Many people often think that drinking water is a simple habit and nothing to worry about. However, the reality shows that if you do not pay attention to how you drink water, this can negatively affect your health, even potentially causing cancer.

Is boiled water or water left overnight safe?

The question of whether boiled water or water left overnight causes cancer has been thoroughly researched by experts. After a series of experiments, they found that even though the water was boiled continuously up to 20 times, the nitrite content in the water was still very low, only about 0.038mg/L. This proves that nitrite exists in the water from the beginning and is not created by the boiling process. Therefore, boiling water many times does not lead to the production of carcinogens.

According to Associate Professor Fan Zhihong from the Department of Nutrition and Food Safety of China Agricultural University, nitrite – a carcinogen – is only formed in the presence of nitrate. Most mineral water or purified water that we use every day does not contain nitrate, so leaving water overnight does not pose a cancer risk.

Two types of water that actually "nourish" cancer cells

Contrary to popular belief, water that has been boiled repeatedly or left overnight is not a direct cause of cancer. Instead, the following two types of water should be noted:

1. Water that is too hot

Drinking water that is too hot (above 50-60°C) for a long time can cause serious damage to the esophageal mucosa. This continuous stimulation can lead to hyperplasia of the esophageal mucosa, thereby increasing the risk of developing esophageal cancer. To ensure safety, you should wait for the water temperature to drop to about 18-30°C before drinking.

2. Unboiled tap water

Home tap water is often treated with chlorine for disinfection. This process can create a number of toxic chemical compounds such as chloroform and hydrogen halides – substances that can cause cancer if consumed directly without boiling. In addition, untreated water can irritate the digestive tract, leading to problems such as bloating, abdominal pain and diarrhea.

To remove these toxic substances, you need to boil the water to a temperature above 100°C. The high temperature will help the toxins evaporate with the steam, providing a cleaner and safer water source.

To maximize the benefits of drinking water, you need to follow some of the following principles:

- Drink a glass of water in the morning

A glass of warm water (about 250ml) every morning not only helps reduce blood viscosity but also improves blood circulation and dilates blood vessels. This is especially useful in preventing cardiovascular diseases such as hypertension and cerebral embolism. In addition, this habit also aids digestion, helping to minimize constipation.

- Control water temperature

Ideally, keep the water temperature at around 25℃. This is the temperature at which water has high biological activity, easily penetrating cell membranes to provide moisture to the body. Water that is too cold or too hot can be harmful to the digestive system and other organs.

- Drink water before and after meals

Before meals: Drinking about 100ml of water half an hour before meals helps stimulate digestive juices and increase nutrient absorption. At the same time, this also creates a feeling of fullness, helping to control weight effectively.

After meals: Drinking 300ml of water after about 2 hours helps promote the secretion of satiety hormones and improve intestinal digestive function.

- Drinking rhythm

Instead of drinking water in one big gulp, divide it into small sips. Drinking quickly can cause you to swallow a lot of air, causing hiccups or bloating. For people with weak digestive systems, drinking water too quickly can also lead to low blood pressure or cerebral edema. Therefore, drinking small sips not only helps the body absorb water better but also creates a feeling of relaxation.

By applying the above principles, you can ensure that drinking water becomes a healthy habit that contributes to your overall health. Always remember that water is a precious resource for the body, but how you use it determines whether it is truly beneficial or not.