A small new study found high rates of precancerous colon polyps in marathon and ultramarathon runners. The research raised questions about extreme exercise and early-onset colorectal risk (New York Times) (New York Times).
The finding matters because many Thais run for health and for charity. The result may change how doctors advise endurance athletes in Thailand.
An oncologist in Virginia recruited 100 runners aged 35 to 50 for colonoscopies. He saw almost half with polyps and 15 percent with advanced adenomas (New York Times).
Advanced adenomas are polyps likely to become cancerous. The rate among these runners far exceeded general population rates for the late 40s age group (New York Times).
The study lacked a published journal paper at the time of reporting. The team presented the findings at an American Society of Clinical Oncology meeting (New York Times).
The study surprised many clinicians who usually promote running. One study participant said she expected running only to help health and longevity (New York Times).
The research does not prove that running causes cancer. The lead investigator said the results show a signal that needs follow-up research (New York Times).
Other experts urged caution because the study had limits. The doctors noted the study had no matched non-runner control group and incomplete family histories (New York Times).
Doctors also argued that most young colorectal cancer patients are not endurance athletes. Specialists said the new work was provocative but preliminary (New York Times).
Scientists proposed possible biological mechanisms to explain the findings. They noted that intense running can cause transient reduced blood flow to the colon, called ischemic colitis (New York Times).
Ischemic colitis can damage colon cells through low oxygen exposure. Repeated damage could, in theory, affect cancer risk over many years (New York Times).
Runners often report gastrointestinal symptoms during long runs. Doctors warned that athletes may dismiss warning signs like rectal bleeding as benign runner\u2019s trots (New York Times).
The study also raised questions about selection and recall bias. Doctors suggested that some runners may have family histories that drove them to run for health reasons (New York Times).
The finding arrives amid a global rise in colorectal cancer among people under 50. This trend prompted a U.S. screening guideline change in 2021 to start at age 45 (New York Times).
Thailand already faces a growing colorectal cancer burden. Colorectal cancer now ranks among the top cancers in Thailand with over 10,000 new cases annually (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Thailand launched a national screening program using FIT testing in 2017. The program targets people aged 50 to 70 and uses FIT to prioritize colonoscopy referrals (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
FIT stands for fecal immunochemical test. Health officials use FIT because it is noninvasive, affordable, and scalable in low-resource settings (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
A 2014 pilot in one Thai province returned a positive FIT rate near 1.1 percent. Colonoscopy follow-up in that pilot detected cancers and advanced adenomas (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Thailand faces capacity limits for colonoscopy. The country has fewer than 1,000 board-certified endoscopists for a population near 70 million (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Public health planners in Thailand use risk scores to prioritize colonoscopies. The Asia-Pacific Colorectal Screening (APCS) score helps target high-risk individuals first (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Combining FIT with risk scores improved detection of advanced neoplasia in Thai studies. This approach reduced unnecessary colonoscopies while catching high-risk lesions (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Thailand adjusted FIT cutoff levels to manage colonoscopy workload. Experts found cutoffs between 25 and 200 ng/mL change the positive rate and resource needs (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
The Thai program considered a 150 ng/mL cutoff as a balance of sensitivity and workload. The program also recommended lower cutoffs for high-risk groups when resources allow (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
The new running study raises specific implications for Thailand. The findings may apply to a minority of Thai runners who train at extreme levels.
Thai runners join marathons and long-distance events in growing numbers. Running events also link to temple fairs and charity drives in many provinces.
Thai culture values health activities that involve community and merit-making. Many families encourage exercise as part of good stewardship of the body under Buddhist precepts.
Public health messaging in Thailand must balance exercise promotion with cancer vigilance. Officials should avoid discouraging moderate exercise that reduces many health risks.
Clinicians should advise endurance athletes to report any rectal bleeding or persistent bowel changes. Doctors should not dismiss such symptoms as only exercise-related without evaluation.
Athletes with warning signs should get FIT testing or colonoscopy as appropriate. Local primary care clinics and village health volunteers can help triage symptomatic runners.
Sports medicine clinics in Thailand can raise awareness. Clinics can add basic bowel symptom screening to pre-race checks and training assessments.
Race organizers can provide information at registration about when to seek medical attention. Organizers can work with local health services to disseminate FIT kits and health leaflets.
Medical societies in Thailand may consider targeted research on endurance athletes. Small, controlled studies could test whether the Virginia findings replicate in Thai runners.
Researchers should design case-control studies with matched non-runner groups. Studies should collect family history, diet, training load, and medication use data.
Local research could also examine biological markers. Scientists could measure inflammatory markers, gut perfusion signals, and microbiome changes after long runs.
Thailand already collects screening data through its national program. Researchers can link screening registries to sports participation data for epidemiologic studies.
