Making informed decisions about what you eat is one part of eating healthy—but how you prepare your food also plays a role. “Research shows that certain cooking methods may change the makeup of our food in ways that could potentially harm our health,” said Donald Hensrud, MD, medical director of the Mayo Clinic Healthy Living Program.
For instance, studies have suggested a link between eating excessive amounts of meat cooked at high temperatures and increased risks of colorectal and pancreatic cancers. No need to panic, though: “There’s a lot we still don’t fully understand, but we do know that some methods are better to use regularly and some are better saved for special occasions,” said Dr. Hensrud.
Understanding how to cook with the following methods can help you create healthy meals.
The takeaway: A nutritious and quick method for preparing vegetables
Blanching is a great technique to help reduce the loss of food quality and maximize its nutritional content. To blanch means to quickly boil and then place the food in a bath of ice water to stop the cooking process suddenly. This technique is especially great for veggies you want to keep a little bit crisp or almost raw. As a result, your vegetables’ colors and nutrients will be locked in, and they will stay bright and fresh-looking.
Blanching does the following:
- Destroys microorganisms on the surface of vegetables.
- Softens the vegetable, brightens color, and slows the loss of vitamins.
- Inactivates enzymes which can lead to loss of flavor, color, and texture in frozen produce.
The takeaway: These methods are both healthy options.
Moist-heat cooking methods, such as boiling and steaming, are the healthiest ways to prepare meats and produce because they’re done at lower temperatures. And if you’re watching your weight, these styles are good for calorie management because they often don’t require oil or butter, said Tricia Psota, Ph.D., managing director of Nutrition on Demand.
For vegetable preparation, steaming trumps boiling for hanging on to nutrients like carotenoids and phytochemicals. “Boiling can cause water-soluble nutrients—like vitamins B and C—to leach out into the water, but they’re retained with steaming,” said Slayton.
The takeaway: It’s safe (and underrated).
This moist-heat technique involves cooking at a gentle simmer in a liquid such as broth or water. Poaching is a healthy and underused way to cook, said Lauren Slayton, RD, founder of the nutrition consulting center Foodtrainers in New York City. “I poach wild salmon and chicken breasts for salads or any type of shredded preparation,” said Slayton.
Know that you can’t tell the meat is safely cooked by looking at it. Use a meat thermometer: Chicken should be cooked to 165 degrees Fahrenheit, while fresh beef and pork should reach an internal temp of 145.
If you’re poaching in something other than water—like milk or oil—you may add calories, said Katie Morford, RD, creator of the food and nutrition blog Mom’s Kitchen Handbook. But part of a healthy diet is enjoying foods you love, too.
The takeaway: It’s OK with the right oils and temperature.
Stir-frying and sautéing are fast and versatile. The downside: Pan-frying requires heating oil at high temps, which may result in harmful by-products. For one, fumes from some overheated cooking oils may contain heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which increase cancer risk, said Dr. Hensrud.
What’s more: “When cooking oil gets heated to high temperatures, it oxidizes and releases free radicals that can cause further oxidation, which can lead to DNA mutations and inflammation in the body.” It’s worth noting that oxidation happens even without cooking.
“Oxidation occurs over time when an oil gets rancid sitting at room temperature,” said Dr. Hensrud. “But the higher you heat an oil, the quicker it gets oxidized.”
Overall, don’t stress about possible harm from a bit of hot oil. “If sautéing gets lots of vegetables and antioxidants into someone’s diet, that’s great,” said Dr. Hensrud. “We’ve got to keep things in perspective.”
By no means do you have to nix your favorite stir-fry recipe from your weekly dinner rotation. You can healthy up a sautéed dish by keeping the cooking time short to control oxidation and using an oil with a higher smoke point to reduce fumes. “In general, an oil with a smoke point of 400 degrees Fahrenheit or greater is good,” said Dr. Hensrud. He recommended avocado oil, which has a smoke point of about 520 degrees, or peanut oil, with a smoke point of 450 degrees.
The takeaway: Balance roasting with other cooking modes, and eat fried foods in moderation.
Roasting starchy plant-based foods (like potatoes and bread) may pose a health risk when cooked too dark. “Acrylamide, which we consider a probable human carcinogen, can form from a chemical reaction in foods that have the amino acid asparagine when they’re heated at high temperatures,” said Paolo Boffetta, MD, associate director of the Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai in New York City.
