Tea Time & Cancer Risk
Tea is a fantastic drink. Unlike soda or juice, tea has no calories, it boosts your metabolism, and may offer other benefits that we're still discovering.
Tea (plain, and multiple varietals) consumption appears to be safe and may be associated with improved CVD health and blood lipids based on large observational studies and meta-analyses. Of note, the evidence is based on tea consumption (sometimes >5 cups/day) without added sugars, sweeteners, or milks and creams (both animal- and plant-based).
Journal of the American College of Cardiology
However, a new study shows that certain tea preparation techniques and preferences may increase your risk of esophageal cancer.
Researchers followed 50,045 individuals in Iran, a country where people love drinking tea, to see whether tea temperature correlates with esophageal cancer risk.
They found that volunteers who preferred drinking their tea while it was very hot (>140 degrees F) had a significant increase in their risk of developing esophageal cancer over 10 years.
Tea Brewing Time & Esophageal Cancer Risk
A similar relationship was seen for tea brewing time. Volunteers who let their tea sit for longer had a lower risk of esophageal cancer. People who preferred to drink their tea immediately after it's poured had an approximately 50% higher risk of developing esophageal cancer, even after adjusting for age, smoking, diet, alcohol consumption, and education.
Letting tea cool for 5 minutes or more correlated with a near normal, if not lower, risk of esophageal cancer.
Esophageal Cancer Statistics
Of course, this all needs to be put in perspective. Esophageal cancer is one of the rarer cancers in the United States. It only makes up 1% of all cancer in the United States.
However, it tends to be deadlier than other cancers. It has a 5 year survival rate of 19.2% overall, according to the National Cancer Institute. Therefore, it makes up 2.6% of all cancer deaths which is disproportionately higher than its prevalence.
Esophageal Cancer Survival Statistics
The overall 5 year survival rate for esophageal cancer has been estimated at 19.2% by the SEER cancer database.
However, this rate depends greatly on when the cancer is diagnosed. If the cancer has metastasized to distant organs and has spread around your body, the prognosis dim. The American Cancer Society estimates a 5% 5 year survival rate.
However, if the cancer is diagnosed before it has spread to the lymph nodes and local tissue, it has a 45% survival rate.
Why this matters
This study shows that a very simple tweak in how you prepare your tea can make it even healthier. Just letting it sit for a few more minutes can dramatically reduce your risk of getting a very deadly form of cancer.
What about Coffee?
Given that the primary variable studied was beverage temperature, this data suggests that individuals who drink very hot coffee may be at a similar risk.
The Working Group found no conclusive evidence for a carcinogenic effect of drinking coffee. However, the experts did find that drinking very hot beverages probably causes cancer of the oesophagus in humans.
Related Article: Tea and Diabetes
Even with this data, we want to note that tea is generally very good for you. In several studies, researchers have found that tea may reduce your odds of diabetes, alongside a weight loss regimen, and can increase calorie burn.
Related Article: Soft Drinks and Cancer
Soda and sugary soft drinks are likely more dangerous than tea overall, even if you prefer your tea steaming hot. A recent study out of Harvard has linked sugary drinks to a significantly higher risk of heart disease and overall mortality. Given that the link between tea and cancer was only found in a relatively rare form of cancer, replacing soda with tea is probably still a good idea.
Related Article: Coffee and Lifespan
Overall, coffee is also probably pretty good for you. A study in the New England Journal of Medicine has shown that drinking more coffee correlates with a lower overall mortality risk. Essentially, coffee may help you live longer.