Public health leaders should prioritize improving colonoscopy capacity. Training more endoscopists will help Thailand meet rising screening needs (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Investing in endoscopy units in provincial hospitals will reduce travel burdens for patients. The health system should also strengthen referral pathways for positive FIT results.
Health authorities can consider targeted screening for high-risk recreational athletes. Policymakers should weigh costs, benefits, and available evidence before setting new guidelines.
For now, clinicians should follow existing risk-based screening guidelines in Thailand. The national program focuses on ages 50 to 70 and FIT-based strategies (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Doctors in Thailand should also take personal and family histories seriously. A strong family history may justify earlier colonoscopy independent of running history.
The new study underlines the need for clear patient counseling. Physicians should reassure patients that moderate exercise remains beneficial.
Clinicians should explain that the study does not show causation. Providers should describe study limits and the need for larger research.
Runners should avoid ignoring gastrointestinal symptoms during training. They should report persistent bleeding, changes in stool, or unexplained weight loss.
A simple FIT test can detect hidden blood in the stool. People can obtain FIT through primary care clinics linked to the national program (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Village health volunteers can help distribute FIT kits in rural areas. The Thai public health network has experience in community screening programs.
Employers and universities can support screening access for active staff and students. Workplaces can offer FIT kits or health days with colorectal screening information.
Sports clubs and running groups can add basic health education to training sessions. Coaches can remind runners that health includes preventive screening.
Race insurance providers may consider offering pre-race health checks. Such checks can identify individuals who need follow-up before a major event.
Future research should track colorectal lesion progression among active runners. Longitudinal studies will show whether early adenomas progress faster in this group.
Clinical trials could test whether particular training loads associate with lesion risk. Trials could also investigate protective measures such as dietary interventions.
Nutrition plays a key role in colorectal cancer risk. Diets high in processed meat and low in fiber increase risk across populations.
Thai diets vary by region but include protective elements. Rice, fish, vegetables, and fruit can support colon health when consumed regularly.
Public health messages should combine dietary advice with screening promotion. Simple, culturally tailored nutrition guidance can help reduce long-term risk.
The Buddhist value of caring for the body can motivate preventive health actions. Framing screening as a duty to care for family resonates in Thai communities.
Families play a strong role in health decisions in Thailand. Encouraging family-based screening can increase uptake of FIT and follow-up colonoscopy.
Policy makers should track screening outcomes in younger age groups. Monitoring will help decide whether to lower screening ages in Thailand.
The U.S. change to start screening at 45 reflected rising early-onset colorectal cancer. Thailand should evaluate local trends before making similar guideline changes (New York Times; Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Clinicians should balance resource limits and equity when prioritizing colonoscopy. Risk stratification tools like APCS can help allocate scarce resources fairly (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Researchers should share data openly to speed knowledge. International collaboration can clarify whether the Virginia findings are generalizable.
Journalists should report such findings carefully to avoid scaring people from exercise. Reporting should emphasize nuance, study limits, and practical steps readers can take.
For Thai readers who run, the immediate actions are clear. Do not ignore rectal bleeding or persistent bowel changes.
Make an appointment with a primary care doctor for concerning symptoms. Ask for a FIT test or a referral for colonoscopy when appropriate.
If you have a strong family history of colorectal cancer, tell your doctor. Family history may require earlier or more frequent screening.
If you run extreme distances, discuss screening timelines with your doctor. Clinicians can help decide on FIT versus colonoscopy based on risk.
Community health workers and clinics can help runners navigate screening. They can explain test options and facilitate referrals.
Thailand should view this study as a call to research, not alarm. The nation should strengthen screening and study local risk factors.
Health authorities should invest in endoscopy training and infrastructure. This investment will pay off by catching cancers earlier.
Sports groups can partner with public health agencies to promote screening. Such partnerships can reach active adults effectively.
Researchers in Thailand can design culturally sensitive studies on runners. These studies can leverage existing screening registries for faster insights.
Medical schools can incorporate sports-related colon health into training. Doctors will then better advise active patients.
In sum, the new study raises important questions about extreme running and colon polyp risk. The evidence remains preliminary and calls for larger, controlled research (New York Times).
Thai health systems can respond now with practical steps. These steps include promoting FIT, prioritizing colonoscopy for high-risk people, and expanding endoscopy capacity (Current Status of Colorectal Cancer and Its Public Health Burden in Thailand).
Runners should keep running for fitness and community. They should also stay alert to symptoms and follow screening guidance from doctors.
Public health leaders should fund research to confirm or refute the link. They should also ensure equitable access to screening for all Thais.
The study reminds us that medical knowledge evolves with new data. Thailand can apply scientific caution and cultural sensitivity as it updates public advice.