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Prudent Diet and Preventive Nutrition From Pediatrics to Geriatrics

Current Knowledge and Practical Recommendations

Abstract of Review from articles by : Coronary Artery Disease in Asian Indians (CADI) Research Foundation, and University of Illinois, Chicago, USA


"A man is what he eats" (German proverb).

Food provides not only the essential nutrients for life but also other bioactive compounds for the promotion of health and the prevention of disease. The results of 50 years of intensive worldwide research support the conclusion that diet is the major environmental cause of atherosclerosis and cardiovascular diseases (CVD), especially in genetically susceptible individuals.

A high-caloric diet, combined with limited physical activity, contributes to dyslipidemia, insulin resistance, diabetes, and obesity.

The public and physicians are constantly bombarded with confusing and conflicting dietary advice.

Facts and Myths about Cholesterol, Fats, and Meats

The modern understanding of the role of nutrition in heart disease began in 1903 when Anitschkow and Chalatow found that a diet of meat, milk, and egg produced atherosclerosis in rabbits.

A decade later, serum total cholesterol (TC) level was found to be the agent responsible. Contrary to common belief, the contribution of dietary cholesterol to serum TC is small.

Nonetheless, high intakes of dietary cholesterol increase the number of circulating low-density lipoprotein (LDL) particles.

Dietary cholesterol is found only in the animal kingdom; 3 oz of beef, lamb, or pork contains 75 mg of cholesterol. Most of the cholesterol in poultry is in the skin, and some in dark meat.

One cup of milk has 33 mg, 2 egg yolks have 560 mg, and 100 g of brain has 2000 mg of cholesterol. One hundred grams of shrimp contain about 150 mg of cholesterol but <1 g of saturated fat.

The contribution of dietary saturated fat to serum TC is very large - 10 times greater than that of dietary cholesterol.

Fats are substances consisting of a combination of fatty acids, which are classified as saturated (SAFA), monounsaturated (MUFA), polyunsaturated (PUFA), and transunsaturated (TRAFA), depending on the location and number of double bonds. It is not often appreciated that the quality of the fat is more important than the quantity of fat consumed.

Saturated fatty acids, the arch villain of atherosclerosis (SAFA): Excessive consumption of SAFA is the principal dietary culprit contributing to elevated serum TC level, which is the primary determinant of atherosclerosis.

Transfatty acids (TRAFA) - the hardened fat that hardens arteries fast: TRAFA is formed during the partial hydrogenation of vegetable oils, a process that converts oils into solid or semisolid fats for subsequent use in food products. <....more on TRANS FAT >

This process not only improves the texture and firmness but also markedly increases the shelf-life of food by minimizing oxidative spoilage. Such oils are used in commercial baked goods, and for cooking in most fast-food chains in western countries.

Perhaps an equally important and often neglected cause of TRAFA formation is the spontaneous hydrogenation of vegetable oils during deep frying. Very small amounts of TRAFA are also found in beef and dairy products.

Butter contains 60% SAFA, whereas stick margarine contains 16% TRAFA. The tub or soft margarine contains only 2 g of TRAFA per 15 ml. Therefore, the fat-spread of choice remains soft margarine; olive oil may be an even better substitute.

Frying fats used in fast-food outlets still contain over 30% of TRAFA. French fries sold in these outlets provide 7 to 8 g of TRAFA per portion.

The TRAFA consumption is likely to be high in Asian because deep-frying is a favorite mode of cooking at home as well as in restaurants.

Deep-frying is associated with spontaneous hydrogenation and TRAFA formation, and repeated re-use of oils previously used for deep-frying may further increase the TRAFA content.

These practices appear to be the norm rather than the exception, and may be of enormous public health importance, especially with regard to elevated Lp(a) levels, and high rates of CAD in this population.

There is an urgent need to ascertain and disseminate the TRAFA content of vanaspathi (vegetable ghee) and frying oils used.

Butter or Margarine

How is Margarine Made?

Margarine has a type of unsaturated fat called "trans" fat.

"Trans" fats raise blood cholesterol more than other unsaturated fats, but not as much as saturated fats.

"Trans" fats are formed when vegetable oil is hardened to become margarine or shortening, through a process called "hydrogenation." The harder the margarine or shortening, the more likely it is to contain more "trans" fat.

Margarines that are free of "trans" fats are now available. Read the ingredient label to choose margarine that is "trans" fat free or contains liquid vegetable oil as the first ingredient rather than hydrogenated or partially hydrogenated oil. Use the food label to choose margarine with the least amount of saturated fat

Which one is better for my health?

Butter or Margarine - which one is better for my health? This certainly is an age-old controversy and the debate is still as hot today as when it first arose.

Butter - Saturated Fats and Cholesterol

Butter, as an animal fat, contains both saturated fats and cholesterol - the two dietary ingredients that give rise to our blood cholesterol.

Saturated fats, mainly found in animal products, can raise LDL cholesterol (the bad cholesterol), thus also raising total blood cholesterol as well.

Cholesterol, on the other hand, has little effect on blood cholesterol in most people. But for some, even a little dietary cholesterol can cause a soar in blood cholesterol levels.

Margarine - Trans Fats

When margarine was first introduced into the market place, it was loaded with trans fats.

Hydrogenation "solidifies" liquid vegetable oil into a spread so it is easier to use. As a result of this hydrogenation process, trans fats are produced.

Similar to saturated fats, trans fats also increase LDL cholesterol (the Bad cholesterol) and lower HDL cholesterol (the Good cholesterol).

In recent years, food manufacturers and the general public began to realize the negative health effects of trans fats.

Another type of margarine is now widely available - non-hydrogenated margarine.  This type of margarine contains minimal trans fat and is softer than the first-generation margarine stick.

