Does Cooking Your Food Destroy Its Nutrients? Here's What Experts Say

When it comes to cooking, we’re often focused on flavor and texture—but what about how it affects nutrition? Some cooking methods can increase or decrease the amount of vitamins, minerals and antioxidants you get by the time it’s ready to eat. Here’s what you need to know to keep your food both delicious and nutritious.

Does Cooking Your Food Destroy Its Nutrients? 

Cooking can change the nutrients in your food, for better or for worse. While some vitamins are sensitive to heat and lose potency during cooking, other nutrients become more bioavailable and easier for the body to absorb. “Cooking can destroy nutrients, but it depends on the method of cooking. Frying and boiling leads to more nutrient loss than steaming and microwaving,” says Hafiz M. Rizwan Abid, M.S., a lecturer and food technologist.

Eating a variety of both raw and cooked foods can help you get the most nutritional benefits. Overcooking can negatively affect the nutrient value of most vegetables. Lightly sautéing, steaming or roasting can preserve many nutrients while still bringing out the vibrant colors and flavors of your favorite vegetables. 

Nutrients That Can Decrease with Cooking 

Water-Soluble Vitamins

Water-soluble vitamins, like vitamin C and the B vitamins—including thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B9) and cobalamin (B12)—are sensitive to heat and may be lost during cooking. “Since these nutrients dissolve in water, boiling or simmering foods like broccoli, spinach or bell peppers can lead to a loss of these vitamins,” Rizwan Abid tells EatingWell. Lightly cooking these foods or enjoying them raw can help you get more vitamin C and its powerful antioxidant benefits.

Meat, poultry and fish may lose some of their B vitamins during cooking, especially when exposed to high heat for long periods, like grilling or frying. Poaching, baking or slow cooking can help preserve the nutritional quality of these foods while still enhancing their flavor.

Some Antioxidants

Hydrophilic antioxidants—which tend to dissolve in water—are often lost during boiling. One study showed that boiling cauliflower resulted in a loss of antioxidants. The same study showed that boiling carrots increased the bioavailability of carotenoids, but ultimately lowered the total polyphenol concentration and antioxidant activity. Antioxidant activity is how well antioxidants can protect the body from oxidative damage by scavenging free radicals.

The study revealed that microwaving or steaming cauliflower and carrots for 15 minutes retained the most antioxidants.

“Time-temperature relationship is an important factor to consider when creating mouthwatering dishes that provide plenty of nutrition,” Rizwan Abid adds. Choosing cooking methods that use lower temperatures or prevent prolonged exposure to heat and water helps preserve these nutrients in your produce. 

Omega-3 Fatty Acids 

Cooking meat, eggs and fish at high temperatures can change their nutritional value. Healthy fats, such as omega-3 fatty acids found in fatty fish like salmon, mackerel and sardines, are highly sensitive to heat. Exposure to high temperatures during grilling, frying or broiling can cause omega-3 fatty acids to degrade, which may reduce their associated heart-healthy and anti-inflammatory benefits.

To preserve these healthy fats, try baking, steaming or poaching your favorite proteins. These cooking methods help protect the omega-3 content, allowing you to experience the full range of their health benefits.

Nutrients That Can Increase with Cooking

Lycopene

“Cooking certain foods can enhance the availability of antioxidants, making them easier for your body to absorb,” says Veronica Rouse, RD, a registered dietitian and expert with WowMD. “Lycopene, found in tomatoes, is a great example,” she adds. 

Lycopene is an antioxidant linked to improved heart health and a reduced risk of certain cancers. Cooking tomatoes increases their lycopene levels, breaking down the cell walls of the tomato, making it easier for your body to absorb this powerful compound. 

Beta Carotene

Cooking carrots and sweet potatoes increases the bioavailability of beta carotene, a nutrient that your body converts into vitamin A, which supports vision and immune function.

Steaming and microwaving carrots and sweet potatoes increases their antioxidant availability without destroying other important nutrients.

“A clue that you're prepping them correctly? Their colors are vivid and they still retain some of their texture,” says Alexandria Hardy, RDN, LDN, owner of Pennsylvania Nutrition Services, an insurance-based private practice.

Calcium

Heat may also reduce compounds that can interfere with nutrient absorption, like oxalates in spinach and kale, which can block your body from absorbing calcium. Lightly cooking these foods can increase the amount of calcium your body can absorb. 

So, Should You Be Worried About Cooking Your Food?

The short answer is no. Cooking makes some foods taste better and can be necessary for food safety. It can also make certain nutrients more available to your body. As with anything, the key is to embrace a balanced approach. 

“Some believe that cooking food at a high heat can destroy nutrients, but some people have a hard time eating vegetables raw. If cooking or roasting vegetables encourages them to eat more produce, then that is the way people should enjoy their veggies,” says Alyssa Smolen, M.S., RDN, CDN, a media and community dietitian.

Eat a variety of fruits and vegetables—both raw and cooked—to get the most nutrients.

The Bottom Line

Raw foods can provide valuable nutrients, while cooking may increase the availability of other nutrients, like lycopene in tomatoes or beta carotene in carrots. Mix it up and use a variety of cooking methods to support your overall health.