Researchers at Seattle's Fred Hutchinson Cancer Research Center have linked regular consumption of deep-fried foods to an increased risk of prostate cancer, specifically a more aggressive form of the cancer. They looked at men who ate deep-fried foods regularly. Specifically, the items were French fries, fried chicken, fried fish, doughnuts, and snack chips. Those who ate one or more servings of fries, fried chicken, or doughnuts per week had a 30% to 37% higher risk of prostate cancer than those who ate less than one serving per week.
We have previously discussed the link between grilling meats and formation of potential carcinogens. This study is different in that it examines the link between deep-fried foods and carcinogens. While the study did not specifically investigate why there is a link between deep-fried foods and increased prostate cancer risk, the researchers suggest one of the factors could be carcinogens in the oil or fat used for frying. When oil is heated to the high temperatures used in frying, some compounds that can be potential carcinogens are also formed. For example, acrylamides are formed when high-carbohydrate, low-protein foods are subjected to very high temperatures, as in the making of potato chips or French fries.
This gets worse when the oil is reheated, which is exactly what happens in a fast food or restaurant setting – the oil will be reused for frying several batches before being replaced.
Fried Foods: The Obvious and Not So Obvious
Mention deep-fried foods and what comes to mind? The obvious ones are steaming hot and instantly grease up your fingers:
- chicken nuggets or chicken strips, or fried chicken (such as KFC)
- fish 'n chips
- hash browns or other kinds of potato patties
- any dough that gets deep-fried: doughnuts, beignets, fritters, beavertails, churros
The following common snack foods are also deep-fried (even though they come out of a bag):
- potato chips
- tortilla chips
- taco shells
Consider these other examples of convenience/frozen food items that are typically pre-fried and then reheated or cooked at home:
- instant noodles
- frozen fries (including those that require baking to serve)
- frozen seasoned pre-cooked chicken wings, nuggets, or ribs
- other frozen appetizers like spring rolls and wontons
In addition, these popular ethnic restaurant items are commonly deep-fried:
- At Chinese restaurants: Sweet-and-sour dishes, lemon chicken, sesame chicken
- At Japanese restaurants: Tempura dishes
- At Greek restaurants: Calamari
- At South Asian or Middle Eastern restaurants: Pakoras or samosas
The Bottom Line
We know on occasion people will eat fried foods. However, it may be worth taking a look at how you define "moderation" when it comes to deep-fried foods. One serving of any of the above food examples once a week is not a very high threshold.
With many deep-fried foods, you are also getting too much of the undesirable type of fat, refined carbohydrates, sodium, and other additives such as preservatives, flavoring, or coloring. While this study looked specifically at men who consume deep-fried foods, the rest of us would still benefit from cutting down on deep-fried foods, Sofia Layarda, MPH, RD