Anti-inflammatory and Antioxidant Effects of Sesame Oil on Atherosclerosis.

In the studies that analyzed the effect of SO and its lignans on a lipid profile, SO has been shown to decrease TC, LDL, and VLDL plasma levels in hypercholesterolemic rodent and rabbit models. However, one reviewed study had stated that SO has no significant effects on lipid levels compared to the control. Study 6 stated that SO treatment was not significantly different from the control treatment, which supported that the beneficial effects resulting from treatment with N-acetylcysteine (NAC) and SO together was only due to NAC; there was not enough SO to counteract the high cholesterol diet, which implies that SO treatment may be dose dependent. Other studies also agree that their research results that indicate the benefits of SO were truly significant at a certain dose. Plant studies showed that plant stanols decreased LDL levels in a dose-dependent manner up to ~17% in a linear fashion when given up to 9 grams/milliliter . The diet fed to the subjects in study 6 was composed of 10% SO compared to other studies that administered SO amounts depending on the weight of the subject. Depending on the weight of the subjects, 10% of SO in the diet may not have been enough to show SO’s anti-lipidemic effects. Since caloric intake is higher than recommended in many populations, research has pointed out that consumption of supplemental oil should be associated with reduced intake of saturated fat. This implies that SO could also be present in high amounts but not enough to induce its effects relative to the subject ingesting it.

In order to research additive effects of SO, some research explored the effects of mixed oils containing SO. Many vegetable oils, like sunflower or olive oils, also show hypocholesterolemic effects when ingested. Research on the use of SO to treat atherosclerosis has yet to accumulate studies and research. So far, there are mixed reviews about SO, some studies stating that SO is not as effective as other edible oils. Study 6 studied the effects of SO in comparison to other oils in order to compare SO as a novel nutritional element to other vegetable oils that are part of our daily nutrition. Results in the study showed that SO was not as effective as the other oils. This can be due to a few reasons, one being that the SO is not isolated and tested on its own. Blending different oils could result in a synergistic, antagonistic, or neutral effect. SO on its own can decrease cholesterol levels in the blood, but studies showed that SO blended with α-lipoic acids decreased cholesterol levels in the blood much more than α-lipoic acids or SO alone. Another reason could be that there is no universal SO used throughout all the studies. There are many brands of SO, which are made with different techniques and compositions that may influence the effects of SO. For example, SO is derived from heating sesame seeds to a certain temperature in order to create many of the lignans that are abundant in the oil but not the seeds. This may increase or decrease the potency of SO compared to other vegetable oils and vice versa. In order to be able to properly compare the studies, one standardized concoction of SO should be created and consistently used throughout the studies.

Another way research explores the effects of SO is to test it in a mix with other components. For example, study 14 compared the effects of nifedipine to the effects of an oil mix of nifedipine with SO and sunflower oil on hypertensive patients, which resulted in a decrease in hypertensive factors. However, it is possible that the benefits could have been from the sunflower oil alone or that the SO had no benefit. It is also possible that the SO could have had adverse effects that negated some of the benefits of nifedipine or vice versa. The conclusion is that many of these studies are limited because they do not isolate the benefit of SO in humans alone and that different concentrations of SO are used in different studies and that a future study should examine the different concentrations of SO and its effects on humans with hyperlipidemia, hypertension, and diabetes mellitus. New studies can compare patients treated with differing mixes of medication, such as nifedipine, statins, metformin, with different concentrations of SO. Like statin therapy, many studies have promising results that show SO, when used as a dietary supplement, to lower LDL levels in the blood in coronary and aortic vasculature, as well as the liver and the brain. The 14 studies did not examine the effects of SO on pancreatic beta cells, and future studies may want to see if SO has any potential effects since diabetes is also often associated with increased cardiovascular disease.

In most of the mentioned studies performed on animal models with SO, the benefits of SO and its components (e.g., sesaminol) can change the amount of gene transcription in different targets, such as endothelial cells, hepatocytes, and macrophages. Lignans such as sesamin and sesamol have gained popularity as they have been shown to have antioxidant and hypocholesterolemic effects. However, many more studies need to be conducted on human participants since only two out of the 14 were on humans and one of the studies did not examine SO directly. In study 4, hypertensive men who took SO showed an increase in short- and long-term FMD and long-term ICAM. While these results look promising, there is a lot more that needs to be examined. In contrast, study 14 compared the benefits of SO and nifedipine with nifedipine alone. Neither of these studies compared the efficacy of SO to current pharmaceutical treatments in treating atherosclerosis. Previous studies have looked at the synergistic benefits as opposed to a direct comparison of SO with insulin-independent diabetic medications and anti-hypertensive medications. These results show that in order to properly assess the effects of SO, there is a strong requirement for human trials with SO. Animal studies have shown that SO has decreased atherosclerotic factors without significant harm to the models, but it is unknown whether the same effects of SO would affect humans in the same way. In order to one day implicate SO and its effects on atherosclerotic patients, SO must past more clinical trials in order to gain traction as a possible treatment for atherosclerosis and other cardiovascular diseases.