You can't effectively squeeze lemon on a fish oil capsule.
NUTRITION I am dispirited whenever restaurants garnish rancid fish with a lemon wedge for diners to squeeze and neutralize malodor. Fresh fish is odorless. Who's the worst offender, the chefs who serve fetid fish or the patrons who happily citrusize and gulp it down? Sure, lemon may be used as part of a recipe, if you like, but not to mask unpleasant smells and tastes. When I was a pescatarian, 80 percent of my fish entrees ordered at restaurants were rejected based on smell alone.
Because of price, convenience, preference or mercury contamination, most people do not consume enough fresh fish to provide all the essential nutrients. Therefore, they resort to less expensive and more convenient supplements like fish oil.
Benefits of Fish Oil
Fish oil has been attributed to a number of health benefits. It's used to aid in treatment of heart diseases, high cholesterol, depression, anxiety, AHDH, low immunity, cancer, diabetes, inflammation, arthritis, IBD, AIDS, Alzheimer's disease, eye disorders, macular degeneration and ulcers. It also helps in weight loss, pregnancy, fertility and skin care (particularly for conditions such as psoriasis and acne). [1,2] That's quite a resumé!
The presence of omega-3 essential fatty acids like Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) account for most health benefits. Other useful essential fatty acids include Alpha-linolenic acid or ALA and Gamma-linolenic acid or GLA. 
Fish oil is commonly included in Vietnamese and Thai food, as well as other Asian dishes. Alternate sources of omega-3 fatty acids for vegetarians include walnuts, flax seeds, soybeans, tofu, flax seed oil and eggs. However, these generally have much lower assimilated concentration of this beneficial nutrient as fresh fish or fish oil. Get in the habit of cooking with flax seed oil instead of butter, olive or other vegetable oils to increase omega-3 intake. "Good enough for me," you say? Not so fast.
Sources of Fish Oil
Fish oil supplements are usually made from mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber, or seal blubber. The supplements often contain small amounts of vitamin E to prevent spoilage.
Licensed acupuncturist, Chris Kresser indicates, "Omega-3 fatty acids are highly vulnerable to oxidative damage. When fat particles oxidize, they break down into smaller compounds, like malondialdehyde (MDA), that are dangerous because they damage proteins, DNA, and other important cellular structures. There is no evidence that people other than those with arrhythmia and chronic heart failure benefit from taking fish oil or that doses higher than one gram of omega-3 fatty acids per day provide any benefit over smaller doses." Kressler recommends eating fatty fish a couple times per week, and taking cod liver oil daily. 
Potential Fish Oil Dangers
In high doses (overdose), fish oil supplements can be toxic. Get emergency help if you have symptoms of an allergic reaction, including hives, difficulty breathing, swelling of throat, tongue, lips or face. Discontinue taking fish oil if you experience irregular heartbeats, flu-like symptoms or chest pain.
|Side Effects From Hyperdoses of Fish Oil |
|Increased risk of bleeding||If taking extremely large amounts, hemorrhagic stroke, blood in the urine and nosebleeds may be manifested.|
|Vitamin toxicity||Fish liver and fish liver oils (like cod liver oil) contain high amounts of vitamins D and A. Fish oil supplements, however, do not contain too much vitamin A or D. Also, vitamin E is sometimes added.|
|Reduction in blood pressure||Small reduction in blood pressure corresponds to increased omega-3 intake, so people that take blood pressure lowering medications or those with low blood pressure should be careful.|
|Slight increases in fasting blood glucose for type-2 diabetics||It seems, however, that scientific evidence doesn't show any long-term side effects on diabetics from taking fish oil.|
|5 to 10% LDL increase||Studies show that LDL (bad cholesterol) levels increase slightly as you take more fish oil.|
|Upper respiratory tract swelling||This side effect of fish oil has only been found in some patients.|
|Allergic reactions||Skin rashes, itching, hives, swelling, difficulty breathing, swelling of the throat usually only happen in people who have fish allergies.|
|Stomach and gastrointestinal upset||Some people get diarrhea from fish oil and it only gets worse for them with higher amounts. Some people also claim fish oil side effects like heartburn, bad breath, fishy aftertaste, burping, stomach pain and bloating, acid reflux, indigestion. These are actually the most common side effects of fish oil omega-3.|
|Too much DHA in infants and small children||Fish oil supplements may not be suitable for infants and small children because the brain doesn't need EPA and in trying to get DHA, it gets too much EPA.|
Okay, you say. Keep fish oil away from small children. If you have a fish allergy, don't take fish oil capsules. Even without a known allergy, avoid overdosing on fish oil to reap all the benefits. Does that sum it up?
Most Fish Oil Is Rancid
Many fish oil products in the market sit on shelves for three years or more. Therefore, they are already rancid before consumers get them home. Likely you've heard the locution, "Repetition is the mother of retention." Well, if you have a tendency to "repeat" after ingesting fish oil capsules, you may not want to retain the bottle. Light, heat and air cause oxidation, affecting capsule longevity. The more a fat is unsaturated, the more likely it is to go rancid. It so happens that EPA and DHA in fish oil are both highly unsaturated fatty components. When damaged, the fats in fish oil oxidize and become lipid peroxides, which cause free-radical damage, hence diseases. 
Norway is a leading nation in high-quality fish oil manufacturing that supplies up to 40 percent of the world's fish oil. A recent Norwegian clinical study showed that 95% of 113 over-the-counter fish oil capsules were so rancid that they did not meet official quality standards.
If you burp up fish oil all day long you should change to a different brand. The oil is rancid.
"For years we have been telling people to open up their capsules - taste and smell what they are swallowing," said Dr. Bo Martinsen, a native Norwegian and co-founder of Omega 3 Innovations in Venice, Florida, USA. "Now Norwegian researchers are echoing these words and adding - 'If you burp up fish oil all day long you should change to a different brand. The oil is rancid." 
Eat or Not?
So what's the bottom line? Omega-3 fatty acids provide numerous benefits and may even be prescribed by physicians to treat various health conditions. Fresh fish is the best source of omega-3 fatty acids. Because of price, convenience, preference and mercury contamination, most people do not consume enough fish to provide all the essential nutrients.
High-quality fish oil capsules are viable supplements in regular but small doses, provided they aren't among the 95 percent of rancid capsules on shelves. Save your receipt whenever purchasing fish oil capsules. Before ingesting, pierce or cut one open and smell for rancidness.  If it's bad, don't just squeeze a lemon on it; return it for a refund or throw it out. If you are a vegan, vegetarian or if high-quality fish oil supplements are not available, include walnuts, flax seeds, soybeans, tofu, flax seed oil or eggs in your weekly diet.
- Fish Oil Supplement. webmd.com
- Health Benefits of Fish Oil. organicfacts.net
- When it comes to fish oil, more is not better. chriskresser.com
- What Are Fish Oil Side Effects? energyfirst.com
- Is Your Fish Oil Rancid and Causing Disease? countdowntofitness.com
- Norwegian Health Authorities Raise Question About Rancid Fish Oil. prweb.com
- How to Know When Fish Oil Is Oxidized. ehow.com
- Fish Oil Manufacturing Process. zhion.com
- Retouched image by antos777 licensed from iStock Photo.