Fat, Saturated Fat And Cholesterol Content Of Butter And Margarines

Food (1 tablespoon) (14.2g)

Total Fat

Saturated Fat

Cholesterol

Butter

11g

7.2g

32mg

Hard Margarine (Hydrogenated)

11.3g

1.9g

0mg

Soft Margarine (Hydrogenated)

11.3g

1.9g

0mg

Soft Margarine (Unhydrogenated) eg. Benecol

4.9g

0.9g

0mg

Butter or Margarine: the Verdict?

BOTH saturated fats and trans fats can raise total cholesterol and LDL cholesterol.

Therefore, try minimizing the intake of BOTH saturated fats and trans fats.

It is clear that butter contains more saturated fats and trans fats when we add up the numbers. In addition, butter also contains cholesterol.

The Verdict?

Instead of butter, choose non-hydrogenated soft margarine. Now, manufacturers have started producing soft margarine without using hydrogenated oils. This type of non-hydrogenated margarine contains no trans fats, or almost none, zero cholesterol, very small amounts of saturated fat and is much healthier than hydrogenated varieties. But always check the label, just to be sure.

For your information, the American Heart Association now recommends the use of this type of margarine as a substitute for butter .

Health advice. If you have atherosclerosis, heart disease, high cholesterol ( hypercholesterolemia) in the upper range 200-239 mg/dL or high triglycerides (hypertriglyceridemia), the American Heart Association recommends a maximum daily limit of 200mg of dietary cholesterol, and advises no more than 7 percent of calories be eaten in the form of saturated fat. <.....make your own choice >

MUFA, the good fat that raises the good cholesterol: Diets high in MUFA (oleic acid) make LDL resistant to oxidation, restore LDL-receptor activity, and markedly lower LDL levels.

Other beneficial effects of MUFA include the favorable influence on blood pressure, endothelial activation, inflammation, and thrombogenesis.

A higher intake of MUFA lowers insulin resistance and diabetes, unlike SAFA and TRAFA, which increase it. Consumption of MUFA offers the unique advantage of effectively lowering LDL levels without lowering HDL or raising TG levels.

Individuals with low HDL levels have a high risk of CAD. Subjects with high TG, especially those with the metabolic syndrome and diabetes, are highly sensitive to the TG-raising effects of a high carbohydrate load.

A high carbohydrate diet is associated with highly atherogenic, small, dense LDL particles, while high-fat diets are associated with less atherogenic, buoyant LDL particles. Thus, replacing SAFA with MUFA is more effective in preventing CAD than reducing the total fat intake.

In Mediterranean countries, the high intake of MUFA in the form of olive oil is inversely related to CAD.

Contrary to common belief, energy-controlled, high-MUFA diets do not promote weight gain, and are more acceptable than low fat diets for weight loss in obese subjects.

The addition of MUFA should be at the expense of SAFA and carbohydrates. Since all fats are high in calories, failure to decrease the energy from carbohydrates and SAFA would invariably result in weight gain, and mitigate most of the beneficial effects of MUFA.

Meat and dairy products, which are also rich in SAFA, provide most of the MUFA in western diets.

Olive oil and canola oil are good sources of MUFA, canola oil appears to be even better as it contains less SAFA and more PUFA, especially alpha-linolenic acid (ALNA).

Mustard oil is high in MUFA but also high in erucic acid, which is known to have toxic effects on the heart.

Canola oil is genetically engineered mustard oil without erucic acid.

Nuts and avocado are excellent sources of MUFA and are recommended, provided the quantity is no more than 50 to 100 g/day.

Groundnut (peanut) products are a rich source of MUFA.

PUFA, another healthy substitute for SAFA: There are 2 series of PUFA that are deemed essential.

  • Linoleic acid is the predominant omega-6 (n-6 PUFA).

  • The predominant (parent) omega-3 (n-3 PUFA) is linolenic acid.

Linoleic acid increases the fecal excretion of steroids, and inhibits the hepatic synthesis of apo B containing lipoproteins. Replacing SAFA with PUFA reverses the suppression of LDL-receptor activity by cholesterol-raising SAFA (similar to that of MUFA). 

Most of the reduction is in LDL, and the number of apo B particles.  PUFA does not raise the TG level, and sometimes lowers it.  The two undesirable effects of PUFA are increased susceptibility for per-oxidation, and lowering of the HDL level.

Contrary to previous fears, omega-6 do not antagonize the anti-inflammatory effects of omega-3 nor do they raise the risks of breast, colorectal, or prostate cancer in humans.

However, a very high omega-6 to omega-3 ratio may increase the thrombogenicity through increased production of arachidonic acid and thromboxane A2.

This is because linoleic and linolenic acids use the same set of enzymes for desaturation and chain elongation.  An omega-6 to omega-3 ratio of 3:1 appears to be optimum.

Japan, which has one of the highest rates of fish consumption, has recently changed the recommendation of this ratio from 4:1 to 2:1; this ratio may be advisable for vegetarians.

Fish, a tasty way to prevent sudden death: Fish do not die from myocardial infarction (MI), and populations that consume large amounts of marine foods have a low prevalence of CVD death.

Replacing high-fat meat with fish is also associated with a decreased risk of CAD. The results of several large studies show that one or two fish meals per week are associated with a 30 to 50% reduction in sudden death.

Greater intake has no additional benefits, and these suggests a threshold effect.  However, a recent large study of 5103 women with diabetes showed a dose-response relationship.

Consumption of fish 1 to 3 times per month was associated with a 40% risk reduction, and a 64% risk reduction was seen among those who consumed fish >5 times per week.  The benefit is seen in people with and without prior heart disease.  These benefits persist as long as the fish consumption is continued.

Fish is a tasty food that contains many essential nutrients, such as selenium, iodine, vitamin D, and omega-3.

The beneficial effects of fish are largely mediated through omega-3, which displace arachidonic acid from platelet phospholipid stores, thereby reducing the available substrate for thromboxane A2 synthesis.

The benefits from omega-3 are greater with DHA and EPA found in fatty fish, shellfish, and marine mammals than with ALNA found in canola oil, soybean oil, and walnut.

