A woman I know, who has a very smart physician, told me about something her doctor said when she last saw him.

“Doctor,” my friend began, “I’ve been hearing so much about problems with a vegan diet. Angelina Jolie said that she was a vegan for years and it almost killed her. Now she eats steak all the time. And I was just reading that different body types require different nutrients, so while a plant-based diet is good for some people, others really need meat! I mean, don’t the Inuit peoples eat mostly fish and seals and whales?”

Her ever-patient doctor sighed heavily, and told her this: “Certainly there are cultures in the world where people eat meat and live long healthy lives. I want you to consider that in none of these cultures do people have diets that include high fructose corn syrup, or other highly refined foods.

“When we think about how our ancient ancestors hunted and lived, we need to consider what their day-to-day activity was, and about all of the foods that they consumed, not just the fact that they may or may not have eaten meat. First, any plants, nuts, or seeds that they ate were truly organic: growing without chemicals or pesticides, without dangerous groundwater contamination, without soil-nutrient depletion from over-farming. The food was far more nutrient dense than those same foods today.

“Second, any meat that they ate needed to be hunted, skinned, cleaned, and cooked with no conveniences of modern living. Try hunting with a really sharp stick, then skinning the animal, then cooking it yourself over an open fire. The amount of physical energy required to eat this way was enormous.

“Our ancestors likely spent their days chasing a lizard for miles, then ate a dinner that consisted of a fistful of berries, nuts, and greens, and a few bites of stringy lizard meat. That lizard (or rodent, more likely) hadn’t been given antibiotics, or fed a questionable diet consisting of food s they were never meant to eat in the first place, the way that conventionally farmed animals are. The lizard, or mole-rat, didn’t live in its own feces, wasn’t slaughtered at a facility where contamination was rampant, and hadn’t been genetically modified or bred to have abnormally large thighs and breasts.

“So if you’re telling me that you want to eat meat on a regular basis, this is how I want you to do it: catch it and kill it yourself, without a gun, please, and skin and clean it yourself. Make sure that the rest of your diet is also truly clean, with no chemicals or fake-food. And make sure that plants still make up the vast majority of your diet.”

Okay, so the doctor was using an extreme example to make a point, but his point is a good one. Our ancestors didn’t eat factory-farmed chickens that were loaded with antibiotics and fed food that no chicken in nature has ever eaten. And our ancestors were physically moving. All. Day. Long. Whether they were hunting, farming, performing daily chores around cooking, cleaning, or caring for children and the elderly, they likely spent very little time sitting down.

The only meat that it is ever safe to eat is pastured, organic meat that is Kosher or Hallal (or has otherwise been slaughtered in a clean and safe way). And only in very small quantities. And not with toxic food to accompany it. Actually, not with anything other than vegetables to accompany it. And maybe once a week.

If you ask me, it’s easier and healthier to just avoid the meat altogether. When I eat a delicious, plant-based meal, I don’t have to ask myself if it’s okay to combine carrots, peppers, onions, greens, hearty grains, and savory spices. Of course it is! Granted, you want to eat produce that is and hasn’t been genetically modified, but that’s easy enough to come by these days if you shop ahead of time and don’t let yourself get desperately hungry before deciding what you’re going to cook for dinner. And if you were stranded in the middle of nowhere, with only a local mini-mart that had a scant selection of conventionally grown fruit and vegetables, the worst banana in the world is still better for you than the best ham and cheese sandwich you could find at said market.

And to address my friend’s concern about Angelina Jolie feeling sick and weak on a vegan diet: I have no idea what kind of vegan Ms. Jolie was. Initially, many people who switch to a plant-based, whole-food diet do feel sick and weak for a short time. This is because their bodies are going through detox, and adapting to food that requires different things from a gut that’s been treated poorly for decades.

Additionally, “vegan” can mean many things. Beer, salsa, chips, French fries, candy, cookies, deep-fried-refined-white-flour foods can all be vegan. Coke and Red Bull are vegan. So are jelly beans. Was Ms. Jolie eating a wide variety of plants including seeds, nuts, grains, legumes, greens, and fruit, and was she doing it daily? Was she drinking plenty of pure water? Was she drinking much alcohol? Was she having coffee and cigarettes for breakfast (something she has admitted she used to do)? Was she over-exercising? I have no idea what the answers to any of these questions are, but I do know one thing: just because Ms. Jolie didn’t do well as a vegan doesn’t mean I shouldn’t follow a plant-based diet.

The data are very clear: most of the longest lived people in the world eat diets that consist of less than 10% animal products, a huge variety of vegetables, and lots of nutrient-dense, whole carbohydrates like yams, buckwheat, brown rice, etc. Why would I worry about what one woman ate or didn’t eat that made her feel sick when there are many millions of examples of people living long, healthy, productive lives while consuming plant-based diets?

And hey, even Bill Clinton is doing the plant-based thing these days! Whether or not you’re a Clinton fan, you can appreciate how much thinner and more vibrant he is now.