With so much conflicting nutrition information, it can be difficult to know what eating pattern is best for your health. Today, we will discuss the benefits of a “plant-based diet,” an eating pattern you may be hearing more and more about. So, what is a plant-based diet? The name does speak for itself. A plant-based diet means eating mainly from plants, including vegetables, fruits, nuts, seeds, whole grains, legumes, and beans. It does not always mean that you need to be vegan (which excludes all animal products) or vegetarian (which generally excludes meat and fish but may include eggs and dairy), but rather includes primarily plant-based foods and fewer animal-based foods [i].
Plant-Based Diets and Cancer
With the advancement of stock farming and food science engineering, red meat and processed meat have become common features on our plate. Although red and processed meat provide protein, eating them too frequently can be damaging to our health. Many studies have found that high intakes of red and processed meats are significantly associated with cancer development, such as breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and renal cancer [i].
To lower the risk of cancer development and recurrence, it is recommended to limit red and processed meat intake. Luckily, we have many healthy and plant-based foods to choose from. A plant-based diet holds anti-cancer properties. The staples of a plant-based diet, such as fruit, vegetables, legumes, and beans, contain all types of vitamins, minerals, fiber, and phytonutrients. These nutrients lower blood pressure, improve immunity, help excrete extra blood cholesterol, and help to decrease cancer risk [ii].
There are several reasons why a plant-focused diet may decrease cancer risk and improve outcomes for those with cancer. One is due to phytonutrients, unique nutrients found in plants that work as antioxidants to prevent body damage and inhibit cancer cell growth [iii]. Fiber is another vital nutrient that can only be found in plant-based products and can help lower the risk of colorectal cancer [iv].
Evidence suggests that a plant-based diet can be an ideal dietary pattern to reduce the risk of certain cancers [iv]. According to the American Institute for Cancer Research (AICR), a healthy plant-based diet includes vegetables, fruits, whole grains, and beans as ⅔ or more of each meal, and animal products as less than ⅓ of each meal. It is well established that high intake of red and processed meat is significantly associated with cancer, whereas high intake of unprocessed plant-based foods can reduce cancer risk [i, v].
Plant-Based Diets and Other Chronic Conditions
A plant-based diet may also be beneficial in preventing and improving several other chronic conditions:
Type 2 Diabetes: Studies have found high soluble fiber intake from unrefined whole grains may help improve insulin resistance and optimize blood sugar control [vi]. High intake of red and processed meat are also associated with an increased risk of type 2 diabetes. Replacing a serving of red or processed meat with one serving of nuts, whole grains, or low-fat dairy each day may help lower the risk of type 2 diabetes by 16% to 35% [vi].
Heart Disease: High intake of saturated and trans- fats have been shown to increase the risk of heart disease. Fried food, baked goods, and red meat are common sources of saturated and trans- fats in the diet. A healthy plant-based diet can help us lower heart disease and stroke risk by decreasing saturated fat intake from meat and increasing antioxidant and fiber intake from plant-based products. Meanwhile, nuts and seeds contain healthy unsaturated fats that can help lower heart disease risk by reducing the LDL (“bad”) cholesterol in our blood and inhibiting atherosclerosis (the leading cause of heart disease) [vii].
Hypertension (High Blood Pressure) and Stroke: Bananas, beans, potatoes, broccoli, and many plant-based products are high in potassium. A high intake of potassium-rich foods can reduce blood pressure and lower the risk of stroke by maintaining vascular homeostasis [vii]. Sodium is another major mineral that can affect blood pressure. Processed food and meat products usually contain high levels of sodium. High sodium intake is a major risk factor for heart disease, hypertension, and stroke. Since a plant-based diet is focused on unprocessed plant foods and whole foods along with little processed food and meat, it is considered a heart-healthy diet. The American Heart Association recommends no more than 2300 mg of sodium per day for adults. Even cutting back sodium intake by 1000 mg per day can significantly improve heart health and blood pressure [viii].
Obesity: Plant-based diets can also provide some additional benefits for weight management. This diet typically contains a low-calorie density due to a low level of saturated fat and high amounts of water and fiber from fruits and vegetables. The high dietary fiber content of a plant-based diet can increase fullness and help with weight loss. Increased fiber intake can also promote healthy gut bacteria and overall gut health [vii, ix].
Are There Any Potential Health Concerns of a Plant-Based Diet?
Even though a plant-based diet is considered one of the healthiest diets, there are still a few important points to consider:
Making Smart Choices: Plant-based doesn’t always mean healthy. Many processed foods, snack foods, and foods with added sugar are technically plant-based. The focus should be on whole plant foods as much as possible and limiting highly processed foods regardless of whether they are “plant-based.”
Protein: Many are concerned they won’t get enough protein on a plant-based diet. However, there are plenty of high protein plant foods. Beans, legumes, nuts, seeds, and whole soy products such as tofu and edamame are great plant-based protein sources. If you are following a fully or mostly plant-based diet, be sure to include one of these with your meals.
