Fish Oil, High Cholesterol & Triglycerides
Information provided by IcelandHealth.com

Triglycerides (TGs) are a group of fatty compounds that circulate in the bloodstream and are stored in the fat tissue. Individuals who have elevated blood levels of cholesterol, or TGs (known as hypertriglyceridemia) appear to be at increased risk of developing heart disease. People with diabetes often have elevated TG levels. Successfully controlling diabetes will, in some cases, lead to normalization of TG levels.

Dietary changes that may be helpful: While consuming moderate amounts of alcohol does not appear to affect TG levels, heavy drinking is believed to be an important cause of hypertriglyceridemia.1 Alcoholics with elevated TG levels should deal with the disease of alcoholism first.

Ingesting refined sugar increases TG levels, as well.2 3 People with elevated TGs should therefore reduce their intake of sugar, sweets, and other sugar-containing foods. There is also evidence that ingesting fructose in amounts that are found in a typical Western diet can raise TG levels, although not all studies agree on that point.4 It should be noted that most studies of fructose investigated the refined form, not the fructose that occurs naturally in some fruits.

In a study of heavy caffeine users (individuals who were consuming an average of 560 mg of caffeine per day from coffee and tea), changing to decaffeinated coffee and eliminating all other caffeinated products for two weeks resulted in a statistically significant 25% reduction in TG levels.5

Diets high in fiber have reduced TG levels in several studies,6 but have had no effect in other studies.7 Water-soluble fibers, such as pectin found in fruit, guar gum and other gums found in beans, and beta-glucan found in oats, may be particularly helpful in lowering triglycerides.

Consumption of a low-fat, high-carbohydrate diet reduced TGs in one study.8 However, in another study, populations that consumed a low-fat, high-carbohydrate diet had higher TG levels, compared with populations that consumed lower amounts of carbohydrates.9 Suddenly switching to a high-carbohydrate, low-fat diet will generally increase TGs temporarily, but making the switch gradually protects against this short-term problem.10

The blood level of TGs following a meal may be a more important indicator of coronary heart disease risk than the fasting level.11 12 However, a low-fat diet (55% carbohydrates, 23% fats, 22 % proteins) that succeeded in normalizing other blood lipids, including fasting TG levels, failed to normalize post-meal TG levels in a group of people with hypertriglyceridemia.13 These results suggest that dietary reduction of fasting TGs, even if the diet controls other blood lipids, may not be enough to provide optimal protection against coronary heart disease. Most doctors recommend a diet low in saturated fat (meaning avoidance of red meat and all dairy except non-fat dairy) to reduce TGs and the risk of heart disease.14

Some,15 16 but not all,17 studies have found that increasing consumption of fish is associated with a lower risk of heart disease. Significant amounts of TG-lowering omega-3 fatty acids (EPA and DHA) can be found in the Fish oil of salmon, herring, mackerel, sardines, anchovies, albacore tuna, and black cod. Many doctors recommend that people with elevated TGs increase their intake of these fatty fish.

Lifestyle changes that may be helpful: Exercise lowers TG levels.18 People who have diabetes, heart disease, or are over the age of 40, should talk with a doctor before beginning an exercise program.

Smoking has been linked to elevated TG levels.19 As always, it makes sense for smokers to quit.

Obesity increases TG levels.20 Maintaining ideal body weight helps protect against elevated TG levels. Many doctors encourage people who have elevated TGs and who are overweight to lose the extra weight.

Nutritional supplements that may be helpful: Many double-blind studies have consistently demonstrated that Fish oils (also called fish-oil concentrates) containing EPA and DHA (mentioned above) lower TG levels.21 The amount of Fish oil used in much of the research was an amount that provided 3,000 mg per day of omega-3 fatty acids. To calculate how much omega-3 fatty acid is contained in a fish-oil supplement, add together the amounts of EPA and DHA. For example, a typical 1,000-mg capsule of Fish oil provides 180 mg of EPA and 120 mg of DHA (total omega-3 fatty acids = 300 mg). Ten of these capsules would contain 3,000 mg of omega-3 fatty acids. Other sources of omega-3 fatty acids, such as flaxseed oil, do not lower TGs. While flaxseed oil has other benefits, it should not be used for the purpose of reducing TGs.

