Health habits started in youth not only have a longer time to impact risk, but they can also have unique and important interactions with the biology of certain developmental stages. Smoking, for example, seems to have the biggest impact on breast cancer risk when it takes place in the years between a woman's first period and when she first gives birth. Likewise, sun exposure and indoor tanning has its biggest impact on melanoma risk when it takes place early in life.Though there is still a lot we don't know about the relationship between early life risk factors and disease risk later in adulthood - largely because the vast majority of studies to date have been done in middle-aged or older populations - it is clear from the studies we do have that the earlier in life we can cement healthy habits, the better.
Yet, a new study of national data shows that there's still great room for improvement in those critical early years. The study, conducted by researchers from the National Center for Chronic Disease Prevention and Health Promotion of the CDC, analyzed results from the 2015 National Health Interview Survey, which asked a random sampling of Americans about a range of health habits and related information.
Across nearly all behaviors reported, there were very few bright spots (see figure below).
Nearly 20 percent of all young adult men and women were obese, meaning they had a body mass index (BMI) of 30 or higher. For someone who is 5 feet, 5 inches tall, that translates to a weight of 180 pounds or more. And these numbers do not even include the percentage of young adults who were overweight (BMI 25 - 29.9) but not obese. While obesity has the largest weight-related impact on the risk of cancer, simply being overweight also adds to risk.
While smoking rates have dropped dramatically from their high-points, 11 percent of young women and 15 percent of young men still smoke tobacco cigarettes. And nearly 8 percent of young men use e-cigarettes, despite their short and long-term risks remaining largely unknown.
Though physical activity is one of the best ways to lower disease risk and improve health and overall quality of life, nearly 30 percent of young women and just over 20 percent of young men get little or no physical activity.
Indoor tanning - which can double the risk of deadly melanoma - remains relatively popular in young women. While, overall, 11 percent of women ages 18 - 24 had used a tanning bed in the past year, this number kicks up to 17 percent in non-Hispanic whites. Two percent or less of young men had indoor tanned.
Perhaps the most striking numbers were the very high rates of sugary drink consumption, processed meat consumption, and lack of HPV vaccination. Over half of men and women drank sugary drinks daily, which increases the risk of weight gain, among other health risk factors. And over two-thirds of men and over half of women regularly ate processed meat, which increases the risk of colon cancer.
Approximately 58 percent of women 18 - 26 years old and 79 percent of men 18 - 21 years old had not had the HPV vaccine, despite it lowering the risk of multiple cancers - including those of the cervix, anus, penis, and throat (which is becoming increasingly common). (Data not included in figure).
We know that half of all cancers could be prevented with a healthy lifestyle, and that that number is likely higher when healthy behaviors start early in life and are maintained through adulthood. The results of this new study show that much more work needs to be done to help instill healthy behaviors in childhood that then continue into the teens and early twenties and beyond.
Parents and other family members play a key role in helping children develop healthy habits. As kids age, and their independence grows, they play an increasing role in their own health. At all stages, though, neither parents nor kids nor adults exist in a vacuum. Our health behaviors are influenced by numerous different factors. Personal choice is just one. And outside of that, our schools, neighborhoods, workplaces, friends and broader social circles, and local and state governments and policies have an important impact on the health behaviors we make and sustain.
Healthy school meals and daily PE can help lay the foundation for a lifetime of healthful eating and regular activity. Nice sidewalks and bike paths can make it easier for families to get out for walks and bike rides. Employers that provide affordable health insurance and allow time off for doctor's appointment make it easier for workers to get important preventive care and screening. Promotion of healthy choices by popular opinion leaders on Snapchat and Instagram can impact attitudes and choices of teenagers influenced by such social media. And targeted taxes on tobacco and sugary drinks can curb purchasing by youth and young adults, who are particularly sensitive to cost.
To make important headway against cancer and other preventable chronic diseases, we need to promote and support prevention on these multiple levels. The lessons from tobacco show that such broad-based approaches work. What is lacking in these other areas are appropriate resources and political will to tackle them as we've been able to do tobacco.
The return on the time and resources invested would, no doubt, be many times over.
