**2. Can vegetable oils and nuts be the natural solution for CVD?**

Oxidative stress is common in many clinically important cardiac disorders, including ischae‐ mia/reperfusion (I/R) injury, diabetes and hypertensive heart disease [42-46]. Several animal models suggest that when endogenous anti-oxidant systems are compromised, as is the case under oxidative stress conditions, exogenous antioxidant supplementation can be used for preventive and/or therapeutic intervention of CVD [42, 43, 47-49].

the prevention of coronary heart disease (CHD) stems from the observed beneficial effects of the Mediterranean diet [57], which includes high consumption of olive oil. MUFAs are less susceptible to oxidation when compared to PUFAs. This in turn leads to increased availability of antioxidants in the active form and better stability of olive oil [58-61]. Olive oil also contains some antioxidant micronutrients, namely polyphenols and squalene [58, 62-64]. The main MUFA in the human diet is oleic acid (C18:1n-9), which has one double bond. MUFA intake has been associated with a slight cardioprotective effect [65]. MUFAs are known to have a beneficial effect on the serum lipid profile and thus decrease the risk of CVD [66-68]. Further‐ more, these fatty acids are stable in oxidative stress conditions and are less likely to react with reactive oxygen species (ROS) when compared with PUFA [58-59]. However, studies reporting associations between dietary intake of MUFAs and CHD risk have been inconclusive [69-71].

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PUFAs are naturally occurring endogenous substances, present in almost all tissues and are essential components of all mammalian cells. They are essential for survival and cannot be synthesized in the body. Hence, they have to be obtained in our diet and are therefore essential [54, 72]. There are two types of naturally occurring PUFAs in the body, the (n-6) PUFAs derived from linoleic acid (LA, C18:2) and the (n-3) PUFAs derived from α-linolenic acid (ALA, C18:3). They are categorized depending on the location of their first double bond: (n-3) PUFAs have their first double bond located at the third carbon molecule and (n-6) PUFAs at the sixth. Both of these two forms of PUFAs are metabolized by the same set of enzymes as their respective long-chain metabolites [73]. The differences between (n-3) and (n-6) PUFAs are shown in Table

Vegetable oils are the predominant sources of alpha linolenic acid (ALA). ALA is found in legumes, flax seeds, walnuts, pinto beans, soybeans and spinach [74]. Dietary intake of ALA among Western adults is typically in the range of 0.5–2g/d [75]. The (n-6) PUFA is the main PUFA in most Western diets and is typically consumed in greater amounts than ALA [75, 76]. The evidence for a beneficial role of dietary (n-6) PUFAs is less convincing and for the purpose of this chapter we will focus on the (n-3) PUFA. The three main forms of (n-3) PUFAs are ALA, eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) [77], with ALA being the simplest form. The (n-3) PUFAs are a family of biologically active fatty acids. The simplest member of this family, ALA, can be converted to the more biologically active and very long-chain (n-3) PUFAs; EPA and DHA. This process, as shown in Figure 1, occurs by a series of desaturation and elongation reactions, with stearidonic acid being an intermediate in

Research has shown that long-chain (n-3) PUFAs protect against CVD [77, 79-82]. The cardi‐ oprotective effects of (n-3) PUFAs have long been recognized. Epidemiologic data suggest that (n-3) PUFAs derived from fish oil reduce CVD. Fish oil is a rich source of EPA (C20:5 n-3) and DHA (C22:6 n-3) (Table 1) [67, 83, 84]. The cardioprotective roles of these two forms of (n-3) PUFA are extensively reviewed by Bester and co-workers [48]. Fish oil may also reduce mortality after a cardiovascular incident, as it plays a role in reducing potentially fatal arrhythmias ([85-87]. There are several prospective studies relating the use of fish or the intake

*2.1.4. Polyunsaturated fat (PUFA)*

1 below.

the pathway [54, 75, 78].

### **2.1. Composition and health benefits of vegetable oils**

### *2.1.1. Dietary fats*

Fats are the most concentrated form of energy for the body. They also aid in the absorption of fat-soluble vitamins (A, D, E and K) and other fat-soluble biologically active components [50]. Chemically, most of the fats in foods are triglycerides, made up of a unit of glycerol combined with free fatty acids, each of which may be the same or different. Other dietary fats include phospholipids, phytosterols and lipoproteins associated with cholesterol [50-52]. A balanced diet, including oils and fats that supply energy and essential fatty acids is needed for good health.