Potato chips and french fries have some of the highest levels of acrylamide, said Dr. Hensrud, but crispy oven-roasted potatoes also have a lot. The compound is believed to either not form or form at lower levels in fish, meat, and dairy.
You probably can’t avoid acrylamide altogether, and it’s unclear if it affects cancer risk in people.
To boost the benefits of roasting, you may reduce the amount of acrylamide by toasting bread to a light brown color or browning potatoes to a golden yellow (the darker the food is cooked, the more acrylamide is formed).
The takeaway: Stick to thin cuts of meat, which will have shorter cook times, and eat broiled meats in moderation.
Broiling, or placing food below your oven’s heat source cooks foods quickly and can give them a charred flavor. The American Heart Association recommends broiling over frying, which adds fat and calories, and thus increases the risk of weight gain and coronary artery disease.
It also delivers a high-heat blast, which could cause acrylamide to form. And you could char the food.
To boost the benefits of broiling, try marinating meat in vinegar, lemon, or herbs like thyme and rosemary. This may act as a barrier against HCAs when broiling or grilling.
The takeaway: It’s not ideal as a daily method, but better for you when done correctly.
Just about everything (bacon! steak!) tastes better charred or crispy. But grilled meat has been associated with higher risks of certain cancers, said Dr. Boffetta. “Grilling meat forms HCAs and PAHs that may cause changes to DNA in the body that might lead to cancer,’ said Dr. Boffetta.
You don’t have to give up grilled meat. “If you constantly eat lots of very well-done meat off the grill, could it conceivably increase your cancer risk? Maybe—but that is very difficult to prove in an individual,” said Dr. Hensrud. “If you eat generally healthy, grilling once in a while is a small fraction of your diet and likely won’t have any great impact on your health.”
Until the research is clearer, have grilled meats in moderation. The National Cancer Institute also recommends the following to make your grilled foods healthier:
- Avoiding direct exposure of meat to an open flame or a hot metal surface and avoiding prolonged cooking times.
- Using a microwave oven to cook meat before exposure to high temperatures can also substantially reduce HCA formation by reducing the time that meat must be in contact with high heat to finish cooking.
- Continuously turning meat over on a high heat source can substantially reduce HCA formation compared with just leaving the meat on the heat source without flipping it often.
- Removing charred portions of meat and refraining from using gravy made from meat drippings can also reduce HCA and PAH exposure.
The takeaway: There are lots of ways to zip up raw veggies.
Prefer munching on your farmers’ market haul uncooked? Steal these RD hacks to pack more tang and zing into plain plants.
Dress them up. “The easiest healthy vegetable dip in the world is mashed avocado with lime juice and salt,” said Slayton. Or drizzle veggies with olive oil and an acid like lemon juice or apple cider vinegar, recommended by Morford. Bonus: Studies have found that eating fresh vegetables with healthy fat helps the body absorb plant nutrients.
Blanch them a bit. “For any vegetables that don’t wow you raw, blanch them,” said Slayton. What does that mean? “Take your asparagus or broccoli, for instance, and place in boiling water for a minute or less,” explained Slayton. “Then transfer it to a bowl of water with ice to stop cooking at that perfect, bright place.”
Try new vegetables. Some people don’t love raw veggies because they think of the usual suspects, like carrots and broccoli. Morford suggested going with offbeat picks (jicama, radish, kohlrabi, fennel) to surprise the taste buds. Try pairing new-to-you veggies with a dip made from Greek yogurt, a splash of olive oil, a pinch of salt and black pepper, and herbs such as basil, mint, cilantro, or parsley.
Shred them in salads. According to research published in the British Journal of Nutrition, people who ate more cruciferous veggies—like cabbage, Brussels sprouts, cauliflower, and broccoli—were 46% less likely to have something known as abdominal aortic calcification, which can be a predictor of future cardiovascular events. Shred some cabbage, cauliflower, or Brussels sprouts into your next salad.
How you cook your food affects its health benefits and how many vitamins and nutrients it contains. Use less oil at a lower heat and avoid charring or cooking your food too dark a color. Try to balance roasting, stir-frying, or sautéing with poaching, steaming, blanching, or eating some foods, like veggies, raw. Enjoy fried foods in moderation.