"Eat your greens." What was once merely a common plea of exasperated moms has now become almost a societal imperative. Vegetarianism and veganism have become so normalized that omnivores may feel they are now in the minority of eaters.
But what does it really mean to eat "green?" People choose all-vegetable diets for many reasons, but what exactly does it mean for your health? Dr. Deanna Elsea, internal medicine physician at the Ochsner Primary Care Clinic at St. Charles Parish Hospital, explains the yays and the nays of plant-based nutrition.
The genesis of "green" eating
Elsea says the concept of flesh avoidance can be traced back to ancient Indian and Mediterranean societies, often as a religious practice. Vegetarians do not eat meat, although many avoid land animals and seafood, while others will consume fish and shellfish.
Vegans avoid all sources of meat as well as products with any ties to animals, including eggs, dairy and leather goods.
"(Vegetarianism) didn't seem to gain popularity in the U.S. until about 1971," Elsea says, "after the publication of Diet for a Small Planet by Frances Moore Lappe. Veganism seems to have become more popular in the last 20 years or so, although the term was actually coined in 1944." The ascendance of veganism reflects a shift toward eating healthily, she says, but the strictness of the regimen suggests a social choice more than a dietary one.
There are advantages to avoiding meat. It's often high in calories and fats, and with emerging research that links frequent consumption of processed and red meats to increased risk of certain cancers, the case for "all veggies, all day" is convincing.
"We've discovered that a vegetarian diet (can provide) vitamins B1, C and E, folic acid and magnesium," Elsea says. "It's a diet that's low in cholesterol and saturated fats, so ... it reduces your risk of type 2 diabetes, cardiovascular disease and obesity."
Add to that the savings at the grocery (produce is typically cheaper than animal protein), and you may be ready to sign up. But, Elsea says, "not so fast."
"The biggest drawback of a vegetarian (and vegan) diet is the nutrients you don't get if you're not eating animal products, for instance, B12, riboflavins, minerals like zinc, iron and calcium, omega-3 and the lack of protein in general," Elsea says. "If you're a vegetarian who (eats) dairy and eggs, then you're more likely to get your calcium and your protein from those sources. Some vegetarians even eat fish and shellfish ... and get omega-3. But if you're a strict vegan, then you have a really hard time getting those nutrients."
Good alternative sources of protein are legumes, whole grains, soy, nuts and seeds. However, constant consumption of these foods has its downside.
"Grains and legumes produce a product called a phytate, which can actually bind several minerals together and prevent them from being absorbed," she says.
Elsea recommends a multivitamin supplement with iron for vegetarians; vegans should consider an additional omega-3 and B12 supplement (a vitamin found primarily in meat and dairy). B12 deficiency can cause symptoms of fatigue, disorientation and memory loss. Riboflavin, another B vitamin found mostly in dairy products, helps convert food into energy, so not getting enough can lead to decreased energy, slowed growth and digestive problems.
Thought for food
If you're considering taking your diet "green," Elsea encourages thorough research first.
"Before you decide to cut out any food groups, be sure that you have a plan to replace it with some other source of the missing nutrients," she says. "Make sure you're eating a well-rounded diet that includes lots of different vegetables. You don't want to get in the habit of eating only spinach and corn for every meal, because you could overdose on some things and not get enough of other nutrients that you need."
Elsea says it's easy to get too much zinc, which causes nausea and vomiting, or too much potassium, which can cause a rapid or irregular heartbeat.
So, what should I eat?
Elsea recommends a Mediterranean-inspired diet, heavy on fruits, vegetables and whole grains. Include lean proteins like fish and poultry, accented by the occasional lean cut of beef. To her, balance is the name of the game — she doesn't recommend completely cutting out any food group. Even fats have their place. Monounsaturated fats (found in avocados, nuts, lean proteins and fats from fish) in moderation have surprising health benefits.
"Our bodies use certain kinds of fats to make hormones, and we use certain types of fats and cholesterols to build the sheaths around neurons to help with brain transmission," she says. "People who go on extremely low-cholesterol diets and develop really low cholesterol — I have concerns that that can damage your nervous system in the long run."
But keep in mind: these are still fats, and even the good kinds can make you ... well, fat, so nosh with care.