Tocotrienols: Vitamin E For Cardiovascular Benefits After All

by Barrie Tan, PhD, and Anne M. Trias, MS

It is probably fair to say that most people have never heard of tocotrienol. It is probably also fair to say that when vitamin E is mentioned, most people only think of it as just vitamin E or alpha-tocopherol. Part of the reason for this lack of recognition derives simply from the time frame of scientific discovery. For, although vitamin E (in the form of alpha-tocopherol) was discovered in the 1920s, it was not until the 1960s that tocotrienols were assessed to be part of the vitamin E family tree (Figure 1).^1,2 Today we know that tocotrienols are naturally derived from several sources, including rice bran, palm fruit, and annatto bean. Tocotrienols are present in various compositions, often alongside tocopherols.

Interest in vitamin Es for cardiovascular health has been ongoing for many decades. Large clinical studies on alpha-tocopherol’s benefits to treat cardiovascular or other diseases have been equivocal or without effect, and possibly harmful.^3–5 While tocopherols have antioxidant value, they lack the ability to regulate cholesterol synthesis. Tocotrienol – due to a slightly different molecular structure – has been shown to decrease total and LDL cholesterol levels, and provides other benefits for those suffering from cardiovascular disease.

Figure 1: Vitamin E family tree.

What Is Tocotrienol, and How Does It Differ From Tocopherol?

Tocotrienols and tocopherols are the two subgroups of the vitamin E family. In simple terms, nature makes 4 tocopherols and 4 tocotrienols, each designated with the Greek symbols alpha, beta, gamma, and delta. Alpha-tocopherol is the best-known form, and has been popularized since its discovery in 1922. Tocotrienols, on the other hand, are almost unknown. The science of tocotrienol is only now emerging, warranting the publication of a first-ever tocotrienol book, Tocotrienols: Vitamin E Beyond Tocopherols, in 2008, with a second edition appearing in fall 2012.

As vitamin E molecules, tocopherols and tocotrienols have similar chemical entities. So why does tocotrienol work so differently from tocopherol? The answer is found in a detailed look at the subtle differences in molecular structure.

The vitamin E molecule looks like a tadpole, with a head and a tail. The head performs the antioxidant work, and determines whether a vitamin E is designated alpha, beta, gamma, or delta, depending on the number of substituted methyl groups. The tail anchors into lipid membranes constituting the cell wall, abundant in all cells of the body.

While both tocopherols and tocotrienols have the same structural head, tocotrienols have shorter and more flexible tails, enabling them to move freely through the cell membrane to cover larger areas for added protection. Generally, fewer methyl groups (desmethyl) and a shorter tail signify smaller molecular size and greater potency, with delta-tocotrienol amounting to the smallest molecular weight among the E vitamers.

The Problem with Alpha-Tocopherol

Tocopherols do not have the cholesterol-lowering ability that tocotrienols do; in fact, the opposite is true.⁶ Alpha-tocopherol has been repeatedly shown to attenuate or interfere with the cholesterol-lowering action of tocotrienols.⁷ Preparations effective in cholesterol-lowering consist of 15% (or less) alpha-tocopherol and 60% (or more) gamma- and delta-tocotrienol, whereas ineffective preparations consist of 20% (or more) alpha-tocopherol and 45% (or less) of gamma- and delta-tocotrienol. This has been supported by clinical studies in which supplements with high alpha-tocopherol content did not contribute to the lowering of cholesterol, whereas supplementation containing low amounts of alpha-tocopherol and high amounts of gamma- and delta-tocotrienol led to a significant decrease in total and LDL cholesterol.^8–12

In addition, tocotrienols absorb better in the body than tocopherols, and tocopherols have even been shown to prevent absorption and organ/tissue delivery of tocotrienols.^13–15 To summarize, alpha-tocopherol is thought to interfere with tocotrienol benefits directly by:

• compromising cholesterol reduction^[7]; ⁷

• attenuating cancer cell inhibition^16,17;

• blocking absorption^13,15;

• inducing tocotrienol catabolism (or breakdown)¹⁸;

By itself, alpha-tocopherol may lead to other predicaments, potentially:

• causing the premature catabolism (or breakdown) of prescription drugs¹⁹;

• increasing cholesterol and blood pressure^7,20–23;

• increasing prostate cancer risk in humans^4,24;

• decreasing bone mass²⁵;

Now while there are still benefits of vitamin E tocopherol, when it comes to cardiovascular health, vitamin E tocotrienols are showing greater efficacy and positive results. Currently, the only tocopherol-free tocotrienol source is derived from the annatto plant native to the Amazon rainforest (Figure 2). In contrast to annatto, both palm and rice tocotrienol sources contain a significant amount of alpha-tocopherol (25%–50% of total vitamin E), which confers interference with tocotrienol functions (Figure 3).

