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November 13, 2024

The Benefits of a Plant-Based Diet for Cancer Prevention

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The Benefits of a Plant-Based Diet for Cancer Prevention

Interest in plant-based diets has increased significantly worldwide. According to the Plant-Based Foods Association (PBFA), 70 percent of US citizens eat plant-based foods as of 2023, up from 66 percent in 2022. Furthermore, sales of plant-based meat alternatives increased by 74 percent between 2018 and 2021. 

An increasing body of research supports the role of plant-based diets in cancer prevention. Adherence to a healthy plant-based diet has been found to significantly reduce the risk of breast cancer.

This article will explore how a plant-based diet can help prevent cancer and how to incorporate more plant foods into daily meals.

How a Plant-Based Diet Can Help Prevent Cancer

The Science Behind Plant-Based Diets and Cancer Prevention

Research suggests that plant-based diets may help reduce cancer risk through multiple mechanisms, including a higher intake of fiber, antioxidants, and phytochemicals.

Understanding the Role of Phytochemicals

Phytochemicals are bioactive compounds generated from plant metabolism in response to environmental changes. They are found in vegetables, whole grains, nuts, beans, herbs, tea, and coffee. The main classes of phytochemicals include carotenoids, indoles, glucosinolates, organosulfur compounds, phytosterols, polyphenols, and saponins. Each class has unique properties and health benefits.

Phytochemicals have shown promise in both cancer prevention and treatment. They modulate many cell signaling pathways involved in cancer progression. For instance, they inhibit the P13K/Akt pathway, which is crucial for cell growth and survival, thereby preventing the growth of cancer cells. Additionally, phytochemicals like curcumin and resveratrol can regulate pathways implicated in cancer stem cell maintenance and growth.

Antioxidants and Their Cancer-Preventive Properties

Plant foods are rich in antioxidants. These compounds help to reduce oxidative damage and are linked to decreased morbidity and mortality from chronic illnesses like atherosclerosis, cancer, and age-related diseases. Plant-based antioxidants do this through direct scavenging of reactive oxygen species (ROS) and enhancing the body’s natural antioxidant defenses.

ROS causes DNA damage, mutations, and genomic instability, which are critical steps in the formation of cancer; therefore, targeting oxidative stress by increasing antioxidants can reduce cancer risk.

Some examples of antioxidant-rich plant foods are green leafy foods and sprouts like broccoli and red cabbage, nuts, and berries.

Fiber and Its Role in Cancer Prevention

Dietary fiber plays a crucial role in supporting digestive health, influencing the composition and activity of gut microbiota. It also stimulates the growth of health-promoting bacteria like bifidobacteria, which can enhance gut health by regulating intestinal flora. Dietary fiber also improves stool consistency and frequency, which can alleviate constipation and stimulate intestinal motility, which is essential for proper digestion and nutrient absorption

Several studies have found an inverse association between dietary fiber intake and colorectal cancer risk. For example, one large prospective study found that elevated dietary fiber intake was associated with a significantly reduced risk of incident distal colorectal adenoma.

Examples of high-fiber foods include fruits like raspberries, pears, and apples; vegetables like green peas, broccoli, and turnip greens; grains like spaghetti, pearl barley, and bran flakes; and legumes such as split peas, lentils, and black beans.

Key Components of Cancer-Preventive Plant-Based Diet

Fruits and Vegetables

Fruits and vegetables play a significant role in cancer prevention, as evidenced by multiple studies. One systematic review found that consuming 550-600g of fruits and vegetables daily was associated with a ~14 percent lower risk of total incident cancer. Green leafy vegetables might help prevent bladder cancer, and non-starchy vegetables and fruits have been found to have a preventive effect against colorectal cancer. Furthermore, allium vegetables, such as garlic and onions, are significantly associated with a reduced risk of endometrial cancer, particularly in premenopausal women.