The different types of fatty acids are the most important characteristics of dietary fats. According to the degree of unsaturation (double bonds and hydrogen content), fatty acids are largely classified into three major types: saturated fatty acids, monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). A fourth form, the trans fatty acids, are mainly produced by partial hydrogenation of polyunsaturated oils in food processing but also occur naturally in animal foods in small amounts [53].

Fatty acids consist of a hydrocarbon chain with a hydrophobic methyl group at one end and a hydrophilic carboxyl group at the other end. Greek letters (α, β, γ, ω) have been used to identify the location of the double bonds in fatty acids. The "alpha" carbon is the carbon closest to the carboxyl group. The methyl group of the molecule is also referred to as the omega end and the terminal carboxyl group is located at the delta end. Current chemical numerical terms number the carbon chain form one to "n", with n being the last carbon at the methyl end. The terms "n" and "omega" are synonymous [54].

#### *2.1.2. Saturated fat*

Saturated fatty acids contain no double bond; they are fully saturated with hydrogen. The main saturated fatty acids are lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0) and stearic acid (C18:0). Saturated fats are found in animal-based products, such as milk, cream, butter and cheese, meat from most land animals, palm oil and coconut oil, as well as manu‐ factured products made from these, such as pies, biscuits, cakes and pastries [55].

#### *2.1.3. Monounsaturated fat (MUFA)*

MUFAs are predominant in vegetable oils, such as olive oil, canola oil and peanut oil and are also found in high proportions in animal fats [56]. Much of the interest in the role of MUFA in the prevention of coronary heart disease (CHD) stems from the observed beneficial effects of the Mediterranean diet [57], which includes high consumption of olive oil. MUFAs are less susceptible to oxidation when compared to PUFAs. This in turn leads to increased availability of antioxidants in the active form and better stability of olive oil [58-61]. Olive oil also contains some antioxidant micronutrients, namely polyphenols and squalene [58, 62-64]. The main MUFA in the human diet is oleic acid (C18:1n-9), which has one double bond. MUFA intake has been associated with a slight cardioprotective effect [65]. MUFAs are known to have a beneficial effect on the serum lipid profile and thus decrease the risk of CVD [66-68]. Further‐ more, these fatty acids are stable in oxidative stress conditions and are less likely to react with reactive oxygen species (ROS) when compared with PUFA [58-59]. However, studies reporting associations between dietary intake of MUFAs and CHD risk have been inconclusive [69-71].

### *2.1.4. Polyunsaturated fat (PUFA)*

**2. Can vegetable oils and nuts be the natural solution for CVD?**

preventive and/or therapeutic intervention of CVD [42, 43, 47-49].

**2.1. Composition and health benefits of vegetable oils**

212 Antioxidant-Antidiabetic Agents and Human Health

occur naturally in animal foods in small amounts [53].

terms "n" and "omega" are synonymous [54].

*2.1.3. Monounsaturated fat (MUFA)*

*2.1.1. Dietary fats*

*2.1.2. Saturated fat*

health.

Oxidative stress is common in many clinically important cardiac disorders, including ischae‐ mia/reperfusion (I/R) injury, diabetes and hypertensive heart disease [42-46]. Several animal models suggest that when endogenous anti-oxidant systems are compromised, as is the case under oxidative stress conditions, exogenous antioxidant supplementation can be used for

Fats are the most concentrated form of energy for the body. They also aid in the absorption of fat-soluble vitamins (A, D, E and K) and other fat-soluble biologically active components [50]. Chemically, most of the fats in foods are triglycerides, made up of a unit of glycerol combined with free fatty acids, each of which may be the same or different. Other dietary fats include phospholipids, phytosterols and lipoproteins associated with cholesterol [50-52]. A balanced diet, including oils and fats that supply energy and essential fatty acids is needed for good

The different types of fatty acids are the most important characteristics of dietary fats. According to the degree of unsaturation (double bonds and hydrogen content), fatty acids are largely classified into three major types: saturated fatty acids, monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). A fourth form, the trans fatty acids, are mainly produced by partial hydrogenation of polyunsaturated oils in food processing but also

