Microwave Ovens

Microwave ovens… approximately 90% of US households have one. With microwave use in offices, dormitories, restaurants, etc., it is hard not to find one wherever you look.

Whether you use it to reheat leftovers, thaw dinner, melt butter, or warm up your beverage, you probably never give it a second thought. After all, they have been in our kitchens for over 50 years.

However, decades of international research will give us pause and ask some questions.

A surprising number of studies from Switzerland, Russia, Germany, and various holistic practitioners point toward significant nutritional, biological, and even environmental concerns associated with microwave use.

Microwave ovens use a magnetron to generate high-frequency electromagnetic waves – about 2.45 GHz – that cause water molecules in food to vibrate millions of times per second. This intense internal friction produces heat, cooking the food from the inside out.

To be clear, this is different from the ionizing radiation [like X-rays] that can damage DNA.

It is this effect on the water molecules that some researchers are concerned with, claiming that microwaves may break apart chemical bonds or create new molecular structures that don’t occur naturally.

This type of molecular agitation is different from the slow, even heating of stovetops or ovens.

One of the most common beliefs about microwave cooking is its negative effect on nutrient levels. While all cooking reduces some vitamins, some researchers concluded that microwaves destroy nutrients at a much higher rate.

This was noted in antioxidant loss as well as degradation of Vitamins B12, B6, and C. Breast milk enzymes, antibodies, and protective compounds were destroyed by microwave exposure.

In addition, proteins may become denatured or structurally distorted, reducing bioavailability. Some studies have found isomeric changes in amino acids, meaning the proteins shift into synthetic forms the human body may not recognize or easily metabolize.

Yet, other researchers contend that microwaving food produces the lowest antioxidant loss compared to pressure-cooking, boiling, or frying.

We see that the research on nutrients is mixed and inconclusive. Any cooking will break down heat-sensitive compounds, while other nutrients are better absorbed by the body when cooked, regardless of the method.

However, there is one major safety issue with microwave use: heating food in plastic containers can cause harmful chemicals to leach into your food.

Two main chemicals are of concern:

Bisphenol A [BPA]: Used to make hard, clear plastics
Phthalates: Used to make plastics more flexible

Both are endocrine disruptors, meaning they can interfere with your body's hormone systems. Research has linked exposure to these chemicals with reproductive issues, metabolic dysfunction, thyroid disease, and increased cancer risk.

When a plastic container is labeled microwave-safe, it simply means the container won't melt or warp in the microwave. It doesn't mean the container won't release chemicals into your food.

A 2023 study found that microwaving food in some plastic containers released billions of micro- and nanoplastic particles. Even BPA-free plastics can release other harmful compounds like bisphenol S [BPS] or bisphenol F [BPF], which have similar effects on the body.

Laboratory testing has shown that heating plastics dramatically increases chemical migration. One analysis found that 70% of common plastic products tested positive for estrogenic activity at room temperature – but this number jumped to 95% when the plastics were microwaved.

Plastic leaching is linked to:

Fertility issues
Thyroid dysfunction
Early puberty
Insulin resistance and weight gain
Reproductive cancers

There is a simple solution: use glass or ceramic containers when microwaving. These materials don't contain endocrine-disrupting chemicals and won't leach anything into your food, regardless of temperature.

And… never use disposable takeout containers or margarine tubs in the microwave.

Microwaves don't heat food as evenly as conventional ovens. This can create hot spots and cold spots. This isn't just about texture – it's a genuine food safety concern.

Cold spots in reheated food can harbor harmful bacteria like Salmonella or E. coli, particularly in protein-rich foods like meat and dairy.

To compensate for the microwave’s unpredictable heating pattern, it is crucial to:

Stir food halfway through heating.
Let food rest for a minute or two after microwaving [this allows heat to distribute more evenly].
Use a food thermometer to ensure food reaches safe temperatures [165°F for most reheated leftovers].
Rotate dishes if your microwave doesn't have a turntable.

Some research has found that microwave heating at high power levels can cause greater formation of acrylamide in certain starchy foods like potatoes. Acrylamide is a compound that forms naturally when starchy foods are cooked at high temperatures, and it's been found to be carcinogenic in animal studies.

However, the connection between acrylamide from cooked foods and cancer in humans isn't yet fully established. The good news: you can reduce acrylamide formation by:

Using lower power settings
Soaking potatoes in water before microwaving
Boiling instead of microwaving starchy foods

If you have lingering doubts about microwave ovens, you are not alone. There is ongoing research on the subject and some of it is controversial. Links in References below.

Research from Russia and Germany reported:

Nitrosamines [known carcinogens] formed in microwaved meats.
Carcinogenic free radicals formed in certain microwaved vegetables, especially root vegetables.
Some grains and milk products developed toxic compounds when microwaved.
Plant alkaloids were converted into harmful forms.

Their research contends that microwaving can create radiolytic compounds – molecules that form when radiation breaks apart chemical structures. These compounds do not naturally exist in foods cooked through conventional methods, meaning that microwaving may create brand-new, biologically questionable substances in your dinner.

Another piece of research on microwave safety comes from Swiss food scientist Dr. Hans Ulrich Hertel. His controlled study from the 1990s found significant, measurable changes in the blood of volunteers after eating microwaved food, including:

Decreased hemoglobin [oxygen-carrying capacity]
Increased white blood cells [a sign of physiological stress]
Shifts in cholesterol ratios—HDL decreased, LDL increased
Changes in blood serum chemistry indicating possible cell damage

Hertel concluded that microwaved food exerted a degenerative force on the human body. His research was so controversial that the Swiss electrical appliance industry attempted to silence it with a gag order, which was later overturned by the European Court of Human Rights.

Regardless of the controversy, the physiological responses he documented suggest that microwaved foods do not interact with the body in a neutral way and affect the immune, hormonal, and neurological systems.

The FDA standards limit microwave leakage to 5 milliwatts per square centimeter at 2 inches from the oven surface, believed to be too low to cause harm.

Microwaves are generally designed with multiple safety features:

Metal shielding to contain radiation
Door seals that prevent leakage
Automatic shut-off when the door opens
Interlocking systems that prevent operation with a damaged door

However, the microwave must be properly maintained. Damaged door seals, warped doors, or broken latches can compromise safety.

Older or poorly maintained units may leak more electromagnetic fields [EMFs] than expected. Long-term, repeated exposure to EMF radiation is still poorly studied.

Documented concerns include: