People often ask me what led to my career choice and will usually tell them about how I happened to grow up around people who had an interest in what we would now call complimentary and alternative medicine (CAM). Because I grew up in a religious community nobody employed crystals or talked about chakras (that I know of) but there was a certain amount of emphasis on using foods, herbs, and other "natural" things to heal whatever ails you. There were still quite a few farms and gardens in existence in the area where I grew up so we didn't usually have a shortage of fresh or frozen vegetables or a shortage of recipes for zucchini! So it doesn't surprise me that when I go to southeastern PA to visit family I hear tales of people who are trying to heal what ails them through a "raw diet" or that there is a raw foods restaurant in one of the smaller towns. I have had an interesting time eating there but it does make me wonder: What does the science say?
**Side bar: Now, if you really want to go down a fascinating (to me) history of CAM in the Mennonite community, do a search for "Mennonite Pow-wow doctors" or "hex doctors" or just start here. My grandmother would also be able to tell you some fascinatingstories about children who had to drink their own urine in order to "cure" bedwetting, washing your face in morning dew to "cure" freckles, etc. Most of these hex doctors had disappeared from the Mennonite community I grew up in, but among the more conservative sects and in the Amish there were still tales of such things going on.
First of all there are several different styles of raw diets, here is an overview in brief:
--Sproutarian Diet--The diet is mostly sprouts.
--Natural Hygiene Diet--Apparently the people who purport to follow this have many disagreements about what the diet should consist of, but apparently the commonalities include a consumption of raw fruits, vegetables, nuts, and seeds. Some will include sprouts, seaweed, and dried fruit, some apparently hotly argue against it. A few people will also include raw milk, cheese, and eggs, and some will even include a few cooked grains and vegetables.
--Instinctive Eating (Anapsology), also called the Raw Paleolithic Diet or Sequential Mono-Eating. Those who espouse this diet only eat one type of food in sequence and are "guided" by their senses in that changes in smell or taste change are a signal to stop eating. Usually they consume raw fruit, raw seafood, raw meat, some raw vegetables and no dairy and/or grains.
--Essene Diet--a diet based on the Essene Gospels of Peace, which is a book published in 1937 that was suppossed to be a translation of "ancient Aramaic manuscripts discovered in 'secret' Vatican vaults." The first book contains an alternate Trinitarian viewpoint in which Jesus is named the "Master" and outlines a plan for a healthy lifestyle including water fasting, raw sprouts, wheatgrass, vegetables, fruit, and fermented raw dairy products.
--Fruitarian Diet--In this diet people eat 75% of their diet from fruit (fruit as in the common usage of the term), and might include sprouts and leafy greens.
--Liquidarian Diet -A diet consisting of only consumes liquids and juices, typically used for "cleansing" only.
--Breatharian--used to describe someone who does not consume food but gets energy from air. Used as part of a rare practice from an obscure Tantric sect.
--Generic Raw Food Diet--Used by those who don't want to be categorized, might be vegan or contain raw dairy. Typically needs to be at least 75% raw foods for someone to call themselves a "raw fooder." (1, 2)
In my career and in my time as a vegetarian, most of the "raw fooders" I encountered fell into the generic and/or natural hygiene diets. Let me focus on the good that I have obeserved first (notice my use of the word observe vs. study or reasearch). The people who follow these type of diets can do some seriously amazing things with vegetables, fruits, and nuts as far as improving the flavor and variety of what they consume. Get bored with eating kale in a salad? Whip out the dehydrator and make kale chips. Tired of eating plain old almonds, whip out the vitamix and make almond mayonaise! Gluten intolerant and missing desserts like baklava? Whip out your food processor and dehydrator and make raw baklava! Can't tolerate dairy and miss ice cream? Whip out the vitamix again and make a banana whip! In other words, it is unlikely you will be bored with the amount of vegetables and ways of preparing them and therefore unlikely that you will suffer from a lack of plant foods in your diet.
