## 4 Health-Promoting Effects of Avocado and Its Bioactives
### Cardiovascular Diseases  
Poor nutrition and excess weight are common risk factors for noncommunicable illness, such as cardiovascular disease (CVD), which impacts millions of people globally. Avocado intake, high in unsaturated fatty acids, can reduce modifiable dietary risk factors for CVD by substituting saturated fats with monounsaturated fatty acids [94]. According to studies, avocado consumers follow better diets, with greater intakes of fiber, vitamins, minerals, MUFA, and PUFA, as well as exhibit a lower BMI and waist circumference than non-consumers. However, systematic reviews have shown inconsistent results regarding the impact of avocado intake on blood lipids. Some studies show a decrease in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides, while others show insignificant alterations in TC, LDL-C, and triglyceride concentrations, but an increase in high-density lipoprotein cholesterol (HDL-C) [94]. A follow-up study to an experiment on an avocado per day as a usual habitual diet was conducted so as to determine if consuming one avocado per day for six months results in an improvement in visceral adiposity, rather than consuming fewer avocados per month. This study displayed high potential as a rigorous assessment of the prospective health advantages of avocado intake on cardiometabolic risk factors, lower fat, and overall diet quality. Given the prevalence of obesity and health-related concerns, such as CVD and diabetes diseases, finding effective nutritional therapies is critical. These studies' strengths include their large randomized controlled design, high recruitment and retention rates, and the application of a multi-center method, which improves their external validity. Despite the limitations caused by the COVID-19 epidemic, the study aimed to document any changes in dietary habits and identify the connection between avocado consumption, visceral adiposity, and cardiometabolic disease risk. In addition, the trial findings have the potential to influence individuals about the limitation of the high risk of cardiometabolic disorders via the consumption of one avocado per day [114]. In recent studies, researchers investigated the effect of three dosages of herbs and spices, including avocado, on gut bacterial composition in individuals who followed an average American diet, regarding the risk for cardiovascular disease. Such studies claimed that consuming culinary amounts of those herbs and spices as part of a consistent background diet resulted in changes in gut bacterial composition. The diversity and taxonomic enrichment of gut bacteria differed across the low-, medium-, and high-spice dosages as compared to the baseline. Moreover, it was found that consuming avocado resulted in decreased levels of bile acids, notably phenodeoxycholic and cholic acids. These findings emphasized the complex connections between gut and host bacteria, which are impacted by the nutrients of certain diets. Hence, it was concluded that including avocado into a diet may affect the gut bacteria composition, which allowed the development of a panel of fecal bacteria biomarkers indicating food constitution [115; 116]. Following this train of thought, more trial studies proved that both vegan and vegetarian diets that include avocado consumption have significantly reduced CVD risk factors that promote type 2 diabetes, as well as indicators like high-sensitivity C-reactive protein and IL-6. A vegan diet's advantages are most likely due to its ideal macro- and micronutrient composition, which contains lower dietary cholesterol and saturated fats and lower total caloric intake. Moreover, the reduced amounts of carnitine and choline in vegan diets leads to decreased levels of proatherogenic-N-oxide (TMAO), which is related to CVD morbidity and death. A vegan diet comprising of avocado may initiate adverse cardiovascular consequences, like an increased risk of ischemic stroke, due to reduced intakes of key nutrients such as amino acids, which dietary fortification can reduce [117; 118; 119].