Thursday, November 4, 2010
Monday, November 1, 2010
Facts on Fats
Health benefits of fats. Sounds quite confusing doesn’t it? And the debate goes on. Are fats good or bad for us? How much fat is consumable? How much is the requirement to the body? What types of fat are good for health? The list of questions often knock our mind in this struggle to stay healthy and look fit besides protecting from diseases.
When it comes to cholesterol, most of us worry about too much of the 'bad' kind, low-density lipoprotein (LDL). It causes plaque to build up in and potentially block the arteries that supply blood to the body from the heart.
But we shouldn't overlook the 'good' cholesterol, high-density lipoprotein (HDL). It helps remove excess cholesterol from arteries and eliminates it from blood. Lifestyle changes can also improve HDL cholesterol. One milligram per deciliter (mg/dL) of blood can reduce heart attack risk by as much as 3 per cent.
Overall, it’s best to have a low level of LDL cholesterol and a high level of HDL cholesterol. For women, an LDL level below 100 mg/dL and a HDL level of 50 mg/dL and above is recommended and for men, it’s best to have the same LDL level, but an HDL level of 40 mg/dL and above. If HDL falls below 50 mg/dL, the person is generally at increased risk of heart disease and heart attack.
Oils and fats form a critical ingredient in any food application. They help make the food nutritious and enhance its taste. Fats are the highest energy source. One gram of fat supplies 9 kcalories. Fats are used in food preparations to provide structure flavour and nutritive value. They provide the essential fatty acids (linoleic and linolenic acid) required by our body for its proper functioning. Fats act as carrier for oil soluble vitamins like A,D, E, K.
Fats and oils are made up of basic units called fatty acids. Each type of fat or oil is a mixture of different fatty acids. “Fats provide many important attributes to foods like flavour, palatability and mouth feel. Apart from making the food more tasty and palatable fat acts as an excellent heat transfer media in cooking, frying and baking applications,” states Dr K D Yadav, vice president, technical, Kamani Oil Industries Ltd.
Depending on their degree of saturation, fatty acids are classified as either saturated fatty acids, monounsaturated fatty acids, or polyunsaturated fatty acids (PUFA).
MUFA Monounsaturated Fatty Acids, refers to the healthy fatty acid, which lowers the levels of bad cholesterol and triglycerides without lowering good cholesterol levels.
MUFA are found mainly in vegetable oils such as canola, olive, mustard and groundnut oils. They are liquid at room temperature. The American Heart Association (AHA) suggests that MUFA rich diet reduces risk of heart diseases. MUFA oils have a higher oxidative stability as compared to PUFA oils and hence have a better shelf life.
PUFA lowers the levels of good and bad cholesterol. This is not beneficial as low good cholesterol increases the risk of developing heart disease. PUFA fulfils several functions in human physiology. PUFA is found in dietary fats and oils, and is known as essential fat. Like vitamins, fatty acids are essential for life; they cannot be made in the body and must be obtained via the diet.
PUFA is found mainly in vegetable oils such as kardi sunflower, corn, soya and cottonseed oils. Polyunsaturated fats are also the main fats found in seafood. They are liquid at room temperature. According to Yadav, “Specific polyunsaturated fatty acids, such as linoleic acid (omega-6) and alpha-linolenic (omega-3) acid, are called essential fatty acids. These are not synthesised in our body but are vital as they are necessary for cell structure and making hormones.” Essential fatty acids hence are obtained from foods we consume. PUFA oils lower both the HDL and the LDL cholesterol.
Commercially prepared salad dressings also may be high in saturated fats and, therefore, careful inspection of labels is important. The word "hydrogenated" on a label means that some of the polyunsaturated fat has been converted to saturated fat.
