Many people believe that “natural” foods are always safe for health. However, if they are prepared or consumed incorrectly, they can seriously harm the kidneys.

According to nephrologist Dr. Hung Yung-hsiang (Taiwan, China), several common foods can produce dangerous toxins when eaten the wrong way, potentially leading to acute poisoning, nerve damage, and kidney failure.

Sharing on his personal page, Dr. Hung said he has treated numerous patients who were hospitalized not because of fast food or processed products, but because they consumed “natural” foods improperly.

One notable case involved a male office worker in his 40s. After discovering a bag of sprouted potatoes in his kitchen, he removed the sprouts and fried the potatoes. About two hours later, he developed nausea, tongue numbness, severe abdominal pain, diarrhea, dizziness, and cold sweats. By the time he arrived at the emergency room, he was confused. Doctors later diagnosed him with solanine poisoning—a natural toxin produced when potatoes sprout.

Based on this case, Dr. Hung identified five types of foods that can generate toxins capable of causing poisoning and kidney damage.

1. Sprouted Potatoes

According to Dr. Hung, when potatoes begin to sprout, the toxin solanine is not limited to the sprouts but may spread throughout the entire potato. Even normal cooking temperatures cannot completely destroy this compound.

Consuming large amounts of solanine can irritate the digestive tract and affect the nervous system, leading to vomiting, diarrhea, confusion, and potentially severe complications, especially in children and older adults.

Experts recommend discarding any potato that has sprouted or turned green, rather than simply cutting off the sprouts and continuing to use it.

2. Undercooked Beans

Dr. Hung also warned that beans such as red beans, kidney beans, and mung beans may contain phytohemagglutinin if they are not cooked thoroughly. This plant toxin can cause severe gastrointestinal poisoning.

He once treated a female patient who suffered intense abdominal pain and persistent vomiting after eating undercooked beans. By the time she was hospitalized, she was severely dehydrated, had low blood pressure, and showed signs of reduced kidney function.

This toxin is only destroyed when beans are cooked at a sufficiently high temperature for an adequate amount of time, so beans should always be fully cooked before consumption.

3. Cassava and Bamboo Shoots Prepared Improperly

Cassava is a staple food in many countries, but it can be dangerous if not processed correctly. Dr. Hung explained that cassava contains compounds that can be converted into hydrogen cyanide, a highly toxic substance.

Numerous cases of mass poisoning have been reported worldwide due to improperly prepared cassava, resulting in nerve damage and even death.

Similarly, fresh bamboo shoots that are not thoroughly cooked can cause nausea, dizziness, and discomfort after eating.

To reduce toxicity, experts recommend soaking cassava and bamboo shoots thoroughly, slicing them thinly, and boiling or cooking them completely. When boiling, the pot should be left uncovered so the toxins can evaporate with the steam.

4. Certain Seeds That Can Release Cyanide

Some seeds, including bitter almonds, peach pits, plum pits, and apple seeds, contain amygdalin, a compound that can release cyanide once ingested.

Consuming excessive amounts may cause headaches, shortness of breath, seizures, and even respiratory failure.

Children who tend to chew fruit seeds are at greater risk because their bodies are more sensitive to these toxins.

5. Natural Foods With Protective Plant Compounds

Experts note that many natural foods contain substances that plants use to defend themselves against insects and disease. If these compounds are not neutralized through proper preparation and cooking, they can become harmful toxins that damage the liver, kidneys, and nervous system.

Protect Your Health by Preparing Food Properly

People should not underestimate the potential risks of familiar foods. Choosing fresh ingredients, preparing them correctly, and cooking them thoroughly remain the most important principles for preventing food poisoning and protecting overall health.