Iron: Iron is an essential nutrient that carries oxygen to all organs in the body. It comes in two forms: heme and nonheme iron. The iron found in animal products, called heme iron, is more easily absorbed by our digestive system than the nonheme iron found in plants. Plant products such as lentils, peas, flaxseeds, spinach, kale, and whole grains, are great sources of non-heme iron. Consuming these iron-rich foods along with Vitamin C-rich foods, such as oranges or tomatoes, can help improve iron absorption [x]. Always speak with your doctor if you are concerned about your iron levels.
Vitamin B12: Vitamin B12 is a water-soluble vitamin necessary for red blood cell and DNA production. It is naturally found only in animal products. People who follow a plant-based diet that still includes animal products, such as eggs and yogurt, may get enough vitamin B12. However, B12 supplements may be necessary for strict vegans [xi]. Ask your doctor or dietitian for vitamin B12 supplementation suggestions.
Calcium: Like iron, calcium exists in many foods, including animal and plant products. But generally, calcium in dairy products such as milk and yogurt has a better absorption rate. In the United States, 72% of calcium intake comes from dairy products. Non dairy food sources such as salmon, broccoli, tofu, and Chinese cabbage are also calcium-rich foods. If you are concerned about not getting calcium from a plant-based diet, calcium-fortified food, such as calcium-fortified oatmeal, may be recommended [xii].
Vitamin D: Vitamin D is a fat-soluble vitamin essential for bone formation and immunity. In nature, vitamin D is only found in a limited number of foods, such as salmon, eggs, and cod liver oil. We may be able to get enough vitamin D from sun exposure. During wintertime, it may be difficult for some people to get enough sunlight. Thus, vitamin D fortified foods such as fortified milk, or a vitamin D supplement, may be recommended by your doctor [xiii].
Plant-Based Protein Sources and Food Ideas
There are many delicious plant-based choices to make sure you are getting a balanced and protein-rich diet:
Plant-Based Protein Foods: beans (kidney, chickpeas, black beans, pinto beans, etc), legumes such as lentils and peas, tofu, nuts and seeds (almonds, walnuts, sunflower seeds, etc), whole soy products (edamame, tofu, soy milk), quinoa.
Plant-Based Iron-Rich Foods: spinach, sweet potatoes, peas, broccoli, kale, whole grains, prunes, strawberries, watermelon, oat cereal, beans.
Plant-Based Vitamin B12 Rich Foods: fortified foods, cereals, mushrooms, and seaweed.
The Take-Home Message
The goal of a plant-based diet is simple: eat more plant-based foods and fewer animal-based foods. To receive all the potential health benefits, it is essential to eat a wide variety of plant-based products, and the simplest way to accomplish that is to “eat the rainbow.” Try to have different kinds and colors of plant foods each day. While several diets can improve our overall health, for example, the Mediterranean diet, DASH diet, or a vegetarian diet, there is one thing all of these have in common: a wide variety of whole, plant-based foods!
References:
[i] Farvid MS, Sidahmed E, Spence ND, Mante Angua K, Rosner BA, Barnett JB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. 2021;36(9):937-951. doi:10.1007/s10654-021-00741-9
[ii] Kane-Diallo A, Srour B, Sellem L, et al. Association between a pro plant-based dietary score and cancer risk in the prospective NutriNet-santé cohort. Int J Cancer. 2018;143(9):2168-2176. doi:10.1002/ijc.31593
[iii] Ranjan A, Ramachandran S, Gupta N, et al. Role of Phytochemicals in Cancer Prevention. Int J Mol Sci. 2019;20(20):4981. Published 2019 Oct 9. doi:10.3390/ijms20204981
[iv] Kunzmann AT, Coleman HG, Huang WY, Kitahara CM, Cantwell MM, Berndt SI. Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Am J Clin Nutr. 2015;102(4):881-890. doi:10.3945/ajcn.115.113282
[v] AICR. Retrieved from https://www.aicr.org/cancer-prevention/food-facts/aicrs-new-american-plate/
[vi] Pan A, Sun Q, Bernstein AM, et al. Red meat consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. Am J Clin Nutr. 2011;94(4):1088-1096. doi:10.3945/ajcn.111.018978
[vii] Satija A, Hu FB. Plant-based diets and cardiovascular health. Trends Cardiovasc Med. 2018;28(7):437-441. doi:10.1016/j.tcm.2018.02.004
[viii] AHA. Retrieved from https://www.heart.org/en/health-topics/high-blood-pressure/changes-you-can-make-to-manage-high-blood-pressure/shaking-the-salt-habit-to-lower-high-blood-pressure#:~:text=The%20American%20Heart%20Association%20recommends,blood%20pressure%20and%20heart%20health.
[ix] Hervik AK, Svihus B. The Role of Fiber in Energy Balance. J Nutr Metab. 2019;2019:4983657. Published 2019 Jan 21. doi:10.1155/2019/4983657
[x] Iron: Fact Sheet for Health Professionals 2018; https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/#h2
[xi] Vitamin B12: Fact Sheet for Health Professionals 2018; https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/#h5
[xii] Calcium: Fact Sheet for Health Professionals 2018; https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
[xiii] Vitamin D: Fact Sheet for Health Professionals 2018; https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/#h5