To lower the bad cholesterol the role of Polyunsaturated fatty acids (PUFA) & Mono-unsaturated Fatty Acid (MUFA) is important in the food items. As per recommended dietary guidelines of WHO/ Japanese Heart Association/ American Heart Association, the ideal ratio of SFA: MUFA: PUFA should be 1:1.5:1
According to a study in PLoS Medicine, the replacement of dietary saturated fatty acids with polyunsaturated fatty acids reduces coronary heart disease events, bringing much needed scientific evidence to an issue debated by experts and clinical guidelines. Dariush Mozaffarian and colleagues from Harvard Medical School and Harvard School of Public Health conducted a systematic review and meta-analysis of randomised controlled trials studying the effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat. They reviewed 8 trials involving over 13,000 participants and found that among those substituting SFA for PUFA (the intervention group), there was a 19% reduced risk of CHD risk compared to participants in the control groups. The consumption of PUFA accounted for 15% of total energy intake in the intervention groups on average but only 5% of total energy intake in the control groups. As such, the researchers report that each 5% increase in the proportion of energy obtained from PUFA reduced the CHD risk by 10%.
Furthermore, they found that the benefits associated with PUFA consumption increased with greater duration of the trials.
While reducing consumption of saturated fat (contained in meat, cheese, and butter, for example) is recommended as a way to prevent CHD, recent large meta-analyses of observational studies have suggested no overall benefits of reducing SFA consumption on CHD events. Few clinical studies have investigated the effects on CHD events of replacing saturated fat in the diet with specific alternative energy sources like carbohydrate, protein, or other types of fat such as polyunsaturated fats, which include vegetable oils. In fact, some experts argue that eating PUFA actually increases CHD risk and some guidelines recommend PUFA consumption should be limited. As a result, there has been a strong need for more scientific study.
"Rather than trying to lower PUFA consumption, a shift towards greater PUFA consumption in place of SFA could significantly reduce rates of CHD," stated the authors.
DIETARY RECOMMENDATIONS
RECOMMENDED DIETARY INTAKE IS 2000 CALORIES/DAY
• TOTAL FAT - 30% or less
• SAFA- 7-10%
• PUFA- 10%
• MUFA- 15%
• TRANS < 1%
• OMEGA 6 AND OMEGA 3
RATIO- 10:1 TO 5:1
• CHOLESTEROL < 300mg /DAY
Saturated Fatty Acids (SAFA) are found mainly in animal sources such as meat and poultry, dairy fat, vegetable oils like coconut oil, palm kernel oil and palm oil. Saturated fats are usually solid at room temperature. Saturated fats contribute to the risk of heart disease by raising blood cholesterol levels. These fats are commonly found in many takeaway (‘fast’) foods, in commercial products such as biscuits and pastries, and in dairy products.
Trans Fat is the common name for unsaturated fat with trans-isomer fatty acids. Trans fats may be monounsaturated or polyunsaturated but never saturated. Trans fats are formed when previously healthy liquid oils are hydrogenated, or hardened, a process often used to improve the texture of packaged foods and increase shelf life.
The manufacturers prefer trans-fat as they increase a product’s shelf life. These oils pose detrimental concerns for an individual's health and the nation's obesity pandemic.
Research shows that trans fats, even in small quantities are worse for us than saturated fats. They raise our Low-density lipoprotein (LDL) bad cholesterol, lower our High-density lipoprotein (HDL) good cholesterol, and increase triglyceride levels in the blood. They also promote inflammation in the body, which can damage blood vessels, a quadruple whammy for the heart.
Unless there is at least 0.5 grams or more of Trans fat in a food, the label can claim 0 grams. Today we find many products with bold label claiming: No trans fat! Especially in items like chips, bread, cereals, and cookies most grocery shops lure consumers towards such products.
This hysteria of trans-fat has manipulated the technique of food, manufacturers select their ingredients, advertisers market food products and consumers get ample of variety brands to choose and buy.
Fat replacers: They are ingredients designed to replace all or part of the fat in a product with minimum impact on the organoleptic quality of the food product. Since fats provide many important attributes to foods like flavour, palatability and mouth feel, but are hold negative attributes, many opt for fat replacers which are meant to serve the above mentioned functions.
