As a vegan, I’ve done my best to eat mostly plant food. It is my belief that humans need only the food that grows on the earth and that everything we need to survive and live a long life is available for us to pick and eat with little preparation. But nutritionists say we need to eat cereals and breads. What is in cereal, bread and pasta that isn’t in vegetables and fruit? Are there vitamins that can be found only in grains? Also, why is soy found only in processed forms like tofu and soymilk? Is there something inedible about soybeans before they are turned into other products?

I’m going to treat these two questions as one since they are somewhat related; both have to do with eating foods in their natural form versus eating foods that require cooking and processing. First, grains and the foods made from them are actually not essential in the diet. There is nothing in these foods that we can’t get from foods that can be consumed in their natural state, such as fruits, vegetables, nuts, and seeds.

In fact, grains were not a part of the diet of our earliest ancestors. The earliest humans ate a raw diet of the foods I noted above, with some small amounts of meat as well. The discovery of fire, some 600,000 years ago, made it easier to eat grains, and the development of agriculture about 12,000 years ago turned these foods into dietary staples, a role they play in cuisines throughout the world today.

Contrary to popular belief, there is no real advantage to eating only the foods that can be consumed in a raw, unprepared state. Rather, cooked foods are often more easily digested than raw (raw foods advocates will likely contest this point, I know, but it is true) and nutrients are sometimes better absorbed from cooked foods than raw. Too much cooking at high temperatures is bad, of course, but some cooking can be very beneficial. Cooking greatly increases the variety of foods available to us. While we don’t have any particular requirement for grains and products made from them, they do make it much easier to meet nutrient needs. The same is true for legumes. These foods also make diets more interesting.

Some people like to take vegan diets to what may appear to be the next logical level—from an all plant diet to an all raw plant diet. But I don’t see any reason to do so. As an ethical vegan, I would like to see people focus on healthful diets that do the least harm to animals and that are the most realistic. When we make vegan diets as easy as possible, it is more likely that more people will eat this way. A raw foods diet is more difficult to plan than a vegan diet (based on both cooked and raw foods) and it is not more healthful. It’s also not any better for the animals.

And who is to say what our "natural" diet is. Is it unnatural to cook food? Is the diet we are meant to eat the one that sustained our earliest ancestors—who aged quickly and died young? Does our natural diet contain meat? If we think of the optimal diet of humans as the one that best protects health over the long term, then I think a diet based on a variety of cooked and raw plant foods is probably just what we should be eating. So, to answer your question, we don’t need grains in order to have a balanced diet, but it is okay to include them in diets and perhaps is even beneficial.

As for soybeans, they are amazingly versatile and lend themselves to all kinds of interesting foods like tofu, soymilk, miso, and imitation meats. But the beans themselves can indeed be consumed. In their immature state, they are green and can be eaten like a vegetable. Green soybeans, which are called edamame (pronounced ed ah mom’ may), are a wonderful delicacy and they are a very common snack item in Japan. Mature soybeans are cooked and eaten like other legumes. In their raw state, soybeans contain compounds that interfere with protein digestion so they must always be cooked. Heat deactivates these compounds—another plus for cooked foods! All soy products are made from heated or cooked soyfoods.