Role of Omega-3 Fatty acids in the prevention of CHDDr.S.Sethupathy,M.D,Ph.D.,Professor of Biochemistry,Rajah Muthiah Medical College,Annamalai University.

Coronary artery disease (CAD) Cardiovascular disease - the most

important cause of mortality in India. Indians - Higher prevalence of CAD even

in low rates of traditional cardiac risk factors like obesity, smoking, cholesterol and hypertension

Diabetes, physical inactivity, low HDL levels have a higher prevalence amongst Indians

Indians develop heart disease about 10

years earlier than other populations Young Indians often have heart disease as

severe as older individuals. Indian doctors who are well aware of

cardiac risk factors die on an average 15 years earlier than non- Indian doctors in the UK.

India showed that first heart attacks among patients younger than 40 have increased 20-fold between 1971 and 1991.

Indians suffer a higher rate of cardiac arrest before reaching the hospital than patients from other ethnic groups.

Serious forms of CAD especially left main CAD and three-vessel disease are twice as common among Indians as in whites, and even more common among Indian women

They have plaque build-up over the entire length of the artery which make them not only unsuitable for angioplasty and surgery.

Indians develop diabetes earlier (10 to 15 years) and at a lower body weight (9.1 to 13.6 kg) than other populations.

From 2000 to 2030, diabetic population in India is projected to increase from 32 million to 79 million.

prevalence of CAD among diabetics is 14-fold higher in those below 45 years and 2-3 fold higher in those older.

India - the diabetes and hypertension capital of the world.

Diabetes is two to four times more common among Indians than other populations

Prevalence of diabetes has doubled in rural India and tripled in urban India over the past three decades.

A high prevalence Risk factors like lipoprotein (a) level, metabolic syndrome, homocysteine, fibrinogen, C-reactive protein (CRP) - among Indians

Other emerging risk Factors may be partly genetic and partly lifestyle-related.

Prevention of CADThe Greenland Inuit people

consumed large amounts of fat from seafood

No cardiovascular disease. The high level of omega-3 fatty

acids consumed by the Inuit reduced triglycerides, heart rate, blood pressure, and atherosclerosis

n−3 fatty acids or ω−3 fatty acids (omega-3 fatty acids) are a family of unsaturated fatty acids that have in common a final carbon–carbon double bond in the n−3 position;

Third bond from the methyl end of the fatty acid.

n−6 fatty acids or ω−6 fatty acids ( omega-6 fatty acids) are a family of unsaturated fatty acids that have in common a final carbon–carbon double bond in the n−6 position

Omega 3 fatty acid

Nutritionally important n−3 fatty acids are α-linolenic acid (ALA), eicosapentaenoic acid (EPA), & docosahexaenoi c acid (DHA)

The human body cannot synthesize n−3 fatty acids de novo

Both n−3 and n−6 fatty acids are essential, i.e. humans must consume them in the diet

But the "short chain" eighteen-carbon n−3 fatty acid α-linolenic acid is converted to long chain forms (EPA, DHA) with an efficiency of approximately 5% in men, and at a greater percentage in women

The chain elongation occur competitively with n−6 fatty acids

Decreases in total mortality and cardiovascular incidents (i.e. myocardial infarction) associated with the regular consumption of fish and fish oil supplements

EPA decreased the thickness of carotid arteries along with improving blood flow in patients with unhealthy blood sugar levels

Dietary consumption of α-linolenic acid (2 to 3 g per day) is useful for the primary and secondary prevention of coronary heart disease

Decreases in total mortality and cardiovascular incidents (i.e. myocardial infarction) associated with the regular consumption of fish and fish oil supplements

Those patients with very high triglyceride levels (above 500 mg/dl) reduced their triglycerides on average 45% and their VLDL cholesterol by more than 50%.

Patients on EPA had superior cardiovascular function

So long-chain n−3 fatty acids obtained directly from food is more effective.(EPA and DHA)

2004- The U.S. FDA gave "qualified health claim" status to EPA and DHA- n−3 fatty acids for the reduction of risk of coronary heart disease

Metabolites of n−6 are more inflammatory than those of n−3.

n−3 and n−6 be consumed in a balanced proportion;

Healthy ratios of n−6 : n−3 range from 1:1 to 1:4

Studies suggest that the evolutionary human diet, rich in seafood provide such a ratio

n-3 prevents monocytes from adhering to arterial walls and contributing to plaque build-up.

