Is Drinking 2 Liters of Water Harmful? 'Slow Aging' Expert Heewon Jung and Nephrology Professor Say "Exaggerated and Fear-Inducing"

"Personal Opinions Can Pose a Threat to Life," Warns Heewon Jung

Dr. Heewon Jung, renowned for her expertise in "slow aging" and serving as the Seoul Metropolitan Government Health Director, refuted the claim that "drinking 2 liters of water a day worsens health" during a discussion with Professor Sejung Kim, a nephrology specialist at Bundang Seoul National University Hospital. They explained that for individuals with normal kidney function, the body adjusts urine output according to its needs, so drinking water when thirsty is the most appropriate approach.

Dr. Heewon Jung (Seoul Metropolitan Government Health Director) conducted a live broadcast with Professor Sejung Kim, a nephrology specialist at Bundang Seoul National University Hospital, to refute the claim that "drinking 2 liters of water a day worsens health." Dr. Jung's YouTube channel

On the evening of August 11, Dr. Jung hosted a live broadcast on her YouTube channel with Professor Kim. Professor Kim is a board member of the Korean Society of Nephrology and serves as the president of the Electrolyte and Hypertension Research Society.

Dr. Jung decided to hold the live broadcast in response to recent claims by Gyeho Lee, an emeritus professor of analytical chemistry at Chungnam National University, who asserted that "drinking 2 liters of water a day worsens health."

A scene from the broadcast of "You Quiz on the Block" aired on the 6th. Captured from tvN YouTube.

On August 6, during an episode of the tvN variety program "You Quiz on the Block," Professor Lee stated, "Some people experience deteriorating health because they do not drink water, while others suffer because they do." He also warned, "There are cases where people eat excessive amounts of vegetables and fruits, or follow extremely low-sodium diets. In such cases, there is a risk of sudden cardiac arrest at night due to hyponatremia."

In response, Dr. Jung said, "I watched this video three times," and emphasized, "I have absolutely no intention of disparaging anyone." However, she pointed out, "The problem lies in attempts to attract attention by provoking curiosity or fear," and expressed concern that "information spread through algorithms can end up being accepted as truth."

She added, "While many people may have been able to discern and digest the content of the video, there may be some who have not. Content that may be a personal opinion could pose a threat to someone's life."

"The 2-Liter Fluid Restriction Is an Exaggeration"

Professor Kim, regarded as an authority in this field, stated that the claim that consuming 2 liters of water can negatively impact health is not appropriate. He said, "The assertion that exceeding 2 liters of fluid intake poses a health risk seems exaggerated. The number itself tends to generate fear, but there is no need for that."

Professor Kim explained, "If the kidneys are healthy, they regulate everything on their own. When the body is lacking water, the kidneys can reduce urine output to about 500cc per day. Conversely, if there is too much water, the kidneys can excrete the excess, physiologically increasing urine output up to 12 liters per day."

He also noted, "The recommended amount of fluid intake varies depending on the patient's specific medical condition. Therefore, understanding the underlying disease is important." He further explained that, except for patients with end-stage renal disease on dialysis or those with hyponatremia, there are almost no cases where restricting fluid intake is necessary.

Regarding Professor Lee's claim that "potassium acts as a diuretic and consuming large amounts of potassium-rich vegetables or fruits leads to hyponatremia," Professor Kim responded, "That is not an accurate statement." He explained, "When a person consumes a lot of potassium, the mechanism for sodium reabsorption in the kidneys is blocked, which can lead to sodium excretion." However, he clarified, "There is a mechanism at the end stage that prevents excessive sodium loss through diuresis, so there have been no reports worldwide of hyponatremia resulting solely from high potassium intake."