It is important to distinguish between lean and fatty fish for cardio protection, because the content of omega-3 is highest in fatty fish. Fatty fish, such as mackerel, sardine, and salmon, are widely available and inexpensive.

Heating is associated with significant loss of omega-3. Frying fish is associated with an even greater loss of EPA and DHA, and may be particularly harmful if fried in SAFA.

Both plant-based (ALNA), and fish-based (EPA and DHA) supplements have shown benefits in secondary prevention.  The totality of the data suggest that omega-3 can be considered as the best antiarrhythmic agent and antifibrillatory treatment.

Cardiologists and their patients should pay serious attention to this new paradigm in the diet-heart hypothesis, and increase the intake of fish and fish oil.

The amount of omega-3 necessary for cardioprotection is surprisingly low. The current recommendation is to take 2 to 3 fish meals per week (200 to 300 g/week of fish).

A less attractive alternative is to consume 1000 mg/day of omega-3 (contained in 3000 mg of fish oil capsules).  Fish is more beneficial than fish oil, but the latter may be required in most patients with CAD to obtain the required amount of omega-3.

Patients with CAD should consume about 1800 mg/day of omega-3(DHA and EPA) as the best insurance against sudden death.

Alpha-Linoleic acid (ALNA) - the omega-3 of the plant kingdom: There is no DHA and EHA in a vegetarian diet. Vegetarians derive their omega-3 almost exclusively from ALNA, which is also the major type of omega-3 in omnivores.

There is increasing evidence for the cardio-protective effects of ALNA, albeit less than EPA and DHA.  In a large study involving 43 700 men, increased intake of ALNA reduced the risk of MI by 60%.

Some vegetable oils are high in ALNA (flaxseed oil 50%, canola oil 10%, mustard oil 10%, soybean oil 7%) while others are low (groundnut oil <0.5%).

Walnuts are a rich source of ALNA; small concentrations are found in green leafy vegetables, corn oil, almonds, hazelnuts, cereals, pulses, millets, and spices.

Walnuts and canola oil account for most of the ALNA in the western diets.

ALNA is readily converted to EPA, and more slowly to DHA; the latter being the major component of phospholipid membranes of the brain and retina.  The beneficial effects of ALNA are less than half that of DHA and EPA, because the conversion of ALNA to the more active longer-chain metabolites is inefficient: <5% - 10% for EPA, and 2% - 5% for DHA.  This explains why vegetarians have lower levels of omega-3 than omnivores, and also higher platelet agreeability.

Since the biological effects of plant omega-3 are significantly lower than marine omega-3, the requirements may be higher (3% of energy) for vegetarians than for nonvegetarians.

Protein: Up to 25% of daily energy from protein is permissible if the major source of protein is plant-based.

Nuts are important sources of plant protein along with soy, bran, beans, and legumes. Substituting protein for carbohydrates increases HDL and lowers TG levels.

Meat: Although meat contains a significant amount of SAFA, almost half the SAFA is stearic acid, which does not raise TC levels. In addition, meat contains up to 45% of cholesterol-lowering MUFA.

Furthermore, lean meat has much less SAFA than fatty cuts of meat.  Lean beef is an excellent source of protein and MUFA, and has less SAFA than chicken (dark meat); 6 oz of lean beef contains 3.0 g of SAFA v. a chicken thigh which contains 5.2 g of SAFA (the term loin or round signifies lean meat whereas prime or rib signifies fat cuts with very high SAFA).

Chicken and lean beef (not fatty meat) have similar effects on plasma lipoproteins, and are interchangeable in a healthy diet.

Glycemic Load: A Potent Predictor of the Metabolic Syndrome and Diabetes

The source, nature, and amount of carbohydrates have a profound influence on postprandial glycemia, which in turn is directly associated with the risk of CAD in patients with diabetes.

Foods containing the same amount of carbohydrate (carbohydrate exchange) may have up to a 5-fold difference in glycemic impact, depending on the differences in the digestion and absorption.

The glycemic index is an extension of the fiber hypothesis, and was proposed in 1981 as a physiological system for the classification of carbohydrate-containing foods.

Carbohydrate classified by glycemic index, in contrast to its traditional classification as either simple or complex, is a better predictor of CAD in epidemiological studies.

The hierarchy of the glycemic index begins with beans, lentils, rice, spaghetti, potatoes, white bread (with refined flour), and refined grain cereals.

A high glycemic index indicates a lower quality of carbohydrate associated with low HDL levels, and low rates of satiety.

Fruits, nonstarchy vegetables, parboiled rice, and legumes have a low glycemic index. The glycemic index of potato is 102%, white bread 100%, whereas that of apple is 55%, and broccoli 13%.

Glycemia observed after consuming dried peas is only one-third that of an equivalent amount of potatoes. Since peas are also high in fiber, their consumption needs to be encouraged, especially in patients with diabetes.

Glycemic load is the product of the glycemic value of the food and its carbohydrate content (per serving) divided by 100. For example, carrot has a high glycemic index but a low glycemic load. The overall daily dietary glycemic load is calculated by adding the glycemic loads of all the different foods consumed in a given day. Accordingly, the glycemic load can be decreased by reducing the amount of carbohydrate intake and/or by consuming foods with a low glycemic index.

In addition to the quality and quantity of carbohydrates consumed, the glycemic load also represents diet-induced insulin demand.

Dietary carbohydrates drive TG much more than dietary fat.  A high glycemic load produces only mild increments in TG levels in individuals with normal TG levels but marked elevation in those with fasting lipemia and/or obesity.

A low HDL level is a strong risk factor for CAD, even when the TC level is not elevated.   A high glycemic load produces a low HDL, particularly when substituted for MUFA or PUFA.

More importantly, a glycemic load promotes diabetes, especially in those with insulin resistance.  This is particularly true for refined carbohydrates, sweets, white bread, and potatoes.

