January 31st, 2000
High blood pressure, or hypertension, has been called the “silent killer” because it often causes no symptoms, but can lead to various serious conditions such as heart attack, stroke, kidney failure and severe organ damage to the brain, and eyes, especially with other risk factors. High blood pressure is defined in an adult with a blood pressure greater than or equal to 140 mm Hg systolic pressure or greater than or equal to 90 mm Hg diastolic pressure.
High blood pressure can occur in children and adults but is particularly prevalent in middle-aged, elderly people and obese people. Individuals with diabetes or kidney disease have a greater frequency of hypertension.
In the US, high blood pressure (HBP) was listed as the primary cause of death of 42,565 Americans in 1997. In addition, HBP was listed as a contributing cause of death in about 210,000 of more than 2 million US deaths that year. A study carried out by the American Heart Association showed that about 50 million Americans age 6 and older have HBP, roughly one in every 5 Americans.
Once you have developed HBP, there is usually no cure. Some people can control their blood pressure by exercising regularly, maintaining a healthy eating habit and weight, and not smoking. However, many need to take medication (drugs such as diuretics, beta-blockers, ACE inhibitors, etc) to keep their blood pressure in a healthy range. Treatment generally must be carried out for life. If treatment with this synthetic drug is stopped, the pressure may rise again. There are side effects associated with these synthetic drugs such as swelling in the legs, headache or dizziness. This resulted in HBP patients seeking out alternative natural medications that may be able to control their condition without these adverse side effects.
A recent animal study published in the Clin. Exp. Hypertens. in November 1999 showed that a natural vitamin E, tocotrienol, found in the highest concentration in palm oil, has the ability to prevent the development of increased blood pressure after supplementation for 3 months. In the study, besides reducing blood pressure, gamma-tocotrienol was found to also reduce the lipid peroxides in plasma and blood vessels and enhanced plasma total antioxidant status including superoxide dismutase (SOD) activity.
The study was carried out with spontaneously hypertensive rats (SHR), comparing them with normal Wistar Kyoto (WKY) rats. SHR were divided into three groups and treated with different dosage of gamma-tocotrienol (gamma1 : 15mg/kg diet, gamma2 : 30mg/kg diet, gamma3 : 150mg/kg diet). Normal WKY and untreated SHR were used as normal (N) and hypertensive control (HC). Blood pressure were measured every fortnightly for three months. At the end of the trial, animals were killed and measurement of plasma total antioxidant, plasma superoxide dismutase activity and lipid peroxides levels in plasma and blood vessels were carried out. All tocotrienol treated SHR have reduced plasma lipid peroxides compared to the normal and non-treated SHR group but was only significant for group gamma1 (gamma1 : 0.109±0.026, HC : 0.132 ± 0.008; p = 0.034). On the other hand lipid peroxides in blood vessels in all treated groups showed a significant reduction (gamma1 : p < 0.05; gamma2 : p < 0.001; gamma3 : p < 0.005). Plasma total antioxidant activity including SOD activity was significantly improved in all treated groups. Correlation studies showed that total antioxidant status and SOD were significantly negatively correlated with blood pressure in normal rats (p = 0.007; p = 0.008) but not in SHR control. This correlation regained in all the three groups SHR’s after treatment with tocotrienol. Lipid peroxides in blood vessel and plasma showed a positive correlation with blood pressure in normal and SHR control. This correlation also remains in treated groups significantly except that in gamma3 where positive correlation with plasma lipid peroxide was not significant. In summary, the study found that antioxidant supplementation with tocotrienol may prevent development of increased blood pressure, reduce lipid peroxides in plasma and blood vessels and enhanced plasma total antioxidant status.
Tocotrienol may be a new word to many. It sounds much like the more familiar “tocopherol”. Indeed, tocotrienols are related to tocopherols. Both tocotrienols and tocopherols are Vitamin E. Tocotrienols differ from tocopherols in their molecular structure only by having an unsaturated isoprenoid side chain. Tocopherols have saturated side chain, ie : lacking double bonds. Tocotrienols are widely distributed in the plant kingdom, with the highest concentration found in palm oil. They are also found in grains such as barley, rice bran, oats, etc.
The above study showed that tocotrienol may hold potential as a natural compound to maintain a healthy blood pressure. Hence, the role of tocotrienols in the prevention of cardiovascular disease may have significant clinical implications. Additional studies on its mechanism of action, as well as long term intervention studies are needed to clarify its function.
Individuals who are diagnosed with high blood pressure and who are interested in maintaining a healthy blood pressure as part of a long term nutritional plan, may want to consider taking the natural tocotrienols vitamin E. Most of the tocotrienols supplements in the market contain typically 30 – 50mg of tocotrienols per capsules.