The fundamental goal of the $3 billion Human Genome Project1 was to discover the genetic origins to common diseases, such as cancer and dementia. Based on this knowledge, scientists believed new treatments could be developed to wipe out conditions rampant in the human population.
The project was launched in 1990 and completed in 2003. While it yielded a bountiful harvest of information for biologists, any treatments have remained elusive.2 Since the goal of sequencing 3 billion units in the human genetic structure was far too expensive, the National Institutes of Health (NIH) devised a shortcut.
They proposed to evaluate just the sites where many have a DNA variant, operating under the theory that since major diseases are common, the genetic variant causing them would be common too. The theory was not fruitful and scientists found a common variant explained only a small fraction of the genetic risk.
In the same time period, John Cairns, a British molecular biologist, produced compelling evidence our responses to the environment determined genetic expression. These changes to genetic expression are accomplished by outside environmental factors such as diet, toxins and heat and cold.
In other words, the behavior of your DNA doesn’t just depend on the sequence you’re born with, but is also affected by epigenetic factors turning your genes “on” or “off” and playing a critical role in the development of disease.3 In yet another study demonstrating risk associated with temperature, researchers found chronic exposure to hot fluid could increase your risk of esophageal cancer.4
Hot Fluid Increases Your Risk of Esophageal Cancer
Previous studies had reported an association between drinking hot tea and the risk of esophageal cancers. However, no study had yet examined the association using prospective strategies and measuring tea-drinking temperatures objectively.
Instead, past research had relied on retrospective historical data, meaning participants were asked to remember and estimate how much tea they drank and at what temperature. Retrospective studies have a subjective recall bias as participants may not accurately remember information.
The intent of the current study was to objectively measure the effects of hot beverages on esophageal tissue and the future risk of esophageal squamous cell carcinoma (ESCC) by gathering data prospectively. The researchers used a population-based prospective cohort of over 50,000 individuals aged 40 to 75.
The individuals lived in northeastern Iran between 2004 and 2008 and were followed for a median duration of a little over 10 years.5 By 2017, 317 new cases of ESCC were identified in individuals who recorded drinking hot tea.
In the current study, researchers found those who drank more than 700 milliliters (ml) (23 ounces) of tea per day at less than 60 Celsius (140 Fahrenheit) had a 90 percent greater risk of ESCC than those who drank less.
The research was led by Dr. Farhad Islami, strategic director of Cancer Surveillance Research at the American Cancer Society.6 The authors believe their results substantially strengthen past studies supporting an association between drinking hot beverages and ESCC.7 Islami cautions while more research needs to be done to understand the mechanism:8
“Many people enjoy drinking tea, coffee, or other hot beverages. However, according to our report, drinking very hot tea can increase the risk of esophageal cancer, and it is, therefore, advisable to wait until hot beverages cool down before drinking.”
Additional Risk Factors of Esophageal Cancer
According to the American Cancer Society,9 over 17,000 cases of esophageal cancer are predicted in 2019 and nearly 16,000 will die from it. Data from the current study supports previous research triggering the World Health Organization to classify drinking very hot beverages as a probable carcinogen.10
There are a number of factors raising your risk of developing esophageal cancer, including regular environmental exposure to drinking hot liquids. Other risk factors are also linked to irritating the cells in your esophagus.
Your esophagus is a long hollow tube running from your throat to your stomach, helping move food through your digestive tract. Cancers may occur anywhere along the esophagus and are classified according to the types of cells involved in the tumor.
Adenocarcinoma begins in the mucus secreting glands in the esophagus while squamous cell carcinoma begins in the thin cells lining the surface of the esophagus. Squamous cell carcinoma is the most common type worldwide while adenocarcinoma is the most common type in the U.S.11
Risk factors influence the development of cancer, but are not directly related to causation. This means some with multiple risk factors may not develop cancers while those with no known risk factors will. However, knowing the risks may help you make informed choices about your lifestyle and health care.12,13
Age and gender — Your chance of developing esophageal cancer increases with age. Less than 15 percent of diagnoses develop in those younger than 55 years. Men have a higher risk of esophageal cancer than women.
Tobacco and alcohol — Any form of tobacco, smoked or chewed, increases your risk, especially squamous cell carcinoma. When combined with heavy alcohol use, your risk is even greater. The longer the period of use, the higher the risk rises.
Gastroesophageal reflux disease (GERD) — Those suffering have a slightly higher risk of adenocarcinoma, which rises with increasing frequency of symptoms. While the risk associated with GERD is slight, the condition increases your risk of Barrett’s esophagus, linked with a greater risk of ESCC.
Barrett’s esophagus — This condition arises with chronic inflammation of the esophageal tissue, from GERD or esophagitis, even in those without symptoms of chronic heartburn. Those with Barrett’s esophagus have a higher than normal risk of esophageal cancer but most do not develop the cancer.
Nutrition and obesity — Being overweight increases the risk of adenocarcinoma. A diet high in processed meat may increase your risk, while a diet high in fruits and vegetable is linked to a lower risk.