Thus, a high glycemic load may be considered a risk factor of equal importance as high SAFA diet in precipitating diabetes. A low glycemic load can reduce insulin secretion in patients with type 2 diabetes, decrease insulin requirements in type 1 diabetes, and improve glycemic control in both types of diabetes.

The incremental benefit from low glycemic load is similar to that offered by pharmacological agents that also target postprandial hyperglycemia, such as alphaglycosidase inhibitors. The benefit of low glycemic load on the development of diabetes is similar to MUFA, PUFA, whole grains, fiber  fruits, and vegetables.

Whole Grains: The Foundation of Healthy Food

Whole grains have been the staple food worldwide for centuries, especially among vegetarians.

Whole grain and legume consumption not only decreases blood sugar and insulin resistance but also prevents the development of diabetes, particularly in people with the metabolic syndrome.  Whole-grain products are a good source of fiber, minerals, as well as several vitamins, including vitamins B and E.

In a 12-year follow-up of 42 898 men, the risk of developing diabetes was 42% lower in those with the highest intake of whole grains. The risk was reduced by 52% in those who also engaged in physical activity, and 87% in those who also had a low BMI.

The risk reduction was attributed to higher intakes of cereal fiber and magnesium. Intake of whole-grain cereal is inversely associated with hypertension, CAD, stroke, and CVD mortality.  In another study, 25% - 30% reduction in stroke was observed with the intake of whole grains - similar in magnitude to that of statins.

In sharp contrast, intake of refined grains increases the risk of diabetes, stroke and CVD. These prospective data highlight the importance of distinguishing whole-grain from refined-grain cereals in the prevention of CVD and diabetes. Efforts should be made to replace refined-grain with whole-grain foods.

A whole-grain food includes all the edible parts of the grain: the bran, the germ, and the endosperm.

Grinding or milling, using modern technology, leads to the loss of many beneficial micronutrients, antioxidants, minerals, phytochemicals, fiber, and much of the germ. As a result, refined grain products are devoid of most vitamins and essential fatty acids, and contain more starch.  Because of the loss of bran and pulverization of the endosperm, refined grains are digested and absorbed rapidly, resulting in a large increase in the levels of blood sugar and insulin. 

Commonly consumed refined grain foods include white rice (idli, dosa), refined wheat and flour (white bread), pancakes, cakes, sweet rolls, English muffins, muffins, waffles, rolls, biscuits, pizza, and refined-grain ready-to-eat breakfast cereal, and their use should be minimized.

Nuts: A Wholesome Food and Powerhouse of Healthy Fats and Nutrients

Extensive studies during the past decade have transformed the image of nuts from fattening snacks to a wholesome and heart-healthy food to be consumed daily.

Nuts are rich sources of protein, antioxidants, fiber, vitamins and minerals (especially potassium and magnesium). Nuts yield 5% - 10% fiber, and 12% - 25% protein. The consumption of nuts is also associated with a reduced risk of CAD.  Yet, nuts are not generally recommended as snacks because of their high fat content.  Although nuts contain 45% - 80% fat, most of the fats are the highly beneficial MUFA and PUFA.

Nuts, particularly almonds, significantly improve lipid profiles because of the high fiber and MUFA component.  Nuts are energy-dense, and contain 160 - 200 cal/oz. It cannot be overemphasized that energy from nuts should replace the unhealthy calories from SAFA and refined grains to prevent weight gain.

Consumption of other nuts (except coconuts) is equally beneficial. For example, a 10% reduction in the LDL level can be achieved by the daily consumption of 40 g of walnuts, peanuts or pistachios, 70 g almonds, 100 g macadamia nuts, and 110 g of pecans.

Nuts are as effective as increasing physical activity and trimming calories to increase HDL levels. Adding 2 oz or 60 g of nuts to a diet is a delicious way to decrease the TC/HDL ratio and CAD risk.

Nuts also improve insulin sensitivity and prevent diabetes.   In a prospective study of 83 818 women, 3206 new cases of type 2 diabetes were observed during a follow-up of 16 years. 

Consumption of nuts was inversely associated with the risk of type 2 diabetes after adjustment for age, body mass index (BMI), physical activity, smoking, alcohol use, and dietary factors (total calories, fat calories, and fiber). The risk of diabetes was reduced by 27% in those who consumed >5 oz/week of nuts or peanut butter compared to those who almost never ate these products.

The proscription of nuts can no longer be justified. In fact, regular nut consumption as replacement for refined grains and high-fat meats is strongly recommended.

Fruits and Vegetables, the Natural Way to Consume Antioxidants and Flavonoids

Fruits and vegetables are rich in a myriad of nutrients and phytochemicals, including fiber, vitamins B and C, antioxidants, potassium, and flavonoids.

Phytochemicals are bioactive nonnutrient plant compounds linked to a reduced risk of chronic diseases. Fruits and vegetables decrease blood pressure, homocysteine, and cancer, especially that of the GI tract.

Since fruits and vegetables are rich in potassium, their liberal intake is recommended for the prevention and treatment of hypertension.

Good sources of potassium include bananas, oranges, beans, fish, and dairy products. While you can get an overdose of potassium from pills, you cannot get an overdose of potassium from food.

Moreover, dietary supplements do not have the health benefits associated with a diet rich in fruits and vegetables. For example, the antioxidant value of 100 g of apple is equivalent to 1500 mg of vitamin C.

Several studies, including one comprising 84 000 women and 42 000 men, have shown a significant inverse association between the consumption of fruits and vegetables and CVD mortality.  In sharp contrast, consumption of potatoes and French fries increase the risk of CAD and stroke.

The landmark study of the Dietary Approaches to Stop Hypertension (DASH) has yielded tremendous insights into the benefits of increased intakes of various types of fruits and vegetables.

The DASH diet is rich in vegetables, fruits, and low-fat dairy products (9 servings of fruits and vegetable combined per day).