Fatty acids consist of a hydrocarbon chain with a hydrophobic methyl group at one end and a hydrophilic carboxyl group at the other end. Greek letters (α, β, γ, ω) have been used to identify the location of the double bonds in fatty acids. The "alpha" carbon is the carbon closest to the carboxyl group. The methyl group of the molecule is also referred to as the omega end and the terminal carboxyl group is located at the delta end. Current chemical numerical terms number the carbon chain form one to "n", with n being the last carbon at the methyl end. The

Saturated fatty acids contain no double bond; they are fully saturated with hydrogen. The main saturated fatty acids are lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0) and stearic acid (C18:0). Saturated fats are found in animal-based products, such as milk, cream, butter and cheese, meat from most land animals, palm oil and coconut oil, as well as manu‐

MUFAs are predominant in vegetable oils, such as olive oil, canola oil and peanut oil and are also found in high proportions in animal fats [56]. Much of the interest in the role of MUFA in

factured products made from these, such as pies, biscuits, cakes and pastries [55].

PUFAs are naturally occurring endogenous substances, present in almost all tissues and are essential components of all mammalian cells. They are essential for survival and cannot be synthesized in the body. Hence, they have to be obtained in our diet and are therefore essential [54, 72]. There are two types of naturally occurring PUFAs in the body, the (n-6) PUFAs derived from linoleic acid (LA, C18:2) and the (n-3) PUFAs derived from α-linolenic acid (ALA, C18:3). They are categorized depending on the location of their first double bond: (n-3) PUFAs have their first double bond located at the third carbon molecule and (n-6) PUFAs at the sixth. Both of these two forms of PUFAs are metabolized by the same set of enzymes as their respective long-chain metabolites [73]. The differences between (n-3) and (n-6) PUFAs are shown in Table 1 below.

Vegetable oils are the predominant sources of alpha linolenic acid (ALA). ALA is found in legumes, flax seeds, walnuts, pinto beans, soybeans and spinach [74]. Dietary intake of ALA among Western adults is typically in the range of 0.5–2g/d [75]. The (n-6) PUFA is the main PUFA in most Western diets and is typically consumed in greater amounts than ALA [75, 76]. The evidence for a beneficial role of dietary (n-6) PUFAs is less convincing and for the purpose of this chapter we will focus on the (n-3) PUFA. The three main forms of (n-3) PUFAs are ALA, eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) [77], with ALA being the simplest form. The (n-3) PUFAs are a family of biologically active fatty acids. The simplest member of this family, ALA, can be converted to the more biologically active and very long-chain (n-3) PUFAs; EPA and DHA. This process, as shown in Figure 1, occurs by a series of desaturation and elongation reactions, with stearidonic acid being an intermediate in the pathway [54, 75, 78].

Research has shown that long-chain (n-3) PUFAs protect against CVD [77, 79-82]. The cardi‐ oprotective effects of (n-3) PUFAs have long been recognized. Epidemiologic data suggest that (n-3) PUFAs derived from fish oil reduce CVD. Fish oil is a rich source of EPA (C20:5 n-3) and DHA (C22:6 n-3) (Table 1) [67, 83, 84]. The cardioprotective roles of these two forms of (n-3) PUFA are extensively reviewed by Bester and co-workers [48]. Fish oil may also reduce mortality after a cardiovascular incident, as it plays a role in reducing potentially fatal arrhythmias ([85-87]. There are several prospective studies relating the use of fish or the intake of long-chain (n-3) PUFAs to lower risk of CVD [88, 89]. Long chain (n-3) PUFAs have several beneficial cardiovascular properties, including antiatherothrombotic, antiarrhythmic, antiinflammatory, antihypertensive and triglyceride lowering [81, 90, 91]. In summary, studies investigating the dietary roles of fatty acids demonstrate that dietary supplementation with (n-3) PUFAs decreases cardiac deaths, nonfatal cardiovascular events and all-cause mortality. These benefits are most apparent in high-risk patients. (n-3) PUFA supplementation appears to confer additional benefits in patients eating a Mediterranean diet.