Achalasia — In this condition, the muscles near the stomach in the esophagus do not relax to allow passage of food into the stomach. Food tends to collect in the lower esophagus, irritating cells from exposure to food for longer than normal. Achalasia increases your risk of squamous cell carcinoma. On average, those suffering will have a much higher risk and cancers may be found approximately 15 years after the condition begins.
Tylosis — This is a rare, inherited disease triggering abnormal skin growth over the top layers of the palms of your hands and soles of your feet. Small growths also occur in the esophagus, increasing the risk of squamous cell carcinoma.
Human papillomavirus (HPV) — There are more than 100 related papillomaviruses; an infection with certain types may increase your risk of certain cancers. Signs of HPV have been found in up to 33 percent of those with esophageal cancer in Asia and South Africa, but not in those with esophageal cancer in other areas of the world.
Workplace exposure — Chemical fumes, including solvents used in dry cleaning, may lead to an increased risk of esophageal cancer.
How to Treat GERD Naturally
While your risk of esophageal cancer is only slightly higher with GERD, the condition affects an estimated 60 million Americans,14 the hallmark symptom of which is acid reflux or heartburn. This creates a burning sensation behind your breastbone that sometimes travels up into your throat.
As GERD is not a disease but rather a condition,15 it’s important to recognize it’s commonly related to other conditions such as a hiatal hernia or a Helicobacter pylori infection. Although the conditions are unrelated, both trigger a chronic low-level inflammation in your stomach lining associated with the development of ulcers.
One study determined acid reflux had doubled in the previous 10 years16 and noted this rise runs parallel to the number who are obese and overweight as this is also a known risk factor. While nearly everyone has experienced heartburn at some point or another, when it occurs more than twice a week with inflammation in the esophagus, it may lead to a diagnosis of GERD.
Since chronic heartburn affects so many, it makes sense the medication developed by the pharmaceutical industry is one of the more popular drugs used in the world. Proton pump inhibitors (PPI) were once only available by prescription, but are now available over-the-counter. The drugs work by targeting acid producing cells.17
However, stomach acid is necessary for digestion and many times the lack of acid is a trigger for GERD and chronic indigestion. In these cases the drugs actually exacerbate the problem and also come with a long list of side effects, including an increased risk of bacterial infections,18 dementia19 and heart attack.20
Research has demonstrated diet plays a crucial role in the reducing acid reflux21 and simple changes may improve your symptoms better than pills. In my previous article, “Acid Reflux May Respond Better to Foods Than Prescribed Pills,” I share 10 natural ways to treat occasional reflux and why you may want to talk to your doctor about getting off PPIs.
Cancer — A Metabolic Disease
The featured study highlighted the effect environmental irritants have on the development of cancer and the Human Genome Project pointed out most cancers are not genetically based. In fact, genetic mutations in some cancers are actually a downstream effect of malfunctioning energy metabolism in the mitochondria.
Thomas Seyfried, Ph.D., professor of biology at Boston College, is a leading expert and researcher in the field of cancer metabolism and nutritional ketosis. He is one of the pioneers in the application of nutritional ketosis for cancer,22 following in Dr. Otto Warburg’s footsteps, who received the Nobel Prize in Physiology or Medicine23 in 1931 for the discovery of metabolism of malignant cells.
Seyfried holds that mitochondrial dysfunction is at the heart of many serious health conditions. This core principle alters treatment options for those suffering from cancer. To date, the cancer industry focuses on the downstream effect of the problem and not on mitochondrial dysfunction that may be the primary trigger.
Although some cancers are a result of environmentally triggered chronic inflammation, some treatment options may be found in nutritional changes. I discuss more about past research, and current prevention and treatment in my previous article, “Top Tips to Optimize Your Mitochondrial Health.”
Health Benefits of Coffee and Tea
Those experiencing higher risk for esophageal cancer in the featured study were drinking fluids hotter than 60 C (140 F). It’s important not to throw out the baby with the bathwater and remember there are significant health benefits to drinking organic, unsweetened coffee and tea, when you pay attention to the temperature of the beverage.
After water, coffee and tea are the most commonly consumed beverages worldwide and also the top sources of caffeine and antioxidant polyphenols for Americans. Tea is more popular in Asia and coffee in North and South America.24
Drinking green tea has been linked with a reduction in risk for stroke, diabetes and depression and demonstrated improvements in blood pressure, abdominal obesity and glucose levels.25 Although more study has gone into green tea, generally speaking, the less it is oxidized the lower its caffeine content and the higher the antioxidant levels.
The different types of tea include black, green, white and oolong. White tea is the least processed, while oolong is semi oxidized, placing it between green and black tea in terms of caffeine and antioxidant levels.26
Research presented at an American Heart Association meeting27 showed benefits to drinking coffee include a 7 percent lower risk and heart failure and an 8 percent lower risk of stroke for each additional cup of coffee consumed per week. Other research28 has linked coffee with a lower risk of cancer, nonalcoholic fatty liver disease and diabetes.
Drinking coffee has also been linked to a lower risk of glioma brain tumor and improved brain function,29 with other research demonstrating one or two cups of coffee each day may lower your risk of Alzheimer’s and other forms of dementia.30 Drinking coffee may enhance long-term memory and caffeinated coffee may improve attention and alertness while decreasing risk of depression.