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Go and drink that cup or two of organic coffee or tea. An October 2020 study has linked drinking four or more cups of green tea every day, combined with two or more cups of coffee, with a 63% lower risk of death in Type 2 diabetes patients
Research continues to pour in that coffee does far more than just stimulate alertness and, like green tea, serves as more than just a pick-me-up every morning. One study found, in fact, that drinking plenty of both beverages is linked to a lower risk of dying from any cause among Type 2 diabetics.
The October 2020 study, published in the journal BMJ Open Diabetes Research & Care, concluded that drinking four or more cups of green tea every day, plus two or more of coffee, translated to a 63% lower risk of death in the subjects over a five-year period.[i]
Green Tea and Coffee: A Winning Beverage Combo for Diabetics
People with diabetes are at an increased risk for disease including dementia, cancer and bone fractures, affecting their quality and length of life.[ii] Regularly consuming green tea and coffee, according to previous research, can be beneficial for health. However, few epidemiological studies on coffee have been done on diabetes patients.[iii]
Green tea consumption, on the other hand, has previously been reported to offer health benefits such as helping to prevent chronic conditions like diabetes. Yet, the connection between green tea consumption and mortality in diabetics is unclear.[iv],[v]
The featured study followed the heath of 4,923 Japanese people, both men and women, with Type 2 diabetes for 5.3 years on average. All the participants were enrolled in the Fukuoka Diabetes Registry, a study looking at the impact of drug treatments and lifestyle on the lifespan of Type 2 diabetes patients.
In the study, the participants completed a food and drink questionnaire that included questions on how much green tea and coffee they consumed daily. They also provided information about their lifestyle, such as their level of exercise, alcohol intake, smoking and number of hours of sleep every night. The researchers then measured height, weight and blood pressure, as well as took blood and urine samples to determine underlying risk factors.
Of the participants, 607 did not drink green tea. Some 1,143 drank up to one cup a day, 1,389 drank two to three cups, and 1,784 drank four cups or more. When it came to coffee consumption, 994 did not drink coffee, 1,306 consumed less than one cup daily, 963 consumed one cup and 1,660 consumed two cups or more.
Subjects who drank green tea or coffee had a lower likelihood of dying from any cause. The lowest odds were linked with drinking higher amounts of both beverages:[vi]
- 51% lower for two to three cups of green tea plus two or more of coffee
- 58% lower for four or more cups of green tea plus one cup of coffee every day
- 63% lower for a combination of four or more cups of green tea and two or more cups of coffee every day
Among green tea drinkers, consuming up to one cup every day was tied with a 15% reduced death risk, two to three cups with 27% lower risk, and four or more cups every day with a 40% lower risk.
In coffee drinkers, up to one cup per day was linked to 12% lower mortality risk, one cup a day with 19% lower risk, and two or more cups with a 41% lower risk. During the study period, 309 subjects died, with cancer and cardiovascular disease as the main causes.
"This prospective cohort study demonstrated that greater consumption of green tea and coffee was significantly associated with reduced all-cause mortality: the effects may be additive," concluded the researchers.[vii] "Our results suggest that consuming green tea and coffee may have beneficial effects on the longevity of Japanese people with type 2 diabetes."
Where Do Green Tea and Coffee Benefits Come From?
While green tea was suggested as a therapeutic agent for treating diabetes more than 70 years ago, the exact mechanisms remain elusive.[viii] Green tea offers antioxidant and anti-inflammatory properties, such as from phenols and theanine, that have been hailed for reducing oxidative stress and slowing the aging process.
For instance, daily consumption of green tea catechin delayed memory regression as well as brain dysfunction in aged mice.[ix] In Vietnamese adults, habitual tea consumption was associated with a decreased risk of Type 2 diabetes.[x] A study on diabetic mice also showed that the green tea extract EGCG prevented glucose intolerance.[xi]
On the GreenMedInfo.com database, we have organized a mere fraction of the research out there that relates to green tea's beneficial role in 400 health conditions, as you can see in our evidence-based research page.
Coffee, on the other hand, contains different bioactive chemicals that include phenols and caffeine, reported to affect health through antioxidant, anti-inflammatory and anti-mutagenic action.[xii],[xiii]
The exact mechanisms behind coffee's benefits against diabetes, specifically glucose metabolism biomarkers, are still being explored.[xiv] However, caffeine is thought to alter insulin production and sensitivity, thus contributing to a reduced diabetes risk.[xv] It also appears that chlorogenic acid may contribute to coffee's beneficial effects against Type 2 diabetes.[xvi]
[i] Komorita Y et al "Additive effects of green tea and coffee on all-cause mortality in patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry" BMJ Open Diabetes Research and Care. 2020;8:e001252. doi:10.1136/bmjdrc-2020-001252.
[iii] Bidel S et al "Coffee consumption and risk of total and cardiovascular mortality among patients with type 2 diabetes" Diabetologia 2006;49:2618-26.doi:10.1007/s00125-006-0435-9.
[v] Komorita Y et al "Additive effects of green tea and coffee on all-cause mortality in patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry" BMJ Open Diabetes Research and Care. 2020;8:e001252. doi:10.1136/bmjdrc-2020-001252.
[vi] MedPage Today October 20, 2020 https://www.medpagetoday.com/endocrinology/diabetes/89223
[vii] Komorita Y et al "Additive effects of green tea and coffee on all-cause mortality in patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry" BMJ Open Diabetes Research and Care. 2020;8:e001252. doi:10.1136/bmjdrc-2020-001252
[viii] Ortsater H et al "Diet supplementation with green tea extract epigallocatechin gallate prevents progression to glucose intolerance in db/db mice" Nutr Metab (Lond). 2012 Feb 14 ;9(1):11. Epub 2012 Feb 14.
[ix] Unno K et al "Daily consumption of green tea catechin delays memory regression in aged mice" Biogerontology. 2007 Apr;8(2):89-95. Epub 2006 Sep 7.
[x] Nguyen C et al "Habitual tea drinking associated with a lower risk of type 2 diabetes in Vietnamese adults" Asia Pac J Clin Nutr. 2018 ;27(3):701-706.
[xi] Ortsater H et al "Diet supplementation with green tea extract epigallocatechin gallate prevents progression to glucose intolerance in db/db mice" Nutr Metab (Lond). 2012 Feb 14 ;9(1):11. Epub 2012 Feb 14.
[xii] Martini D et al "Coffee consumption and oxidative stress: a review of human intervention studies." Molecules. 2016;21:979.doi:10.3390/molecules21080979
[xiii] Poole R et al "Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes" BMJ. 2017;359:j5024.doi:10.1136/bmj.j
[xiv] Reis C et al "Effects of coffee consumption on glucose metabolism: A systematic review of clinical trials" J Tradit Complement Med. 2019 Jul; 9(3): 184-191. Epub 2018 May 3.
[xv] Komorita Y et al "Additive effects of green tea and coffee on all-cause mortality in patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry" BMJ Open Diabetes Research and Care. 2020;8:e001252. doi:10.1136/bmjdrc-2020-001252.
[xvi] Ong K et al "Chlorogenic acid stimulates glucose transport in skeletal muscle via AMPK activation: a contributor to the beneficial effects of coffee on diabetes" PLoS One. 2012 ;7(3):e32718. Epub 2012 Mar 7.