14 replies to this topic

[doug123]

Green Tea Consumption and Mortality

In vitro and animal data suggest that green tea consumption may protect against cardiovascular disease (CVD) and cancer, but data from human studies are lacking. Kuriyama and colleagues report results of a prospective cohort study of Japanese adults who had no history of CVD or cancer at baseline. During 11 years of follow-up, the authors found significant inverse associations of green tea consumption with reduced all-cause and CVD mortality, particularly among women, but found no association with cancer mortality.

Link to source

Vol. 296 No. 10, September 13, 2006

Original Contribution

Green Tea Consumption and Mortality Due to Cardiovascular Disease, Cancer, and All Causes in Japan

The Ohsaki Study

Shinichi Kuriyama, MD, PhD; Taichi Shimazu, MD; Kaori Ohmori, MD, PhD; Nobutaka Kikuchi, MD; Naoki Nakaya, PhD; Yoshikazu Nishino, MD, PhD; Yoshitaka Tsubono, MD, PhD; Ichiro Tsuji, MD, PhD

JAMA. 2006;296:1255-1265.

Context Green tea polyphenols have been extensively studied as cardiovascular disease and cancer chemopreventive agents in vitro and in animal studies. However, the effects of green tea consumption in humans remain unclear.

Objective To investigate the associations between green tea consumption and all-cause and cause-specific mortality.

Design, Setting, and Participants The Ohsaki National Health Insurance Cohort Study, a population-based, prospective cohort study initiated in 1994 among 40 530 Japanese adults aged 40 to 79 years without history of stroke, coronary heart disease, or cancer at baseline. Participants were followed up for up to 11 years (1995-2005) for all-cause mortality and for up to 7 years (1995-2001) for cause-specific mortality.

Main Outcome Measures Mortality due to cardiovascular disease, cancer, and all causes.

Results Over 11 years of follow-up (follow-up rate, 86.1%), 4209 participants died, and over 7 years of follow-up (follow-up rate, 89.6%), 892 participants died of cardiovascular disease and 1134 participants died of cancer. Green tea consumption was inversely associated with mortality due to all causes and due to cardiovascular disease. The inverse association with all-cause mortality was stronger in women (P = .03 for interaction with sex). In men, the multivariate hazard ratios of mortality due to all causes associated with different green tea consumption frequencies were 1.00 (reference) for less than 1 cup/d, 0.93 (95% confidence interval [CI], 0.83-1.05) for 1 to 2 cups/d, 0.95 (95% CI, 0.85-1.06) for 3 to 4 cups/d, and 0.88 (95% CI, 0.79-0.98) for 5 or more cups/d, respectively (P = .03 for trend). The corresponding data for women were 1.00, 0.98 (95% CI, 0.84-1.15), 0.82 (95% CI, 0.70-0.95), and 0.77 (95% CI, 0.67-0.89), respectively (P<.001 for trend). The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality. This inverse association was also stronger in women (P = .08 for interaction with sex). In women, the multivariate hazard ratios of cardiovascular disease mortality across increasing green tea consumption categories were 1.00, 0.84 (95% CI, 0.63-1.12), 0.69 (95% CI, 0.52-0.93), and 0.69 (95% CI, 0.53-0.90), respectively (P = .004 for trend). Among the types of cardiovascular disease mortality, the strongest inverse association was observed for stroke mortality. In contrast, the hazard ratios of cancer mortality were not significantly different from 1.00 in all green tea categories compared with the lowest-consumption category.

Conclusion Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.


Author Affiliations: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine (Drs Kuriyama, Shimazu, Ohmori, Kikuchi, Nakaya, and Tsuji), and Division of Health Policy, Tohoku University School of Public Policy (Dr Tsubono), Sendai, Japan; Division of Epidemiology, Miyagi Cancer Center Research Institute, Natori, Japan (Dr Nishino).

[John Schloendorn]

the authors found significant inverse associations of green tea consumption with reduced all-cause and CVD mortality

Inverse association with reduced mortality?? [:o]

[Athanasios]

I think the word reduced should not have been put into the sentence. The rest of the data seems to support that it was gramatical error : "The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality."

[doug123]

Inverse association with reduced mortality??  [:o]

The key terms are "all cause" and CVD. Let's take a look into what this means...

However, this is a HIGHLY credible publishing that the medical community can't laugh off as hype. If you aren't aware, the (I can say with confidence) most respected medical journals in the world are JAMA and The Lancet. JAMA is a publication of the American Medical Association.

