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Literature Review Final

The Effects of Different Types of Diets in Cardiovascular Health 

Daniel Annang, Zyara Davila, Calvin Morse

Department of English: The City College of New York

Writing for The Sciences – ENGL 21003

Professor Anna Voisard 

March 19th, 2024


Cardiovascular disease is one of the leading causes of death globally, and various factors have contributed to its rise in America. A significant factor is diet: the increase in processed and fast foods, which are rich in saturated fats and sugar, has contributed to the increase in cardiovascular disease cases. This paper uses cross-sectional studies to analyze the impact of three types of diets on cardiovascular health: omnivore diet/standard diet, vegetarian diet, and vegan diet. Omnivore diets, which include animal products, pose cardiovascular risks due to their high levels of saturated fats and cholesterol. In contrast, vegetarian diets, which exclude animal meats, are associated with improved cardiovascular health metrics. They emphasize plant-based foods rich in fiber and unsaturated fatty acids. Vegan diets, excluding all animal-derived products, offer similar cardiovascular benefits. However, they require careful planning to ensure adequate intake of essential nutrients. Despite the potential for deficiencies, vegan diets have been linked to reduced risks of coronary heart disease and stroke mortality. Overall, the study suggests that the vegan diet provides the most benefits for cardiovascular health, while the omnivore diet is the least beneficial.


Cardiovascular disease (CVD) is one of the most common causes of death globally. In the United States, one in three deaths is caused by cardiovascular disease (Casas et al., 2018). CVD is caused by various factors, including drinking, smoking, leading a sedentary lifestyle, unhealthy diets, and other health issues like obesity. A diet high in saturated fats, excessive sodium, and sugar components poses a high risk for coronary heart disease. However, it’s not the only health issue that can arise; it could also lead to hypertension, strokes, diabetes, and even cancer (Gropper, 2023). Therefore, to reduce the mortality rate of CVD and promote healthier lifestyles, researchers have studied and analyzed different types of diets and their effects on the cardiovascular system. Among the most significant diets with greater impacts on cardiovascular health are vegetarian, vegan, and omnivore diets. Omnivore diets are associated with cardiovascular health risks due to their higher content of saturated fats and cholesterol from animal meat. For this reason, veganism and vegetarianism might be more suitable for a healthier diet. By reviewing all three specialized diets, we will analyze how they are beneficial and contradictory for cardiovascular health.

Omnivore diet

            Dietary restrictions are something that many people follow and are impacted by, like vegetarian and vegan diets, omnivore diets have their own distinct features to them that affect cardiovascular health. Typically an omnivore diet is defined as a species that has a diet composed of both plant and animal materials, which in return impacts your cardiovascular health in a multitude of ways both beneficial and negatively. For instance according to Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins by the national library of medicine , the primary outcome was the difference in low-density lipoprotein cholesterol concentration from baseline to endpoint with the secondary outcome measuring what were the changes in cardiometabolic factors “(plasma lipids, glucose, and insulin levels and serum trimethylamine N-oxide level), plasma vitamin B12 level, and body weight. Exploratory measures were adherence to study diets, ease or difficulty in following the diets, participant energy levels, and sense of well-being.” (Landry et al., 2023). Although showing more of a comparison aspect it still highlights important details in an omnivorous diet, whilst also explaining more in depth about how exactly these variables such as vitamin B12 levels and insulin levels are in fact impacted by this diet. In addition to this another similar article goes in depth about more of the negative effects than the neutral of this diet, the article Cardiovascular risk in vegetarians and omnivores: a comparative study by the national library of medicine, dives into the aspects of what negative lingering effects come from such a diet by doing a study in a Clinical, where a epidemiological study had demonstrated a strong association between eating habits and chronic diseases, “particularly cardiovascular events, although not all the mechanisms of action are understood. With the end outcome being that an unbalanced omnivorous diet with excess animal protein and fat may be implicated, to a great extent, in the development of noncommunicable diseases and conditions, especially in the CVR.” Through this it can be inferred that if not properly balanced with other nutritional aspects it can lead to complications down the line. Moreover after evaluating another source it discusses the potential benefits that can come from a diet like this and how it can positively impact your cardiovascular health. The article Omnivore vs. Vegan for Nutrition, by trifecta nutrition, discusses how omnivore diets can supply more quality complete proteins that are easily absorbed. “They are also higher in vitamin B12 found only in animal foods  along with more zinc, vitamin D, and EPA and DHA omega-3 fatty acids”, but even throughout the positive praise the article provides it stillacknowledges some of the drawbacks this diet does have just like every diet. Overall what can be perceived from this, is that an omnivorous diet is very intricate and has its ups and downs like many other food lifestyle choices.

Vegetarian diet

A vegetarian diet primarily consists of cereals, fruits, vegetables, legumes, and nuts, excluding animal products such as meats, poultry, fish, milk, dairy products, and eggs (Ashen, 2013). However, different variations of the vegetarian diet may incorporate meats, poultry, fish, milk, dairy products, and eggs in small amounts. Variations of vegetarian diets vary considerably in dietary restrictions; some variations include vegan, lacto-vegetarian, ovo-vegetarian, and semi-vegetarian diets. Despite the different forms of vegetarianism, studies have shown that the variations do not significantly influence positive cardiovascular effects in correlation with the diet.

