CDE

Are Fish Oil Supplements good for kidneys

According to the American Heart Association (AHA), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the “omega-3 fatty acids” found in fish, can reduce the risk of developing heart disease1. Fish oil supplements, which are about 30% omega-3 fatty acids, may be especially helpful for hemodialysis patients, especially those:

  • That suffer from itching (technically known as “uremic pruritus”).
  • Whose grafts clot often.
  • With low albumin levels. Albumin is a measure of protein in the body.
  • Whose hemoglobin does not seem to increase, or stay within, the goal range, despite high doses of erythropoietin (“epogen”).
  • With heart disease or at risk of developing heart disease2,3.

How Much is Enough?
According to the AHA, people with, or at risk for, heart disease should consume a total of one gram (g, or 1000 milligrams, mg) of EPA and DHA per day, or seven g (7000 mg) per week. Most of us eat only about one-tenth this amount, or 100 mg per day. Even those without heart disease (or any risk factors such as high cholesterol or a family history) should eat “oily” fish twice a week in order to consume the recommended daily amount of 650 mg of omega-3’s4.
People on hemodialysis may need as much as 2000 mg, or more, of EPA and DHA daily 1,2,3. To determine the dose that’s right for you, talk to your dietitian or physician.

Which Supplement?
Fish oil consists of a variety of fatty acids, only about 30% of which are EPA and DHA. A typical supplement contains one g of fish oil, of which about 180 mg is EPA and 120 mg is DHA (for a total of 300 mg of omega 3’s) per capsule., a private testing firm, analyzed a random sampling of fish oil supplements. Of 20 products tested, six were found to contain as little as 50% of the DHA, and one had only 33% of the EPA, stated on the label. The rest lived up to their claims, including:

  • Dale Alexander’s Omega-3 Fish Oil Concentrate;
  • Puritan’s Pride’s Inspired By Nature TM Salmon Oil;
  • Shaklee’s EPA Omega-3 Fatty Acid Dietary Supplement; and
  • Solgar’s Omega-3 “700” EPA and DHA from Cold Water Fish.

General Tips
General tips when shopping for a fish oil supplement include the following:

  • Avoid brands made from halibut and/or shark liver oils. Such brands may contain toxic levels of Vitamin A.
  • Choose brands that have 1-2 mg Vitamin E per g of fish oil. Vitamin E helps to prevent the fish oil from going rancid.
  • Choose a brand that is best for you (i.e., if you would rather not take pills, an emulsified form that is squeezed onto a spoon from a packet,such as Coromega, may be the best choice).
  • Read labels to check the total amount of omega-3’s (i.e., the amount of EPA plus the amount of DHA) each capsule or packet provides. They vary from as little as 100 mg to as much as 600 mg.

Tip: After purchasing, keep the fish oil supplements in the refrigerator.

Reducing/Preventing Side Effects
The most commonly reported side effects are “fishy burps” and indigestion. Taking the supplements at night or with a meal, rather than on an empty stomach, can help prevent these side effects.

If you are allergic to fish or omega-3 fatty acid supplements, you should not take fish oil supplements.

Prolonged or excessive bleeding, while rare, may occur, especially if you are taking “blood-thinning” medication such as Coumadin. Therefore, it is important to:

  • Advise your primary care physician and other health providers (e.g., cardiologist, endocrinologist) before you begin taking the supplement;
  • Alert your physician immediately if prolonged or excessive bleeding occurs; and
  • Discontinue fish oil supplements prior to surgery6.

It is important to keep your healthcare team updated regarding any changes in your medications, dietary supplements, and/or herbal preparations.

Don’t Want to Take Supplements?
If you want all the benefits but prefer not to take fish oil supplements, you can increase your intake of oily fish. In fact, some research suggests that increasing one’s fish intake is equally as effective as taking fish oil supplements7.  The following types of fish, in the amounts listed, each provide about 2000 mg of omega-3 fatty acids:

3.5 ounces of:
Fresh or canned salmon
Canned sardines
Canned herring
Canned pink salmon

Seven ounces of: 
White albacore tuna, canned in water
Rainbow trout

[Note: Pregnant women and women of childbearing age should limit their intake of shark, swordfish, King mackerel, and tilefish, since these fish contain potentially toxic levels of mercury8.]

Enjoy Your Fish
Enjoy grilled salmon with steamed jasmine rice and poached green beans, or a simple tuna fish salad and romaine lettuce sandwich on a hard roll, or a light dinner of sardines* and onions on crackers!

(* Edible bones, such as those found in canned sardines and canned salmon, should not be eaten due to their high phosphorus content. Bones should, therefore, be removed before eating these nourishing and delicious fish.)

1. Kris-Etherton, PM, Harris, WS, and Appel, LJ. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease.  Circulation (2002;106:2747-2757).
2. Vergili, JM. Benefits of Fish Oil Supplementation for Hemodialysis Patients. Journal of the American Dietetic Association, Autumn 2003.
3. Schmitz, P, McClound, L, Reikes, S, Leonard, CL, and Gellens, ME. Prophylaxis of Hemodialysis Graft Thrombosis with Fish Oil: Double-Blind, Randomized, Prospective Trial. Journal of the American Society of Nephrology (2002;13:184-190).
4. Scheppers, A. Making Heads or Tails of Fish Oil Supplements: What to Look For. Environmental Nutrition, March 2003, p. 7.
5. ConsumerLabs website: Accessed June 16, 2003.
6. Donnelly, SM, Ali, MA, and Churchill, DN. Effect of Omega-3 Fatty Acids From Fish Oil on Hemostasis, Blood Pressure and Lipid Profile of Dialysis Patients. Journal of the American Society of Nephrology (1992:1634-1639).
7. Kutner, NG, Clow, PW, Zhang, R, and Aviles, X. Association of Fish Intake and Survival in a Cohort of Incident Dialysis Patients. American Journal of Kidney Diseases (2002:1018-1024).
8. Food and Drug Administration’s Center for Food Safety and Applied Nutrition Consumer Advisory website: Accessed January 5, 2003.

About the Author
Joyce M. Vergili, MS, RD, CDN, CDE, is a Renal Dietitian at Northern Hudson Valley Dialysis Center (an affiliate of The Kingston Hospital) in Catskill, NY. This article was originally posted on the website in August 2003.

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