By Becky Bell
Cooking food can improve its taste, but it also changes the nutritional content.
Interestingly, some vitamins are lost when food is cooked, while others become more available for your body to use.
Some claim that eating primarily raw foods is the path to better health. However, certain cooked foods have clear nutritional benefits.
This article discusses the benefits of both raw and cooked foods.
What Is a Raw-Food Diet?
Raw foods are foods that have not been cooked or processed.
While there are varying levels of raw-food diets, all of them involve eating mostly unheated, uncooked and unprocessed foods. In general, a raw-food diet is made up of at least 70 percent raw foods.
The diet often includes fermented foods, sprouted grains, nuts and seeds, in addition to raw fruits and vegetables.
Many raw foodists consume a vegetarian or vegan diet, eliminating animal products and eating mostly raw plant foods. However, a small number also consume raw dairy products, fish and even raw meat.
Advocates claim that raw foods are more nutritious than cooked foods because enzymes, along with some nutrients, are destroyed in the cooking process. Some believe that cooked food is actually toxic.
While there are some clear benefits to eating raw fruits and vegetables, there are also some potential problems with a raw-food diet.
A strict raw-food diet is very difficult to follow and the number of people that stick to a completely raw diet in the long term is very small.
Furthermore, some foods contain dangerous bacteria and microorganisms that are only eliminated by cooking. Eating a completely raw diet that includes fish and meat comes with a risk of developing a food-borne illness.
Summary: Raw food diets involve eating mostly raw fruits and vegetables. Eating raw foods has some benefits, but there are also potential problems.
Cooking May Destroy Enzymes in Food
When you consume a food, digestive enzymes in your body help break it down into molecules that can be absorbed (1).
The food you eat also contains enzymes that aid digestion.
This is one of the primary arguments in favor of raw-food diets. When a food's enzymes are altered during the cooking process, more enzymes are required from your body to digest it.
Proponents of raw-food diets claim that this puts stress on your body and can lead to enzyme deficiency. However, there are no scientific studies to support this claim.
Some scientists argue that the main purpose of food enzymes is to nourish the growth of the plant—not to help humans digest them.
Furthermore, the human body produces the enzymes necessary to digest food. And the body absorbs and re-secretes some enzymes, making it unlikely that digesting food will lead to an enzyme deficiency (4, 5).
Moreover, science has not yet demonstrated any adverse health effects of eating cooked foods with denatured enzymes.
Summary: Cooking foods deactivates the enzymes found in them. However, there is no evidence that food enzymes contribute to better health.
Some Water-Soluble Vitamins Are Lost in the Cooking Process
Raw foods may be richer in certain nutrients than cooked foods.
Some nutrients are easily deactivated or can leach out of food during the cooking process. Water-soluble vitamins, such as vitamin C and the B vitamins, are particularly susceptible to being lost during cooking (6, 7, 8, 9, 10).
Some minerals and vitamin A are also lost during cooking, although to a lesser extent. Fat-soluble vitamins D, E and K are mostly unaffected by cooking.
Boiling results in the greatest loss of nutrients, while other cooking methods more effectively preserve the nutrient content of food.
Lastly, the length of time that a food is exposed to heat affects its nutrient content. The longer a food is cooked, the greater the loss of nutrients (9).
Summary: Some nutrients, particularly water-soluble vitamins, are lost during the cooking process. Raw fruits and vegetables may contain more nutrients like vitamin C and B vitamins.
Cooked Food May Be Easier to Chew and Digest
Chewing is an important first step in the digestive process. The act of chewing breaks down large pieces of food into small particles that can be digested.
Improperly chewed food is much more difficult for the body to digest and can lead to gas and bloating. Additionally, it requires significantly more energy and effort to properly chew raw foods than cooked ones (16).
The process of cooking food breaks down some of its fibers and plant cell walls, making it easier for the body to digest and absorb the nutrients (17).
Cooking also generally improves the taste and aroma of food, which makes it much more enjoyable to eat.
Although the number of raw foodists who consume raw meat is small, meat is easier to chew and digest when it's cooked (18).
Properly cooking grains and legumes not only improves their digestibility, but it also reduces the number of anti-nutrients they contain. Anti-nutrients are compounds that inhibit the body's ability to absorb nutrients in plant foods.
The digestibility of a food is important because your body can only receive a food's health benefits if it's able to absorb the nutrients.
Some cooked foods may provide the body with more nutrients than their raw counterparts because they are easier to chew and digest.
Summary: Cooked foods are easier to chew and digest than raw foods. Proper digestion is necessary to absorb a food's nutrients.