By Alice Callahan
The case has never been clearer: Eat less bacon and more beans.
An analysis published Wednesday in the journal BMC Medicine, drawing on data from 37 studies, adds to the evidence that eating fewer animal-based foods — especially processed meats — and replacing them with whole grains, legumes and nuts is linked to a reduced risk of cardiovascular disease and Type 2 diabetes.
The study is particularly useful because it details which dietary changes are most strongly linked to better health, said Qi Sun, an associate professor of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health, who was not involved with the study. For example, the study estimated that replacing one serving per day of processed meats — such as hot dogs, sausage, deli meats or bacon — with a serving of whole grains, nuts or beans was associated with a 23% to 36% lower risk of cardiovascular issues, including stroke, heart attack and coronary heart disease.
The analysis combined the results from studies in the United States, Europe and Asia that asked participants detailed questions about the foods they typically ate. Researchers followed them for an average of 19 years and looked for correlations between their diets and health. They adjusted for other factors that can affect health, including calorie intake, physical activity, smoking and alcohol use.
These types of studies can’t determine if plant-based foods directly prevent cardiovascular disease or Type 2 diabetes — only that there is an association between eating more of such foods and a lower risk of developing these conditions, said Sabrina Schlesinger, an epidemiologist and nutrition scientist at the German Diabetes Center in Dusseldorf, Germany, and a lead author of the study. But the findings were consistent between studies, she said, and are supported by other research that points in the same direction.
The study was partially funded by the Alpro Foundation, a nonprofit research arm of a Belgium-based company that makes plant-based milks and yogurts; the organization was not involved with planning, conducting or interpreting the study, Schlesinger said.
Why more plants and less meat can be beneficial.
The benefits of following a diet rich in whole grains, nuts and legumes and lower in red and processed meats are backed by at least 30 years of scientific evidence, said Maya Vadiveloo, an associate professor of nutrition at the University of Rhode Island.
Those plant-based foods are full of heart-healthy fats and fiber, which can help control blood sugar and lower diabetes risk, Sun said. They also contain beneficial plant-based compounds; legumes, for example, are rich in isoflavones, which are thought to reduce inflammation and act as antioxidants, he said.
Red and processed meats, on the other hand, can be higher in saturated fat, sodium or certain compounds that can promote inflammation, all of which may contribute to chronic disease risk, Schlesinger said.
The study researchers found that eating nuts instead of processed meats was associated with a 22% lower risk of Type 2 diabetes and a 21% lower risk of early death. Replacing unprocessed red meat with plant-based foods was also tied to better health outcomes, although the reductions in risk were smaller and the evidence less certain.
The researchers also found that substituting eggs with nuts was linked with a reduced risk of Type 2 diabetes, cardiovascular disease and early death. That’s somewhat surprising, Sun said, since most research suggests that it’s OK to eat one to two eggs per day. But in a head-to-head comparison, nuts may be healthier, he said.
The study did not look at plant-based milks and yogurts or meat substitutes; more research is needed to know how these products affect health, Schlesinger said.
How to make plant-based shifts
The study showed that even relatively small dietary swaps are linked to better health, Schlesinger said. “Adopting a plant-based diet does not necessarily mean eliminating all animal products.”
Taking steps toward eating less red meat “can be good for cardiovascular health, and can help you have a more balanced, higher overall diet quality that’s also good for the environment,” Vadiveloo said. It’s also linked to a reduced risk of some cancers, and it might save you money at the grocery store, too, she added.
Vadiveloo recommended identifying small changes that feel doable and focusing on foods that you already enjoy. If you usually have bacon for breakfast or a sandwich with deli meat for lunch, try alternatives a few days per week, she said — such as beans or chicken instead of bacon, or peanut butter and jelly instead of a club sandwich. You can also make gradual substitutions in some meals, such as replacing some of the ground beef in your tacos with beans, she said.
People sometimes worry that they won’t get enough protein if they eat less meat, but beans, tofu and nuts all provide high-quality protein, Sun said. By reducing meat consumption and adding these nutritious plant-based foods, “you cannot go wrong,” he said.