However, these results are all from Japanese subjects. As we learned in this article -- where you live might have a lot to do with how long you live. Genetic factors may be involved.

[Athanasios]

The key terms are "all cause" and CVD.  Let's take a look into what this means...

However, this is a HIGHLY credible publishing that the medical community can't laugh off as hype.  If you aren't aware, the (I can say with confidence) most respected medical journals in the world are JAMA and The Lancet.  JAMA is a publication of the American Medical Association. 

However, these results are all from Japanese subjects.  As we learned in this article -- where you live might have a lot to do with how long you live.  Genetic factors may be involved.

An inverse association with REDUCED mortality means that green tea led to increased mortality. I think that is what John was getting at.

[doug123]

The key terms are "all cause" and CVD.  Let's take a look into what this means...

However, this is a HIGHLY credible publishing that the medical community can't laugh off as hype.  If you aren't aware, the (I can say with confidence) most respected medical journals in the world are JAMA and The Lancet.  JAMA is a publication of the American Medical Association. 

However, these results are all from Japanese subjects.  As we learned in this article -- where you live might have a lot to do with how long you live.  Genetic factors may be involved.

An inverse association with REDUCED mortality means that green tea led to increased mortality. I think that is what John was getting at.

The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality.

And the conclusion from the entire study is clear:

Conclusion Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.

This is the strongest evidence to support the use of green tea as an anti-aging supplement that I've seen. Reduced mortality = reduced death.

But if you read the other link I included, a Harvard study found a HUGE discrepancy in life expectancy when they looked at different regions in the USA. I'd say any study that comes from Harvard University is also pretty damn credible.

I'll paste it here:

Wide gaps in US life expectancy
Data vary across races, regions

By Scott Allen, Globe Staff  |  September 13, 2006

Asian women in Bergen County, N.J., typically live at least 30 years longer than Native Americans in South Dakota, highlighting an enormous gulf in life expectancy between the longest - and shortest-lived people in the United States, according to a provocative new Harvard University study.

Nationally, the study finds that Asians live the longest -- 84.9 years on average -- while urban blacks in high -crime areas have the shortest life expectancy, just 71.1 years. But people in certain counties face even shorter lives: Residents of six South Dakota counties typically die before age 67, while people in Baltimore live an average of 68.6 years, according to the study. Native American men in one South Dakota county typically only live to about 58.

Dr. Christopher Murray , the lead author, said he was surprised to find large groups in the United States whose mortality rates rival those he's seen in the Russian Federation and sub-Saharan Africa. He said millions of people, such as rural blacks in the South, don't get nearly enough help managing chronic conditions like cancer and heart disease, or reducing preventable injuries caused by drunken-driving accidents and assaults.

``If we're able to deliver [AIDS drugs] to rural Zambia, why can't we manage cholesterol and blood pressure in rural Mississippi?" said Murray, a specialist on health problems in developing countries.

Massachusetts ranks fifth among states in life expectancy, at 78.4 years, but the counties containing Boston and Springfield lag behind at 76.5 and 76.7 years respectively. Four southeastern counties -- Norfolk, Barnstable, Dukes , and Nantucket -- had the longest life expectancies in the state, all above 79 years.

Connecticut, New Hampshire , and Rhode Island also ranked in the top 10 states for longevity.

Murray's study, in this month's edition of the journal PLoS Medicine, adds to a body of research that indicates the United States is making little progress at improving the health of its disadvantaged residents. A federal Health Resources and Services Administration study this year showed the ``longevity gap" between the most and least advantaged populations has doubled since 1980.

Murray's work ``is very consistent with what we have found," said study coauthor Gopal K. Singh , who believes the widening gap reflects growing inequality in income, access to health care , and other basics.

But Murray concludes that popular health care reforms, such as expanding insurance or boosting care for children and the elderly, won't by themselves significantly reduce the longevity gap. He said chronic diseases and preventable injuries that strike young and middle-aged adults -- insured and uninsured alike -- are the main reason that blacks, Western Native Americans , and some low - income whites have shorter average life spans . If governments want to improve life expectancies, Murray said , they need to do a better job of combating the leading killers for each group.
© Copyright 2006 The New York Times Company

Maybe this discrepancy is due to green tea? Of course, I am only kidding...

[Brainbox]

How can we avoid drinking green tea with "additives" like pesticides? A few years ago there was a warning in my country to be careful with green tea. The demand being higher than the production capacity was and could still be a reason for green tea producers to take draconian measures to increase production.

