Treating Metabolic Syndrome using a Mediterranean Diet and High Intensity Interval Exercise
With the constant demands of everyday life, people are finding it more difficult to obtain a healthy body weight (Richard et al. 2012). There seems to be a viscous cycle of being overweight, not having enough time to stick to an extensive exercise schedule, and not eating correctly which feeds back into being overweight. This lifestyle may lead to dysfunction and ultimately health problems like metabolic syndrome. Some people may even have genetic predisposures to metabolic syndrome in their DNA (Chrysohoou et al. 2004). Metabolic syndrome is a condition that is categorized by high rates of adiposity, heart problems, and high blood pressure (Dunn et al. 2014). In addition, those suffering from metabolic syndrome also experience pro-inflammatory levels of Interleukin-6 (IL-6) leading to an insulin resistance in the body (Pitsavos et al. 2007).
IL-6 is an inflammatory marker that is characterized by chronic low-grade systemic inflammation which is linked to metabolic syndrome (Cullen et al. 2016). It is made primarily by lymphocytes and causes antibodies to take action. However, IL-6 is elevated during exercise and even during an illness, so it often believed that exercise can be dangerous because inflammation occurs. During an illness, the body is trying to fight off the bacteria; therefore, the immune cells create pro-inflammatory levels. Similarly, the body becomes inflamed during exercise; however, the more exercise that occurs, the more the body will get used to the inflammation which results in anti-inflammatory levels. This is beneficial because anti-inflammatory levels combat the occurrence of metabolic syndrome and type 2 diabetes.
Individuals with metabolic syndrome may find a regular exercise schedule, also termed “Moderate-Intensity Continuous Training”, to be unappealing, impossible, and ultimately not effective (Van Biljon et al. 2018). However, the research behind High Intensity Interval Exercise (HIIE) suggests this is a far more effective plan of action (Lahoz et al. 2018). HIIE involves high levels of activity performed in alternating short bursts and rest periods. One recent study concluded that over half of the eleven participants saw a reduction in capillary glycaemia, a heart health issue, after performing HIIE (Viana et al. 2018).
Using this method, individuals with metabolic syndrome experienced weight loss, reduced blood pressure, and anti-inflammatory IL-6 levels (Cullen et al. 2016). Therefore, HIIE can help reduce metabolic syndrome from the exercise side of life, but what about the unhealthy eating side of the issue?
There are many different diet trends and most are ineffective or yield only temporary results (Ajith et al. 2018). If someone is looking for reducing the risk of metabolic syndrome, the best diet to choose is the Mediterranean diet (Vitale et al. 2018). The Mediterranean diet is recommended in those with metabolic syndrome and even type 2 diabetes due to its high levels of polyunsaturated fatty acids, omega-3, and fiber (Estruch et al. 2016). There was a recent study conducted in Spain in which over 7,000 individuals who were at risk for cardiovascular disease adopted either a Mediterranean diet or a simple reduced-fat diet.
The researchers concluded that those who adhered to the Mediterranean diet showed a much lower risk of heart disease than those who ate reduced-fat only (Spence et al. 2018). In summation, studies illustrated the roles IL-6 have on metabolic syndrome, as well as those that demonstrate how metabolic syndrome can be counteracted by Mediterranean dieting and HIIE, respectively. The purpose of this current study is to determine whether or not HIIE and a Mediterranean diet would decrease the risk of Metabolic Syndrome. It was hypothesized that IL-6 levels would be reduced following this alternative intervention for metabolic health. Approval for this study was granted by the University of New South Wales Research Ethics Committee and the University of La Verne released approval for the data to be used. Data was gathered from a study performed in New South Whales, Australia in 2014 by a team of researchers that categorized the effects of HIIE and Mediterranean dieting on numerous metabolic syndrome markers including IL-6 levels (Dunn et al. 2014). Thirty-four women between the ages of 18 and 25 volunteered to participate in the study. The participants were divided into two groups; a control group of 17 women who did not change their dietary or exercise habits, and an experimental group of 17 who adhered to a Mediterranean diet and HIIE for the duration of the study. Twenty-four hours prior to testing, all participants were instructed to refrain from consuming caffeine and performing any vigorous activity. They were also asked to fast 12 hours prior. The women kept a food diary for 3 days/week pre- and post- intervention to track their meals and Mediterranean eating. The dietary intake was analyzed using dietary analysis software (Foodworks, Australia). A Mediterranean diet score was used to provide information on a scale from 0 (least adherent) to 9 (most adherent). Their scores were based off median values calculated from mean scores.
