Both green tea and coffee are regularly in the headlines for their potential health benefits. They're also easy to find and affordable. Both have pros and cons. Which is better comes down to personal taste, how you drink them, and your overall health.
The Basics
Green tea and coffee are both popular hot beverages. Many people make both a part of their daily diet.
Source
Green tea comes from the Camellia sinesis plant, the same plant black tea originates from. Coffee comes from the seeds of the Coffea plant.
Processing
Green tea leaves are harvested and dried to prevent oxidation. This process helps retain more nutrients and makes the tea less acidic. The dried green tea leaves are either left loose or manufactured into tea bags and steeped in hot water to make the beverage. To make coffee, Coffea seeds are dried and roasted to become coffee beans, which are then ground and filtered with hot water.
Health Benefits
Coffee was once considered unhealthy because of its caffeine content, but experts have changed their tune. Research shows both green tea and coffee have many potential health benefits.
Cardiovascular Disease Risk
Both coffee and tea appear to reduce the risk of mortality from cardiovascular disease.
- A 2011 meta-analysis showed green tea consumption significantly lowered total and LDL (bad) cholesterol but had no effect on HDL (good) cholesterol.
- Animal studies show the catechins in green tea may block the intestinal absorption of lipids. Lipids may contribute to cardiovascular disease risk.
- A separate analysis found green tea lowered cholesterol and blood pressure.
- The 2015 U.S. Dietary Guidelines state consuming caffeinated or decaffeinated coffee in moderation may reduce your total mortality risk and your cardiovascular mortality risk.
Antioxidants
Both coffee and green tea are high in antioxidants.
- Green tea contains polyphenols, a type of antioxidant known as catechin, including a substance known as EGCG or epigallocatechin gallate.
- Coffee is also high in antioxidants. One study showed the antioxidants in coffee may help reduce inflammation that leads to cardiovascular disease and other inflammatory illnesses.
Cancer Prevention
Both brews appear to be beneficial for cancer prevention, as well.
- A review of in vitro, in vivo, and epidemiological studies on green tea and ovarian cancer determined the brew may play a role in preventing and treating ovarian cancer and reducing the risk of recurrence.
- A study on green tea and colorectal cancer found non-smokers who drink green tea at least three times a week for six months have a reduced risk.
- According to a CBS News report, research showed caffeinated coffee lowered colon cancer recurrence and cancer death in people with stage three colon cancer. Decaf coffee showed no benefit.
More study is needed to determine the extent of both beverages' effects on cancer.
Brain, Metabolism, and Mood
Both green tea and coffee may have mood enhancing benefits, and the caffeine in both beverages may improve concentration and alertness, as well as positively affecting metabolism.
- A WebMD report mentions a study that showed people over 60 who drank green tea one to six times weekly have less mental decline. Another study may have discovered why. Researchers found green tea increased parieto-frontal brain connectivity associated with improved memory performance.
- Caffeine in both beverages is also known for being a stimulant that offers a quick pick-me-up or energy boost by increasing serotonin in the brain.
- Caffeine/coffee stimulates the metabolism.
Diabetes
Both green tea and coffee may help prevent diabetes. However, results of studies are mixed.
- According to a 2015 study, regularly drinking green tea may help regulate glucose levels and improve type II diabetes.
- Other research showed the antioxidants in green tea may prevent metabolic syndrome. Metabolic syndrome is a group of diabetes risk factors, such as a large waist, high blood sugar, high cholesterol, and high blood pressure.
- A review of studies found long-term consumption of caffeinated and decaffeinated coffee may "have a weak ability to help persons achieve weight loss." The weight loss may help reduce the risk of diabetes. Findings also suggest decaffeinated coffee may help regulate blood sugar better than caffeinated.
Athletic Performance
Both coffee and green tea may help boost athletic performance, although this is mostly likely due to the caffeine content.
- According to an abstract published at NCBI, research shows the caffeine in coffee improves short-term exercise performance.
- Caffeine in green tea may help exercise performance also, but no scientific studies exist confirming that theory.
Bone Density and Osteoporosis
While both coffee and green tea seem to have similar properties regarding several health issues, when it comes to bone density and osteoporosis, the two part ways.
- Cleveland Clinic notes coffee may reduce bone density, which may lead to osteoporosis.
- On the other hand, some studies show green tea consumption may have a protective effect against development of osteoporosis.
Parkinson's Disease
Both beverages may be beneficial for people with Parkinson's disease.
- A study on older Japanese-American men found the caffeine in coffee may reduce the risk of Parkinson's disease.
- Another study found 100 mg of caffeine twice daily, the amount in about two cups of coffee, may help reduce Parkinson's symptoms, such as daytime sleepiness and motor problems.
- According to a study funded by the Michael J. Fox Foundation for Parkinson's Research, green tea polyphenols may reduce early untreated Parkinson's symptoms.
Caffeine in Green Tea and Coffee
The caffeine content in green tea and coffee varies by brand. In general, coffee has anywhere from twice the amount of caffeine as green tea to four times the amount.
- According to Mayo Clinic, eight ounces of brewed green tea averages 24-45 mg of caffeine.
- Eight ounces of brewed coffee averages 95-200 mg.
- According to an article on Dr. Andrew Weil's website, the decaffeination process of green tea reduces polyphenols by 15 to 25 percent.
- One study showed decaffeinated coffee also had fewer antioxidants than coffee with caffeine.
Hydration
Both coffee and green tea have similar effects on hydration. However, caffeine is a diuretic, which may make you run to the bathroom to urinate more than usual. With its higher caffeine content, coffee may cause more fluid loss than green tea. However, according to the Mayo Clinic, caffeine and its diuretic effect does not lead to dehydration. Caffeinated drinks like green tea and coffee help you meet your daily requirement of fluids.
And the Winner Is...
It depends. Whether you're on team coffee or team green tea, both offer important potential health benefits, help keep you hydrated, and contain antioxidants. Both have caffeine to help keep you alert and possibly reduce your risk of dementia, although coffee tends to be much higher in caffeine than green tea. However, when it comes to bone density and prevention of osteoporosis, green tea may have an edge. Drinking either in moderation won't hurt, and they may even confer certain health benefits.