One of the major claims made by raw foodists that is a problem, however, is that all food has a "life force" and that heating food over 116 degrees kills this force. Foods that are "alive" are best for optimum health and "dead" foods are not. Which means...absolutely nothing. The concept of the life force is left undefined, and if you can't define something, how can you possibly kill it in the physical world. And the concept of optimum health is also left vague and wide open to interpretation. In other words, no evidence.
A related claim, one that tries to sound more scientific I suppose, is that the heating of the vegetable matter and the milk (during pasteurization) kills off plant enzymes and milk enzymes needed for digestion. Actually, the enzymes that are in the plant are for the use of the plant itself, the enzymes that we as humans need to digest the plant matter are already found in our digestive system. Same with milk, the enzymes that we need to digest it are already in our systems (although a large portion of people stop producing lactase, needed to digest lactose, after the age of three or four years). (Link)
Another claim is that the heating of the vegetables destroys the vitamins and minerals present in the vegetables. The people who make this claim are somewhat correct in that boiling the heck out of vegetables can destroy the vitamin C content of fruits and vegetables, but if the vegetables are steamed, stir-fried, made into soup where you retain the broth, you only get a 5-20% loss. Sometimes cooking can actually enhance the absorption of certain vitamins and minerals as is the case with beta-carotene. Also, in previous posts I mentioned that most vegetables have anti-nutrients which might keep us from absorbing certain items. One example of this is the oxalic acid found in spinach--cooking helps neutralize the oxalic acid so that we can actually absorb iron and calcium. (Link). So when it comes to vegetables, it looks like a mixture of raw and cooked would be a good thing. Sometimes you might put the spinach in your smoothie, sometimes you might steam it, it's all good as long as you actually eat your vegetables.
Another problem with the raw vegan diets is that most people do wind up having to take a B12 supplement and supplement with zinc. Any eating plan that requires the purchasing of supplements should raise a red flag. Now once again, as I said in previous posts, some people will choose to follow a vegan diet (raw or otherwise) as part of their ethical code, and it is their choice, but you might want to take a supplement if you do not include any animal products in your diet.
One of the problems that I see in the raw paleolithic plan is the use of the term instinctive. I see this as implying that paleolithic people had some sort of special knowledge about what to eat and how to eat it (which would explain some of the myths associated with the creation of food), whereas humans actually evolved eating whatever the hell happened to be around. Chances are there were early humans who ate certain plants that were toxic, especially if their usual source of food was around, and if said humans became sick or died horrible deaths, any survivors probably tried to convey to others they shouldn't eat that. If times were hard enough, they probably found ways to "process" whatever they found by pounding or cooking just to see if they could get something to eat that didn't taste bitter or make the eater sick soon after consuming. Given that there is evidence of good dental, bone, and heart health among paleolithic people, apparently some people survived the trial and error long enough to live healthy lives until they were killed in a hunting accident, etc. (Link) From a modern day safety standpoint, most commercial raw meats are teeming with bacteria and parasites which are killed by cooking (unless it's rancid); even some "wild" or foraging animals have been known to contain pathogens. (Link). Keep in mind to that the cooking of meat also makes the protein and other vitamins and minerals more bioavailable; once again I would highly recommend the book "Catching Fire: How Cooking Made Us Human" by Richard Wrangham for more information on this subject.
Keep in mind that charring the surface of meat, eating meat that has been breaded and deep fried, or cooking in processed oils might increase your intake of potentially carcinogenic compounds. We are just not sure how much you can take in safely. (Link) This also doesn't mean that you can't ever enjoy sushi, ceviche, or kitfo if you like that sort of thing, but of course you are always having to put your trust in the restaurant.
Raw milk is often illegal to buy and might also contain unwanted bacteria, make sure you trust your source.
Take home message--enjoy a variety of fruits and vegetables cooked and raw; when consuming raw vegetables make sure they are thoroughly washed. Meats are best enjoyed cooked, if you are going to consume rare or raw make sure that you do a little homework on the source beforehand.