Your food choices do more than just help your heart or reduce your risk of Type 2 diabetes. They may also play a role in cancer prevention. Take the Mediterranean diet, for example. With its emphasis on fruits, vegetables, whole grains, and lean or plant-based protein, research suggests it can lower the risk of many types of cancer, and even support those in remission.
You might think that’s all there is to it, but oncologists remind us that dietary impact on cancer risk isn’t just about what you eat. The method of preparation is important too.
“Many potent anti-cancer components in plants—certain vitamins and phytochemicals—are quite fragile,” notes Dr. Andrew Pecora, who specializes in skin and sarcoma at Hackensack Meridian John Theurer Cancer Center. “They can break down with heat or dissolve into cooking water.”
Dr. Pecora points out that vitamin C and various B vitamins are sensitive to heat and water-soluble.
“If you cook broccoli by boiling it, a big chunk of those vitamins will end up in the water that many people just pour away,” he explains. “Also, a beneficial compound in broccoli called sulforaphane is activated only when it’s chopped or chewed. High heat can destroy the enzyme needed for this activation.”
Interestingly, cooking methods like air frying can be healthier compared to others. However, there are some considerations.
“Air frying is often a healthier choice than deep frying but comes with its own drawbacks,” says Dr. Adeel Khan, a hematologist and oncologist at the University of Texas Southwestern Medical Center.
One concern is that cooking food until it’s overly crisp can increase cancer risk. Dr. Brian Helfand, another oncologist, explains that over-crisping can create harmful compounds like acrylamide and heterocyclic amines (HCAs), which have been associated with DNA damage in long-term exposure studies.
While there’s still a lot to explore about the dangers of over-crisped foods, oncologists are learning that aiming for perfectly cooked food is generally better.
“At the cellular level, the ways these harmful compounds damage cells are under continuous research,” Dr. Khan adds. “What we do know is that they can interfere with essential bodily functions and may cause mutations that could lead to cancer.”
And, it’s worth noting that while some compounds are more directly linked to cancer, not everything is clear-cut. For example, studies on acrylamide show mixed results regarding its cancer risks, while others like HCAs and PAHs have stronger associations with various cancers.
These harmful substances tend to be more prevalent in charred or burnt animal proteins, such as chicken, fish, or red meat.
This Is Why You Shouldn’t Stress Over Occasional Over-Crisping
Hearing that over-crisping can increase cancer risk may feel unsettling, but oncologists want to clarify that this shouldn’t incite panic.
“If you occasionally over-crisp your vegetables while mostly eating healthy, it’s not a cause for concern,” Dr. Helfand reassures. “Overall patterns of dietary habits are what really matter, not isolated incidents. Balance is essential.”
Moreover, it’s possible that you’ve still benefited from some nutrients.
“Vegetables provide significant protective benefits thanks to their fiber, antioxidants, and phytochemicals,” Dr. Helfand emphasizes. “The goal should be to limit frequent charring and favor gentler cooking methods when you can.”
Dr. Khan echoes this sentiment, noting that there’s no specific safe level for over-crisped food, and it’s somewhat unavoidable. The key is to reduce its occurrence whenever possible.
Identifying Over-Crisped Foods
A little common sense goes a long way! Dr. Pecora advises that over-crisped food typically shows distinct visual, scent, and taste characteristics. “A well-cooked item should show a golden or deep brown color, which comes from the Maillard reaction that yields flavorful food,” he explains.
Foods that are extensively blackened fall into a “danger zone.” “When food is truly burnt, it’s going to have noticeable black areas,” he elaborates.
Taking a sniff can help too; that acrid smell signals combustion, and you generally want to avoid ingesting such contaminants. Over-crisped foods might also carry a bitter taste, warning your taste buds to be cautious.
Dr. Khan suggests avoiding completely burned food, but if you do end up with some, you can simply cut away the heavily charred parts.
Healthy Cooking Alternatives
While you might want to limit over-crisping, Dr. Pecora suggests other cooking methods that won’t elevate cancer risks. These include:
- Braising: Searing in a hot pot and then adding liquid for a slow cook.
- Stewing: Similar to braising, often with smaller pieces fully submerged in liquid.
- Steaming: A gentle method that uses water vapor to cook.
- Sous-vide: Cooking sealed food in a controlled water bath for a long time without burning.
It’s important to remember that oncologists emphasize not spiraling into worry if you’ve been over-crisping food. Instead, think of it as an opportunity to explore new cooking techniques that might lower your cancer risk over time.