The original observation is from almost 57 years ago, when Hugh M. Sinclair [92] published his observations on the negative effects of essential fatty acid deficiency on CVD. He strength‐ ened his hypothesis by noting the low mortality rate from CHD (coronary heart disease) in Greenland Eskimos, a population consuming a high fat diet, but rich in (n-3) PUFAs [92]. Clinical studies suggest that (n-3) PUFAs reduce mortality from coronary heart disease and the rate of sudden cardiac death [92-95]. Significant antiarrhythmic effects of (n-3) PUFAs were observed in some but not all human studies on atrial fibrillation [96, 97]. In addition, animal studies show strong antiarrhythmic effects of (n-3) PUFAs [98-102].


**Table 1.** Molecular structure, types and food sources of (n-3) and (n-6) PUFAs.

Long-chain (n-3) PUFAs are important constituents of all cell membranes and confer on membranes properties of fluidity and thus, determine and influence the behaviour of mem‐ brane-bound enzymes and receptors [103-107]. These PUFAs are found in abundance in the myocardium, retina, brain and spermatozoa, and are essential for the proper functioning of these tissues and growth, being important modulators of many physiological processes. The fact that these tissues have developed the cellular machinery to preferentially incorporate these minor dietary components into their membranes suggests that these PUFAs play a role in the proper function of the cell [108-110].

myocardial membrane phospholipids are rich in (n-3) PUFAs after fish oil consumption [111, 112]. Diet-induced changes in the PUFA composition of a cell membrane have an impact on the cell's function, partly because these fatty acids represent a reservoir of molecules that perform important signalling roles within and between cells. In particular, dietary (n-3) PUFAs compete with dietary (n-6) PUFAs for incorporation into all cell membranes [113,114]. (n-3) PUFAs modulate the expression of adhesion proteins such as selectins [115] and exert an effect by modulating the intracellular signalling pathways associated with the control of transcrip‐ tion factors (e.g., nuclear factor-κB) and gene transcription [116,117]. Research has shown that enrichment of monocyte membranes with (n-3) PUFAs results in the synthesis and secretion

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**Figure 1.** The biosynthesis of (n-3) PUFA.

The fatty acid composition of myocardial membrane phospholipids, in particular, is sensitive to the type of fatty acid consumed in the diet. Studies show that indeed the myocardium and

**Figure 1.** The biosynthesis of (n-3) PUFA.

of long-chain (n-3) PUFAs to lower risk of CVD [88, 89]. Long chain (n-3) PUFAs have several beneficial cardiovascular properties, including antiatherothrombotic, antiarrhythmic, antiinflammatory, antihypertensive and triglyceride lowering [81, 90, 91]. In summary, studies investigating the dietary roles of fatty acids demonstrate that dietary supplementation with (n-3) PUFAs decreases cardiac deaths, nonfatal cardiovascular events and all-cause mortality. These benefits are most apparent in high-risk patients. (n-3) PUFA supplementation appears

The original observation is from almost 57 years ago, when Hugh M. Sinclair [92] published his observations on the negative effects of essential fatty acid deficiency on CVD. He strength‐ ened his hypothesis by noting the low mortality rate from CHD (coronary heart disease) in Greenland Eskimos, a population consuming a high fat diet, but rich in (n-3) PUFAs [92]. Clinical studies suggest that (n-3) PUFAs reduce mortality from coronary heart disease and the rate of sudden cardiac death [92-95]. Significant antiarrhythmic effects of (n-3) PUFAs were observed in some but not all human studies on atrial fibrillation [96, 97]. In addition, animal

First double-bond on the sixth carbon counting from the

methyl end (the "nth" carbon)

Linoleic acids (LA) [C18:2] Arachidonic acid (AA) [C20:4]

Corn oil(LA) Soybean oil (LA) Sunflower oil (LA) Poultry (AA) Meats (AA)

Long-chain (n-3) PUFAs are important constituents of all cell membranes and confer on membranes properties of fluidity and thus, determine and influence the behaviour of mem‐ brane-bound enzymes and receptors [103-107]. These PUFAs are found in abundance in the myocardium, retina, brain and spermatozoa, and are essential for the proper functioning of these tissues and growth, being important modulators of many physiological processes. The fact that these tissues have developed the cellular machinery to preferentially incorporate these minor dietary components into their membranes suggests that these PUFAs play a role in the

The fatty acid composition of myocardial membrane phospholipids, in particular, is sensitive to the type of fatty acid consumed in the diet. Studies show that indeed the myocardium and

to confer additional benefits in patients eating a Mediterranean diet.

studies show strong antiarrhythmic effects of (n-3) PUFAs [98-102].

