Do Omega-3 fatty acids aid in the prevention of heart disease?

Jen SmithUniversity of California, San Francisco

Objectives…..

• Significance of the problem

• What are Omega-3 fatty Acids?

• What are the cardiovascular benefits?

• Review the literature

• Intake recommendations

• Future research

Significance of the Problem?• In 2006, 631,636 people died of heart disease in the

US. Heart disease caused 26% of deaths—more than one in every four—in the United States.

• Heart disease is the leading cause of death for both men and women. Half of the deaths due to heart disease in 2006 were women.

• In 2010, heart disease will cost the United States $316.4 billion. This total includes the cost of health care services, medications, and lost productivity.

http://www.cdc.gov/heartdisease/facts.htm

What can we do?

• Diet and exercise is KEY!

• Are we as American’s missing a key component to our diet?

Omega 3 intake• Dietary intake of omega-3 and omega 6 fatty acids

varies within and between different populations

• NHANES III (the largest database of nutrient consumption of Americans), reports a median intake of EPA+DHA of 0 and <1 g/d of ALA.

• The ratio of omega-6 to Omega-3 intake is estimated to be 20 to 1 in a modern Western diet, compared with that of our Paleolithic ancestor who ate a diet much richer in omega-3’s (estimated ratio of 1:1)

• We need to balance our Omega-3 to 6 ratio

“Omega-3”

• Three types of naturally occurring fats classified by the number of double bonds present in their fatty acid chains

• ALA, EPA, DHA

• EPA and DHA have been proven most cardioprotective

COOH

C20:5 ω-3 Eicosapentaenoic(EPA)

H3C

C18:3 ω-3

ω-3 family

-Linolenic• Flaxseed Oil• Canola Oil• Soybean Oil

C22:6 ω-3 Docosahexaenoic(DHA)

COOHH3C

• Oily Fish• Fish Oil Capsules

H3CCOOH

ω-6 family

C20:4 ω-6

C18:2 ω-6 Linoleic

Arachidonic

H3CCOOH

More thrombotic and inflammatory metabolites

• Corn Oil• Safflower Oil• Sunflower Oil

Essential Fatty Acid Families

Less thrombotic and inflammatory metabolites

H3C COOH

Omega 6 rich foods• Flax seed oil, Flax seeds, Flax seed meal, Hemp seed oil,

Hemp seeds, Grapeseed Oil, Pumpkin seeds, Pumpkin oil

• Sesame oil, Walnut oil, Pine nuts, Pistachio nuts, Sunflower seeds (raw), Olive oil, Olives, Borage oil, Evening primrose oil

• Black currant seed oil, Chestnut oil, Wheatgerm oil

• Corn, safflower, sunflower, soybean and cottonseed oils are also sources of linoleic acid, but are refined and may be nutrient-deficient as sold in stores.

• Chicken

• mayonnaise

• DHA+EPA-Fish …halibut, herring, mackerel, oysters, salmon, lake trout, sardines and albacore, tuna.

• ALA - plant sources like flaxseed, chia, purslane, lingonberry, and hemp. walnuts, soy beans and tofu

What foods contain Omega-3 Fatty Acids?

AHA Recommendations for Omega-3 FA Intake

Kris-Etherton PM et al. Circulation 2002;106:2747-2757.

Population Recommendation

Patients without documented CHD

Eat a variety of (preferably oily) fish at least twice a week. Include oils and foods rich in -linolenic acid (flaxseed, canola, and soybean oils; flaxseeds; and walnuts)

Patients with documented CHD

Consume ~1 g of EPA+DHA per day, preferably from oily fish. EPA+DHA supplements could be considered in consultation with the physician

Patients needing triglyceride lowering

2–4 grams of EPA+DHA per day provided as capsules under a physician’s care

Ways to Get 1 g/d EPA+DHA

• Fish

• 2–3 oz salmon, sardines, mackerel per day

• Dietary Supplements (Fish oil)

• Low Potency: 300 mg EPA+DHA/g(Typical drug store capsules; 3 g/d)

• Mid Potency: 500–700 mg EPA+DHA/g(Mail-order, online, etc; 2 g/d

• Drugs

• High Potency: 850 mg EPA+DHA/g(Omega-3 acid ethyl esters; 1 g/d)

• Cod Liver Oil

• 1 tsp (RDA for vitamin D; 2 RDA for vitamin A)

Omega-3’s through food or supplements?

• Research has shown omega-3’s may be better absorbed from food than supplements

• The AHA recommends two servings of omega-3 rich fish per week….but for most people it is not practical

• The fish you get from your local store may not be fresh, which could compromise the quality of the oils

What is fish oil?• oil derived from the tissues of oily fish sold

in the form of a supplement

• Many different brands to choose from

• Risk of toxins

• Look for a “mecury free”’ fish oil supplement

• Reputable companies source their fish from pristine waters. They use deep sea fish which are less likely to ingest pollutants.

