It also found that in many of those samples, the content of omega-3 fatty acids, including DHA (good for the brain, heart, and eyes) and EPA (supports the immune system), can be lower than they are claimed by 83 percent and 31.7 percent, respectively.
3-MCPD Found in 95 Percent of the Samples
The test also found that one contaminant, 3-monochloropropanediol (3-MCPD), which may cause damage to the kidneys and the central nervous system and affect the male reproductive system if taken in higher amounts, was contained in more than 95 percent (24 types) of fish oil samples. The following three samples were found to exceed the EU upper limit of 2,500 mcg/kg (micrograms/kilogram):
- GNC Super Fish Oil (180 capsules package): 6,800 mcg/kg.
- Adrien Gagnon Heart Health Extra Strength Omega 3: 15,000 mcg/kg.
- Miracle Life Supreme DHA Fish Oil Pills: 2,800 mcg/kg.
According to the Consumer Council, during the high-temperature deodorization process of oils and fats above 160 degrees centigrade, contaminants of 3-monochloropropanediol fatty acid esters (3-MCPD esters, 3-MCPDE) may be produced. Intake by humans of 3-MCPDE-contaminated oils and fats will hydrolyse 3-MCPDE in the gastrointestinal tract to release toxic 3-MCPD.
More Than Half Contain Genotoxic Carcinogen Glycidol
Fourteen samples were found to contain genotoxic carcinogen glycidol, a substance that could increase the risk of cancer.
The report indicates glycidyl esters (GE) may be produced during the high-temperature deodorisation process of oils and fats above 200 degrees centigrade. After human consumption, GE will be hydrolysed in the gastrointestinal tract to release the genotoxic carcinogen glycidol. JECFA (Joint FAO/WHO Expert Committee on Food Additives) recommends that the intake of genotoxic carcinogens should be avoided as much as possible, and there is no acceptable intake level yet. With reference to EU regulations, the upper limit of glycidol content in fish oil is 1,000 micrograms per kilogram.
Only Three Samples Were Free of POPs
Persistent organic pollutants (POPs) dioxins, dioxin-like polychlorinated biphenyls, or non-dioxins-like polychlorinated biphenyls were found in 22 samples.
Dioxins and polychlorinated biphenyls are both industrial pollutants. For example, they are produced when chlorinated organic chemicals such as plastics are burned. They can exist in the environment for a long time and accumulate along the food chain and pass on to the human body and accumulate there, especially in the adipose tissue of animals, and are cancer-causing substances in humans.
The report refers to the classification of EU regulations and evaluates the contents of dioxins, dioxin-like PCBs, and non-dioxin-like PCBs in each sample, respectively, and all samples were within the EU standards.
Genotoxic Carcinogen PAHs Detected in Six Samples
Polycyclic aromatic hydrocarbons (PAHs) are produced during the heating, drying, and smoking processes of food or by environmental pollution. Some PAHs have been confirmed to be carcinogenic. Among them, benzo[a]pyrene can be used as an indicator of possible carcinogenic PAH in food. It is more common in high-temperature cooking of fatty foods. It is a genotoxic carcinogen and should be avoided as much as possible. The EU stipulates that the upper limit of benzo[a]pyrene for edible oils and fats is 2.0 mcg per kg, while the upper limit of the sum of the four PAHs (including benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene) is 10.0 mcg per kg.
PAH in varying amounts was detected in six samples, including “L&F,” “Meiriki of Japan,” “Miracle Life,” “AUSupreme,” “Hansei of Japan,” and “Nutronic.” The “Nutronic” sample included the highest total amount of the four PAHs detected among the six samples, with the total amount of the four PAHs at 54.0 micrograms per kilogram, and the content of benzo[a]pyrene detected in this sample was 12.7 micrograms per kilogram.
Amount of DHA and EPA in Many Samples Lower Than Shown on Label
The Consumer Council purchased 25 fish oil supplement samples from the market, of which 23 were in capsules while the other two were non-capsulated. The prices ranged from HK$73.3 (about US$9.4) to HK$788 (about US$100) per bottle. Among the test samples, 24 models were marked with DHA and EPA content, and the highest detected amount was Miracle Life high-strength DHA fish oil, with 444.8 mg.
On the other hand, the detected amount of DHA from “Hansei Szyy Best for children” was the lowest, at only 30.9 mg against its label stating it contained 60.6 grams of DHA per 100 grams, but the test results showed that the sample contained only 10.3 grams per 100 grams, which was just 17 percent of the claimed amount. The test results of the same brand of DHA for pregnant women also showed a similar result, at just 27 percent of the declared value.
As for the lowest amount of EPA detected, “Meiriki of Japan Brain Health Supplement Platinum” contained only 12.3 mg of EPA. The highest was found in Webber Naturals’ Triple Strength Omega-3 EPA/DHA. For the only sample sourced from China, the “L&F Alaska Deep Sea Fish Oil” actually contains only 123 mg of EPA per three capsules, which is 31.7 percent less than the claimed amount of 180 mg EPA per three capsules.
Centre for Food Safety Recommends Certain Fish as DHA and EPA Intake
Kelly Ching Yan-yee, director of external affairs of the Hong Kong Dietitian Association (HKDA), said that DHA and EPA could perform a wide range of beneficial functions in the human body, such as being the structural components of the phospholipid layer of cell membranes or to synthesise signal molecules, which are beneficial to the cardiovascular, immunity, and endocrine systems. However, the human body cannot directly synthesise DHA or EPA by itself, but it can only be converted from alpha-linolenic acid (ALA). But because the conversion process is slow and varies from person to person, it can hardly produce enough to meet normal physiological needs. Therefore, direct intake of DHA and EPA from food or dietary supplements is one way to increase the levels of these two fatty acids in the body.
The World Association of Perinatal Medicine recommends that pregnant women consume at least 200 mg of DHA daily. Although regular consumption of seafood can also meet this need, it must be noted that some seafood types can be a source of neurotoxins such as mercury.
Therefore, the FDA and the American College of Obstetricians and Gynaecologists recommend that pregnant women should limit their seafood intake to 340 grams (12 oz) per week to limit foetal exposure to mercury. This serving of fish is roughly equivalent to an average of about 200 mg of DHA per day.
To achieve both objectives, women who are pregnant and/or breastfeeding should eat at least eight to 12 ounces each week from several types of seafood that are high in DHA but low in mercury.
Referring to the recommendations of the Hong Kong Centre for Food Safety, better choices include salmon, black bonito, false halibut, barramundi, mangrove red snapper, skipjack tuna, and the like. On the contrary, those that should be avoided include shark, swordfish, albacore tuna, bigeye tuna, bluefin tuna, yellowfin tuna, and the like. Vegetarians can also choose walnuts, flax seeds, chia seeds, or algae oil as natural sources of DHA.
Eat Fish At Least Twice a Week for Enough Omega-3 Fatty Acids Intake
Studies have shown that omega-3 fatty acids are effective in lowering blood pressure and heart rate, improving blood vessel function, lower triglycerides, and possibly also reducing inflammation. The American Heart Association (AHA) recommends that all adults eat fish high in omega-3 fatty acids (about three ounces per serving) at least twice a week to get an adequate amount of omega-3 fatty acids. For patients with chronic heart disease, AHA recommends supplementing one gram of DHA and EPA per day, and patients with hyperlipidemia who need higher doses, should seek guidance from medical professionals.