As for exercise training, supervised women were given a 5-minute warm-up and cool down and sprinted on a stationary bike for 8 seconds followed by a 12 second rest period known as LifeSprints. They repeated this for 20 minutes, 3 times a week, for 12 weeks at 80%-85% of each women’s peak heart rate. Baseline and post-test readings were taken for a variety of factors including body composition and blood pressure. The IL-6 levels of each participant were quantified using enzyme-linked assay kits (ELISA), which was determined by dual wavelength absorbance measurement. (Dunn et al. 2014). Finally, all data underwent statistical analysis using the IBM Statistical Package for the Social Science for Windows software (SPSS, version 25). An independent t-test was completed to assess any significant differences between the two groups pre- and post-testing. A p-value of less than 0.05 was considered significant. The purpose of this study was to determine whether or not HIIE and a Mediterranean Diet would lower the risk of metabolic syndrome through a reduction in IL-6 levels. The hypothesis was that HIIE and a Mediterranean diet would in fact lower IL-6 levels, thus lowering the risk of metabolic syndrome. Thirty-four women volunteered to participate in this study. Demographics about the women are shown in Table 1. The experimental group of 17 women were given a diet to follow and a HIIE program to complete for 12 weeks, while the control group was asked to not change any of their diet or exercise habits. Both groups were tested pre- and post-intervention to determine the differences. An Independent T-test on SPSS was performed between the control and experimental group to assess their pre- and post-intervention IL-6 measurements for significance. For the experimental group, IL-6 levels decreased significantly by 32% [difference/pre IL-6=% change (Table 2)].
A two-tailed independent sample t-test showed there was a significant difference in pre- and post-tests between treatment and control group [t(34) = 2.61, p = 0.014], such that the treatment group showed greater improvement than the control group. Overall, the data collected from this experiment supports the notion that HIIE paired with a Mediterranean diet has a positive effect on IL-6 levels in the body. Between the control and experimental group, pre- and post-study, IL-6 measurements were statistically compared. For the experimental group, IL-6 levels decreased significantly by approximately 32%. However, the control group’s IL-6 levels only decreased by about 3% due to the fact that they were instructed to not change their diet and exercise habits. Collectively, the experimental group showed greater improvement than the control group for this study, supporting the hypothesis that HIIE paired with a Mediterranean diet has a positive effect on metabolic syndrome, specifically IL-6 levels in the body. Previous studies on HIIE have proven results for weight loss. Using this method, individuals with metabolic syndrome experienced weight loss, reduced blood pressure, and anti-inflammatory IL-6 levels (Cullen et al. 2016). In addition to HIIE, dietary improvements can also aid in the pursuit to reduce metabolic syndrome. Overall, the best dietary intervention is the Mediterranean diet (Vitale et al. 2018). The Mediterranean diet is recommended in those with metabolic syndrome and even type 2 diabetes due to its high levels of polyunsaturated fatty acids, omega-3, and fiber (Estruch et al. 2016). The limitations of this study include geographic and demographic specificities. The sample population for the study included only university women between 18 and 25 years of age living in New South Wales. Metabolic syndrome can be found in other countries such as the United States; however, this study cannot be fully related to America because the lifestyles may vary to some degree that cannot be predicted with this data alone. Similarly, men can also experience metabolic syndrome as well as women, but that group is not included in this study either.
To gain the full scope of knowledge regarding metabolic syndrome, similar research would have to be conducted at least in all developed countries. Various age groups would need to be observed and all genders would need to participate as well. Such a study would take many researchers years and much funding to gather the data alone. Therefore, while that is the best theoretical path to take, it is not ideal. Instead, the research might be expanded upon one or two more groups to get a better grasp of how well the treatment works. Perhaps additional information could be gathered on men of the same age or women of more varied ages.Extreme IL-6 levels in the body indicate an individual who may be suffering from metabolic syndrome (Cullen et al. 2016). During exercise, these levels are known to be reduced. The most efficient exercise method to reduce such levels was found to be HIIE training. Risks of metabolic syndrome can also be reduced through diet. The Mediterranean diet has showed to yield great results for this. When the two methods were utilized together in this study, it was found to be extremely beneficial. IL-6 levels decreased significantly by approximately 32% when compared to the control group. Overall, this study shows that both HIIE and Mediterranean diet should be used simultaneously in order for individuals to get the best results of lowered IL-6 and decreased risk of developing metabolic syndrome.