Not all plant-based is created equal

Whether you’re seated in a restaurant, scrolling social media feeds, or walking the supermarket aisles, the term “plant-based” will hit you soon enough. It’s everywhere.

Health professionals have been recommending a plant-based or a plant-forward eating pattern – foods that comes mostly from plants – for many decades. The recent plant-based trend explosion, however, is fueled by the meatless burger revolution. Demand for Beyond Meat and Impossible Burger patties has skyrocketed, and Beyond Meat’s IPO was incredibly successful. These products look and taste like meat, and enable people to eat a vegan burger with little sacrifice.

Which is good news for animals, as fewer cows will be factory farmed and slaughtered. It’s also very good news for the environment – raising cattle is a huge drain on land and energy resources, and destroys the ecosystem.

Now that plant-based hamburgers have become mainstream and can be found in fast-food joints and college campuses, are we also going to see a boon to public health?

Plant-based for health

Recommendations for plant-based diets are based on large studies– very many of them – that find that plant-centered and Mediterranean style eating patterns correlate with good health. Vegetarian and Mediterranean eating patterns are associated with reduced risk of heart disease, type 2 diabetes, hypertension and certain cancers, and also with lower rates of obesity and a longer life.

These eating patterns have a wide range of adherence and animal-product avoidance, but generally they focus on fruits, vegetables, nuts, seeds, whole grains, beans, and legumes. When health professionals recommend a plant-centered diet what they’re talking about is a healthy plant based eating pattern, or a whole-foods plant-based diet.

Because not all foods of plant origin are healthy: Potato chips and soda are perfectly vegan, and obviously not good for you.

And since meat avoidance, in and of itself, doesn’t tell us enough about what people actually eat, we need to look at studies that grade plant-based diets according to their healthfulness.

A new study in the American Journal of Clinical Nutrition looks at data from large cohorts such as the Nurses Health Study and the Health Professionals Follow-up, including almost 130,000 people, to see if plant-based diets affect weight gain. Overweight and obesity are important risk factors for many chronic ailments, therefore the link between plant-based diets and weight is an important health measure.

The researchers look at three indexes of plant-based diets. The first is an overall plant-based index, in which plant-based foods receive a positive score, and animal foods receive a negative one. The other two are subcategories of the first one: healthful plant based (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea/coffee) receive positive scores, less healthy plant foods (sweetened beverages, refined grains, potatoes, sweets/desserts) and animal foods received reverse scores, and unhealthful plant-based (sugary beverages, refined grains, potatoes and desserts receive positive scores and healthy plant-foods and animal foods receive negative ones).

The cohorts were followed for over 20 years, during which participants gained on average 2 to 4.5 pounds every 4 years. Diets that were more plant-based ameliorated weight gain. But not all plant-foods and meat avoidance are the same – weight gain differed greatly among the subgroups. People who ate a more healthy plant based diet gained 1.5 pounds less. People who ate an unhealthy plant-based diet gained about 1 pound more.

The same group of researchers previously reported similar findings when studying type 2 diabetes: Overall high plant-based diets and especially healthy plant-based diets were linked with lower the risk of diabetes. Unhealthy plant-based diets, however, were actually associated with higher rates of type 2 diabetes.

What about heart disease? Again, although, overall, sticking to a more plant-based diet seems to be protective, when you look at subgroups of plant-based patterns the picture is different: Healthier plant-based diets are linked with lower heart disease risk, and unhealthy plant-based foods with higher risk.

Far from the tree

Meat manufacturers argue that meatless burgers shouldn’t be called meat; wholesome plant-based diet advocates could argue that they’re hardly a plant, either.

Calling these products plant-based takes advantage of the health halo attached to this term, and applying it to what's actually a highly processed food product, one whose plant origins are pretty distant.

Don’t get me wrong, I welcome these meat alternatives, I’m thrilled by their success; their benefit to animal welfare and the environment is reason enough to support them.

But to actually reap the benefits of a plant-based diet you’ll need to do more than replace your burger with a meatless alternative.

Dr. Ayala