[Athanasios]

And the conclusion from the entire study is clear:

Conclusion Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.

Nobody has yet tried to refute the validity of the study. We only pointed out a gramatical error, see my post to john above.

[jmmathieu]

How can we avoid drinking green tea with "additives" like pesticides?

Buy organic green tea.

Interesting stuff, but I'm waiting for the day we find something that increases maximum lifespan. There are thousands of things you can do to decrease your risk of mortality.

[Athanasios]

How can we avoid drinking green tea with "additives" like pesticides?

Buy organic green tea.

Interesting stuff, but I'm waiting for the day we find something that increases maximum lifespan. There are thousands of things you can do to decrease your risk of mortality.

The years that you get by squaring the curve seem very significant in a technological progress perspective. Technology is important for finding something that increases maximum lifespan. I think people downplay this point all too much when talking of supplements and healthy lifestyles. Me?, I want to do those thousands of things.

[doug123]

Here's a follow up on this:

The Japan Times

Saturday, Sept. 16, 2006

BENEFITS EMERGE IN LARGE GROUP OF JAPANESE
Green tea cuts risk of stroke, but not cancer: study

By LINDSEY TANNER
CHICAGO (AP) Can drinking green tea really protect against two big killers, strokes and cancer? A study involving more than 40,000 people in Japan suggests yes and no: It might lower your risk of stroke but will not save you from cancer.

The study's authors say their findings might explain why Japanese are less likely than Americans to die of heart disease and stroke. Even so, the answers are not clear. Green tea has been researched a lot and many of the studies have yielded conflicting results.

Earlier this year, the U.S. Food and Drug Administration said an analysis found no credible scientific evidence to support manufacturers' claims that green tea can cut cardiovascular disease risks.

The National Cancer Institute says human studies on tea and cancer prevention have produced contradictory results. But there is still hope, and the institute is funding rigorous studies testing whether tea extract can help prevent several kinds of cancer.

Tea contains antioxidants that can help keep cells healthy. Green tea has more of them than black tea, and studies in animals have shown that tea antioxidants, called catechins, seem to shrink cancerous tumors. Some studies on humans have suggested tea can also help keep arteries and cholesterol healthy.

The current study was funded by the Japanese government and is published in Wednesday's Journal of the American Medical Association. Shinichi Kuriyama of Tohoku University in Sendai is the lead author.

The study is different from many previous studies because it involved so many people -- 40,530 Japanese adults. Those who drank a lot of green tea were less likely than those who drank only a little tea to die from cardiovascular disease and other causes, but not cancer.

Because tea-drinking is popular among Japanese people from all lifestyles and economic groups, the research seems to refute a criticism of previous studies -- that people who drink green tea are higher income and more health-conscious and thus apt to be healthier anyway.

However, heavy tea drinkers in the study also tended to eat more fruits and vegetables, and such a diet also might reduce cardiovascular disease and cancer risks, said John Folts, a professor of medicine at the University of Wisconsin.

Study participants were generally less overweight than Americans, and it is unknown if similar results would be found in a more diverse group of people, said Alice Lichtenstein, a Tufts University nutrition professor and spokeswoman for the American Heart Association.

The results from this study, which observed people and their habits over many years, "point you in a direction" but are not conclusive, she said.

The Japanese volunteers filled out questionnaires on tea-drinking and other habits including diet, alcohol and tobacco use, weight, job and educational background, and physical activity.

During seven years of followup, 1,134 participants died of cancer and 892 died from cardiovascular disease.

Women who drank five or more cups of green tea daily had a 31 percent lower risk of dying from cardiovascular disease than women who drank less than one cup daily. In men, the comparable reduced risk was 22 percent.

Cardiovascular disease includes heart disease and stroke. While heavy tea drinkers had less heart disease than those who drank little tea, the results suggest the difference for heart disease alone might have been due to chance.

Green tea appeared to work best against clot-related strokes. Among the five-cup-a-day group, women had a 62 percent lower risk of dying from these strokes than women who drank little tea, and for men the reduced risk was 42 percent.

The researchers said more men were smokers, and that might have explained the gender differences since smoking affects cardiovascular disease risks.

There were no significant differences in cancer death rates among heavy and light tea drinkers of either sex.

While the study is not the last word on whether tea-drinking is good for you, tea is generally harmless and has no calories, so if you like the taste, most researchers would probably tell you to drink it.

"The point is, if you're drinking green tea, that's fine. It's premature to recommend that somebody start drinking" it to protect their health, Lichtenstein said.

