Study Warns Prolonged Sitting May Raise Cancer Risk Even If You Exercise Regularly

New Delhi: Sitting at work, watching TV or using the phone for long periods of time has become a common habit for many people. In modern society, sitting at a computer for hours has become a habit for millions of people. After work, many people spend most of their time watching television, using their phones, or playing video games. A sedentary lifestyle has long been considered a risk factor for many chronic diseases, and now new evidence suggests it may also be linked to cancer.

What does the study reveal?

A recent study published in the journal PLOS Medicine found that prolonged sitting or lying down increases the risk of developing and dying from various types of cancer. Researchers found that replacing prolonged sitting with just one hour of moderate physical activity per day can significantly reduce the risk of cancer death.

What is the link between sitting and cancer?

The study involved more than 91,000 adult participants from the UK Biobank database. All wore activity trackers for seven days and their health was monitored for an average of 12 years.

Researchers define prolonged inactivity as periods of continuous sitting or lying down for 30 minutes or more, with more than 90 per cent of the time spent in a resting position. In contrast, periods of sitting that are interrupted by physical activity are classified as intermittent inactivity. 

The study results showed that people who consistently sit for extended periods of time have a significantly higher risk of developing cancer and dying from cancer. Specifically, with each additional hour of continuous sitting, the risk of cancer-related death increases by approximately 10 per cent.

Cancers associated with a long-term inactive lifestyle include colorectal cancer, breast cancer, liver cancer, kidney cancer, pancreatic cancer, ovarian cancer, esophageal cancer, and thyroid cancer.

What did the expert say?

According to Dr Abhishek Shankar, assistant professor in the Department of Radiation Oncology at AIIMS Delhi, a sedentary lifestyle can promote weight gain and obesity, factors that have been proven to increase the risk of several types of cancer.

"Regular exercise remains essential, with adults advised to get 150-300 minutes of moderate physical activity a week, but it should be combined with frequent movement throughout the day. Spending long, uninterrupted hours seated appears to independently increase the risk of cancer and cancer-related mortality," he said.

He explained that excess body fat can lead to chronic inflammation, which is believed to be one of the mechanisms that promote the formation and growth of cancer cells. Furthermore, obesity is also associated with an increased risk of colorectal cancer. Furthermore, long-term lack of exercise can lead to hormonal imbalances, increasing the risk of certain hormone-sensitive cancers, such as breast cancer.

“Sitting itself does not directly cause cancer, but these changes, along with reduced blood circulation and impaired immune function, may increase the risk of colorectal, breast and endometrial cancers over time, especially when combined with other unhealthy lifestyle factors,” he said.