Cardiology > Dyslipidemia
— High dose recommended in science advisory
by Nicole Lou, Staff Writer, MedPage Today August 20, 2019
Prescription omega-3 fatty acids are an "effective and safe option" to cut down triglycerides, according to a science advisory released by the American Heart Association (AHA).
However, over-the-counter omega-3 supplements are not reviewed or approved by the FDA and should not be used in place of prescription medication for the long-term management of high triglycerides, cautioned writing group chair Ann Skulas-Ray, PhD, of the University of Arizona, Tucson, in a press release.
Prescription omega-3 fatty acids "at a dose of 4 g/d, are clinically useful for reducing triglycerides, after any underlying causes are addressed and diet and lifestyle strategies are implemented, either as monotherapy or as an adjunct to other triglyceride-lowering therapies," her group concluded.
Fish oil products containing eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) taken at that dose have been shown to reduce triglyceride levels by at least 30% in patients with triglycerides of 500 mg/dL or greater, according to the statement published online in Circulation.
EPA-only formulations did not raise LDL cholesterol in this group, whereas combination EPA-DHA did, authors noted.
Among people with hypertriglyceridemia in the 200-499 mg/dL range, the 4-g/day dose of prescription omega-3 fatty acids lowered triglycerides by 20% to 30% without significantly increasing LDL cholesterol.
Nevertheless, these supplements may be accompanied by mild gastrointestinal complaints or nausea, so the AHA document recommended taking them with meals.
Available prescription omega-3 fatty acids include Lovaza (EPA+DHA) and Vascepa (EPA only), the latter of which was shown to reduce major adverse cardiovascular events by 25% over 5 years among statin-takers in the REDUCE-IT trial.
Next year, the STRENGTH trial is expected to shed light on the cardiovascular outcomes of prescription EPA+DHA in patients with high triglycerides and low HDL cholesterol on statins, Skulas-Ray's group noted.
Another question is whether omega-3 fatty acid supplementation works in children and adolescents: Negative findings have been reported from trials using lower doses or including smaller samples that in some cases included minors with only mildly elevated triglycerides.
The AHA statement said the supplements are "apparently safe," but larger trials testing at least 3 g/d EPA+DHA in children with 200–499 mg/dL triglycerides are needed to better establish efficacy, safety, and tolerability in this population.
Nicole Lou is a reporter for MedPage Today, where she covers cardiology news and other developments in medicine.
Disclosures
Skulas-Ray disclosed no conflicts.
Several writing group members listed personal and research ties to industry.
iStock Omega-3 fatty acids from fish oil possess the unique ability to reduce triglycerides. There's no doubt that omega-3s do this quite effectively.
After all, the FDA approved prescription fish oil, Lovaza Omega-3 fatty acids stand out for their unique triglyceride-reducing property. No other fraction of fatty acids, like omega-6, monounsaturated or saturated, can match the triglyceride-reducing effect of omega-3s. Ounce for ounce, omega-3 fatty acids are at least 10-fold more potent for triglyceride reduction than any other food oil. But why and how does fish oil reduce triglycerides? First of all, what
are triglycerides? As their name suggests, triglycerides consist of three ("tri-") fatty acids lined up along a glycerol (sugar) "backbone." Triglycerides are the form in which most fatty acids occur in the bloodstream, liver, and other organs. (Fatty acids, like omega-3, omega-6, mono- or polyunsaturated, or saturated, rarely occur as free fatty acids unbound to glycerol.) In various lipoproteins in the blood, like LDL, VLDL, and HDL, fatty acids occur as triglycerides. When triglycerides
are present at high levels (greater than 100 mg/dl), they interact with other particles in the blood and cause distorted size and function. High triglycerides are part of the reason, for instance, that small LDL particles develop, the most oxidazable and most heart disease-causing form of LDL. Triglycerides develop most commonly from excessive carbohydrates in the diet. Of all lipoproteins, chylomicrons (the large particle formed through intestinal absorption of fatty acids and
transported to the liver via the lymph system) and VLDL (very low-density lipoprotein, very low-density because they are mostly fat and little protein) particles are richest in triglycerides. The emerging evidence suggests that omega-3 fatty acids from fish oil reduce triglycerides through: Reduced VLDL production by the liver
®, to treat a condition called familial hypertriglyceridemia, a genetic condition in which very high triglyceride levels, typically 500 mg/dl or greater, develop. Omega-3 fatty acids, prescription or otherwise, reduce triglycerides in this condition by hundreds of milligrams. While most of us don't need this much triglyceride reduction, omega-3 fatty acids can still exert substantial triglyceride reduction even when we have less
marked elevations to start.
Accelerating chylomicron and VLDL elimination from the blood
Activation of peroxisome proliferator-activated receptor gamma (PPAR-gamma) - Omega-3s ramp up the cellular equipment used to convert fatty acids to energy (oxidation)
In my view, given the extraordinary safety record of omega-3 fatty acids from fish oil, their wide availability and low cost, omega-3s should be first choice for triglyceride reduction when treatment is necessary. (In my cardiology and lipid consultative practice, I am always astounded at how many people are put on various drugs as the first effort to reduce triglycerides, but not fish oil.) Triglyceride-reducing effects begin with an omega-3 dose (EPA + DHA, not of the total fish oil content) of 1000 mg per day, with greater reductions at higher doses.
Because carbohydrates, such as wheat flour, cornstarch, and sugars, all increase VLDL production by the liver and thereby increase triglycerides, reducing these foods also serves to reduce triglycerides.
Combine omega-3 fatty acids from fish oil with a low-carbohydrate diet and you
have an extremely potent means of reducing triglycerides.
Meet Our Writer
William Davis, M.D.
William R. Davis is a Milwaukee-based American cardiologist and author. He wrote for HealthCentral as a health professional for Heart Health and High Cholesterol.