Whole Grains and Legumes

Legumes and whole grains have been shown to reduce cancer risk through various mechanisms. They are rich in dietary fiber, which is associated with a reduced risk of colorectal and small intestinal cancer. Furthermore, intake of legumes was associated with reduced prostate cancer risk. Some examples of whole grains and legumes include brown rice, quinoa, whole wheat pasta, lentils, black beans, and chickpeas.

Nuts, Seeds, and Healthy Fats

Nuts, seeds, and healthy fats have positive effects on overall health. For example, consuming macadamia nuts significantly lowers inflammation markers, improving overall health. Furthermore, nut consumption increases the proportion of beneficial fecal bacteria that benefit gastrointestinal health. Healthy fats like omega-3 reduce levels of inflammatory cytokines and improve metabolic markers and lipid profiles, which supports overall health.

There are several mechanisms through which nuts, seeds, and healthy fats can reduce cancer risk:

  • Omega-3 fatty acids modulate the production of inflammatory eicosanoids, which can reduce local inflammation, a key factor in cancer development.
  • Omega-3 fatty acids can induce cell death in cancer cells. 
  • High intake of omega-3 is associated with reduced risk of oral, pharyngeal, esophageal, colon, and ovarian cancers. 
  • Meta-analyses have shown that a higher intake of nuts is associated with a lower risk of lung, gastric, pancreatic, and colon cancer.
  • Seeds contain many chemicals that have protective effects against certain cancers, including carotenoids, flavonoids, terpenes, and sterols.

Plant foods containing omega-3 include chia seeds, brussels sprouts, algae, hemp seeds, walnuts, and flaxseed.

Practical Tips for Transitioning to a Plant-Based Diet

Start with Small Changes

Transitioning to a plant-based diet doesn’t have to be an all-or-nothing approach. Begin by incorporating more plant-based meals gradually. For example:

  • Start with “Meatless Mondays” to experiment with plant-based recipes once a week.
  • Replace one meal daily with a plant-based option, such as oatmeal for breakfast or a vegetable stir-fry for lunch.
  • Gradually increase the number of plant-based meals as you become more comfortable.
  • Try plant-based versions of familiar dishes, like lentil bolognese or chickpea curry.

Remember, reducing animal product consumption can have positive health and environmental impacts.

Planning Balanced Meals

Creating nutritionally balanced plant-based meals is key to a successful transition. Ensure each meal contains a protein source (e.g., legumes, tofu, tempeh), complex carbohydrates (e.g., whole grains, sweet potatoes), and healthy fats (e.g., avocado, nuts and seeds). You can also use the “plate method,” filling half your plate with vegetables, a quarter with whole grains, and a quarter with plant-based protein. 

Spice things up and experiment with different plant-based cuisines such as Indian, Mediterranean, or Ethiopian food. Meal-prepping foods on the weekends can also help you adhere to changes in your diet throughout the week.

Person eating healthy salad

Addressing Common Concerns

Many people worry about nutrient deficiencies when transitioning to a plant-based diet. But it is possible to maintain a healthy diet:

  • Protein: Consume legumes, whole grains, nuts, and seeds throughout the day to ensure adequate protein intake. 
  • Iron: Consume iron-rich plant foods like lentils, spinach, and fortified cereals, along with vitamin C-rich foods, to enhance absorption.
  • Vitamin B12: Consider a B12 supplement or regularly consume fortified plant-based milk and nutritional yeast.
  • Omega-3s: Include ground flaxseeds, chia seeds, and walnuts.

Remember to consult a healthcare professional or registered dietitian for personalized advice, especially if you have specific health concerns or nutritional needs.

Summary: How a Plant-Based Diet Can Help Prevent Cancer

A plant-based diet offers a powerful approach to cancer prevention and overall health. Key components like phytochemicals, antioxidants, and fiber are vital in reducing cancer risk. Incorporating more fruits, vegetables, whole grains, legumes, nuts, and seeds can significantly benefit health by lowering inflammation and supporting digestive health. Transitioning to a plant-based diet can be gradual, with small changes making a big impact. The long-term benefits of this dietary shift include improved well-being and a reduced risk of chronic disease, making it a valuable investment in your health.

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