Article from the Wall Street Journal Featuring a Water Study by Dr. Chan

WALL STREET JOURNAL
HEALTH JOURNAL
By MELINDA BECK
Studies Lead You to Water,
But How Much to Drink?
July 1, 2008; Page D1

Lately it's been in vogue to dismiss the advice to drink eight glasses of water a day as a "medical myth."

Books and medical-journal articles have declared there's no scientific evidence for claims that "8 x 8" -- eight ounces of water, eight times a day -- can bring a wide range of benefits, from speeding weight loss to ridding the body of toxins, fighting constipation, fatigue, dry skin and hastening recovery from colds and flu. Headlines have jeered that 8 x 8 "doesn't hold water" and "water advice doesn't wash."

How many glasses of water a day do you drink? Do you think everyone should drink eight glasses a day? Share your thoughts.It's really more a dispute over whether the glass is half empty or half full. Many studies have linked drinking extra water with health benefits, but critics generally dismiss them as statistically insignificant, inconclusive or not widely applicable.

For instance, a 10-year study of nearly 48,000 men published in the New England Journal of Medicine in 1999 found that the risk of bladder cancer fell 7% for every cup subjects drank per day. Other studies have found that the more water subjects drank, the fewer precancerous colon polyps they had. And a study of 20,000 Seventh-day Adventists in California in the American Journal of Epidemiology found that women who drank at least five glasses of water a day had a 41% lower risk of fatal heart disease, and men had a 54% lower risk, compared with those who drank just two glasses a day.

Physiologist Heniz Valtin of Dartmouth Medical School discussed these studies and more in a seminal 2002 article in the American Journal of Physiology -- and still concluded that they didn't support a universal recommendation that everyone drink 8 x 8, just people "known to have a propensity for the disease(s) in question." Six years later, Dr. Valtin says, "I haven't seen a single scientific report that disagrees with my conclusion."

Similarly, an editorial in the Journal of the American Society of Nephrology in April brushed off small studies suggesting that water increases thermogenesis (calorie-burning), reduces migraines and increases blood flow to the skin. The piece repeated Dr. Valtin's conclusion: "There's no clear evidence of benefit from drinking increased amounts of water." But, it added, "we concede there is also no clear evidence of lack of benefits."

That frustrates researchers in the field. "There's enough data to suggest that we should go get more data," says Jodi Stookey, a scientist at Children's Hospital and Research Center in Oakland, Calif. Her studies have found that substituting water for sweetened beverages helped female dieters cut overall calories (whereas diet drinks seem to stimulate more eating) and that women on four popular diets who drank at least one liter (34 ounces) of water a day lost more weight than those who didn't, regardless of their diet.

It's impossible to sort out cause and effect from casual associations in such studies, and participants aren't always accurate when asked to remember what they ate or drank. So what would satisfy skeptics as evidence? "Only large and expensive randomized trials could settle these questions definitely," the April editorial notes. "Given that water cannot be patented, such trials seem unlikely."

Urologists do agree that extra water can reduce the recurrence of kidney stones. But they don't know if water will prevent them in the first place. "Kidney stones occur in 4% to 5% of the population, so it's not practical to tell everyone to drink that much," says Stanley Goldfarb, a kidney specialist at the University of Pennsylvania Health System and co-author of the editorial.

He also disputes the notion that drinking extra water improves the function of various organs -- because it doesn't stick around. "You don't accumulate those eight glasses of water. They're in the toilet," he says, noting that the body has an exquisite system of self-regulation, excreting anything it doesn't need. And that doesn't mean the body is flushing out extra toxins, either, he says; the same toxins are just diluted in more water.

Experts also agree that people's water needs vary considerably: You'll need more if you're playing in the U.S. Open than if you're sitting at a computer in an air-conditioned office. But most nephrologists, and the National Academy of Sciences, say that thirst alone is a perfectly sufficient guide to how much you need. "Thirst is one of the most powerful human motivators -- it's way above sex," says Dr. Goldfarb.

Actually, that's a point of contention, too. Fereydoon Batmanghelidj, a controversial researcher who extolled the benefits of water in two books, called relying on thirst to regulate hydration "the greatest tragedy in medical history." He and other water aficionados believe that by the time people feel thirsty, they are already dehydrated. This camp believes that the body needs at least two liters of water a day to replace what it loses, and that other beverages, particularly caffeinated ones, don't count.

That's another big area of contention: In 2004, The Institute of Medicine reported that U.S. women who appeared to be adequately hydrated consumed the equivalent of about 91 ounces of fluids each day, and men about 125 ounces -- far more than the 64 ounces in eight glasses of water -- but stated that beverages other than water and the fluid in solid foods also counted toward the total. "Even a slice of white bread is more than 30% water," says Dr. Valtin.