This is by reducing thromboxane A2 which promotes clotting and vasoconstriction

A study carried out involving 465 women showed serum levels of eicosapentaenoic acid is inversely related to the levels of anti-oxidized-LDL antibodies.

Oxidative modification of LDL plays an important role in the development of atherosclerosis

Clinical studies indicate that the ingested ratio of n−6 to n−3 fatty acids is important in maintaining cardiovascular health.

Typical Western diets provide ratios of between 10:1 and 30:1 - i.e., dramatically higher levels of n−6 polyunsaturated fatty acids

Dietary SourcesSalmon, flax seeds and walnuts are

excellent sources of omega-3 fatty acids.

Very good sources include scallops, cauliflower, cabbage, cloves and mustard seeds.

Good sources include halibut, shrimp, cod, tuna, soybeans, tofu, kale, collard greens, and Brussels sprouts.

Ratios of n−6 to n−3 FA in common vegetable oils Canola2:1, Soy bean 7:1, Olive 3–13:1, Flax 1:3, Corn oil 46:1 Cottonseed , peanut, grapeseed oil,

sunflower (no n−3),

The most widely available dietary source of EPA and DHA is cold water oily fish such as salmon herring, mackerel, anchovies and sardines, which they obtain from consumption of algae .

Oils from these fish have seven times as much n−3 as n−6.

Beware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxin, in fishes.

Although fish is a dietary source of n−3 fatty acids, fish do not synthesize them; they obtain them from the algae or plankton in their diet

Krill oil ,a superior source of n−3 fatty acids

Not contaminated like fish Contain a special antioxidant

called astaxanthin. But astaxanthin not a very potent

antioxidant

The microalgae Crypthecodinium cohnii and Schizochytrium are rich sources of DHA (22:6 n−3)

They can be produced commercially in bioreactors

This is the only source of DHA acceptable to vegans.

Polyunsaturated oils, including the omega-3 fats, are extremely susceptible to damage from heat, light, and oxygen.

When exposed to these elements for too long, the fatty acids in the oil become oxidized and becomes rancid.

Oils rich in polyunsaturated fatty acids should be stored in dark glass, tightly closed containers in the refrigerator or freezer.

These oils should never be heated on the stove.

Use flaxseed or walnut oil for a salad dressing

Fish FryFoods containing omega-3 fatty

acids lose their heart benefits when the foods are fried.

Fried fish containing omega-3s provide less heart protection than baked or broiled fish containing the same amount of omega-3s.

The health benefit of fish is due, at least in part, to the fact that it often replaces an alternative protein source: red meat,which increases the risk of cardiovascular disease.

One of the concerns about eating lots of fish or fish oil is the possibility of consuming harmful Polychlorinated biphenyls (PCBs) and methyl mercury.

Fish oil supplements may be safe in that regard but cautious about dose.

Three grams or more per day of EPA and DHA may cause excessive bleeding in certain people.

Algae-derived omega-3 supplements generate DHA but not EPA.

Omega-3s from ALA-rich plant sources like flax or walnuts yield primarily EPA

To get an ideal ratio of EPA and DHA for full cardiovascular benefits of omega-3s, combine algae for its DHA boost with plant foods for their ALA-to-EPA boost.

Fish oil capsules contain both DHA and EPA.

Supplements containing EPA not recommended for infants or small children because they upset the balance between DHA and EPA during early development

Fish oil capsules may cause minor side effects, such as loose stools, abdominal discomfort, and belching

Vegetarian dietsTypically contain limited amounts of

DHA. Supplemental plant oil ALA increase

EPA but not DHA. DHA, available in algae-derived oils

or capsules, has been shown to increase DHA levels.

So Combine both

Take home message High risk for CAD in IndiansSimple solution is eating fish

regularly. (Salmon fish a rich source)

Thank you