While refrigerators are indispensable for preserving most fresh foods, certain ingredients can develop harmful compounds when subjected to low temperatures.
Kim Tae-kyun, a gastroenterologist who hosts the popular health YouTube channel "Doctor Dingyo," recently flagged specific foods that can generate carcinogens when kept in cold storage. At the top of his list of foods that should never be refrigerated are potatoes.
"When potatoes are stored in the cold, their internal starch converts into reducing sugars," Kim Tae-kyun explained. "If you then cook those altered potatoes at high temperatures—such as making French fries—a hazardous chemical called acrylamide forms."
He further noted that acrylamide is classified as a Group 2 carcinogen, with studies linking it to neurotoxicity and an elevated risk of ovarian cancer. Beyond the carcinogen risk, the elevated sugar content in cold-stored potatoes also makes them significantly worse for blood sugar control compared to their normal, starchy state.
Choosing Safer Cooking Methods to Minimize Risk
Because acrylamide is primarily generated at cooking temperatures of 120°C or higher, Kim Tae-kyun recommends boiling or steaming potatoes instead of frying them. "If you absolutely must fry them, you should cook them at the lowest possible temperature for the shortest amount of time," he advised.
Boiling remains the healthiest preparation method. Long-term exposure to acrylamide has been shown to increase the risk of neurodegenerative conditions, including Alzheimer’s disease. Furthermore, regular consumption of fried foods carries a distinct metabolic risk; a study published in the international journal The British Medical Journal (BMJ) confirmed that frequent consumption of French fries is associated with an increased risk of developing type 2 diabetes.
Maximizing Health Benefits Through Proper Storage
When stored and prepared correctly, potatoes offer substantial nutritional value. According to data from the Rural Development Administration, potatoes are exceptionally rich in potassium, a mineral vital for helping the body excrete excess sodium. This makes them highly effective at preventing fluid retention after consuming salty meals and assisting individuals with hypertension in managing their blood pressure.
Additionally, the vitamin C found in potatoes helps combat stress-induced fatigue. While vitamin C in many vegetables degrades rapidly during cooking, the specific composition of a potato shields the nutrient, keeping it relatively stable even when heated. Potatoes also possess natural anti-inflammatory properties, making them an excellent dietary choice for individuals suffering from frequent gastritis.
To preserve these benefits without inducing chemical changes, potatoes are best kept in a cool, dark, and well-ventilated space. While it may be tempting to wash and dry them before storage, they should actually be kept with their original soil intact inside a cardboard box. Exposure to ambient light causes the skin to turn green, triggering the production of solanine—a toxic alkaloid. Covering the storage box with paper or a similar dark material is an effective way to block out light and ensure safety.
