DEAR DOCTOR K: My daughter and several of her college friends are on the “paleo” diet. What is that? Is it healthy?
DEAR READER: The paleo diet, short for “Paleolithic” diet, restricts what you eat to foods the hunter-gatherers of the Stone Age ate 10,000 years ago. While the diet doesn’t require you to live like a caveman, it does require you to eat like one.
Here’s an example of what you can and can’t eat on the paleo diet:
Do eat: meat (especially game meat), poultry, fish and shellfish; fresh fruits, fresh vegetables, eggs, seeds, nuts, and olive, coconut and flaxseed oils.
Don’t eat: Any food that is processed, man-made or prepackaged; all grains; legumes (including peanuts); dairy, salt, sugar, vegetable oils, potatoes.
At first glance, the paleo diet appears reasonable. It is rich in many of the foods nutrition professionals highlight. These include fresh fruits and vegetables, healthy fats, lean protein, and limited amounts of sodium and sugar. And it stresses whole foods rather than prepackaged and processed foods.
But there’s a downside. Following the paleo diet increases the risk of certain nutritional deficiencies. For example, cutting out all grains and legumes removes sources of certain B vitamins from the diet. Excluding dairy could lead to a calcium deficiency. There are ways around these issues. Organ meats, particularly liver, provide B vitamins, and dark leafy greens and fish (such as sardines with the bones) are good sources of calcium.
The paleo diet is not the best option for vegetarians. Without grains, legumes and dairy, vegetarians may be hard pressed to eat enough protein. (Soy is out because it’s a legume.)
Supporters of the paleo diet claim that our ancient ancestors who ate this way didn’t suffer from the diseases that plague the modern world, such as heart and blood vessel disease and Type 2 diabetes. I think that’s a silly argument. The fact is that these ancient ancestors lived half as long as we do and never got old enough to develop diseases that typically start in older adulthood.
Bottom line: At this time, there is no strong scientific evidence for claims that a paleo diet helps prevent or treat these medical conditions.
Please don’t misunderstand: I’m not making fun of the basic idea behind the paleo diet. In fact, I’m sympathetic to it. We humans of the 21st century are not all that different, physically, from ancient humans. Yet many aspects of our life, surely including our diet, have changed radically. Maybe our health would be better if we ate like our ancient ancestors did, since that’s what our bodies were built to do. It’s a reasonable idea.
But the world is full of reasonable ideas about how to improve health, and some of them turn out to be dead wrong. Only long-term scientific studies could tell us if the paleo diet really is healthy.
This is what I tell my patients who have asked about it: Try it to see if you like it. If so, vitamin B and calcium supplements may be a good idea.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.