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The Oil & Fat Story: What Is the Healthy Intake?
18 February, 2016
- PUFA, Saturated Fats, Trans Fats, Omega 3 Fatty Acids, Mono Unsaturated Fats, Butter, Visible Fats, Fish oils…. Blah Blah. So much of information on fats just can’t be comprehended well by majority of health conscious citizens. Poor understanding of Fat facts have resulted in reliance on television commercials. Shinier the advert, healthier the oil - this had been the current day idea about healthy fat intake. Let’s attempt to get into the depth of the oily tale and find out the facts
- .Fat is generally a highly valued element of the diet to provide energy, palatability to dry foods or to serve as a cooking medium. If we go to the molecular level, fats are composed of fatty acids & esters which help in building the cell membrane of human cells, important biochemical neurotransmitters, hormones, and provide energy on demand. But there is a property of fats to get accumulated as they are not the fastest moving energy resource of the body.
- Unfortunately, they often accumulate in the blood vessels of heart and brain, sometimes in arteries of limbs and other vital organs and in due time takes a toll on the health of these organs causing heart attacks, brain strokes and gangrenes. Let’s figure out who are the culprits. It’s a well known fact that Cholesterols who take important part in forming steroid and thyroid hormones are harmful in excess. When we speak of cholesterol we seldom notice that the total amount of cholesterol in our body is basically composed of sub groups like Low Density Cholesterol (LDL), High Density Cholesterol (HDL), Very Low Density Cholesterol (VLDL), and Intermediate Density Cholesterol (IDL). Of which LDL is the bad cholesterol and HDL is the good cholesterol. HDLs are called the cholesterol scavengers. They scavenge cholesterol from target organs such as heart, brain, arteries and bring them back to the liver. Whereas LDL cholesterol does the reverse. Their concentration in the blood is directly related to Mortality due to cardiovascular events. Hence fat intake should be directed in reducing LDL and increasing HDL. Saturated and Trans Fats are predominant source of LDL, whereas, diets rich in Poly Unsaturated fats and Omega 3 Fatty Acids, promote formation of HDL cholesterol. Intake of oil is the major source of fat entry into our body. So choice of oil and foods rich in fat is the deciding factor in creating the cholesterol milieu in our body. Nutritionists have recommended that the ratio of PUFA: MUFA: SFA should be 1:1:1
- Well, complete absence of saturated fat is not recommended. Interestingly not a single dietary source or oil has got such combination of fats. Oils rich in Saturated fats can be identified by the fact that they are solid in physical form in room temperature. E.g. Butter, Ghee, Margarine. Mono-Unsaturated fats are liquid in room temperature but become hazy when cooled down e.g. olive oil, peanut oil. And Poly-Unsaturated fats are liquid in physical form all through e.g. canola oil, sunflower oil, walnut oil. So we need a blend of all these three in appropriate proportions
- Needless to state that Olive Oils score high amongst oil fraternity. Not only because of its high content of MUFA, but also due to potent antioxidant properties. The chief active components of olive oil include oleic acid, phenolic constituents, and squalene. The main phenolics include hydroxytyrosol, tyrosol, and oleuropein, which occur in highest levels in virgin olive oil and have demonstrated antioxidant activity.
Antioxidants are believed to be responsible for a number of olive oil's biological activities. Oleic acid, a monounsaturated fatty acid, has shown activity in cancer prevention, while squalene has also been identified as having anticancer effects. Olive oil consumption has benefit for colon and breast cancer prevention. The oil has been widely studied for its effects on coronary heart disease (CHD), specifically for its ability to reduce blood pressure and low-density lipoprotein (LDL) cholesterol. Antimicrobial activity of hydroxytyrosol, tyrosol, and oleuropein has been demonstrated against several strains of bacteria implicated in intestinal and respiratory infections
- Although the majority of research has been conducted on the oil, consumption of whole olives might also confer health benefits. The use of raw EVOO added to foods after cooking (or as a salad oil) is the best way to express the original flavour and to maximize the intake of natural antioxidants and compounds related to positive effects on human health (hypotensive, anti-inflammatory, and anti-cancerogenic,). EVOO, however, also exhibits its protective properties during/after cooking. Different chemical interactions between biophenolic compounds and other food ingredients (water, milk proteins, carotenoids of tomato, omega-3 polyunsaturated fatty acids in canned-in-oil fish and meat or fish proteins) occur. Even during cooking, EVOO exhibits strong antioxidant properties and influences the overall flavour of cooked foods. Pure Olive oil however lacks the property of antioxidants.