Cod-liver oil, another source of omega-3 fatty acids, has also been found to lower TGs.22 Cod-liver oil is less expensive than the fish-oil concentrates discussed in the previous paragraph. However, cod-liver oil also contains relatively large amounts of vitamin A and vitamin D; too much of either can cause side effects. In contrast, fish-oil concentrates have little or none of these vitamins. Individuals wishing to use cod-liver oil as a substitute for a fish-oil concentrate should consult a doctor.

Omega-3 fatty acids from Fish oil and cod-liver oil have been reported to affect blood in many other ways which might lower the risk of heart disease.23 However, these supplements sometimes increase LDL cholesterol—the bad form of cholesterol. A doctor can check to see if Fish oil has this effect on an individual. Research shows that when 900 mg of garlic extract is added to Fish oil, the combination still dramatically lowers TG levels but no longer increases LDL cholesterol.24 Therefore, it appears that taking garlic supplements may be a way to avoid the increase in LDL cholesterol sometimes associated with taking Fish oil. People who take Fish oil may also need to take vitamin E to prevent the oil from undergoing potentially damaging oxidation in the body.25 It is not known how much vitamin E is needed to prevent such oxidation; the amount required would presumably depend on the amount of Fish oil used. In one study, 300 IU of vitamin E per day prevented oxidation damage in individuals taking 6 grams of Fish oil per day.26

In a preliminary study of ten individuals with elevated cholesterol and triglyceride levels, supplementation with 800 mg of calcium per day for one year resulted in a statistically significant 35% reduction in the average TG level.27 However, in an eight-week study, calcium supplementation had no effect on TG levels.28 One of the differences between these two studies, aside from the duration of treatment, was that more patients in the former study had initially elevated TG levels.

In a double-blind study, 30 non-insulin-dependent diabetics received 200 mcg of chromium per day (as chromium picolinate) for two months and a placebo for an additional two months. The average TG level was significantly lower by an average of 17.4% during chromium supplementation than during the placebo period.29 Whether chromium supplementation affects TG levels in non-diabetics is not known.

L-carnitine is another supplement that has lowered TGs in several studies.30 31 However, the effect of carnitine is unpredictable, and some individuals have experienced an increase in triglyceride levels after receiving this supplement.32 Some doctors recommend 1–3 grams of carnitine per day, in the form known as L-carnitine.

Several double-blind studies have looked at the ability of fructo-oligosaccharides (FOS) or inulin to lower blood cholesterol and triglyceride levels. These studies have shown that in individuals with elevated total cholesterol or triglyceride levels, including people with type 2 diabetes, FOS or inulin (in amounts ranging from 8 to 20 grams daily) produced significant reductions in triglyceride levels; however, the effect on cholesterol levels was inconsistent.33 34 35 36 In individuals with normal or low cholesterol or triglyceride levels, FOS or inulin produced little effect.37 38 39

Pantethine is a special form of the B vitamin pantothenic acid. Several studies show that 300 mg of pantethine taken three times per day will lower TG levels.40 41 42 The form found in most B vitamins—pantothenic acid—does not have this effect. Some doctors recommend supplementing with pantethine to reduce TG levels.

The niacin form of vitamin B3 is used by doctors to lower cholesterol levels, but niacin also lowers TG levels.43 The amount of niacin needed to achieve worthwhile reductions in cholesterol and TG levels is several grams per day. Such quantities can cause side effects, including potential damage to the liver, and should not be taken without the supervision of a doctor. Some doctors recommend inositol hexaniacinate (a special form of vitamin B3) as an alternative to niacin. A typical amount recommended is 500 mg three times per day.44 45 This form of vitamin B3 does not typically cause a skin flush and is said to be safer for the liver than niacin. However, the alleged safety advantage of inositol hexaniacinate needs to be confirmed by additional studies. Moreover, it is not clear whether inositol hexaniacinate is as effective as niacin at lowering cholesterol and TG levels.

