Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the world of health. Nutrition. Exercise. Diet. Supplementation. If there’s something new, I look at the science behind them, and let you know whether it’s real or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
I’ve decided to revisit a topic from several years ago to update the information. The topic? Vegetarian diets. What prompted the topic then was a comment by a long-time listener. They were upset about a position paper by the Academy of Nutrition and Dietetics (AcadND) on vegetarian diets. In their opinion, the Academy did not go far enough to support the vegetarian diet and didn’t cover all the reasons that people undertake a vegetarian lifestyle. While that position paper still exists, the AcadND has developed another way of evaluating vegetarian diets and disease prevention using the Evidence Analysis Library (EAL).
The EAL is a synthesis of the best, most relevant nutritional research on important dietetic practice questions. This is an approach used by the United States Physicians Task Force only geared toward the practice of dietetics instead of medicine. They use a panel of experts who examine all the relevant research and come up with Best Practices. Those become the standard of care in the field, in this case, dietetics and nutrition. Before we get into that, let’s define a vegetarian diet and take a look at the possible benefits of a adopting a vegetarian diet.
Vegetarian can mean many different things. Some people consider no red meat vegetarian, limiting their meat to chicken and fish. That’s a stretch. More than likely, most vegetarians eat only plant-based foods. They also eat foods that don’t harm animals like cheese, milk, and eggs. Finally, there are the very hard core and those would be the vegans.
The question is simple: why do people decide not to eat animals or animal products? There are three reasons that the long-time listener gave. They match what many vegetarian organizations suggest--so here we go.
The primary reason people eat a vegetarian diet is for the potential health benefits. Eating a plant-based diet appears to have benefits ranging from a decreased risk of heart disease, type 2 diabetes, and many other degenerative diseases. It’s also used as a treatment for some of those diseases such as heart disease. Dr. Dean Ornish and Dr. Carl Essylstein have both published research demonstrating a reversal of heart disease and T2D on a strict vegan diet.
The environment may be another reason. Growing animals generates a lot of waste products. Not just the excess nitrogen found in the nitrates from chicken waste and especially pig waste ponds. Not just the antibiotics which are used to keep the animals healthy—although due to public demand, there has been a huge reduction in antibiotic use. As I record this, a major fast food provider just announced that they are going back to using antibiotics in the animals they produce. They just won’t use the ones used in humans. How reassuring to all of us.
Many animals are grain fed, especially corn. Corn is the largest crop grown in the US, the bulk of which is used as animal feed. That takes a lot of water, herbicides, and pesticides, all of which come from or end up in the environment. There is also the cost in terms of using fossil fuels to plant, harvest, and distribute the grains and the animals. People may adopt a vegetarian way of life as a way to protect the environment and keep it sustainable for succeeding generations. That remains to be seen.
The last point is the animals themselves. Some people just don’t want to harm animals, any animals. We’ve probably all seen videos of what a slaughterhouse is like. It is brutal to watch but with 330 million people to feed, everything has to be done like the production of any product from cars to televisions. It’s an assembly line. As I said, it’s brutal to watch. When you think about it, is there any humane way to kill anything?
I’m not an expert in the environment or the production of meat from the beginning to end. I’m going to focus on the health benefits of a vegetarian diet. This is the statement that upset the listener.
“I think they deny science with the ambiguous statement "may prevent and treat chronic diseases ... ." In the listener’s mind, they wanted a definitive will “prevent and treat.” The wishy-washy language is intentional. Here’s why.
The plant-based diet is a healthy way to eat. Eating more vegetables, fruits, whole grains, and beans is good for your health. But that doesn’t mean that there is irrefutable proof the vegetarian diet has been proven to prevent and treat disease. I know it sounds strange but proving nutrition benefits is difficult in large populations. Let’s look at the updated version of the research-based findings of the Academy related to vegetarian diets and disease prevention and disease management .
As it relates to disease prevention, the research question went something like this: In adults who are apparently healthy, what are the relationships between all forms of vegetarian diets compared to non-vegetarian diets in health outcomes for a variety of diseases, nutrient status, BMI, body compositions, and other biomarkers like BP.
They analyzed 27 papers that met specific criteria and these were their findings:
There is moderate evidence vegetarian diets reduced people getting CVD compared to non-vegetarian diets. That’s about it. There was some evidence that it may reduce biomarkers of CVD but there was also evidence that a vegetarian diet can cause harms such as lower bone density and increased fractures. Not exactly overwhelming evidence for benefits and some potential harms.
Let’s turn to vegetarian diets and disease management. Vegetarian diets have been recommended to reduce dietary fats and cholesterol while providing CV health-promoting foods rich in fiber, antioxidants, and phytochemicals. The researchers focused on randomized controlled trials (RCTs) to answer this research question: what are the effects of vegetarian diets in managing diseases in adults with CVD risk factors, or who already have diagnosed CVD or T2DM.
When comparing vegetarian diets with traditional dietary approaches, analyzing a total of 27 RCTs, found that those people with the risk factor of a high BMI, a vegetarian would likely reduce BMI. Take home? You can lose weight on a vegetarian diet. Again, not overwhelmingly positive, is it?
Observational studies show benefits in large populations but going from observing to stating “will prevent” is a big step. When you look at epidemiological studies and cross-sectional studies, people who follow a vegetarian diet have less heart disease, less cancer, less obesity, less just about everything in the world of disease. Clinical trials have shown that vegetarian diets reduce the risk of those diseases when used for 5 years or longer. Excellent! But from a research perspective, they cannot say “will prevent” because the science doesn’t back that claim. Trends and population studies can tell you a lot about a large group of people. What they cannot tell you is what will happen to you if you follow a vegetarian diet.
Do I think that eating a plant-based diet will benefit someone’s health? Yes. Is a vegetarian diet healthy? Yes. Is it necessary for optimal health for everyone? That we just don’t know but what I will say is this: vegetarian or not, you can eat a more plant-based diet and still eat animal products and your health will benefit. Eat less. Eat better. Move more. I’m out of time. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
J Acad Nutr Diet. 2016;116:1970-1980.
https://www.andeal.org/topic.cfm?menu=5271