- The approximate content of SFA: MUFA: PUFA is around 15:75:10.Canola Oil is another entrant in the race for healthy oils. It’s worth mentioning that there is nothing called canola plant or seeds. After searching the internet database it has been found that canola oils are basically rapeseed oils which have been genetically engineered and undergo a high temperature purification, deodorization & degummation process. These complicated procedures that convert the oil into edible format causes loss of the antioxidants.
- The approximate content of SFA: MFA: PUFA in canola oil is around 8: 64: 28. The high content of MFA and PUFA makes it healthier for cholesterol milieu of the body. In a recently conducted clinical trial published in American Journal of Clinical Nutrition, May 2014, it has been concluded that consumption of Canola DHA( Docosahexanoic Acid) , a novel DHA-rich canola oil, improves HDL cholesterol, triglycerides, and blood pressure, thereby reducing risks for cardiovascular risk scores compared with other oils varying in unsaturated fatty acid composition.Among other high quality oils are the walnut oil, peanut oil and sesame oil. The ratio of MUFA: PUFA in peanut & sesame oil is 1:1 with less than 20% SFA
- However, there is indeed a question of cost benefit ratio as because these special oils are quite heavy on the wallet. One of highlighted confusions in the kitchen is the choice between butter & margarine. Well, since the common belief is that margarines are healthy replacement of butter, few facts needs to be made clear. Both butter & margarine are solid fats and very likely to be unhealthy for the heart. Butter has high content of saturated fats and low in trans-fat as because they are not produced by hydrogenation whereas margarines are product of hydrogenation and are rich is trans-fats and low in saturated fats. Margarines which undergo partial hydrogenation are low is trans-fats. Hence, liquid margarine may be a healthy replace of both. With evolving nutrition science, margarines and cooking products, and to a lesser extent dressings, have been adapted to contain less trans fatty acids (TFA), less SFA and more essential (polyunsaturated, PUFA) fatty acids. This has been possible by using careful fat and oil selection and modification processes.
- By blending vegetable oils rich in the essential PUFAs alpha-linolenic acid (vegetable omega-3) or linoleic acid (omega-6), margarines and dressings with both essential fatty acids present in significant quantities can be realized. In addition, full hydrogenation and fat rearrangement have enabled the production of cost-effective margarines virtually devoid of TFA and low in SFA. Dietary surveys indicate that vegetable oils, soft margarines and dressings are indeed often important sources of essential fatty acids in people's diets, whilst providing negligible amounts of TFA and contributing modestly to SFA intakes. Before consumption of a particular brand of margarine it is wise to go through the nutritional facts on the label and check the trans-fat concentration
- One might wonder about the natural sources of dietary fats. Most of natural sources of healthy dietary fat come from fish oils, nuts, olives and low fat dairy products. The association between fish consumption and risk of cardiovascular disease (CVD) has been extensively studied. There is little doubt that long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFAs) in fish are the key nutrients responsible for the benefits and are important for CVD prevention. Omega-3 PUFAs are responsible for rise in HDL Cholesterol and decrease LDL.
- Often people ask whether they can supplement their diet with fish oil capsules instead of whole fish. Well, in this regard researches have speculated that although fish is valued as a source of these fatty acids, it also provides other nutrients that may have cardio protective effects. It is likely that the beneficial effects of fish consumption on the risk of CVD are the synergistic effects among nutrients in fish, and the integrative effects of fish consumption may reflect the interactions of nutrients and contaminants in fish.To conclude it must be emphasized that all of your dietary fat source should be consisting predominantly of unsaturated fats; PUFAs & MUFAs.