There seem to be few controversies with more staying power than microwaving food and nutrition.
The argument centers on zapping food and losing nutrients, but science says otherwise. Sometimes anti-microwave advocates argue microwaves are even unsafe.
“Whenever you cook food, you'll have some loss of nutrients," says registered dietician and certified food scientist Catherine Adams Hutt. "The best cooking method for retaining nutrients is one that cooks quickly, exposes food to heat for the smallest amount of time and uses only a minimal amount of liquid."
Microwave cooking meets those three criteria.
Vitamins C and B12 degrade quickly when a food is heated. Other nutrients, though, may benefit from the rise in temperature. Carotenoids, antioxidants found in vegetables like carrots and tomatoes, increase when the proteins that bind them break down during microwave heating.
There is some confusion over when and where the controversy started, but it’s perpetuated by natural food experts who claim microwaving will deplete your food of nutrients while also changing it’s molecular structure in dangerous ways.
“A large part of all the microwave alarmism today can be traced back to a single story that was spread on the Internet until it went viral and was eventually accepted as factual,” Tom Venuto writes at Burn the Fat Blog. “It’s the story of the infamous ‘Swiss research’ done by ‘food researcher’ Hans Hertel, who allegedly performed his own private study to see how microwaved foods affected the results of blood tests.”
Yet, millions of microwaves have been used by billions of people for many years, which places the controversy somewhere on the same shelf with the continuing argument over fluoride in water that millions of people consume. You may have an opinion on that as well. Many people still do.
Many scientists believe that microwaving food offers health benefits, but there is a loss of nutrients connected to the amount of water used to cook the food. But microwaving in the right container (with a lid) cooks from the inside out and relies on steam and very little added water.
“A fast and convenient way to steam vegetables, microwaving can help people retain more water-soluble nutrients often lost when drowning vegetables in water and cooking them too long,” says Caroline Kaufman, a registered dietician nutritionist based in Los Angeles. “Microwaving also helps preserve heat-sensitive nutrients like vitamin C due to a faster cook time,” Kaufman said.
Microwaving meat instead of pan-frying or grilling can also “substantially” reduce the formation of chemicals (heterocyclic amines HCAs and polycyclic aromatic hydrocarbons PAHs) that cause cancer in animals, and “may be linked to colorectal, pancreatic and prostate cancer in humans,” Kaufman adds.
Research from the University of Oslo found that microwaving or steaming carrots, spinach, mushrooms, asparagus, broccoli, cabbage, green and red peppers, and tomatoes “led to an increase in the antioxidant content of the foods (in that the antioxidants become more available for absorption),” writes New York city nutrition expert Mike Rousell.
More research shows that lycopene, the antioxidant that gives tomatoes and watermelon their red color, is better absorbed by the body “when it’s consumed in cooked or processed tomato products — salsa, spaghetti sauce, ketchup, etc. — rather than fresh tomatoes,” Rousell writes.
The moral of the story here is to hold onto your convenient microwave, learn what foods are best to cook in it, use the right container and a lid that facilitates steaming — and don’t douse the food in water, which actually does remove nutrients.
November 30, 2016
Christopher Nystuen, MD, MBA