**(n-3) PUFA (n-6) PUFA**

First double-bond on the third carbon counting from the methyl end (the

Eicosapentaenoic acid (EPA) [C20:5] Docosahexaenoic acid (DHA) [C22:6]

**Table 1.** Molecular structure, types and food sources of (n-3) and (n-6) PUFAs.

"nth" carbon)

214 Antioxidant-Antidiabetic Agents and Human Health

**Types** α-Linolenic acid (ALA) [C18:3]

Canola oil (ALA) Soybean oil (ALA) Oily fish (EPA/DHA) Fish oil capsules (EPA/DHA)

proper function of the cell [108-110].

**Food sources** Flaxseed oil (ALA)

**Molecular structure**

> myocardial membrane phospholipids are rich in (n-3) PUFAs after fish oil consumption [111, 112]. Diet-induced changes in the PUFA composition of a cell membrane have an impact on the cell's function, partly because these fatty acids represent a reservoir of molecules that perform important signalling roles within and between cells. In particular, dietary (n-3) PUFAs compete with dietary (n-6) PUFAs for incorporation into all cell membranes [113,114]. (n-3) PUFAs modulate the expression of adhesion proteins such as selectins [115] and exert an effect by modulating the intracellular signalling pathways associated with the control of transcrip‐ tion factors (e.g., nuclear factor-κB) and gene transcription [116,117]. Research has shown that enrichment of monocyte membranes with (n-3) PUFAs results in the synthesis and secretion

of reduced quantities of cytokines (e.g., tumour necrosis factor-α, interleukin-1β) that are involved in the amplification of the inflammatory response [117,118]. Therefore, at a cellular level, (n-3) PUFAs from fish oils can directly or indirectly modulate a number of cellular activities associated with inflammation.

Of all the vegetable oils, RPO has the highest content of tocotrienols with γ-tocotrienol the most abundant. This form of vitamin E has been demonstrated to reduce cholesterol produc‐ tion and platelet aggregation [147-151]. RPO may also exert a neutral or positive effect on the serum lipid profile through the effects of its fatty acid composition and tocotrienols [152-155]. Investigations into vitamin E showed that tocotrienols are more potent than tocopherols as antioxidants. The tocotrienols present in palm oil have been shown to offer protection from myocardial I/R injury in an isolated perfused rat heart model [156, 157]. Animal studies with tocopherols and tocotrienols that investigate these compounds' potential against chronic diseases are extensively reviewed by Aggarwal and co-workers [158]. These authors argue that the evidence overwhelmingly suggests that tocotrienols may be superior in their biological properties than tocopherols and that their anti-inflammatory and antioxidant activities could

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Carotenoids are nature's most widespread pigments, well known for their orange-red to yellow colours, which they impart to many fruits and vegetables. These fat-soluble phyto‐ chemicals have also received substantial attention because of their provitamin A and antioxi‐ dant roles [159]. Carotenoids are polyenoic terpenoids with conjugated trans double bonds. They include carotenes (*β*-carotene and lycopene), which are polyene hydrocarbons and xanthophylls (lutein, zeaxanthin, capsanthin, canthaxanthin, astaxanthin and violaxanthin) that have oxygen in the form of hydroxy, oxo, or epoxy groups [160]. The majority of the 600 carotenoids found in nature are 40 carbons in length and may be pure hydrocarbons, called carotenes, or possess oxygenated functional groups, in which case they are called xanthophylls [161]. The long-chain conjugated polyene structure accounts for the ability of these compounds to absorb visible light, but also makes them quite susceptible to oxidation. This latter property

The properties and therefore functions of a carotenoid molecule are primarily dependent upon its structure and hence its chemistry [163]. In particular, the conjugated C = C double bond system is associated with energy transfer reactions, such as those found in photosynthesis [164]. In human plasma and tissues, several carotenoids have been well characterized includ‐ ing cyclic (such as β-carotene and α-carotene) and acyclic carotenes (such as lycopene and phytoene), together with a number of xanthophylls (such as zeaxanthin, lutein and betacryptoxanthin), all of which can be directly derived from dietary sources [165]. Carotenoids have generated considerable interest as several studies have suggested an inverse association between the dietary intake of carotenoids and the risk for CVD [166, 167]. Conversely proox‐

As mentioned earlier, RPO supplementation does offer protection against myocardial I/R injury via several suggested mechanisms. Amongst the proposed mechanisms are the NO– cyclic GMP pathway, phosphorylation of mitogen-activated protein kinases and scavenging

prevent CVD among other chronic diseases.

is closely related to their ability to act as antioxidants [162].

idant roles of these phytochemicals have also been reported [168-170].

of deleterious reactive oxygen species by RPO [42, 43, 47, 48].

