Antihypertensive and antioxidant effects of dietary black sesame meal in pre-hypertensive humans. Essay Example

Use of dietary black sesame meals for pre-hypertensive humans.

The choice of the meals to consume depends on the lifestyle the consumer lives. With the change in lifestyle, the society today is vulnerable to many diseases as most meals relating to their lifestyle are having adverse health effects. Although the article has presented a lot of evidence to show the role sesame seeds play in reducing hypertension, it is not conclusive that pre-hypertensive humans benefit from eating dietary black sesame meals.

Introduction

The article states high blood pressure as a major contributing factor to some adverse cardiovascular outcomes such as heart attack, stroke heart failure and kidney disease (Wichitsranoi, Jatuporn, et al. 2011). The lifestyle practiced by most people by eating meals with too much salt and fats and failing to engage in physical activities has paved the way for the rise in the rate of blood pressure. Alcohol and tobacco abuse are also some factors that are contributing to hypertension. Alternatively, the blood pressure rate can increase due to a person suffering from other conditions as a secondary factor. A person suffering from kidney disease may end up having hypertension.

Some methods are encouraged to reduce the effects brought about by hypertension through enabling prevention of the condition while others are relevant to the treatment. One treatment is through pathogenesis that acts on hypertension by increasing the balance between the relaxing and contracting factors in the blood vessels (Wichitsranoi, Jatuporn, et al. 2011).

The article reports sesame seeds as a way of treating hypertension by improving their oxidative stress. Sesame seeds contain vitamin E and lignan, a source of lignin that decreases oxidant stress (Wichitsranoi, Jatuporn, et al. 2011). The seed is traditionally known as a healthy diet in countries in the Middle East and Japan. Sesame seeds are also very rich in oil and protein with 50% and 20% of the content respectively. Researchers have found other uses of the seed due to its therapeutic effect such as anti-oxidative and to some extent anti-cancer.

Previous studies on the effect of vitamin E on the blood pressure have recorded contradicting results to the aim of the study. To test the hypothesis, the research administered black sesame meal on people with high blood pressure over four weeks. People with slightly elevated pressure were also used to test the oxidative effect by also feeding on the meal.

Design and setting

The study is a randomized, double-blinded and placebo controlled where the patients, who were the test subjects were blinded to the composition of the content of the meal. The test was carried in the year 2008-2009 where subjects were split into two groups. To permit the research, consent, both verbal and written, was obtained from all the subjects and the guidelines provided in the Declaration Helsinki were followed to the letter. Since the research used humans as the test subjects, issues regarding ethics emerged and to seek approval; Khon Kaen University Ethics Committee was consulted and approved to allow the research to continue (Wichitsranoi, Jatuporn, et al. 2011).

In determining the test subjects, an annual check-up program at the Khon Kaen University Department of Associated Medical Sciences was done in the period 2008 to 2009. To select the sample size, a change in systolic blood pressure was used where a 5mmHg was recorded and to acquire 90% power at a level of 0.05%, at least, 15 subjects were needed (Wichitsranoi, Jatuporn, et al. 2011). Thirty adults were selected from the population of the sample size to increase power, of them twenty-two men and eight women. The subjects were similar at the beginning of the trial as all the subjects were suffering from no other disease apart from elevated levels of blood pressure. For the all the subjects, the systolic blood pressure ranged from 120 to 139 mmHg, or else their diastolic blood pressure ranged from 80 to 89 mmHg (Wichitsranoi, Jatuporn, et al. 2011).

For comparison, the subjects were split into two equal groups, each having 11 men and four women. The subjects of a group were matched for age, BMI and blood pressure to ensure equality. The first group, with 15 subjects aged between 49.3 years to 57 years was subjected to black sesame meals pills whereas the second one, also with 15 subjects aged between 50.3 years to 55.9 years was to take placebo capsules (Wichitsranoi, Jatuporn, et al. 2011). Both of the groups were blinded as to the composition of the meals and tablets they were taking.

Medication

Treatments between the subjects of the two groups were allocated equally where all the subjects were treated equally on the two visits. The first visit was four weeks before the administration of either black sesame meal capsules or placebo capsules whereas the second visit was four weeks after the administration (Wichitsranoi, Jatuporn, et al. 2011).

Any other treatment was also equal between the subjects where they all took six capsules at one time for three times a day, of their respective treatment during the four weeks of the study with water after taking a meal. The subjects were also to avoid consuming all dietary supplements such as vitamins and also maintain routine in their diet during the trial period. During the two visits, the subjects were supposed to fast for 12 hours to facilitate for the collection of blood samples to be used to measure blood parameter (Wichitsranoi, Jatuporn, et al. 2011).