What are the cardiovascular benefits of omega-3?

• Reduction in arrhythmias• Increased heart rate variability• Antithrombotic effects• Improved endothelial reactivity-production of nitric oxide• Anti-inflammatory effects• Slight lowering of blood pressure• Lower triglyceride levels

Safety?

• Omega-3 intake is very well tolerated by patients through diet or supplements

• Low incidence of side effects•Gastrointestinal complaints• “fishy taste” from fish oil supplements

Research?

Greenland Eskimos• First recognized over 45 years ago

• Revealed low incidence of heart disease

• Ironic because at the time a low saturated fat diet was recommended for prevention of hear disease and the Greenland Eskimos were eating a diet very high in saturated animal fat.

• Also contained high amounts of fish

GISSI-Prevention trial• Large clinical trial 11,712 patients with recent MI • Randomized to either

1. Omega-3 supplements2. Vit E3. Both4. Or none (along with Mediterranean diet)

Results- Omega-3 supplementation reduced all-cause death by 20% and nonfatal MI and stroke by 15%

DART

• 2033 Welsh men after a recent MI

• Intervention- group randomized to 2 servings of fish per week or given supplements

• Findings-29% reduction in cardiovascular and total mortality in two years

Physician's Health Study

• Began in 1982-Epidemiological

• 20,000 healthy male physicians

• Lifestyle, coronary risk factors, and diet data collected at entry and lifestyle and diet were collected at 12 months after entry

• Findings: men who consumed one or more fish meals per week had a 50% lower risk of developing sudden cardiac death than men who rarely ate fish (less than one fish meal per month).

Nurses’ Health Study• Began in 1976

• 80,000 female nurses completed lifestyle and diet questioners

• Followed for 16 years for the development of coronary artery disease

• Findings : compared to women who rarely ate fish (less than one fish meal per month), women who ate fish once a week had a 29% lower risk of developing coronary heart disease.

Effect of fish-oil supplements of endothelial function

• Study design-Randomized control trial, double-blinded, crossover

• Objective: to examine whether a fish oil supplement offers protection of endothelial function after a high fat meal. (studies have shown that endothelial function is acutely impaired after a high fat meal)

• Sample: 20 healthy volunteers

Intervention: Given fish oil ( 1 gram)/or placebo after high fat meal ( lactose capsules)

Measure: flow mediated dilation of the brachial artery was done before and after high fat meal in both groups

Results: The main finding was that 1 gram of fish oil was able to preserve endothelial function after a high fat meal

Medication?• Omacor/Lovaza

• made from omega 3 fish oil-in each 1 gram capsule EPA - approximately 465 mg and DHA approximately 375 mg.

• Used to lower triglycerides

• But……new study suggests taking Lovaza at a very high dose does not decrease the risk of occurrence of A-fib

Efficacy and Safety of Prescription Omega-3Fatty Acids for the Prevention of Recurrent

Symptomatic Atrial Fibrillation

• Randomized control trial, double blinded

• 663 outpatients with documented symptomatic paroxsysmal or persistent a-fib

• Received placebo or prescription Omega-3 PUFA capsules at 8g/day for the first seven days followed by 4 g/day for a total of 24 weeks

• Results- The Omega-3 group did not have a reduced risk of recurrence of a-fib over 6 months

Efficacy and Safety of Prescription Omega-3

Fatty Acids for the Prevention of RecurrentSymptomatic Atrial Fibrillation

• Secondary findings-1. Reduction in average ventricular rate during the

first a-fib recurrence2. Reduction in triglyceride levels

• specific patient population

• This trial was based on a majority of patients with paroxysmal a-fib. The study does not support other patient populations with a-fib, such as post-op patients, or patients with advanced heart disease

Omega-3 index?What do you know about it?

Omega-3 index: A modifiable risk factor?

• The Omega 3 Index measures the amount of EPA and DHA omega 3s in red blood cells and is expressed as a percent of total fatty acids.  

• The results of the Omega 3 Index test are represented by a score that can be used to assess you risk of heart disease, with a score of 4% or less indicating higher risk and a score of 8% or more indicating relatively low risk.

• Could it be a “risk factor” for heart disease??

Omega-3 Index: A Modifiable Risk Factor?

• Omega-3 Index is responsive to changes in omega-3 FA intake (fish or capsules)

• Correcting the Omega-3 Index is…

• Safe: Highest AHA recommended intake for CHD prevention (1 g/d) is 1/3 of amount the FDA regards as safe for inclusion in the food supply

• Easy: Eat more oily fish or take 1–3 fish oil capsules per day

• Affordable: Standard drug store capsules can provide about 1 g/d for as little as 7¢

Check your omega 3 levels at home?

• The Gene Smart Omega 3 Index Home Blood Test Kit

• One easy payment of 149.95!

