"In women, adolescent exercise participation, regardless of adult exercise, was associated with reduced risk of cancer and all-cause mortality," says Prof. Nechuta.
The study was conducted by Sarah J. Nechuta, an assistant professor of medicine at Vanderbilt Epidemiology Center in Nashville, TN, and colleagues. Their findings are published in Cancer Epidemiology, Biomarkers & Prevention.
Participating in exercise as an adolescent was associated with a reduced risk of cancer and all-cause mortality, regardless of the level of exercise attained by the women assessed in the study as adults, the authors state.
Previous research has indicated that healthy living can have far-reaching health benefits. Medical News Today reported on a study published earlier this year in JAMA Oncology that found men who kept a high level of fitness in their midlife would be less likely to die from certain cancers after the age of 65 than less fit peers.
In particular, the risk of men with high cardiorespiratory fitness were 55% less likely to develop lung cancer and 44% less likely to develop colorectal cancer than men with low cardiorespiratory fitness.
According to Prof. Nechuta, it is vitally important that researchers work toward understanding the long-term impact of modifiable lifestyle factors such as exercise during adolescence. Research into this area can have public health implications for disease prevention over the course of life, she explains.
For the study, data were obtained from the Shanghai Women's Health Study (SWHS), a population-based prospective study that has followed around 75,000 women in Shanghai, China, since 1996, recording specific causes of death and the incidence of specific cancers in the cohort.
The SWHS is funded by the National Cancer Institute and is led by Dr. Wei Zheng of the Vanderbilt Epidemiology Center.
Participating women are interviewed in person every 2-3 years to collect baseline and follow-up data, including information on adult lifestyle-related factors and mortality outcomes. Information obtained at the beginning of the study included self-reported exercise participation between the ages of 13-19 and blood and urine samples.
Continuing to exercise from adolescence through to adulthood most beneficial
The researchers found that, after an average of 12.9 years of follow-up, there had been 5,282 deaths among the participants. Of these, 2,375 were attributed to cancer and 1,620 were due to cardiovascular disease.
Women who had reported participating in exercise as adolescents had lower risks of death from cancer and all causes compared with those who had not exercised.
Those who exercised as adolescents for 1.33 hours a week or less were 16% less likely to have died from cancer and 15% less likely to have died from all causes. Women who had exercised for more than this were 13% less likely to die from all causes.
Participating in team sports as an adolescent resulted in a 14% lowered risk of death from cancer and a 10% lowered risk of death from all causes. When exercise participation continued from adolescence into adulthood, the risk of death from all causes was lowered by 20%.
Prof. Nechuta told MNT that they were surprised to not observe a dose-response for all-cause mortality after adjustment for adult factors. She added:
"It is important to note that adult factors, such as adult exercise, body mass index (BMI) and chronic diseases are potentially influenced by adolescent exercise, and adjusting for adult factors in these types of studies may not always be the best approach, as overadjustment could be a concern."
The study is limited by reliance on self-reported information and a lack of information on occupations and modes of transport used. Despite this, Prof. Nechuta believes their findings help illustrate the value of exercise.
"Our results support the importance of promoting exercise participation in adolescence to reduce mortality in later life and highlight the critical need for the initiation of disease prevention early in life," she concludes.
Earlier this month, MNT reported on another study that suggests the rate of aging can be tracked in early adulthood and not just later in life.