Fat replacers are of 3 types: Fat mimetics, Low caloric fats, Fat substitutes
Fat substitutes are compounds designed to replace fats on a weight-by-weight basis
Fat mimetics are compounds that reproduce physical and sensory physical attributes associated with fats
Low calorie fats are low-calorie synthetic triglycerides consisting of unconventional fatty acids to a glycerol backbone.
Refined oil: This type of oil has been purified with chemicals to remove any suspended particles, toxic substances, flavour components, colour and odour, thereby leaving behind a clear and bland oil.
Filtered oil: Obtained by the traditional cold pressing method, this is filtered once or twice to remove suspended particles.
Deficiency of fats
Deficiency of fats causes a deficiency of essential fatty acids, linoleic and linolenic acids, and subsequently a deficiency of arachidonic acid. The deficiency results in characteristic eczemadry, scaly skin, hair loss, low body weight, cold intolerance, bruising, poor growth, lower resistance to infection, poor wound healing, loss of menstruation. Deficiency of fat may result in a deficiency of fat-soluble vitamins, and growth and weight may be affected in children. Since fat is present in minute quantities in almost all foods including the deficiency in adults is unlikely. Today the greater concern is the problem related to excessive intake. Excess intake of fat causes obesity when more kilocalories are consumed than required by the body. The excess fat gets stored in the adipose tissue. Excessive consumption of saturated fats can elevate blood cholesterol levels. A high intake of saturated fats and cholesterol are predisposing factors for cardiovascular diseases, while foods rich in Omega-3 fatty acids have protective effect.
Oil Combinations
Oils combinations are the best recommended for healthy and nutritious diet with right amount of combination of nutritional benefits. To derive maximum benefits from oil, it is beneficial to consume a mix of oils in order to maintain a balance between the three fatty acids.
Manually combining oils wouldn't be a smart move. But today the market is flooded with a variety of blended oils. For instance, blends of ricebran and sunflower oils by companies like Sunrise, Sundrop Heart. Such products are the best buys and are suitable even for frying.
Another alternative could be using two or more different kinds of oils that could be used for different purposes or using them alternately. Some oils can be used only for specific purposes. For example, olive oil for salads, groundnut oil is suitable for frying and soyabean oil for other cooking purposes. Such combinations help to take advantage of the health benefits offered by each oil.
When it comes to cholesterol, most of us worry about too much of the 'bad' kind, low-density lipoprotein (LDL). It causes plaque to build up in and potentially block the arteries that supply blood to the body from the heart.
But we shouldn't overlook the 'good' cholesterol, high-density lipoprotein (HDL). It helps remove excess cholesterol from arteries and eliminates it from blood. Lifestyle changes can also improve HDL cholesterol. One milligram per deciliter (mg/dL) of blood can reduce heart attack risk by as much as 3 per cent.
Overall, it’s best to have a low level of LDL cholesterol and a high level of HDL cholesterol. For women, an LDL level below 100 mg/dL and a HDL level of 50 mg/dL and above is recommended and for men, it’s best to have the same LDL level, but an HDL level of 40 mg/dL and above. If HDL falls below 50 mg/dL, the person is generally at increased risk of heart disease and heart attack.
Oils and fats form a critical ingredient in any food application. They help make the food nutritious and enhance its taste. Fats are the highest energy source. One gram of fat supplies 9 kcalories. Fats are used in food preparations to provide structure flavour and nutritive value. They provide the essential fatty acids (linoleic and linolenic acid) required by our body for its proper functioning. Fats act as carrier for oil soluble vitamins like A,D, E, K.
Fats and oils are made up of basic units called fatty acids. Each type of fat or oil is a mixture of different fatty acids. “Fats provide many important attributes to foods like flavour, palatability and mouth feel. Apart from making the food more tasty and palatable fat acts as an excellent heat transfer media in cooking, frying and baking applications,” states Dr K D Yadav, vice president, technical, Kamani Oil Industries Ltd.
Depending on their degree of saturation, fatty acids are classified as either saturated fatty acids, monounsaturated fatty acids, or polyunsaturated fatty acids (PUFA).
