Break Long Sitting Spells to Lower Cancer Risk, Say Experts

Spending more than 30 minutes sitting continuously may be associated with a higher risk of cancer-related death, according to a new study by researchers at the University of Glasgow. The study, published in PLOS Medicine, tracked more than 91,000 adults over an average of 12 years and found that replacing prolonged sedentary time with even light physical activity could lower the risk

Researchers observed that uninterrupted periods of sitting lasting more than 30 minutes were associated with a greater risk of cancer death. Replacing an hour of sedentary time with light activities such as walking or household chores was linked to a lower risk. However, the researchers noted that the study was observational and did not establish a direct cause-and-effect relationship

Doctors say the findings reinforce the importance of reducing prolonged inactivity as part of a healthy lifestyle, while cautioning that sitting alone should not be viewed as the sole cause of cancer

Dr. Praveen Adusumilli, Senior Medical and Hemato Oncologist at CARE Hospitals, said modern lifestyles have made prolonged sitting increasingly common

“Most people understand the importance of exercise, but what often goes unnoticed is the amount of time we spend sitting continuously at work, while commuting, or in front of screens. Many assume that a morning walk or an evening workout is enough to compensate for sitting the rest of the day. Unfortunately, our bodies don’t work that way,” he said

He noted that prolonged sedentary behaviour can influence metabolism, hormone regulation, inflammation and the body’s natural defence mechanisms

“The reassuring part is that the solution doesn’t have to be complicated. Simply standing up every 30 minutes, taking a short walk around the office, stretching, climbing a flight of stairs, or even doing routine household chores can help break long periods of inactivity,” Dr. Praveen said

He added that cancer prevention depends on a combination of everyday habits. “Avoiding tobacco, limiting alcohol, maintaining a healthy weight, eating a balanced diet, staying physically active, participating in age-appropriate cancer screening, and reducing prolonged sitting all work together to lower overall cancer risk.”

Dr. A. Venugopal, Senior Consultant Medical Oncologist and Hemato-Oncologist at Medicover Hospital, said the findings should be interpreted carefully. “This study adds to the growing evidence that prolonged, uninterrupted sitting may be associated with poorer health outcomes, including a higher risk of cancer-related death. However, it is important to understand that this is an observational study. It shows an association, not proof that sitting itself causes cancer progression or cancer death,” he said.

According to him, cancer patients and survivors should focus on remaining as physically active as their medical condition permits

“Even simple measures such as standing up every 30 minutes, taking a short walk, or doing light stretching can help reduce sedentary time and improve overall health, muscle strength, cardiovascular fitness and quality of life,” he said

He added that multiple studies have already demonstrated the benefits of regular physical activity in improving outcomes for cancers such as breast and colon cancer. “Encouraging patients to move more and sit less is a safe, practical and evidence-based recommendation.”

Dr. Kalyan Vangara, Consultant Surgical Oncologist and Advanced Laparoscopic and Robotic Surgeon at Amor Hospitals and Amor Cancer Centre, said there is strong evidence supporting the role of physical activity in reducing cancer risk, although more research is needed on the specific impact of sitting for 30 minutes at a stretch

“A healthy lifestyle and regular exercise improve metabolic function, reduce inflammation and improve endocrine function. Many studies have shown that regular physical activity can reduce the risk of cancer,” he said

He cautioned against drawing definitive conclusions from the latest study alone. “Whether 30 minutes of sedentary behaviour itself significantly increases cancer risk cannot be concluded from this research alone. Further studies are needed. However, increasing physical activity has well-established benefits for reducing the risk of cardiovascular disease as well as cancer.”