Figure 2: Rainforest annatto plant (Bixa orellana), popularly known as lipstick plant.

Figure 3: Typical compositions of vitamin E in natural tocotrienol sources.

Lipid Management: A First Sign of Tocotrienol’s Cardiovascular Benefits

Recognition for tocotrienol began to emerge in the early 1980s at the University of Wisconsin through the efforts of Asaf Qureshi and Charles Elson, who were the first to delineate the function of tocotrienol from tocopherol. The mechanism of tocotrienol’s hypolipidemic action involves posttranscriptional suppression of HMGR (3-hydroxy-3-methyl-glutaryl-CoA reductase – the enzyme/protein responsible for the body’s cholesterol production) via controlled degradation of the reductase protein.^6,26 This protein degradation is only seen with gamma- and delta-tocotrienol.

In animal studies,

gamma- and delta-tocotrienols showed the greatest decrease in cholesterol levels (32% total and 66% LDL cholesterol), whereas alpha-tocopherol had no effect on cholesterol-lowering. HDL/LDL cholesterol ratios were improved by 123% to 150% in chickens, which more closely reflect the lipogenic activity and cholesterol levels of humans.²⁷

Clinical studies on tocotrienol’s cholesterol-lowering effect are sparse, but two open-label studies showed that 75

Other Cardiovascular Benefits of Tocotrienols

Tocotrienol and Monocyte-Endothelial Cell Adhesion

One of the first steps of atherogenesis is fatty streak formation in arteries, which begins with the adherence of circulating monocytes to the endothelium. Tocotrienols have been shown to reduce cellular adhesion molecule expression and monocytic cell adherence.^28,29

In particular, delta-tocotrienol showed the most profound inhibitory effect on monocytic cell adherence as compared with tocopherols and other tocotrienol isomers. Delta- and gamma-tocotrienol were 60× and 30× more potent than alpha-tocopherol, respectively. It has been suggested that this phenomenon occurs via inhibition of VCAM-1 expression by delta- tocotrienol.³⁰

Essentially, delta-tocotrienol dramatically reduces the “Velcro effect” of circulating monocytes on the arterial wall, a process known to initiate plaque formation.³¹

Tocotrienol and Hypertension

Approximately 33% of American adults have hypertension, and 25% have prehypertension.³²

Recent animal studies showed that tocotrienols lower blood pressure, reduce plasma, and blood vessel lipid peroxides, and improve total antioxidant status.³³ Gamma-tocotrienol was shown to reduce systolic blood pressure significantly, and improved nitric oxide synthase activity (NOS), both of which play a critical role in the pathogenesis of essential hypertension.³⁴ In humans, tocotrienols have been shown to increase arterial compliance and reduce blood pressure.^35,36

Tocotrienol and Atheroma Formation

Before turning 35, two out of three Americans will have some degree of plaque build-up in their arteries.³⁷ This may be variously termed coronary, carotid, or peripheral atherosclerosis and/or stenosis. Comparison animal studies investigated the impact of tocotrienol supplementation vis-à-vis tocopherol or nonsupplementation in atheroma formation. Results to date indicate that animals on an atherogenic diet and given desmethyl tocotrienols had 60% lower plasma cholesterol than the control group, and the size of atherosclerotic lesions was reduced 10-fold. Alpha-tocopherol, on the other hand, had no effect.³⁸ Fully methylated tocotrienols and tocopherols (meaning larger size) – namely alpha- and beta-isomers – do not have the cardiovascular benefits characteristic of desmethyl tocotrienols.³⁹

Tocotrienol and Carotid Arteriosclerosis

A 4-year study on patients with carotid arteriosclerosis showed that tocotrienol supplementation caused regression of the disease. In 88% of patients who took the supplement, carotid artery stenosis was regressed or stabilized. Of the control group receiving a placebo, 60% deteriorated, and only 8% improved.^40,41 Interestingly, total cholesterol in the supplemented group decreased 14% and LDL cholesterol fell 21% in the fourth year of the study.⁴²

Cardiometabolic Benefits of Tocotrienols

Besides 24 million diabetics and perhaps as many as 60 million prediabetics, an estimated 36% of US adults, 74 million, have metabolic syndrome.^43–46 The occurrence of metabolic disorders mirrors the US obesity pandemic, with two in three adults being overweight.^47,48 Some of the AHA and NIH defining hallmarks of metabolic syndrome include^49,50:

• increased serum triglycerides (above 150 mg/dl)

• elevated blood pressure (above 130/85 mm Hg)

• elevated serum glucose (100 mg/dl and higher)

• decreased good HDL (under 40 mg/dL for males and under 50 mg/dL for females)

• increased waist circumference (above 102 cm/40in. for males and above 88 cm/35in. for females)

In patients with type 2 diabetes, progression of atherosclerosis is more rapid, and 80% of patients die of atherosclerotic events. In addition, LDL-lowering therapies normally prescribed for patients with diabetes have many side effects, creating a need for alternative treatment.