Jacquelin Chan, an epidemiologist at Loma Linda University and the lead investigator on the Adventist heart study, says that some fluids like juice have been shown to increase blood viscosity, whereas water decreases it, at least temporarily. "That's why we tell people to drink water frequently during the day," says Dr. Chan, whose studies have also linked a lowered risk of stroke to drinking at least five glasses of water a day, which she also believes is due to reduced blood viscosity.

Dr. Chan also notes that fluid intake has already increased over the years: The mean intake of plain water is now six cups a day, up from just 2.6. in 1976, according to a big government study. But intake of caloric beverages and food has also increased sharply; She's now examining data from 97,000 Americans to further assess water and health links.

Whether the average human needs that much, many diet advisers -- from the late Robert Atkins to Oprah Winfrey -- firmly believe that drinking extra water helps people feel fuller and makes the body retain less fluid, even though some concede the benefit may be as much behavioral as metabolic.

"If your usual habit is to have a bowl of popcorn or peanuts on your desk, sipping on a glass of water instead is satisfying and keeps your hands and mouth busy," says Karen Miller-Kovach, chief scientific officer at Weight Watchers, which recommends six glasses a day.

"So many of my patients -- including physicians -- tell me that water improves their weight loss and reduces constipation and cuts fluid retention," says Manhattan weight-loss coach Stephen Gullo. "Try it yourself and see if it makes a difference. There's no downside."

Some marathoners have died from downing large quantities of water very quickly. The human body can absorb only about one quart of water per hour, max, and after that, the brain can swell dangerously, says Dr. Goldfarb.

Hyponatremia, in which the sodium concentration in the blood falls dangerously low, is another hazard in drinking too much water. But it's rare in healthy people. Drinking eight glasses a day "is not likely to harm you, but it's very unlikely to help you in any way that the conventional wisdom has been claiming," says Dr. Goldfarb.

Is there a bottom line in this debate? For one thing, more research is in order to verify the intriguing existing data. (Could it be that people who drink more water are just apt to be more thirsty because they exercise more?) In the meantime, if you don't overdo it, drinking water may possibly give you an edge in a number of health areas -- particularly if you drink it instead of caloric beverages. Even Dr. Goldfarb says, "We didn't say you shouldn't drink eight glasses of water a day, just that you don't have to.

• Email: healthjournal@wsj.com

Water, Other Fluids, and Fatal Coronary Heart Disease

The Adventist Health Study

Jacqueline Chan1,2, Synnove F. Knutsen1,3, Glen G. Blix2, Jerry W. Lee2 and Gary E. Fraser1,3

1 Adventist Health Studies, School of Public Health, Loma Linda University, Loma Linda, CA.
2 Department of Health Promotion and Education, School of Public Health, Loma Linda University, Loma Linda, CA.
3 Department of Epidemiology, School of Public Health, Loma Linda University, Loma Linda, CA.

Whole blood viscosity, plasma viscosity, hematocrit, and fibrinogen are considered independent risk factors for coronary heart disease and can be elevated by dehydration. The associations between fatal coronary heart disease and intake of water and fluids other than water were examined among the 8,280 male and 12,017 female participants aged 38–100 years who were without heart disease, stroke, or diabetes at baseline in 1976 in the Adventist Health Study, a prospective cohort study. A total of 246 fatal coronary heart disease events occurred during the 6-year follow-up. High daily intakes of water (five or more glasses) compared with low (two or fewer glasses) were associated with a relative risk in men of 0.46 (95% confidence interval (CI): 0.28, 0.75; p trend = 0.001) and, in women, of 0.59 (95% CI: 0.36, 0.97). A high versus low intake of fluids other than water was associated with a relative risk of 2.47 (95% CI: 1.04, 5.88) in women and of 1.46 (95% CI: 0.7, 3.03) in men. All associations remained virtually unchanged in multivariate analysis adjusting for age, smoking, hypertension, body mass index, education, and (in women only) hormone replacement therapy. Fluid intake as a putative coronary heart disease risk factor may deserve further consideration in other populations or using other study designs.

blood viscosity; coronary disease; dehydration; fluids and secretions; hemorheology; men; water; women

Abbreviations: CI, confidence interval

American Journal of Epidemiology Vol. 155, No. 9 : 827-833
Copyright © 2002 by The Johns Hopkins University School of Hygiene and Public Health

Water Charity and Local Partners

The Approach

Water Charity operates by forging partnerships with local organizations in the countries, cities, and communities in which we operate. Each situation we encounter is unique to the culture of the location and the needs of the people.