As compared with a diet high in sodium, the DASH diet with a low sodium intake led to a decrease in systolic blood pressure. The benefits of the DASH diet on lipoprotein levels were equally spectacular, without significant effects on TG levels.

Men had a greater reduction in LDL level than women. These results suggest that the DASH diet is likely to reduce the risk of CAD and can be recommended as an overall eating plan.  The DASH diet is feasible in the real world, unlike the array of drastic diets which are impossible to continue for more than a few months.

Flavonoids: Flavonoids are secondary metabolites that plants use to attract pollinators, repel predators, and to color flowers, leaves, and fruits.

Important biological effects of flavonoids include the scavenging of oxygenderived free radicals, inhibition of LDL oxidation, increase in HDL levels, and protection against CVD and several chronic diseases.

The beneficial effects of these natural products on health were known long before the discovery of flavonoids.

The major sources of flavonoids are vegetables (onions, kale, broccoli), fruits (apples, grapes, berries), olive oil, and beverages such as tea and wine.  Other sources include grains, bark, roots, stems, and flowers.

Flavonoids present in red wine could be partly responsible for the low CAD mortality seen in red wine drinkers ("French Paradox").

Red wine is the major source of flavonoid in France and Italy (40%), onions and apples in Finland, and olive oil in Greece.  The strong taste of extra-virgin olive oil is partly caused by the abundance of flavonoids.

Antioxidants: Oxidative modification of LDL accelerates atherosclerosis whereas dietary antioxidants prevent LDL oxidation.

These antioxidants include vitamin C, vitamin E, beta-carotene, selenium, flavonoids, magnesium, and MUFA.  It is worth emphasizing that vitamin pills are no substitute for a healthy diet.

Although an earlier study suggested some benefits from antioxidant vitamin supplementation, several subsequent studies involving more than 100000 patients have consistently failed to demonstrate any benefit.

More recent studies suggest that possible harm may outweigh the benefit of these vitamins.  Current scientific evidence does not support any protective role of vitamins E, C, and beta-carotene supplements; their use only creates a diversion away from proven therapies.

It is worth noting that the oxidative modification of LDL continues to be relevant, and people should obtain their antioxidant vitamins from food sources. (However, folic acid fortification is recommended in women who are pregnant or might become pregnant.)

Non-nutritive Food Adjuncts

Fiber: The term dietary fiber was coined to describe the plant cell wall removed during the refining process.

Dietary fiber improves coagulation, fibrinolysis, insulin sensitivity, LDL, and blood pressure levels.  Fiber is particularly concentrated in bran.

Insoluble fiber shortens the intestinal transit, resulting in less time for carbohydrate absorption.

Soluble (viscous) fiber, such as beta-glucan, which is found in oat bran, delays gastric emptying, and slows the absorption and digestion of carbohydrates.

These processes lead to a slower release of glucose into the circulation, resulting in a reduced demand for insulin.  An intake of 16 g of total fiber is associated with a 12% decrease in CAD risk.

Psyllium supplementation significantly lowers TC and LDL levels; it is safe and well tolerated.

The benefit of whole grains appears to be mediated primarily through the greater intake of fiber, and is greater with cereal fiber than vegetable or fruit fiber.

Approximately one-fourth of the fiber provided by cereal sources is water soluble.  Cereal fiber consumption is associated with a 21% lower risk of incident CVD, and 30% lower risk of diabetes.

Cereal fiber consumption may reduce the risk of CVD via the substitution effect, replacing the intake of other foods having potentially detrimental effects. In addition to cereal grains, legumes are also excellent sources of water-soluble dietary fiber. Half a cup of cooked beans contains, on an average, 6 g of total fiber and 2 g of soluble fiber.

A high intake of dietary fiber, above the level recommended, particularly of the soluble type, improves glycemic control, insulin levels, and plasma lipid concentrations in patients with type 2 diabetes.

Plant sterols and stanols: Plant sterols and stanols are structural analogues of cholesterol.

Low-fat plant stanol containing margarines lower plasma LDL levels (by as much as 12%) in those with hypercholesterolemia by suppressing cholesterol absorption.  Various plant supplements have been shown to reduce LDL by 40%.

Spices: Plants have the capacity to synthesize a diverse array of chemicals.

Spices are aromatic vegetable substances, the significant function of which is food seasoning rather than nutrition.

Typically, spices are the dried aromatic parts of plants, generally the seeds, berries, roots, pods, and sometimes leaves, that mainly grow in tropical countries.

Common spices include turmeric, paprika, saffron, cinnamon, nutmeg, red and black pepper. In contrast, herbs used in cooking are typically composed of leaves and stems.

Caffeine: Caffeine is found in coffee, tea, soft drinks, chocolate, and some nuts. Consumption of large quantities of boiled unfiltered coffee raises cholesterol and homocysteine levels.  Data suggest that daily consumption of 1–2 cups of coffee is safe with no particular health benefits or risks.

Tea: Tea, the most widely consumed beverage in the world other than water, has been associated with lower cardiovascular risk.

Unlike coffee, tea consumption is associated with a substantial reduction in LDL levels. Tea is rich in flavonoids.

Green tea contains catechins, whereas black tea, formed from the polymerization of catechins, contains theaflavins.

In one recent study, theaflavinen riched green tea extract reduced the LDL level by 16%.  Adding milk to tea, as is common in the UK and India, abolishes the beneficial effect of tea.

Alcohol: Moderate intake of alcohol (one drink a day for women and 2 drinks a day for men) may decrease the risk of CAD.

Recently, it has been shown that only one drink per week is enough to provide cardiac protection (45 ml of spirits or 350 ml of beer or 120 ml of wine); the cardioprotection is similar for beer, wine, whiskey, brandy, vodka, rum, and drinks in equivalent amounts.

More than 2 drinks per day does not provide any additional protection and, in fact, the net effect may be harmful until the age of 45 years in men and 55 years in women.