The Japan Times
© All rights reserved

[doug123]

How can we avoid drinking green tea with "additives" like pesticides? A few years ago there was a warning in my country to be careful with green tea. The demand being higher than the production capacity was and could still be a reason for green tea producers to take draconian measures to increase production.

That's a good point. Today's news is that Lingering pesticides linked to Parkinson's:

DIET, EXERCISE AND COFFEE MIGHT HELP 

More than 1 million people in the USA have Parkinson's, a disease that strikes mostly after age 60. Scientific evidence suggests these steps might help protect the brain:

• Drink a cup of coffee every day. Studies suggest that coffee drinkers are less likely to develop Parkinson's. Some researchers speculate that the caffeine in coffee helps protect the brain.

• Go to the gym, take a walk or just get out and move most days of the week. Research indicates that people who exercise regularly lower their risk.

• Eat foods rich in antioxidants, such as dark, leafy greens or fruits like blueberries and oranges. Antioxidants are natural substances that help limit damage to brain cells and thus might help ward off Parkinson's.


Sources: USA TODAY research and Gary Miller, Emory University


By Kathleen Fackelmann, USA TODAY
Past exposure to low levels of pesticides that linger in the environment might accelerate the development of Parkinson's, which would put baby boomers and millions of other aging Americans at risk of developing the brain disease earlier in life.
At the American Chemical Society meeting in San Francisco last week, researchers presented new findings that link Parkinson's to exposure to the pesticides dieldrin and DDT. The federal government banned the toxins in the 1970s, but low levels still linger in the soil, says lead researcher Gary Miller of Emory University in Atlanta. Miller's research focused on how exposure to the pesticides from years ago affected the later development of Parkinson's.

"If you're exposed to a pesticide like dieldrin, you might be diagnosed (with Parkinson's) at age 70 instead of at 80," Miller says.

The preliminary report at the ACS meeting fits with evidence from a large study published in July that suggests that exposure to pesticides might increase the risk of developing the degenerative brain disease, which often is diagnosed after age 60. That report didn't zero in on a specific pesticide, but Miller and his colleague Kurt Pennell at the Georgia Institute of Technology did.

The team examined brain tissue taken from 14 Parkinson's patients and 12 people who did not have the disease. They found that levels of dieldrin were three times higher in the brain tissue taken from the Parkinson's patients. That tissue also had the same high levels of a breakdown product of DDT.

A second report by the same team helps explain how pesticides might injure the brain.

Miller and Pennell gave small doses of dieldrin to laboratory mice. After only a month, the team found that the pesticide increased the amount of brain damage done by free radicals, highly reactive molecules that are a byproduct of metabolism.

The team found evidence that free radicals had damaged certain brain cells that produce dopamine, a neurotransmitter that plays a key role in Parkinson's disease. People who sustain damage to these same brain cells start to develop the symptoms of Parkinson's, such as a shuffling walk, Miller says.

He believes Parkinson's is kicked off by a combination of factors, including genes, but then the disease speeds up as a result of exposure to pesticides such as dieldrin.

The findings add to others that have linked pesticides to Parkinson's, including a study of more than 143,000 people conducted by researcher Alberto Ascherio of the Harvard School of Public Health and published in the July issue of the Annals of Neurology. He found that people who had reported exposure to pesticides had a 70% greater risk of Parkinson's.

Ascherio says pesticides still in use, such as those for a home garden, also might pose some risk to these sensitive brain cells. To be safe, he says, "people should limit their exposure."

[Athanasios]

When I have time I will look up the study on green tea and cancer. In the past, it was shown that cancer was possibly delayed by drinking 10 cups of sencha a day. Depending on what teas this study was looking at, as well as what they considered as a heavy drinker, it may or may not contradict the previous study.

[doug123]

If you aren't aware, the (I can say with confidence) most respected medical journals in the world are JAMA and The Lancet.  JAMA is a publication of the American Medical Association. 

I forgot all about the New England Journal of Medicine!

Edited by nootropikamil, 23 September 2006 - 08:23 PM.

[Athanasios]

When I have time I will look up the study on green tea and cancer. In the past, it was shown that cancer was possibly delayed by drinking 10 cups of sencha a day. Depending on what teas this study was looking at, as well as what they considered as a heavy drinker, it may or may not contradict the previous study.

Yeah, they stopped at the 5+ cup level, which is still in line with the other study implying that green tea of 10+ cups would delay cancer.