*2.1.8. Possible mechanism(s) of action*

*2.1.7. Carotenoids*

#### *2.1.5. Polyphenols*

Polyphenols constitute one of the most numerous and ubiquitously distributed groups of plant secondary metabolites, with more than 8000 phenolic structures currently known. Natural polyphenols can range from simple molecules (phenolic acids, phenylpropanoids, and flavonoids) to highly polymerised compounds (lignins, melanins, tannins), with flavonoids representing the most common and widely distributed sub-group [119]. These secondary plant metabolites are known to have potential antioxidant activity and radical scavenging capacity [120-124]. Polyphenols are gaining increased importance due to their beneficial effects on health. Flavonoids are the most abundant polyphenols in our diets. They can be divided into several classes according to the degree of oxidation of the oxygen heterocycle: flavones, flavonols, isoflavones, anthocyanins, flavanols, proanthocyanidins and flavanones [125]. A complication of the epidemiological observations regarding members of the flavonoid family is that subtle differences in their chemical structures can translate into marked differences in their absorption, metabolism and bioactivities [126]. South African herbal teas, rooibos (*Aspalathus linearis*) and honeybush (*Cyclopia ssp*.) are currently gaining popularity worldwide [127, 128], owing to their anti-oxidant, anti-cancer and anti-mutagenic properties [129-131]. Rooibos is a herbal tea made from the leaves and stems of the indigenous South African plant, *Aspalathus linearis* (*Brum.f*) *Dahlg.* (*family Fabaceae; tribe Crotalarieae*) [132,133]. Research has demonstrated that this herbal tea is rich in flavonoids [127, 134]. Animal studies that have investigated the cardioprotective effects of natural or synthetic flavonoids have focused mainly on the acute pharmacological activity of these compounds. For example, *in vivo* studies using animal models have reported acute cardioprotection obtained from intravenous injections of natural or synthetic flavonoids [135,136].

#### *2.1.6. Vitamin E*

Natural vitamin E is composed of eight chemical compounds: α-, β-, γ- and δ-tocopherols and their corresponding tocotrienols. α-Tocopherol is the most active form of vitamin E *in vitro*. The tocopherols are saturated forms of vitamin E, whereas the tocotrienols are unsaturated and have an isoprenoid side chain. Tocopherols possess a chromanol ring and a 15-carbon tail. The presence of three *trans* double bonds in the tail distinguishes tocopherols from tocotrienols [137-139]. This may account for the differences in their efficacy and potency *in vitro* and *in vivo* [140,141].

Red palm oil (RPO) is a rich source of vitamin E. It contains 560–1000 parts per million of vitamin E, of which approximately 18–22% are tocopherols and 78–82% tocotrienols [142-144]. RPO has been shown to offer protection against I/R injury [42, 43, 47, 48] leading to a reduction in oxidative stress [145]. It has also been suggested that palm oil may have some anti-arrhyth‐ mogenic effects, which may reduce sudden death after ischaemic incidents [146].

Of all the vegetable oils, RPO has the highest content of tocotrienols with γ-tocotrienol the most abundant. This form of vitamin E has been demonstrated to reduce cholesterol produc‐ tion and platelet aggregation [147-151]. RPO may also exert a neutral or positive effect on the serum lipid profile through the effects of its fatty acid composition and tocotrienols [152-155]. Investigations into vitamin E showed that tocotrienols are more potent than tocopherols as antioxidants. The tocotrienols present in palm oil have been shown to offer protection from myocardial I/R injury in an isolated perfused rat heart model [156, 157]. Animal studies with tocopherols and tocotrienols that investigate these compounds' potential against chronic diseases are extensively reviewed by Aggarwal and co-workers [158]. These authors argue that the evidence overwhelmingly suggests that tocotrienols may be superior in their biological properties than tocopherols and that their anti-inflammatory and antioxidant activities could prevent CVD among other chronic diseases.