Like carbohydrates, consumption of large quantities of alcohol raises TG levels. Other dangers of excessive alcohol consumption includes alcohol dependence, liver disease, high blood pressure, obesity, stroke, traffic accidents, spousal abuse, suicide, and breast and other cancers.

Weight Gain and Weight Loss Diets

Excess calories and obesity: Diets of any type containing more energy than needed or expended will lead to obesity and dyslipidemia.

A calorie is a calorie whether it comes from carbohydrates, fat, or protein. Excess calories of any kind will eventually be converted by insulin to body fat.

A common misconception is that dietary fat of any kind is fattening, while low-fat and high-protein diets have slimming properties.

It is absolutely vital that both physicians and the public understand that it is the excess calories and not diet composition that causes weight gain.

There is no evidence of weight gain with a high MUFA diet, compared with a high carbohydrate diet, under isoenergetic conditions.

Obesity is not only a reflection of overnutrition but also an important contributor to the mass dyslipidemia.

Obesity in general is accompanied by the increased production of apo B and a decrease in the HDL levels.

Humans have a limited capacity to store energy as carbohydrates. When carbohydrate intake exceeds storage and oxidation capacities, the excess is converted to fat by de novo lipogenesis that leads to high TG levels.

This process is increased several-fold in people with the metabolic syndrome which, if left untreated, leads to overt diabetes.

Body fatness and not lean body mass is the principal determinant of diabetes and prediabetes.  Although obesity and dyslipidemia are uncommon in less affluent societies, some individuals may be excessively sensitive to caloric excess.

Fast foods rapidly produce plaques. A third of vegetable taken in the USA are either French fries or potato chips.  Restricting the dietary cholesterol can achieve a 3% reduction in TC level, whereas losing weight from trimming extra calories can reduce LDL by 5% to 20%.

Weight loss: The recipe for effective weight loss is a combination of motivation, physical activity and caloric restriction; maintenance of weight loss is a balance between caloric intake, and physical activity, with life-long adherence.

Each pound of body fat contains 3500 cal. Therefore, a person who consumes 500 cal less than he spends each day can lose 1 lb of fat a week. Any higher weight loss is due to a more severe caloric restriction or water loss rather than fat loss.

The minimum caloric intake in a medically unsupervised weight loss diet is 1500 cal/day for men, and 1200 cal/day for women. The greater success rate is due to higher palatability of the high-fat diet provided by mixed nuts and lean meat.

Furthermore, the long-term outcome of a reduced-fat diet consumed ad libitum for weight control is dismal.  Until more information becomes available, "the prudent diet," which is a balanced diet, is the one to follow for young and old alike.

Very low fat diet: Some experts have argued for a very low-fat diet (<10%). Since these diets are not high protein diets (like the Atkins diet), they are in reality very high in carbohydrate.

High-carbohydrate diets (the Macrobiotic diet) increase insulin resistance and induce the metabolic syndrome.

In controlled trials, low-fat, highcarbohydrate diets decreased HDL levels.  The effect is strongest when carbohydrates replace SAFA but is also seen when carbohydrates replace MUFA and PUFA.

The effect is seen in both short- and long-term trials, and is therefore not a transient phenomenon. Therefore, replacement of SAFA must be achieved through increasing MUFA and not by carbohydrates.

The adverse effects of high-carbohydrate diets (high glycemic load) in the metabolic syndrome and diabetes have not received due attention.

The allure and dangers of very low-carbohydrate, high-protein diets: High-protein diets that are extremely low in carbohydrates are touted as a new strategy for successful weight loss by many.

Most such diets contain <10% carbohydrates, 25% - 35% protein, and 55% - 65% fat. Because the protein is provided mainly by animal sources, these diets are high in SAFA and cholesterol. Thus, these diets are truly high-fat diets masquerading as high protein diets.

Advocates of this diet often promote serious misconceptions about carbohydrates, insulin resistance, ketosis, and fat burning as the mechanisms of action for weight loss.

To avoid excess load on the kidneys, the total protein intake should not exceed 100 g/day.

More importantly, the body has an obligatory requirement for glucose of about 100 g/day, largely determined by the metabolic demands of the brain.

In one study, a low-carbohydrate diet produced a 4% greater weight loss at 6 months than did the conventional diet, the differences did not persist at 1 year. Furthermore, adherence was poor, and attrition was high in both the high- and low-carbohydrate groups.

Longer and larger studies are required to determine the long-term safety and efficacy of low-carbohydrate, high-protein, high-fat diets.

Two recent studies have provided insight into high-protein diets; the initial weight loss is due to fluid loss and ketosisinduced appetite suppression. The monotony of this diet also results in involuntary caloric restriction.

The beneficial effects on blood lipids and insulin resistance are due to the weight loss, and not the change in caloric composition. Such diets increase LDL but decrease TG levels, in sharp contrast to high-carbohydrate diets, which increase TG, and decrease HDL levels.

Although these diets may not be harmful for most healthy people over a short period of time, there are no long-term scientific studies to support their overall efficacy and safety.

Markedly atherogenic profiles have also been reported in children with ketogenic diets. At 6 months, the high-fat ketogenic diet significantly increased plasma LDL levels by 50 mg/dl, triglycerides 58 mg/dl, apo B 49 mg/dl, and non-HDL cholesterol 63 mg/dl. The mean HDL-cholesterol levels decreased significantly.

These lipid abnormalities in children are more than likely to translate into a high risk of heart disease as young adults.

High-protein diets also do not provide the variety of foods needed to continue the diet on a long-term basis.

High-protein diets are not recommended, and are perhaps dangerous because they restrict most healthful foods that provide essential nutrients, especially fruits and vegetables.

Individuals who follow these diets are therefore at risk for compromised vitamin and mineral intake, as well as potential cardiac, renal, bone, and liver abnormalities overall.