Tocotrienols, which have no known side effects, were shown in several clinical studies with metabolic syndrome and diabetes patients to reduce the symptoms associated with the disease. Some studies report reductions in serum total lipids by 23%, total cholesterol by 30%, and LDL-cholesterol by 42% within 60 days in type 2 diabetics.⁵¹ In two open studies, fasting blood lipids were measured before and after 2 months of annatto tocotrienol (75 mg/day) supplementation.¹² In both groups, the LDL/HDL ratio was reduced by 12% to 21%. Important to metabolic health promotion, triglyceride levels dropped 20% to 30%.

Addressing Inflammation as Cardiovascular Risk Factor*

Following the JUPITER and various other studies, it is now clear that high cholesterol should not be singled out as the only risk factor for cardiovascular disease. In fact, approximately half of the patients with cardiac events have perfectly “normal” cholesterol levels, but may be suffering from undiagnosed inflammation that contributes to oxidative and atherosclerotic processes.

Tocotrienols were shown to have potent anti-inflammatory properties minus the side effects. Qureshi and others evaluated the effect of tocotrienols in reducing inflammation in experimental mice.⁵² They demonstrated that alpha-, gamma-, and delta-tocotrienols strongly inhibited the inflammatory response using such markers as chymotrypsin, trypsin, and tumor necrosis factor-a, with delta-tocotrienol being the most effective. Results of this study indicated that tocotrienols can function as powerful proteasome modulators, while increasing the immune system’s ability to fight inflammation. At the same time, tocotrienols induce a hormone that produces an anti-inflammatory steroid to block inflammation directly.

Delta-tocotrienol was also shown to efficiently reduce nitric oxide and tumor necrosis factor-a levels in animals, and worked in synergism with natural alternatives quercetin (a well-known polyphenol) or riboflavin (vitamin B2).⁵³ Finally, delta-tocotrienol was the most potent vitamin E compound in the downregulation of COX-2 expression (a gene responsible for inflammation and pain), and potently reduced major proinflammatory cytokine IL-6 levels.^54,55

Tocotrienols vs. Statins*

In 2011, nearly 21 million patients in the US were prescribed statins, with Lipitor becoming the world’s best-selling drug at more than $125 billion in sales over 14½ years.^56,57 Like statins, tocotrienols affect the HMGR pathway. Statins are competitive inhibitors of the enzyme and block not only cholesterol, but also other important intermediates in the pathway. This is the culprit causing various undesired side effects.

Unlike statins, tocotrienols “dial down” cholesterol production without side effects, and hence they are discriminate cholesterol reducers. Delta- and gamma-tocotrienol degrade the HMGR protein, a mechanism of action that was elucidated in the early 1990s, and revalidated 15 years later.^6,26

In various clinical studies administering tocotrienol supplements, patients did not experience side effects as are observed with statin cholesterol-lowering drugs, many of which are due to statin’s inhibition of CoQ10 synthesis. Instead, preliminary open-label studies with 75 mg/day tocotrienols increased CoQ10 levels by up to 20%.¹² Tocotrienol’s ability to increase the body’s own CoQ10 production is novel.^58–60

While statins lower LDL cholesterol by a startling 40% to 60%, tocotrienols have been shown to lower these levels by a modest 15% to 20%, but without side effects. Consumers are increasingly turning to natural nutritional alternatives to address preventive health measures. Although less dramatic than statins, tocotrienols have been shown to be effective in cholesterol management and anti-inflammation without the sometimes debilitating side effects. In this sense, tocotrienols have made a comeback for vitamin E application in cardiovascular disease.

Daily Recommended Dosage

The optimal dose of tocotrienol for cholesterol and triglyceride reduction is 100 mg/day.¹¹ There are presolubilized forms of vitamin E, but they tend to be in large capsules and are difficult to swallow. Even less desirable, they contain additives not found in the original plant extracts where tocotrienol is derived from. To keep it simple, all lipid-soluble vitamins – such as A,D,E, and K – should be taken unadulterated and with a meal to increase absorption.⁶¹

*Excerpts previously appeared in

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