Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid fish-derived omega-3 supplements if allergic or sensitive to fish, fish oil, or omega-3 fatty acid products derived from fish. Avoid plant-derived omega-3 supplements if allergic or sensitive to nuts, seeds, or plants from which they are derived.

Skin rash and allergic response have been reported.

Some studies suggest that fish exposure during infancy and childhood may help reduce the risk of allergy in childhood.

Side Effects and Warnings

Omega-3 is considered likely safe when taken as a supplement in recommended doses for up to 2-3.5 years, or when included in the diet (1-2 fish meals per week). The U.S. Food and Drug Administration (FDA) has ruled that the use of EPA and DHA, the primary omega-3 fatty acids found in fish, as dietary supplements is safe and lawful, as long as daily intakes do not exceed three grams per person daily from food and supplement sources.

Omega-3 is considered possibly safe when taken by mouth in amounts found in foods during pregnancy and breastfeeding. There is not enough information at this time regarding the safety of fish oils when used in amounts greater than those found in foods during pregnancy and breastfeeding. Up to 20 grams of fish may be well tolerated by most adults, although some experts warn that high doses may cause bleeding complications.

Omega-3 may increase the risk of bleeding, particularly at doses of three grams daily or greater. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

Omega-3 may affect blood sugar levels. Caution is advised in people with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

Omega-3 may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.

Use cautiously in all people, as omega-3 may affect levels of cholesterol and may cause vitamin E deficiency.

Use cautiously in people who are at risk for hormone imbalance or those undergoing hormone replacement therapy.

Use cautiously in people who have abnormal heart rhythms, asthma, and inflammatory bowel disease, as worsened outcomes have been reported with omega-3 use.

Use cautiously in people with liver disease or those using agents that may be toxic to the liver. Changes in liver function tests have been reported with omega-3 use.

Use cautiously in people who are at risk for colon cancer. Fish oils may increase the risk of colon cancer.

Use cautiously in large amounts, as vitamin A and D toxicity may occur.

Use cautiously in children and in pregnant or breastfeeding women, due to the potential that fish meat may contain mercury.

Avoid fish-derived omega-3 supplements if allergic or sensitive to fish, fish oil, or omega-3 fatty acid products derived from fish. Avoid plant-derived omega-3 supplements if allergic or sensitive to nuts, seeds, or plants from which they are derived.

Omega-3 may also cause abnormal heart rhythm, abnormally high urination, acid reflux, anemia, anorexia, bad breath, bad taste in the mouth, bloating, bloody urine, blurred vision, burping, cancer, changes in energy and physical activity (in infants whose mothers received supplementation), changes in homocysteine levels, the common cold, constipation, diarrhea, dizziness, excess fat in the stool, fainting (in pregnant women at birth), a feeling of ants crawling on the skin, a feeling of burning or prickling, a feeling of lifelessness, fever, fishy hiccups, gas, headache, heart attack, hospitalization (chest pain, congestive heart failure, or nervous system problems), increased risk of stroke, indigestion, intolerance to capsule number or size, mania, memory problems, muscle pain or swelling, nausea, the need for surgery (coronary revascularization), nervous system toxicity, nosebleed, restlessness, sleep problems, sudden cardiac death, skin problems (irritation, itching, rashes), stomach pain, throat pain, tiredness, vomiting, and weight gain.

Pregnancy and Breastfeeding

High DHA intakes have been reported in healthy pregnant women in Spain, Germany, and Hungary, ranging from 119 to 155 milligrams.

Fertility research suggests that fertile men may have higher levels of omega-3 compared to infertile men.

There are concerns that some species of fish may contain contaminants that may be harmful to pregnant or breastfeeding women. Mercury tends to build up in fish meat more than in fish oil, and fish oil supplements appear to contain almost no mercury. As a result, safety concerns may apply to eating fish, but likely not to taking fish oil supplements.

The U.S. Environmental Protection Agency recommends that pregnant and breastfeeding women limit sport-caught fish intake to one six-ounce meal per week. For farm-raised, imported, or marine fish, the FDA recommends that pregnant and breastfeeding women avoid eating types with higher mercury levels (such as mackerel, shark, swordfish, or tilefish) and less than 12 ounces per week of other fish types. Women who might become pregnant are advised to eat up to seven ounces per week of fish with higher mercury levels or up to 14 ounces per week of fish types with lower mercury content (such as marlin, orange roughy, red snapper, or fresh tuna). Some experts recommend more than one weekly portion of oily sea fish, or a DHA supplement, for pregnant women.

Omega-3 fatty acid levels of mother and infant may be related. Taking fish oil during pregnancy may promote higher DHA concentration in the newborn. DHA supplementation of the mother may increase DHA in the mother's blood and breast milk.

It is still unclear whether omega-3 supplementation during pregnancy and breastfeeding may benefit infants. Although it has been suggested that omega-3 during pregnancy may increase the birthweight and length of the baby, high doses may not be advisable due to a potential bleeding risk. Some studies report that DHA supplementation of mothers may affect infants' body mass index, fat mass, and weight. DHA may be important in the growth and development of the infant brain and has been studied for potential benefits in preventing respiratory illnesses during the first year of life. However, more research is needed.

Omega-3 has been studied for its potential effects in reducing the risk of preterm birth.

Fish oil supplementation of the mother during breastfeeding may cause decreased physical activity level and increased energy, starch intake, and blood pressure in infant boys.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com