The consumption of a very low-carbohydrate diet for 6 weeks delivers a high acid load to the kidney, increases the risk of stone formation, decreases body calcium, and may increase the risk of bone loss and fractures.

A high-protein diet is the ultimate antithesis of the prudent diet. It is important to realize that diets are not for 6 weeks, 6 months or 6 years, but for a lifetime.

Although most quickfix diets have a short-term success rate >90%, the longterm failure rate is 100%.

Healthy and Contaminated Vegetarian Diets: Omnivores or non-vegetarians outnumber vegetarians 10 to 1 in western cultures.

Vegetarians include vegans who do not consume any animal products, ovo-vegetarians who consume egg, lacto-vegetarians who consume milk, ovolacto- vegetarians who consume egg and milk, and semilacto- vegetarians who eat small amounts of meat (<1 time/ week).

Western vegetarians generally consume a healthier diet than omnivores; healthy foods such as soy, nuts, legumes and vegetables replace meat.  They generally have twice the fish consumption of non vegetarians.  US vegetarians eat more whole-grain products, dark green and deep yellow vegetables, whole-wheat bread, brown rice, soy milk, tofu, meat substitutes, legumes, lentils, garbanzos, walnuts, and pecans.

A healthy vegetarian diet is characterized by more frequent consumption of fruits and vegetables, whole grains, legumes and nuts, resulting in higher intakes of dietary fiber, antioxidants and phytochemicals.

Thus a vegetarian diet contains a portfolio of natural products that can improve both the carbohydrate and lipid abnormalities in diabetes.

Vegetarians eat about two-thirds of SAFA, and one-half of cholesterol as omnivores; vegans consume one-half of SAFA and no cholesterol.

Cholesterol levels among western vegetarians are lower than omnivores.  Vegans have very low levels of LDL.  Nuts, viscous fibers (from oats and barley), soy proteins, and plant sterols in vegetarian diets improve serum lipid levels.

Furthermore, substituting soy or other vegetable proteins for animal proteins reduces the risk of developing nephropathy in type 2 diabetes.

With the exception of tropical oils, calories from plant sources are negatively correlated with CAD mortality, whereas calories from animal sources are positively correlated.

Olive oil, fresh fruits, and vegetables are protective against heart disease, and seem to play a greater role in the French paradox than wine.

Studies suggest a protective effect of vegetarianism against many diseases. Vegetarians in western countries enjoy remarkably good health, exemplified by low rates of obesity, diabetes, CAD and cancer, and a 3 - 6 year increase in life expectancy.

It is not clear whether this is due to abstinence from meat or to a greater consumption of heart-healthy food.

Indian vegetarianism, a form of "contaminated vegetarianism": Most Asian Indians are lacto-ovovegetarians, unlike western vegetarians.

About 50% of Asian Indians are vegetarians, but their lipoprotein levels, and rates of diabetes and CAD are no different from those of non-vegetarians.

This phenomenon is due to contaminated vegetarianism, wherein vegetarians manage to consume excessive amounts of SAFA and TRAFA.

Indian vegetarians consume liberal amounts of bakery products, butter, ghee, cheese, ice cream, curd, and other dairy products to overcompensate for not using meat.

Contrary to popular belief, dairy products are the major source of SAFA, even in the western diet. It is worth highlighting that SAFA intake from high-fat dairy products increases LDL levels 3 times as much as it raises the HDL level.

Meat is expensive, and consumed in very small quantities by Indian omnivores because of cultural and financial reasons.

Prolonged cooking of vegetables, as is practised in India, virtually destroys every nutrient before it is consumed.

A major problem overlooked in the Indian diet is the high glycemic load, resulting in high TG and low HDL levels.

Deep-frying and reuse of frying oil: Deep-frying, a common form of cooking among Asian, is associated with spontaneous hydrogenation, and the formation of TRAFA.

Reuse of oil used for deep-frying has been shown to produce endothelial dysfunction.  Repeated reuse of such oil is exceedingly common among Asian.

Fats that have been heated for prolonged periods in air contain many dangerous products from oxidation and breakdown of lipids.

In one study, fast-food restaurant cooking oil, just before the weekly change, was compared to unused oil. The repeatedly used oil had 4 times higher peroxide levels, 7 times higher carbonyl levels, and 17 times higher levels of acids.

Ghee: Ghee is one of the most important sources of dietary fat and a common cooking medium.

Ghee or clarified butter is anhydrous milk fat, and is rich in MUFA (32%) and SAFA (62%), most of which are cholesterol-raising (myristic acid 17%, palmitic acid 26%).

It is perhaps more harmful than butter due to the added presence of cholesterol oxides, which are generated during its preparation by prolonged heating of butter.

Tropical oils: The term tropical oils refers to coconut, palm kernel, and palm oils.

These oils contain a very high percentage of SAFA, unlike other vegetable oils such as rapeseed oil (mustard oil), sesame oil, and rice bran oil, which are low in SAFA and high in MUFA.

Tropical oils are more atherogenic and thrombogenic than mutton and beef fat.  In fact, these oils contain more TC-raising SAFA than animal fats - coconut oil 89%, palm kernel oil 71%, and palm oil 46% compared to <30% for butter fat, beef fat, pork fat, and chicken fat.

Tropical oils are also found in commercially baked cakes, biscuits, cookies, and "snack foods".

Coconut oil: Coconut oil contains mostly cholesterol raising SAFA (8% caprylic, 6% capric, 45% lauric, 17% myristic, and 8% palmitic acid).

In a comparative study of diets rich in beef fat versus coconut oil, the plasma TC, LDL, and HDL responses were lower with beef fat than coconut oil, commensurate with the lower proportion of cholesterolraising SAFA in beef (29%) than coconut oil (89%).

Consumers need to be educated about the atherogenic and antiatherogenic effects of various cooking oils, as well as animal and vegetable ghee.

There is little awareness, and even controversy, about the atherogenic effects of certain foods and oils, especially in regions where the production, sale, and consumption of such oils have a profound impact on the regional economy.