MUFA Monounsaturated Fatty Acids, refers to the healthy fatty acid, which lowers the levels of bad cholesterol and triglycerides without lowering good cholesterol levels.
MUFA are found mainly in vegetable oils such as canola, olive, mustard and groundnut oils. They are liquid at room temperature. The American Heart Association (AHA) suggests that MUFA rich diet reduces risk of heart diseases. MUFA oils have a higher oxidative stability as compared to PUFA oils and hence have a better shelf life.
PUFA lowers the levels of good and bad cholesterol. This is not beneficial as low good cholesterol increases the risk of developing heart disease. PUFA fulfils several functions in human physiology. PUFA is found in dietary fats and oils, and is known as essential fat. Like vitamins, fatty acids are essential for life; they cannot be made in the body and must be obtained via the diet.
PUFA is found mainly in vegetable oils such as kardi sunflower, corn, soya and cottonseed oils. Polyunsaturated fats are also the main fats found in seafood. They are liquid at room temperature. According to Yadav, “Specific polyunsaturated fatty acids, such as linoleic acid (omega-6) and alpha-linolenic (omega-3) acid, are called essential fatty acids. These are not synthesised in our body but are vital as they are necessary for cell structure and making hormones.” Essential fatty acids hence are obtained from foods we consume. PUFA oils lower both the HDL and the LDL cholesterol.
Commercially prepared salad dressings also may be high in saturated fats and, therefore, careful inspection of labels is important. The word "hydrogenated" on a label means that some of the polyunsaturated fat has been converted to saturated fat.
To lower the bad cholesterol the role of Polyunsaturated fatty acids (PUFA) & Mono-unsaturated Fatty Acid (MUFA) is important in the food items. As per recommended dietary guidelines of WHO/ Japanese Heart Association/ American Heart Association, the ideal ratio of SFA: MUFA: PUFA should be 1:1.5:1
According to a study in PLoS Medicine, the replacement of dietary saturated fatty acids with polyunsaturated fatty acids reduces coronary heart disease events, bringing much needed scientific evidence to an issue debated by experts and clinical guidelines. Dariush Mozaffarian and colleagues from Harvard Medical School and Harvard School of Public Health conducted a systematic review and meta-analysis of randomised controlled trials studying the effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat. They reviewed 8 trials involving over 13,000 participants and found that among those substituting SFA for PUFA (the intervention group), there was a 19% reduced risk of CHD risk compared to participants in the control groups. The consumption of PUFA accounted for 15% of total energy intake in the intervention groups on average but only 5% of total energy intake in the control groups. As such, the researchers report that each 5% increase in the proportion of energy obtained from PUFA reduced the CHD risk by 10%.
Furthermore, they found that the benefits associated with PUFA consumption increased with greater duration of the trials.
While reducing consumption of saturated fat (contained in meat, cheese, and butter, for example) is recommended as a way to prevent CHD, recent large meta-analyses of observational studies have suggested no overall benefits of reducing SFA consumption on CHD events. Few clinical studies have investigated the effects on CHD events of replacing saturated fat in the diet with specific alternative energy sources like carbohydrate, protein, or other types of fat such as polyunsaturated fats, which include vegetable oils. In fact, some experts argue that eating PUFA actually increases CHD risk and some guidelines recommend PUFA consumption should be limited. As a result, there has been a strong need for more scientific study.
"Rather than trying to lower PUFA consumption, a shift towards greater PUFA consumption in place of SFA could significantly reduce rates of CHD," stated the authors.
DIETARY RECOMMENDATIONS
RECOMMENDED DIETARY INTAKE IS 2000 CALORIES/DAY
• TOTAL FAT - 30% or less
• SAFA- 7-10%
• PUFA- 10%
• MUFA- 15%
• TRANS < 1%
• OMEGA 6 AND OMEGA 3
RATIO- 10:1 TO 5:1
• CHOLESTEROL < 300mg /DAY
Saturated Fatty Acids (SAFA) are found mainly in animal sources such as meat and poultry, dairy fat, vegetable oils like coconut oil, palm kernel oil and palm oil. Saturated fats are usually solid at room temperature. Saturated fats contribute to the risk of heart disease by raising blood cholesterol levels. These fats are commonly found in many takeaway (‘fast’) foods, in commercial products such as biscuits and pastries, and in dairy products.
