For Your Health

Type 2 diabetes

Plant-based diets have consistently been found to be protective against developing type 2 diabetes [1-3]. Despite being high in carbohydrates, a plant-based diet has also proven successful in improving blood sugar control, reducing diabetes medication requirements, and even putting type 2 diabetes into remission, whereby individuals have normal blood sugar control without the need for medication [4,5]. The reasons a plant-based diet is so effective for type 2 diabetes are mainly that it is higher in fiber, which helps to regulate blood sugars, is lower in saturated fat, which improves insulin sensitivity in the cells, and promotes weight loss due to its low caloric density. Improvements can be seen in as few as 7 days [6].

Obesity

People who follow a plant-based diet consistently have a lower body mass index and body weight than those who follow a vegetarian, pescatarian, or omnivorous diet [1,7]. A plant-based diet has also proven to be a successful strategy for weight loss [8]. Research done by the Physicians Committee found that following a plant-based diet results in an average weight loss of around 13 pounds over 14 weeks, while simultaneously improving other markers of cardiometabolic health [9]. Plant-based diets promote healthful weight control by being lower in saturated fat, lower in calorie density, and higher in fiber, while also increasing the amount of energy one’s body expends digesting food after a meal (the after-meal calorie burn) [9].

Heart Disease

Cardiovascular disease is the leading cause of death both globally and in the United States. A plant-based diet benefits heart health because it contains no dietary cholesterol, very little saturated fat, and abundant fiber. These characteristics enable a plant-based diet to address several risk factors for heart disease, including high cholesterol, diabetes, obesity, and hypertension. Even in the case of established heart disease, two clinical trials have found that a low-fat vegan or vegetarian diet was able to partially reverse the narrowing seen in arteries with plaque in their walls, resulting in improved blood flow to the heart [10,11]. With those changes came reduced chest pain, also called angina.

Cholesterol

While cholesterol has many important functions in our body, such as being used in the production of hormones and vitamin D, having cholesterol levels that are too high increases the risk of heart disease, among other conditions. In fact, dietary cholesterol is unnecessary because our bodies are able to produce all the cholesterol we need. A plant-based diet is effective at maintaining normal cholesterol levels and at lowering high cholesterol because it is low in saturated fat, devoid of cholesterol, and high in fiber [12].

Cancer

Processed and red meat contain cancer-causing compounds and are noted as a Group 1 and Group 2A carcinogen, respectively, according to the World Health Organization [13]. Meat is linked to an increase in many different types of cancer, most notably colorectal cancer. Plant-based diets, on the other hand, reduce the risk of many cancers [14]. And many components of a plant-based diet are especially protective against certain cancers; for example, fiber is protective against colorectal cancer, and soy is protective against breast cancer [15,16].

To learn more about these conditions and the impact a plant-based diet has on other health conditions, visit PCRM's Health Topics page.

References

1. Tonstad S, Butler T, Yan R, et al. Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 2009;32:791-796. doi:10.2337/dc08-1886

2. Satija A, Bhupathiraju SN, Rimm EB, et al. Plant-based dietary patterns and incidence of type 2 diabetes in us men and women: results from three prospective cohort studies. PLoS Med. 2016;13(6):e1002039. doi:10.1371/journal.pmed.1002039

3. Chiu THT, Pan WH, Lin MN, Lin CL. Vegetarian diet, change in dietary patterns, and diabetes risk: a prospective study. Nutr Diabetes. 2018;8(1):12. doi:10.1038/s41387-018-0022-4

4. Barnard ND, Cohen J, Jenkins DJ, et al. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Diabetes Care. 2006;29(8):1777-1783. doi:10.2337/dc06-0606

5. Panigrahi G, Goodwin SM, Staffier KL, Karlsen M. Remission of type 2 diabetes after treatment with a high-fiber, low-fat, plant-predominant diet intervention: a case series. Am J Lifestyle Med. 2023;17(6):839-846. doi:10.1177/15598276231181574

6. Campbell TM, Campbell EK, Attia J, et al. The acute effects of a DASH diet and whole food, plant-based diet on insulin requirements and related cardiometabolic markers in individuals with insulin-treated type 2 diabetes. Diabetes Res Clin Pract. 2023;202:110814. doi:10.1016/j.diabres.2023.110814

7. Spencer EA, Appleby PN, Davey GK, Key TJ. Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int J Obes Relat Metab Disord. 2003;27(6):728-734. doi:10.1038/sj.ijo.0802300

8. Tran E, Dale HF, Jensen C, Lied GA. Effects of plant-based diets on weight status: a systematic review. Diabetes Metab Syndr Obes. 2020;13:3433-3448. doi:10.2147/DMSO.S272802

9. Barnard ND, Scialli AR, Turner-McGrievy G, Lanou AJ, Glass J. The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity. Am J Med. 2005;118(9):991-997. doi:10.1016/j.amjmed.2005.03.039

10. Esselstyn CB Jr, Gendy G, Doyle J, Golubic M, Roizen MF. A way to reverse CAD? J Fam Pract. 2014;63(7):356-364.

11. Ornish D, Scherwitz LW, Billings JH, et al. Intensive lifestyle changes for reversal of coronary heart disease. JAMA. 1998;280(23):2001-2007. doi:10.1001/jama.280.23.2001. Erratum in: JAMA 1999;281(15):1380.

12. Yokoyama Y, Levin SM, Barnard ND. Association between plant-based diets and plasma lipids: a systematic review and meta-analysis. Nutr Rev. 2017;75(9):683-698. doi:10.1093/nutrit/nux030

13. International Agency for Research on Cancer. IARC Monographs evaluate consumption of red meat and processed meat. IARC Monographs. 2015. Accessed June 28, 2024. https://www.iarc.who.int/wp-content/uploads/2018/07/pr240_E.pdf

14. Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser G. Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiol Biomarkers Prev. 2013;22(2):286-294. doi:10.1158/1055-9965.EPI-12-1060

15. Arayici ME, Mert-Ozupek N, Yalcin F, Basbinar Y, Ellidokuz H. Soluble and insoluble dietary fiber consumption and colorectal cancer risk: a systematic review and meta-analysis. Nutr Cancer. 2022;74(7):2412-2425. doi:10.1080/01635581.2021.2008990

16. Boutas I, Kontogeorgi A, Dimitrakakis C, Kalantaridou SN. Soy isoflavones and breast cancer risk: a meta-analysis. In Vivo. 2022;36(2):556-562. doi:10.21873/invivo.12737