A cross-sectional study conducted by Yun-Min He et al. (2022) analyzed the cardiovascular health of the Taiwanese population using a health database collected between 2000-2016 and demonstrated the cardiovascular benefits of the vegetarian diet. The study indicates that vegetarian diets are associated with better cardiovascular health metrics than non-vegetarian diets. Vegetarians exhibit more favorable indicators such as blood pressure, total cholesterol, serum glucose, and BMI. This improvement in cardiovascular health metrics among vegetarians is attributed to several factors, including differences in nutrition profiles favoring plant protein, fiber, and unsaturated fatty acids. Furthermore, subgroup analysis of different variations in vegetarian diets confirms consistent trends in cardiovascular health metrics, suggesting that dietary variations within vegetarian diets do not significantly influence positive cardiovascular effects in correlation with the diet. A confounding result of the study is the location; the study focuses primarily on the Taiwanese people, which limits its generalizability. To address this gap and gain broader insights, this paper will examine a study conducted by Shridhar et al. (2014) in India. The study, “The Association between a Vegetarian Diet and Cardiovascular Disease (CVD) Risk Factors in India,” investigates the relationship between a vegetarian diet and cardiovascular disease risk factors. Although the study primarily focuses on adults in India, it compares its findings to Western vegetarians. This comparative analysis enables the drawing of broader conclusions across both populations. The study found that vegetarians in the Indian region similar to western vegetarians  presented lower LDL cholesterol and blood pressure levels than non-vegetarians. In this comparison, Indian vegetarians exhibited lower levels of LDL cholesterol compared to their Western vegetarian counterparts. Also the Indian vegetarian diet contained more fruits and vegetables and less fish and meat relative to the Western diet, which suggests a higher consumption of vegetables,  may be responsible for the effect. However, this was not the only difference between the two populations; Western vegetarians showed higher physical activity levels and increased tobacco use relative to populations in India. These findings question what makes a vegetarian diet particularly beneficial for cardiovascular health.

A study by Ashen (2013) delves more into the details of vegetarian diets and their potential benefits. Ashen examined various studies and concluded the benefits of vegetarian diets. Among the multiple studies used, Ashen analyzed a study on the 10-year risk of coronary heart disease in Buddhist monks following a vegetarian diet and omnivore men. The monks’ vegetarian diet excludes all animal products and vegetables in the Allium family, with soybeans as the primary source of protein. The omnivore men were not on special diets. The study found that Buddhist monks had a significantly lower predicted cardiovascular disease probability than omnivore men. Despite having lower socioeconomic status and less physical activity, Buddhist monks exhibited lower cardiovascular risk factors such as lipid levels, blood pressure, glucose metabolism, and body mass index than omnivores. Overall, the study found that an increase in the consumption of plant products and a decrease in animal products was associated with lowered blood pressure. The study found that a vegetarian diet reduces cholesterol levels and heart disease risk. These findings report that an entirely plant-based vegetarian diet poses the most benefits. In this realization, analysis of the vegan diet, which is entirely plant-based, is essential in concluding the relationship between diet and cardiovascular health.

Vegan Diet

A vegan diet is often confused with vegetarianism because they are both plant-based diets. Vegan diets emphasize cereals, vegetables, fruits, grains, legumes, and nuts, excluding all animal-based products like dairy (Koutentakis et al., 2023). Although being vegan might prevent various cardiovascular diseases, it is also known to not provide sufficient protein consumption and calcium for better bone development. However, under a “well-planned vegan diet,” these needs can be met with the combination of distinct grains or cereals like quinoa (Koutentakis et al., 2023). Vegan diets lack foods such as fish, eggs, dairy, and meats, which also impedes the body from getting vitamin B12, which could potentially be harmful without the current B12 supplements. However, as the intake of fruits and vegetables increases, there is a higher fiber content associated with low-density lipoprotein (LDL) cholesterol levels and a lower risk of stroke mortality (Craig, 2009). More legumes and fiber-rich foods in a vegan diet promote cardioprotective nutrients, thereby offering protection against cancer as well. According to Craig (2009), “Fruit and vegetables are described as protective against cancer of the lung, mouth, esophagus, and stomach” (p. 2). Overall, vegan diets contribute to deficiencies in vitamins, including vitamin D, which could lead to other health issues. However, these deficiencies can be controlled by taking the correct supplements. On the other hand, it is proven that a vegan diet reduces the chances of coronary heart disease by 40%, making it extremely beneficial for the cardiovascular system. With more extensive research over time, more data on the impacts of veganism on the heart could provide a more accurate cardiovascular outcome.


In summary, this study has examined how different diets impact cardiovascular health, focusing on omnivore, vegetarian, and vegan diets. Each type of diet has unique effects on cardiovascular risk factors. Omnivore diets, which include a lot of animal products, raise cardiovascular risks because they contain high levels of saturated fats and cholesterol. On the other hand, vegetarian diets, which avoid meat, show better cardiovascular health metrics by emphasizing plant-based foods rich in fiber and unsaturated fatty acids. Similarly, vegan diets, which exclude all animal products, offer similar cardiovascular benefits but require careful planning to ensure that essential nutrients are consumed adequately.

Despite these findings, further research is needed to understand the specific components of plant-based versus animal-based diets that contribute to cardiovascular health. Additionally, investigating which plant-based foods provide the most cardiovascular benefits and studying the long-term effects of these diets on heart health are important areas for future research. This will help in developing comprehensive dietary guidelines aimed at promoting heart health effectively.


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Casas, R., Castro-Barquero, S., Estruch, R., & Sacanella, E. (2018). Nutrition and Cardiovascular Health. International journal of molecular sciences, 19(12), 3988. https://doi.org/10.3390/ijms19123988

Gropper S. S. (2023). The Role of Nutrition in Chronic Disease. Nutrients, 15(3), 664. https://doi.org/10.3390/nu15030664

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