As if learning about which foods are healthy and which are not isn’t enough to think about, it turns out we also have to consider how to prepare those foods. The way foods are cooked actually has a major impact on their nutrient content and availability.

And this can certainly feel confusing. Do you opt for steaming, stir-frying, baking, or simply leaving as much as possible in its natural, raw form?

If you are putting your hard-earned money and energy into purchasing top quality foods for yourself and your family, you might as well reap the maximum nutrient benefits possible. Below are ways to make these choices easier.

How are nutrients affected by cooking?

carrot kale walnuts raspberries

Image via Pixabay under license CC0

Before getting into specific foods and cooking methods, let’s take a look at exactly how certain nutrients are altered by cooking and heating. It’s not a cut and dry issue, as the digestibility and nutrient absorption are improved in most cooked foods, but other key nutrients are also lost. The key is to find the least damaging cooking method, which can vary from food to food.

The following vitamins and minerals are reduced in the cooking process:

-Fat and water soluble vitamins, such as vitamins C, A, D, E, K and B.

-Minerals such as magnesium, potassium, calcium and sodium.

If you suffer from poor digestion, you are likely better off cooking your vegetables. For those with optimal digestion, try eating at least some of your vegetables raw, but make sure you chew them thoroughly. Some health experts believe that goitrogenic vegetables should never be eaten raw due to their potentially negative effects on the thyroid gland. These include broccoli, cabbage, kale, cauliflower, collard greens, mustard greens, bok choi and turnips.

Common cooking methods (from best to worst) for nutrient preservation:

Steaming – You might have already heard that steaming is the healthiest method of preparing food, and this is largely true. In terms of preserving the maximum amount of nutrients (particularly water soluble vitamins), steaming is the best method.

steamed vegetables

Image via Pixabay under license CC0

For example, one study showed that steaming spinach and broccoli only lowers their vitamin C content by 9-15%, compared to up to 50% when boiling.

The only downside to steaming vegetables is the taste, which can be a bit boring. Spice things up by adding a healthy fat after steaming (organic butter or olive oil, for example) along with your favorite spices and seasonings.

Stir-frying – Quite similar to sautéing (stir-frying is generally on higher heat for a shorter duration), these methods also work well to preserve nutrients. Be sure to opt for a cooking fat that withstands high heat, such as organic butter, ghee or coconut oil. Save less stable oils such as olive oil to use as dressings, dips or cooking on low heat.

asian wok stir fry shot from over head

Stir-frying has been shown to work well in preserving B vitamins, and this method has also been proven to greatly increase the absorption of beta-carotene in carrots (versus eating them raw).

However, one study showed that vitamin C loss is much greater when stir-frying broccoli and red cabbage, so choosing another method for these vegetables is preferred.

Baking and roasting – These two cooking methods (which are pretty much the same, except that roasting generally refers to meats), are just about on par with stir-frying in terms of nutrient retention, meaning they are a good choice for most foods. The only point to consider is that since baking and roasting involve long duration cooking at high temperatures, important B vitamins are typically lost, particularly in meat.

roasted ham and potatoes

Image via Pixabay under license CC0

Microwaving – Whether or not microwaving is a safe cooking method is definitely debated in the world of holistic nutrition, but in terms of studies looking specifically at nutrient preservation and loss, it’s not half bad.

In fact, one study even showed that microwaving is the best cooking method in order to preserve the antioxidant content in mushrooms and garlic. While a certain percentage of vitamin C is lost when microwaving, it is a smaller percentage than in the majority of cooking methods.

Boiling – Poaching and simmering can also be included in this category, as the only difference is water temperature. All of these methods involve submerging your foods into water and heating them, and most drastically reduces the water-soluble vitamin C, as well as B vitamins.

boiling corn

Image via Pixabay under license CC0

However, if you are making a soup (or any other dish where you will be consuming the liquid), then you will still retain the bulk of even water-soluble vitamins.

Boiling does, however, seem to have a lesser impact on brain-healthy omega 3 fatty acids, and preserves these important nutrients more than other cooking methods.

Frying – On the opposite end of the spectrum from steaming, frying generally isn’t the healthiest of cooking methods (although it has its time and place, if done in the right way). There are several important factors to consider when frying.

fried potatoes rosemary

Image via Pixabay under license CC0

First, the type of oil used is important. Most commercially prepared fried foods are cooked in rancid vegetable oils such as canola, soy or corn, which are all highly inflammatory. Oils best for frying are ones that can safely sustain high heats, such as butter, lard and coconut oil.

While certain vitamins can actually be better retained through frying (like vitamins C and B vitamins), delicate omega 3 fatty acids are damaged. Studies have shown that the omega 3 content of fatty fish can actually be degraded by up to 85%.

However, vitamins C and B-containing potatoes might actually be better fried, as these nutrients remain more in tact than in other cooking methods.

Recap and tips of how to best retain nutrients

-Prepare soups or dishes where the water used for cooking is consumed.

-Boil or simmer foods in as little water as possible.

-Try to cook foods whole and then chop, as less of the food will be exposed to heat and water.

-Cook vegetables as minimally as possible. Just a few minutes is enough to break down the nutrients enough for better absorption, while losing as little as possible.

-When cooking meat, add back the juices left in the pan before eating.

-Avoid peeling vegetables whenever possible (especially if they are organic), as many valuable nutrients are found in the skin.

If some of these methods are new to you, play around with spice combinations and cooking fats to maximize taste. By understanding the healthiest ways to cook, you can be sure that your investment in good foods is paying off.