Can I drink coffee every day instead of plain water?

Answer:

Coffee is a common beverage and can be beneficial to health when consumed in moderate, safe amounts. However, when intake exceeds recommended limits, it stops being just a “stay-awake aid” and can become a risk factor for cardiovascular disease.

Caffeine stimulates the sympathetic nervous system, increasing heart rate, temporarily raising blood pressure, and boosting the heart’s oxygen demand. In people with coronary artery disease, sudden spikes in heart rate and blood pressure can trigger angina or even a heart attack. Over time, excessive consumption overstimulates the heart and blood vessels.

In addition to caffeine, Vietnamese phin (filter) coffee contains natural oils such as cafestol and kahweol. These compounds can raise levels of low-density lipoprotein (LDL), or “bad” cholesterol, and reduce the liver’s ability to metabolize cholesterol, thereby accelerating atherosclerosis.

Studies show that consuming five cups of unfiltered coffee may increase total cholesterol by about 8-10 mg/dL. At higher intake levels (over five cups per day), LDL cholesterol can rise by an additional 15-20 mg/dL or more. Drinking up to 10 cups daily may result in cafestol intake of 20-30 mg, enough to continuously elevate cholesterol levels and promote unstable plaque formation, increasing the risk of acute heart attack.

Caffeine also suppresses melatonin, the hormone that regulates sleep and helps protect the cardiovascular system through its antioxidant effects. It can keep cortisol levels elevated at night, contributing to inflammation and insulin resistance. As a result, excessive coffee consumption is associated with insomnia, which negatively impacts heart health.

For safety, caffeine intake should be limited to under 400 mg per day for healthy individuals, and under 200 mg per day for those with cardiovascular disease or high blood pressure.

It is best to drink coffee in the morning or early afternoon and avoid it after 4 p.m. High coffee intake should not be combined with smoking, alcohol, or prolonged late-night work.

Coffee should never replace plain water.

Dr. Nguyen Huy Hoang

Internal Medicine Specialist at Vietnam National Association of Underwater Medicine and Hyperbaric Oxygen