Posts Tagged ‘PUFA’

A totally fat free diet is unhealthy

A totally fat free diet is unhealthy

Fats are feared by the health conscious, favoured by the gourmet lover and ferociously penned by the medical bodies on its vices or virtues. Fats are let us say, less temperamental unlike carbohydrates that can instantly spike one’s blood sugar or proteins that can give you a sudden allergic reaction. Their effects remain unobtrusive until a blood test or heart attack alerts you to take note of it in your diet.

When nutritionists talk about eating low fat the message gets misunderstood, because what they mean is to lower one’s bad fat intake or a presently unhealthy fat diet. They certainly do not mean eating fat free! There are several people who, on being diagnosed with high cholesterol or triglycerides eat without fat and then complain that despite eating no fat, blood lipids do not improve on a long term. A totally fat free diet is unhealthy. It serves no good to the purpose behind it which may be to reduce weight or decrease total or LDL cholesterol.

Why we need fats

Fats are essential to the body just as are proteins and carbohydrates. Apart from being the denser source of energy than carbohydrate or proteins, fat also protects proteins from being broken down for energy. Most of our muscles require fatty acids for energy. The adipose tissue (commonly referred to as fat) insulates the body, maintaining the body heat and temperature. Adipose tissue is what cushions our organs and protects them from external trauma.

Fat in food is essential to transport and absorb fat soluble vitamins like A, D and E. Fat in food also delays gastric emptying and buffers gastric juices. Fat brings out the flavour of foods and lends satiety to the meal. Fat gives shapes our body.

What is right and how much is good?

There is a basic rule of eating fat which is undisputedly agreed upon by scientists everywhere. That is to “eat the right kind of fats in the right amount”. There are the good – the mono and poly unsaturated fats (MUFA and PUFA), bad – saturated (SFA), and very bad fats – trans fatty acids. Going into the composition of these is beyond the scope of this article, nor its purpose. But what is necessary here is learning how to eat fats in one’s diet.

Eat your fat and stay healthy

Numerous researches point to the fact that to control cholesterol changing from saturated to monounsaturated fats help irrespective of the quantity of fat consumed as versus reducing fat and instead increasing refined carbohydrates.

Calories from fat should constitute 30 to 35 per cent of total calories. This means for an adult moderately active, say on 2400 kcal/day, 80grams of fat in a day. Now, note that this includes both added fats like ghee, butter, oils in cooking, and those naturally found in nuts, seeds, avocadoes, olives, beans, grated coconut, whole milk or curds, egg, fish, poultry, meat.

Present recommendations are zero TFA and restricted SFA – to about 7 per cent of fat calories in a day. Majority of the remaining should come ideally from monounsaturated fats. We can only classify oils as predominantly MUFA, PUFA or SFA because all oils contain a mix of unsaturated and saturated fats.

Since we do not eat by percentages, how can a good proportion be achieved?

•The only kind of fats that you need to totally avoid are partially hydrogenated fats – found in commercial foods, fast foods, processed foods

•Keep saturated fats to a minimum. This is achieved by not eating red meat, using low fat or skimmed milk and curds and using ghee and butter sparingly. Sources of SFA are ghee, butter, mayonnaise, animal fats, fat in milk and curds, tropical oils – coconut and palm oils, coconut milk.

•Use more of oils like sesame, peanut, soybean, olive, corn, safflower for cooking. Look for the word high oleic while choosing cooking oils. Use two or three kinds in a day. For example, use sesame oil at breakfast time, Sunflower for preparing lunch and olive for dinner. Keep changing the oils frequently.

•Use some kind of seeds and nuts especially flaxseeds, peanuts and sesame seeds daily.

•Skip red meat and eat fish. Cook fatty fish in its own fat, or make sure you use up the fat from the fish.

(The writer is a dietician based in Kochi)

Article source: http://www.thehindu.com/health/diet-and-nutrition/fat-myths/article3984677.ece

Share and Enjoy

Dietary Unsaturated Fat May Reduce Risk of Heart Disease

Fat in the diet comes in many forms, and you probably already know that some fats are better for your health than others. Omega-3 fatty acids from sources such as fish oils for example can decrease chronic inflammation known to lead to conditions such as arthritis, diabetes, and Alzheimer’s disease. But another type of polyunsaturated fat, omega-6 fatty acids, may also help decrease risk for coronary heart disease.

What exactly is a polyunsaturated fatty acid (PUFA)? Chemically, these are fatty acids that contain more than one double bond. Where that bond is located within the structure determines whether it is an omega-3, omega-6, or omega-9 fatty acid. Examples of omega-6 fatty acids include linoleic acid, arachidonic acid (AA), and gamma-linolenic acid (GLA).

Ads by Google

Researchers at the University of Cambridge in the UK gathered data from participants in the European Prospective Investigation into Cancer (EPIC)-Norfolk which included 2,424 patients aged 40 to 79 at baseline who were followed for more than 10 years. Each completed a questionnaire on their medical history, smoking, alcohol intake, physical activity, social class and education.

Blood samples were taken and evaluated for concentrations of 22 different phospholipid fatty acids which were then grouped into one of six “families”: even-chain saturated, odd-chain saturated, omega-6 polyunsaturated, omega-3 polyunsaturated, monounsaturated, and trans-fatty acids.

Patients who had the highest plasma concentration of omega-6 PUFAs had a significantly lower risk of coronary heart disease (CHD) compared with those who had the lowest concentrations.

There was also an association between higher levels of saturated fats in the blood and an increased risk of developing cardiovascular disease, although the relationship was weaker than expected, but Kay-Tee Khaw MA MSc FRCP suggests that this could be due to “measurement errors in the dietary assessment of fat intake (due to) recall errors” among other factors such as a variability in the fatty acid composition of foods.

Past studies, including one from Maastricht University Medical Center in the Netherlands, note that exchanging saturated fats in the diet for polyunsaturated fats can decrease postprandial (after-meal) fats in the blood and reduce markers of inflammation which all reduce the risk of developing heart disease.

For example, for a heart-healthy diet, instead of butter, rich in saturated fat, substitute a polyunsaturated, trans-fat free margarine on foods for flavor. Saturated fats are also found in fatty meats (beef, pork, lamb), poultry with skin, processed meats, whole and 2% milk, and lard. Certain plant oils also contain saturated fat, such as palm and palm kernel oils, coconut oil, and cocoa butter. Instead consume lean meats such as round, sirloin and loin, remove the skin from poultry, drink skim milk, and use small amounts of PUFA vegetable oils such as olive and canola.

Journal references:
Khaw KT, et al. “Plasma phospholipid fatty acid concentration and incident coronary heart disease in men and women: the EPIC-Norfolk Prospective Study” PLoS Med 2012;9:e1001255.
Masson CJ, Mensink RP. “Exchanging saturated fatty acids for (n-6) polyunsaturated fatty acids in a mixed meal may decrease postprandial lipemia and markers of inflammation and endothelial activity in overweight men” J Nutr. 2011 May;141(5):816-21. Epub 2011 Mar 23.

Additional resource:
Virginia Cooperative Extension (Virginia Tech)

Article source: http://www.emaxhealth.com/1506/dietary-unsaturated-fat-may-reduce-risk-heart-disease

Share and Enjoy