Does cooking food kill nutrients?

Does cooking food kill nutrients?

So often, I hear an argument that cooking “kills” nutrients.

With all the cooking humans have done since the discovery of fire, we would have died from malnutrition long ago.

And while I will not argue that malnutrition is a significant issue globally, I guarantee you that cooking or heating food isn’t the issue.

Malnutrition comes from many things.

Lack of access to nutrient-rich foods.

We are not choosing nutrient-rich foods even with access to healthy foods (think of a person who prefers “junk foods” over fruits and vegetables.

And to clarify that malnutrition is poor nutrition status. Malnutrition isn’t always the emaciated person you may picture. A person with poor nutrition status can come in all sizes. Even a person with excess body weight can have malnutrition if they do not meet their vitamin, mineral, and macronutrient needs.

And, again, this isn’t because they chose cooked food.

Why am I writing this?

For one, I still get people who insist that microwaving kills nutrients. It doesn’t.

Boiling kills nutrients. It doesn’t. 

Here are a few things that contribute to this misnomer.

Cooking an egg denatures protein but does not take away nutrients in that egg.

Protein is often “denatured” when a protein’s shape and structure change permanently.

For example, cook an egg, and the heat denatures the protein. And that is not reversible.

Add an acid like lemon juice or vinegar to milk, and it curdles. Those milk proteins are now permanently denatured—no going back.

Cook a piece of meat and that protein is now denatured. No going back.

Add acid to raw seafood, and it “cooks” it.

Denaturing is part of what our body will do anyway. For example, the acid in our stomach will denature protein when it gets there. It is part of the digestion process to break protein into amino acids. 

Cooking or heat is not killing the nutrients but likely helps the digestion process a bit. 

So, cooking is not killing our ability to utilize protein. In many cases, cooking helps us access more nutrients from food.

If we ate uncooked or raw beans, lectins would inhibit our ability to access the nutrients in beans. Soaking them in water and cooking them removes the lectins and allows us access to those nutrients.

Some nutrients are more bioavailable (or absorbable) in cooked food.

However, certain nutrients are lost when some foods, like vegetables, are overcooked, especially in water. 

The water-soluble vitamins, including vitamin C and the eight B vitamins, may be destroyed or lost with heat. For example, if you bake a potato or roast a potato, there is a lot less loss of vitamin C than in boiled potatoes, and the water drains into the sink.

But does cooking a pork loin or an egg destroy the riboflavin (one of the B vitamins)? Not necessarily.

What does cooking do?

Cooking will kill most bacteria that can get us sick, including salmonella and E. Coli.

Cooking will help us get a variety of edible food.

Cooking will allow us to eat grains, including rice and wheat.

We can choose cooked vegetables and raw vegetables.

We can choose pasteurized dairy products – for safety and still get plenty of nutrients from them, including protein and calcium.

We can choose cooked meats. And not raw meats. 

Raw fish is OK to eat raw or cooked. Eat what you like.

Whether roasting, steaming, microwaving, baking, sautéing, boiling, or grilling foods (or burying them in the ground for a day or two), the benefit of cooking food safely and adequately is clear.

The benefit of choosing a variety of food from all food groups in their raw or cooked state is all fine, and there is no better or proper way to eat them. Other than observing basic food safety practices.