For all the subjects, they were suffering from no other disease apart from elevated levels of blood pressure. Between the two groups; the Sesame group and the placebo group, there were no significant differences in the age, body compositions and anthropometry (Wichitsranoi, Jatuporn, et al. 2011).

Four weeks after administration of black sesame meal capsules, the systolic blood pressure was significantly decreased. The records were 112.0 to 130 mmHg after the administration of the tablets compared to 122.5 to 136.1mmHg before the administration. In the placebo group, systolic blood pressure was slightly decreased (Wichitsranoi, Jatuporn, et al. 2011). The levels four weeks after administration ranged from 125.6 to 135.2 mmHg in comparison with levels before administration of capsules that ranged between 121.1 to 140.1 mmHg (Wichitsranoi, Jatuporn, et al. 2011). The decline in the systolic blood pressure among the group taking black sesame capsules was greater when compared to that of placebo group with a P<0.05.

For diastolic blood pressure, the group administered with sesame capsules recorded a decrease four week after the treatment. The new readings after administration ranged from 63 to 82.6 mmHg as compared to 69.6 to 84.4 mmHg before the capsules administration (Wichitsranoi, Jatuporn, et al. 2011). On the other group where placebo capsules were administered, an increase in diastolic blood pressure was recorded. After the administration of the capsules, the rates ranged between 73.9 to 98 mmHg as compared to the rates before the treatment that ranged between 72.9 to 88.3 mmHg (Wichitsranoi, Jatuporn, et al. 2011). The changes in the diastolic blood pressure between the groups were not significant with a P=0.76.

The recording of the plasma MDA concentrations before and after administration of treatment showed a decrease in the concentration levels for both groups. The sesame group recorded a significant decline in the plasma MDA levels after the four weeks of administration where the levels ranged from 0.6 to 1.8 comparing to 1.2 to 2.4 (Wichitsranoi, Jatuporn, et al. 2011). For the placebo group, the decline was not significant with concentrations ranging from 1.3 to 2.3. The plasma vitamin E levels were significantly increased for the sesame group whereas the levels for the placebo group increased slightly.

Discussion

The results show the importance the administration of sesame meal capsules weighing 2.52g plays by decreasing the systolic blood pressure by 8.2mmHg. Earlier on, a study by Intersalt had associated a decline of 2 to 3 mmHg for the systolic blood pressure with 4% decrease in the deaths caused by cardiovascular diseases both in the United States and the United Kingdom. In Japan, a similar decline reduced the mortality rates by 6% (Wichitsranoi, Jatuporn, et al. 2011).

Black sesame meal capsules were observed to produce better results in reducing the blood pressure and increasing the concentrations levels of plasma vitamin E. Sesame increases the balance between relaxing and contracting factors in the endothelium of the blood vessels lowering blood pressure (Wichitsranoi, Jatuporn, et al. 2011). The increase in the plasma vitamin E may be due to the increased vitamin E, provided with the sesame seeds.

The results can also be related to another non-oxidative mechanism where the supplementation of gamma-tocopherol increases the production of protein through nitric oxide synthase (Wichitsranoi, Jatuporn, et al. 2011). The process, in turn, increases vasorelaxation thus contributing to low blood pressure. Gaps in knowledge present a major challenge to the understanding of the role of sesame vasorelaxation in striking the balance in the endothelium of the blood vessels.

Conclusion

Although the article outlines the benefits associated with consumption of black sesame meals in reducing the blood pressure of hypertensive persons, it does not provide conclusive evidence. The increase in plasma vitamin E is not entirely due to the consumption of sesame meal since it can be brought about by increase in vitamin E (Wichitsranoi, Jatuporn, et al. 2011). It can also be brought about by inhibition of catabolism of vitamin E.

To further criticize the article, research showing lack of a linkage between oxidative stress and blood pressure is used. Other processes such as gamma-tocopherol supplementation also lead to vasorelaxation (Wichitsranoi, Jatuporn, et al. 2011). Therefore vasorelaxation cannot be fully attributed to increase in plasma vitamin E. To address the deficiency in knowledge, further research is needed in the field.

Works cited

Suarez, Rivera M. P, Eric Boerwinkle, Mark L. Williams, Kelly Volcik, and Michael Braun. Factor H Variant Y402h and the Prevalence of Hypertension and Proteinuria: The Atherosclerosis Risk in Communities Study. , 2008. Print.

Wichitsranoi, Jatuporn, et al. «Antihypertensive and antioxidant effects of dietary black sesame meal in pre-hypertensive humans.» Nutrition Journal 10.1 (2011): 1.