Gene smart Omega 3 index Home testing kit

• The Gene Smart Omega 3 Index Home Blood Testing Kit measures your Omega 3 index and your Omega 6 to Omega 3 ratio

• More research could be done?

Pro’s and Con’s to increasing

Omega-3 intake??

Implications for our practice?

Conclusion

• Omega 3’s have many cardioprotective effects observed in epidemiological and experimental studies.

• Most Americans do not get the optimal amount of Omega-3’s in their diet

• Omega-3’s are safe, easy, and affordable

• Omega-3 index may soon be classified as a “risk factor” for heart disease.

• Omega-3 index tests are becoming more readily available to monitor the amount of Omega-3 in your blood

References• References

• Burr, M. L., Gilbert, J. F., Holliday, R. M., Elwood, P.C., Fehily, A. M., Rogers, S., Sweernam, & P.M., Deadman, N. M. (1989). The Lancet, 757-761.

• Breslow, J. L. (2006). n-3 Fatty acids and cardiovascular disease. American Journal of Clinical Nutrition, 83,1477S-82S.

• Corretti, C.M., Anderson, T. J., Benjamin J .E ., Celermajer, D., Charbonneau, F., Creager, M. & Vogel, R. (2002). Guidelines for the Ultrasound Assessment of Endothelial Dependent Flow-Mediated Vasodilation of the Brachial Artery. Journal of the American College of Cardiology, 39, 257-265.

• Defillippis, A.P., Blaha, M.J., & Jacobson, T.A. (2010). Omega-3 Fatty Acids for Cardiovascular disease prevention. Current Treatment Options in Cardiovascular medicine, 12 (4), 365-80.

• Engler, M. & Engler, M.B., (2006). Omega-3 Fatty Acids. Role in Cardiovascular Heath and Disease. Journal of Cardiovascular Nursing, 20 (1), 17-24.

• Engler, M. M., Engler, M. B., Malloy, M.L., Paul S.M., Kulkarni, K. R. & Mietus-Snyder M.L. (2004). Effect of Docosahexaenoic Acid on Lipoprotein Subclasses in Hyperlipidemic Children. The American Journal of Cardiology, 95, 869-871.

References• Fahs, C.A., Yan, H., Ranadive, S., Rossow, L.M., Agiovlastis, S., Wilund, K.R., & Fernhall, B.

(2010). The effect of acute fish-oil supplementation on endothelial function and arterial stiffness following a high-fat meal. Applied Physiology, Nutrition, and Metabolism, 35(3), 294-302.

• Harris, S.W. (2010). The Omega-3 index: Clinical Utility for Therapeutic Intervention. Current Cardiology Reports, 12, 503-508.

• Harris,W. (2010). Omega-6 and Omega-3 fatty acids: partners in prevention. Current opinion in Clinical Nutrition and Metabolic Care, 13, 125-129.

• Harris, W. & von Schacky, C (2004). The Omega-3 Index: a new risk factor for death from coronary heart disease? Preventative Medicine, 39, 212-220.

• Kowey, P.R., Reiffel, J.A., Ellenbogen, K.A., (2010). Efficacy and safety of prescription omega-3 fatty acids for the prevention of recurrent symptomatic atrial fibrillation. A randomized controlled trial.JAMA, DOI:10.1001. Retrieved from http:jama.ama-assn.org cgicontent/full/jama.2010.1735v1.

• Rizza, S., Tesauro, M., Cardillo C., Galli A., Iantorno, M., Gigli, F.....Lauro, D. (2009). Fish oil supplementation improves endothelial function in normoglycemic offspring of patients with type 2 diabetes. Atherosclerosis, 206, 569-574.

• Sacks, F. M., Stone, P. H., Gibson, C.M. Silverman, D.I., Rosner, B., & Pasternak R. C. (1995). Controlled trial of fish oil for regression of human coronary atherosclerosis. HARP

Research group. Journal of American College of Cardiology, 25 (7), 1492-1498.

References• Singh, R. B., Niaz, M. A., Sharma, J. P., Kumar, R., Rastogi, V., & Moshiri (1995).

Randomized, Double-Blind, Placebo-controlled Trial of Fish Oil and Mustard Oil in Patients with Suspected Acute Myocardial Infarction: The Indian Experiment of Infarct Survival. Cardiovascular Drugs and Therapy, 11, 485-491.

• Von, S. C., Angerer P., Kothry, W., Theisen, K., & Mudra, H. (1999). The effect of dietary omega-3 fatty acids on coronary atherosclerosis. A randomized, double-blind, placebo- controlled trial. Annuals of internal medicine, 130 (7), 554-62.

• Walser, B., Giordano, R. M., & Stebbins, C. L. (2006). Supplementation with omega-3 polyunsaturated fatty acids augments brachial artery dilation and blood

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