Trans Fat is the common name for unsaturated fat with trans-isomer fatty acids. Trans fats may be monounsaturated or polyunsaturated but never saturated. Trans fats are formed when previously healthy liquid oils are hydrogenated, or hardened, a process often used to improve the texture of packaged foods and increase shelf life.
The manufacturers prefer trans-fat as they increase a product’s shelf life. These oils pose detrimental concerns for an individual's health and the nation's obesity pandemic.
Research shows that trans fats, even in small quantities are worse for us than saturated fats. They raise our Low-density lipoprotein (LDL) bad cholesterol, lower our High-density lipoprotein (HDL) good cholesterol, and increase triglyceride levels in the blood. They also promote inflammation in the body, which can damage blood vessels, a quadruple whammy for the heart.
Unless there is at least 0.5 grams or more of Trans fat in a food, the label can claim 0 grams. Today we find many products with bold label claiming: No trans fat! Especially in items like chips, bread, cereals, and cookies most grocery shops lure consumers towards such products.
This hysteria of trans-fat has manipulated the technique of food, manufacturers select their ingredients, advertisers market food products and consumers get ample of variety brands to choose and buy.
Fat replacers: They are ingredients designed to replace all or part of the fat in a product with minimum impact on the organoleptic quality of the food product. Since fats provide many important attributes to foods like flavour, palatability and mouth feel, but are hold negative attributes, many opt for fat replacers which are meant to serve the above mentioned functions.
Fat replacers are of 3 types: Fat mimetics, Low caloric fats, Fat substitutes
Fat substitutes are compounds designed to replace fats on a weight-by-weight basis
Fat mimetics are compounds that reproduce physical and sensory physical attributes associated with fats
Low calorie fats are low-calorie synthetic triglycerides consisting of unconventional fatty acids to a glycerol backbone.
Refined oil: This type of oil has been purified with chemicals to remove any suspended particles, toxic substances, flavour components, colour and odour, thereby leaving behind a clear and bland oil.
Filtered oil: Obtained by the traditional cold pressing method, this is filtered once or twice to remove suspended particles.
Deficiency of fats
Deficiency of fats causes a deficiency of essential fatty acids, linoleic and linolenic acids, and subsequently a deficiency of arachidonic acid. The deficiency results in characteristic eczemadry, scaly skin, hair loss, low body weight, cold intolerance, bruising, poor growth, lower resistance to infection, poor wound healing, loss of menstruation. Deficiency of fat may result in a deficiency of fat-soluble vitamins, and growth and weight may be affected in children. Since fat is present in minute quantities in almost all foods including the deficiency in adults is unlikely. Today the greater concern is the problem related to excessive intake. Excess intake of fat causes obesity when more kilocalories are consumed than required by the body. The excess fat gets stored in the adipose tissue. Excessive consumption of saturated fats can elevate blood cholesterol levels. A high intake of saturated fats and cholesterol are predisposing factors for cardiovascular diseases, while foods rich in Omega-3 fatty acids have protective effect.
Oil Combinations
Oils combinations are the best recommended for healthy and nutritious diet with right amount of combination of nutritional benefits. To derive maximum benefits from oil, it is beneficial to consume a mix of oils in order to maintain a balance between the three fatty acids.
Manually combining oils wouldn't be a smart move. But today the market is flooded with a variety of blended oils. For instance, blends of ricebran and sunflower oils by companies like Sunrise, Sundrop Heart. Such products are the best buys and are suitable even for frying.
Another alternative could be using two or more different kinds of oils that could be used for different purposes or using them alternately. Some oils can be used only for specific purposes. For example, olive oil for salads, groundnut oil is suitable for frying and soyabean oil for other cooking purposes. Such combinations help to take advantage of the health benefits offered by each oil.
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