Omega 3-fatty acids—the heart protecting oil

 

by

 

Dr. Sashi Acharya

Shiva Hospital, Nepal

   shivahp@atcnet.com.np

 

                                                                              

 

Omega -3 fatty acids: All omega 3 fatty acids are polyunsaturated essential fatty acids. They are liquid at room temperature so are also known as oils. They provide protective benefits to the heart of healthy people, and the heart of those who are at high risk for coronary heart disease (CHD) and those who have had already heart attacks. They make the blood vessels less likely to be clogged and block the arteries, protecting heart against fatal heart attacks and arrhythmias. Some researchers showed that men with a higher blood level of the omega 3 fatty acids had an almost 50%lower CHD as compared to the men with lower levels of them.

 

What are fatty acids: A fatty acid is an organic compound consisting of a long hydrocarbon chain and a terminal carboxyl (COOH) group. All the carbon atoms in saturated fat are saturated with hydrogen atoms whereas in unsaturated fats some carbon atoms are not saturated with hydrogen atoms. They posses unstable double bond carbon atoms with missing hydrogen atoms in them. The structure of saturated and unsaturated fats and omega 3 fatty acid are given in fig 1, 2 &3 respectively

 

 

Figure 1.A saturated fatty acid

Figure 2.An unsaturated fatty acid (omega 6 fatty acid-The first double bond is after the 6th carbon atom, so we call this Omega 6 Fatty Acid)

 

 

Fig 1 and Fig 2 (Medlib.med.utah.edu/NrtBiochem/Fatty Acids/3-2ht)

 

 

Fig.3 from( http://www.thepetcenter.com/gen/fa.html

Saturated fats stimulate hepatic cholesterol production, thus increasing blood cholesterol levels.Saturared fats we get basically from animal foods like red meat, meat products and high fat dairy products. Fish contain low saturated fats and cholesterol. They do not increase our cholesterol or triglyceride levels. High cholesterol level is one of the major risk factor of coronary heart disease (CHD), the higher the blood cholesterol level the greater will be the risk for CHD.

 

Omega 3 fatty acids and their sources: Omega-3 fatty acids are usually derived from marine and vegetable sources. Two main omega fatty acids that are found in most fatty fishes like salmon, sardines ,mackerel and tuna are Eicosapentaenoic acid (EPA) and docosahexaenoic acids(DHA).Canola oil, wheat germ oils, flaxseeds pumpkin seeds, soybeans, dry beans and walnuts contain Alpha Linolenic acid(ALA).ALA turns into EPA and DHA (omega 3 fatty acids ) in our body. Our body needs both the omega 3and 6 acids in the definite proportion not less than 1:5.Percentage of omega fatty acids in some vegetable oils are as follow. See table 1.Omega 6 fatty acids are plenty in our food whereas omega 3 fatty acids are comparatively rare.

 

Omega-3 fatty acids protect the heart in several ways: Researchers have shown that they protect our heart in the following ways:

·        decrease risk of arrhythmias, which can lead to sudden cardiac death

EPA and DHA have an effect on clotting just like that of aspirin, preventing platelets aggregation and sticking them to the artery walls.Omega-3 fatty acids can reduce triglyceride (TG) levels in the blood. EPA in the fish lowers total cholesterol and TG levels, by inhibiting the synthesis of VLDL and TG in the liver.

 

 

 

 

Table 1.Percentage of omega 6 &3 fatty acids in some vegetable

 

Name of the oil

Omega 6 fatty acids

               %

Omega 3 fatty acids

              %

Canola oil

                22

                10

Flaxseed oil

               17

               55

Safflower oil                                      

               76

               Trace

Sunflower oil                        

               71

               1

Corn oil

               57

               1

Olive oil

               9

               1

Soybean oil

               54

               8

Coconut oil

               2

               0

Peanut oil

               33

               Trace

Conclusion: Omega 3 fatty acids seem to be very effective to the people who are at higher risk for coronary heart disease and who have had already heart attack. They lower the chances for second heart attack. AHA Dietary Guidelines 2002 recommends twice weekly eating fatty fish see fig 4. Alternative sources of omega 3 fatty acids for vegetarians and those who could not afford for fish are vegetable oil rich in omega 3 fatty acids. It is highly recommended to use soybean oil and canola oil for cooking food. Flax seed oil contains omega 3 fatty acids about double that of fish. In the Countries like ours where poverty and other so called religious and superstitious believes affect social habits, vegetable oils may play a very positive role in lowering fatal heart attacks and deaths from CHD.    Pregnant women and children should limit their consumption of fish with high mercury level such as sword fish, shark, whale and king mackerel though omega 3 fatty acids are being observed to prevent premature childbirth.

 

Figure 4. Relative risks of fatal coronary heart disease and nonfatal myocardial infarction, according to frequency of fish intake

http://www.americanheart.org/presenter.jhtml?identifier

 

 

Bibliography

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Fish Oil–Derived Fatty Acids, Docosahexaenoic Acid and Docosapentaenoic Acid, and the Risk of Acute Coronary Events

 

4.      Circulation, November 19, 2002;106(21):2747-57

5.      Simon, Joel A., et al. Serum fatty acids and the risk of coronary heart disease. American Journal of Epidemiology, Vol. 142, No. 5, September 1, 1995, pp. 469-76.

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9.      Netherlands Journal of Medicine 51, 1997, p. 1-9) d

10. Roger Mason Control cholesterol level, improve heart and artery health and live longer naturally without resorting to drugs

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13. Fatty Acids, You and Your Pet http://www.thepetcenter.com/gen/fa.html

14. Daily Requirements for Essentail Fatty Acids (EFAs)Daily Requirements for

            Essential Fatty Acids (EFA).http://www.thepetcenter.com/gen/fa.html