Plant-Based Diet Reduces Risk of Major Chronic Diseases


A recent prospective cohort study published in JAMA Network Open used dietary data from more than 126,000 middle-aged participants who were followed for over a decade. Researchers found that greater adherence to a healthful plant-based diet was associated with a lower risk of chronic illnesses such as cancer and cardiovascular disease regardless of genetic predisposition or disease risk factors compared to individuals who did not eat the healthy diet. In addition to its focus on plant-based foods, the healthy diet also contained low amounts of animal foods, refined grains, potatoes, fruit juices, sugary drinks, snacks, and desserts.

This latest study adds to the growing body of research demonstrating the myriad health benefits of a Mediterranean plant-based eating pattern. A study published last year found that breast cancer survivors who ate a Mediterranean diet had longer recurrence-free survival and better nutritional status than women who ate the typical Western diet. Another study published earlier this year demonstrated that adherence to a Mediterranean diet was associated with higher health-related quality of life during the Covid-19 lockdown. Additionally, a 2021 review explained that the Mediterranean diet has been shown to reduce the risk of cognitive decline, diabetes, metabolic syndrome, and obesity. In fact, the Mediterranean diet has the largest body of evidence on the prevention and treatment of chronic illnesses and mortality. The U.S. News & World Report has named the Mediterranean diet the number one healthiest diet in the world for six consecutive years.

The Dangers of Ultra-Processed Foods

One of the reasons the Mediterranean diet is so health-promoting is that it emphasizes whole, minimally processed foods. “Minimally processed, fresh foods tend to be more nutritious and contain higher concentrations of vitamins, minerals, bioactive compounds, beneficial bacteria, and fiber compared to highly processed foods,” explained Conner Middelmann, BSC, DipION, an author and nutritionist based in Boulder, CO, who specializes in the Mediterranean diet. “Many processing methods can strip away important nutrients or add substances that decrease nutrient quality.” 

Research continues to demonstrate the harmful effects that processed foods have on health. A study published earlier this year in The Lancet found a connection between high consumption of ultra-processed ready-to-eat foods and increased risk of cancer, especially ovarian cancer in women. This is troublesome given that so many patients eat these foods. In one study, participants got 60 percent of their calories from processed foods.

One of the best ways to reduce the consumption of processed foods is to eat a Mediterranean diet.

Increasing Plant-Based Foods

Most concerning to Middelmann are ultra-processed foods branded as “healthy” or “natural,” such as protein bars, veggie chips, or highly processed keto or vegan foods.. “Unfortunately, these foods are marketed to appeal to the health-conscious consumer,” she said. ”However, just because a food is labeled as healthy or natural does not mean it is actually nutritious,” she said.

Middelmann said she teaches her clients to proactively add more plant-based foods to their diet. Among others, she said she shows them how to make soups and stews packed with vegetables, legumes, herbs, and spices or how to add fruit and nut butter to oatmeal or smoothies. 

The Bottom Line

When it comes to dishing out dietary advice, it’s often more important to explain to patients what not to eat as is it what to eat. This is certainly the case when it comes to ultra-processed foods, Middelmann said.

Research bears out the fact that encouraging patients to eat a minimally processed, whole foods, Mediterranean-style diet is likely to help them live longer and hopefully disease-free.