A double-blind, placebo-controlled study found that a supplement of 5 grams of creatine plus 1 gram of glucose taken four times per day for five days followed by twice a day for 51 days significantly lowered serum total triglycerides in both men and women.46

Are there any side effects or interactions? Refer to the individual supplement for information about any side effects or interactions.

Herbs that may be helpful: More than thirty-two human studies, mostly double-blind, have demonstrated the ability of garlic to lower serum TG levels. Common garlic intakes in these studies ranged from 600 to 900 mg per day for four to sixteen weeks. Reports that have analyzed the results of all of studies combined indicate that over a one- to four-month period, garlic supplements reduce TG levels by 8–27%.47 48

People with no aversion to the odor can chew one whole clove of raw garlic daily. Otherwise, odor-controlled, enteric-coated tablets standardized for allicin content can be taken in the amount of 900 mg daily (providing 5,000 mcg of allicin), divided into two daily doses. For health maintenance, half of the therapeutic amount may be adequate.

Guggul, a mixture of ketonic steroids from the gum oleoresin of Commiphora mukul, is an approved treatment of hyperlipidemia in India and has been a mainstay of Ayurvedic herbal approaches to preventing atherosclerosis. Clinical studies indicate that guggul is effective in the treatment of high TGs; in one study, serum TGs to fell by 30.3%.49

The recommended daily intake of guggul is typically based on the amount of guggulsterones in the extract. The recommended amount of guggulsterones is 25 mg three times per day. Most extracts contain 5–10% guggulsterones. Guggul’s effect on TGs should be monitored over a three- to four-month period and may be taken long-term if successful in lowering TGs.

Fenugreek has been shown to lower total and low-density lipoprotein (LDL) cholesterol and triglyceride levels in people with high lipid levels in open clinical trials.50 Bread made with 50 g defatted fenugreek powder twice daily was used in the study. Similar results have been seen at half that amount in people with diabetes and elevated blood levels of various lipids.51 A small randomized trial found similar results using 100 g fenugreek seeds daily.52 Mild diarrhea and gas can accompany the first few days of fenugreek use, though it almost always fades as the person taking it adapts.

Psyllium seeds and husks have shown a modest ability to lower blood levels of triglycerides in some,53 54 but not all,55 studies. Further research is needed looking at the effect of psyllium on triglyceride levels more closely, as much of the study so far has focused on lowering cholesterol levels.

Intake of 3 cups or less of green tea daily has been shown not to affect blood triglyceride levels.56 Intake of four or more cups per day has been correlated with lower triglyceride levels.57 Overall the evidence is unclear on how much of an effect high levels of intake of green tea has on triglyceride levels.

Animal studies suggest the mushroom maitake may lower fat levels in the blood.58 However, this research is still preliminary and requires confirmation.

Are there any side effects or interactions? Refer to the individual herb for information about any side effects or interactions.

Checklist for High Triglycerides

Ranking

Nutritional Supplements

Herbs

Primary

Fish oil (EPA/DHA)

Pantethine

Niacin (vitamin B3)

Garlic

Guggul

Oats

Secondary

L-carnitine

Fructo-oligosaccharides (FOS)

Inositol hexaniacinate (vitamin B3)

Fenugreek

Green tea

Psyllium

Other

Creatine monohydrate

Fiber
Maitake

Information about the effects of a particular supplement or herb on a particular condition has been qualified in terms of the methodology or source of supporting data (for example: clinical, double blind, meta-analysis, or traditional use). For the convenience of the reader, the information in the table listing the supplements for particular conditions is also categorized. The criteria for the categorizations are: "Primary" indicates there are reliable and relatively consistent scientific data showing a health benefit. "Secondary" indicates there are conflicting, insufficient, or only preliminary studies suggesting a health benefit or that the health benefit is minimal. "Other" indicates that an herb is primarily supported by traditional use or that the herb or supplement has little scientific support and/or minimal proven health benefit.
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References:

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