Prudent Diet for All Ages and the Entire Population

The traditional Mediterranean diet is characterized by abundant plant foods (vegetables, breads, pastas, beans, nuts, and seeds).

Fresh fruit is the typical daily dessert, and olive oil is used as the principal source of fat.

Dairy products (principally cheese and yogurt), fish, and poultry are consumed in low-to-moderate amounts.

Red meat and egg are consumed in low amounts (0 - 4 eggs weekly).

Wine is consumed in low-to-moderate amounts, normally with meals.

This diet is typically high in total fat (35% - 45%) but low in SAFA (7% - 8% of energy).

Greater adherence to the traditional Mediterranean diet is associated with a significant reduction in total mortality.

The 6 beneficial components of this diet have recently been elucidated.

They are vegetables, legumes, whole-grain cereal, fish, fruit, and nuts, which form the basis for the "prudent diet".

According to the new paradigm, dietary pattern rather than individual nutrients appears to be more important.

The "prudent diet" has a higher intake of vegetables, fruits, legumes, whole grains, fish, and poultry, whereas the "western diet" is characterized by a higher intake of red meat, processed meat, refined grains, sweets, desserts, French fries, and high-fat dairy products.

Consumers are bombarded on a daily basis with the Babel of nutritional breakthroughs.

The dangers of the current western diet and the contaminated vegetarian diet, and the remarkable benefits of the prudent diet need to be disseminated among cardiologists, physicians, and the public.

Several countries have developed dietary guidelines to reduce nutritional information anarchy. See also The New Food Pyramid - Asian Diet

Current Knowledge on Preventive and Therapeutic Nutrition

The TC/HDL ratio is the single best lipid predictor of CVD. This ratio is determined by 3 partly opposing dietary factors - the proportion of energy from SAFA, which raises TC; the proportion of energy from total fat, which raises HDL; and the excess in total energy intake, which produces obesity and secondarily lowers HDL.

The greatest reduction in CVD risk is achieved by LDL-lowering by reducing SAFA intake. Decreasing SAFA intake is best accomplished by reducing the intake of high-fat dairy products, and increasing fiber-rich foods.

A diet incorporating lean beef, skinless chicken, and fatty fish has been shown to improve the lipid profile by 5% - 10%.

The preferred replacement for SAFA is MUFA or PUFA and not carbohydrates.

Replacing SAFA with carbohydrates decreases the LDL levels but makes LDL small, dense, and more dangerous by increasing the TG levels.  Substituting carbohydrates with MUFA decreases the LDL level, and increases the HDL level. PUFA and MUFA increase insulin sensitivity, and decrease the risk of type 2 diabetes.

Substantial evidence indicates that diets using MUFA and PUFA as the predominant form of dietary fat, an abundance of fruits and vegetables, and adequate omega-3 fatty acids can offer significant protection against CAD, stroke and diabetes.

Adequate consumption of fruits and vegetables provides most of the necessary antioxidants, and are preferable to dietary supplements in the form of pills.

Replacing a high glycemic with a low glycemic index, and reducing the glycemic load can reduce the risk of diabetes.

Nuts, once deemed unhealthy because of their high fat content, have become an important part of diets designed to control weight, lower blood pressure and cholesterol, and achieve secondary prevention of CAD, besides adding variety, texture and flavor to dishes.

The liberal use of butter, ghee, palm oil, and coconut (oil and milk) should be discouraged.

However, in diets with a negligible intake of fish, meat, milk, and dairy fat, the modest use (<7% of energy) of such oils may be preferable to no fat at all.

Practical Recommendations

Better food habits can help reduce the risk of diabetes, MI, stroke, and death.

A healthy eating plan means choosing the right foods to eat, and preparing them in a healthy way.

A healthy diet involves a decrease in the use of refined grains, tropical oils, egg yolks, animal, dairy, and hydrogenated fats, and an increase in the consumption of whole grains, vegetables, nuts, legumes, and fruits.

Increasing the MUFA intake up to 20% of energy, as a replacement for SAFA and carbohydrates, may help prevent and treat the metabolic syndrome, diabetes, and CVD.  Such a strategy can also significantly reduce the need for lipidoptimizing drugs.

Since meat contains one-third MUFA and one-third cholesterol - neutral stearic acid, its consumption can also be incorporated into a healthy diet, provided lean cuts are used, and the quantity limited to 150 g/day.

Conclusions

People eat specific foods because of their taste, easy availability and affordability, but are often unaware of the health benefits and risks.

Dietary modifications remain the cornerstone of both the treatment and prevention of diabetes and CVD, the twin epidemics of the twenty-first century.

A prudent diet together with regular physical activity, avoidance of smoking, and maintenance of a healthy body weight may prevent the majority of diabetes and CVD.

A variety of whole grains, not refined grains, as well as various types of fruits and vegetables should be the main form of carbohydrates.

Prolonged cooking of vegetables should be avoided. It is important to realize that the vegetarian diet is healthy only when it is low in SAFA, and the predominant energy is from foods with a low glycemic index.

Cooking oils containing high SAFA should be replaced with those containing high MUFA. Deep-frying, especially with previously used oils, should be discouraged.

Nuts are healthy, wholesome foods, and their use should be encouraged as a replacement for unhealthy calories.

A diet rich in fish has multiple benefits, including raising HDL, and lowering TG levels, and preventing sudden death.  Consumption of fish is preferable to taking a large number of fish oil capsules.

There is increasing evidence that dietary and lifestyle modifications begun in childhood are likely to have benefits later in life.

Therefore, these dietary guidelines are applicable to everyone >2 years of age, and not just those with diabetes or heart disease.

Learn more on ..........

Trans Fatty Acid

The Asian Diet

Super Food

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The above opinionated views and information serves to educated and informed consumer . The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. .It should not replaced professional advise and consultation. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions

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The Banting Diet
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