Lifestyle changes and future health

Background

Cancer often develops slowly, with prolonged exposure to risk factors having the most significant impact. Few studies have demonstrated that making healthy lifestyle changes in adulthood can halt or delay cancer development and prevent premature death.

One reason for the lack of evidence is the scarcity of studies where participants have successfully made long-lasting healthy changes. Another reason is that studies have not followed participants long enough after potential lifestyle changes.

In this project, we aim to determine whether healthy lifestyle changes can extend the number of healthy years lived by monitoring participants in various population studies over an extended period.

NORCCAP cohort

We followed up on the mortality of adult women and men after their lifestyles were measured twice with a three-year interval when they were in their 50s.

In this group, we observed that those who changed their habits within a three-year period from not meeting to meeting national health recommendations had lower mortality rates before the age of 67. The health recommendations are based on being smoke-free, maintaining a normal body weight, engaging in sufficient physical activity, and having a healthy diet. The study showed that each recommendation that participants changed led to a 21% reduction in premature mortality. Read more about the NORCCAP cohort here. 

The Oslo survey

We monitored cancer incidence in 1,200 men in the Oslo Study. Men in their 40s were divided into two groups in the 1970s. One group received advice to change their diet and quit smoking to improve heart health, while the other group received no advice. The group that received advice made long-lasting healthy changes to their diet.

Over 43 years, the group that received lifestyle advice had a lower incidence of lifestyle-related cancer types. For example, the number of cases of cancer in the digestive organs was lower. The effect of lifestyle changes became evident around 18-25 years after receiving advice. Men who received lifestyle advice, therefore, enjoyed more cancer-free years than men who made no changes.

Swedish Women's Lifestyle and Health Study

We followed up on cancer incidence in Swedish women after their lifestyles were measured twice with a 12-year interval in adulthood. We investigated whether changes in lifestyle factors were associated with lifestyle-related cancer types.

The EPIC study

In the European EPIC Cohort, we examined whether changes in lifestyle, measured as the "Healthy Lifestyle Index" (HLI) score, were associated with future colorectal cancer and all lifestyle-related cancer types combined. The study on colorectal cancer incidence showed that an improvement in lifestyle was associated with a lower risk, while a deterioration in lifestyle was associated with a higher risk of colorectal cancer. Even small improvements had a significant impact on reducing the risk.