We respect the knowledge of the community in determining the hierarchy of needs, and the best solutions for their problems. Local participation assures that the projects have support, and will be maintained into the future, as the local groups have a stake in the outcome.

Our approach is to target projects, find local partners, establish quantifiable objectives, guide the projects to timely completion, and evaluate effectiveness of the processes and the outcomes.

We remain open and flexible in our approach, allowing us to move around obstacles and learn from our experiences. We tailor the approach to the circumstances surrounding the project at hand.

The Benefits

There are numerous benefits that accrue from local partnerships. The first is cost-effectiveness. The utilization of scarce project resources is multiplied by using local staff. Sending outside administration and labor from distant places to perform work on the ground is largely prohibitive.

Local partners can better understand the important economic and political issues that will impact on projects. Their knowledge of local customs, traditions, laws, and politics are essential for success.

Local partners, with their knowledge of the local resources and economy, can better navigate the planning and construction processes. It is often difficult for outside consultants to know about the availability of local products and labor necessary for the success of the project.

Using local partners gives us flexibility in staffing and scheduling. We can operate with a core staff, and multiply our capabilities with partnerships as the time comes and the need arises.

In summary, we have found that great benefit is obtained by seeking out and funding organizations to carry out or assist with projects. We have developed selection procedures that assure we will partner with local groups that are in the best position to implement the projects.

The Continuity

Our ability to partner with local groups not only assures the success of the immediate project, but it has long-lasting impact. It becomes more likely that the project will be maintained into the future. The skills learned by our local partners can be replicated, taught to other local groups, and expanded into other projects.

After a successful project with a partner, with our new experience gained in the locality, it often is logical to plan subsequent projects along the same model. Another job with the same partner becomes much easier, as compared with starting a new selection process from scratch.

The Selection Process

Thus, it is seen that the process to select local partners is crucial to the success of the project. Within the geographical area we have selected as meeting our criteria for need and feasibility, we establish a list of potential partners.

We review available information on candidate partners, and request further information from those in which we see a potential.

We then conduct an in-depth in-country analysis of potential relationships. We look at past and current projects of potential partners, and check references with government agencies, community groups, and individuals.

There are many factors that enter into the evaluation of partnership organizations. These include the nature of the organization, their past performance in similar projects, their technical capability, their financial condition, their ability to interact with other organizations and individuals, their ability to interact with the existing social and political structures, and their ongoing capability to provide support after project completion.

Conclusion

The approach of partnering with local groups is well established, and provides a multitude of benefits. It assures that our limited resources will move us as far and as fast as possible toward our established goals.

Turbulent Waters

MSN Health & Fitness

Turbulent Waters
By Allison J. Cleary, EatingWell.com

They're everywhere. Bottles of water have become near-fashion statements for the nutritionally hip, sloshing about in the hands of college students, mall shoppers, office workers and joggers. From construction site to corporate boardroom, we sip them throughout the day, urged on by health-care professionals, parents and teachers to drink more. In the unsettled rivers of nutrition advice, at least one message has run strong for decades: drink eight 8-ounce glasses of water every day or risk the consequences of neglected health. But recent studies question just how much water we really need each day.

For years, says Heinz Valtin, a kidney specialist at Dartmouth Medical School, he and colleagues who specialize in the field of water balance have suspected that the recommendation to drink 64 ounces of water a day (also called the "8-by-8" rule) might lack proof. So when The American Journal of Physiology invited him to review the scientific literature for evidence that supports the claim, Valtin began a 10-month search that came up empty.

"I have found absolutely no scientific evidence that supports the recommendation that everyone drink at least eight 8-ounce glasses of water a day to promote health and avoid dehydration," Valtin writes.

For some people who have found the two-quart advice difficult to swallow, the news may come as a relief, to their bladders at the very least. Valtin suggests that for the average healthy adult, living in a temperate climate and leading a sedentary existence—working in an office, for example—between six and seven 8-ounce glasses of fluid are probably enough.

Not everyone in the medical establishment agrees. Jacqueline Chan, a researcher on the Adventist Health Study, tracked the health and lifestyles of more than 20,000 Seventh-Day Adventists in California and found that the more water a person drinks, the more likely he or she will avoid fatal heart attacks.

"Men drinking five or more glasses of water a day can reduce their risk of a fatal heart attack by 50 percent. That's as much as stopping smoking," Chan marvels.

Chan suspects that the protection water seems to provide may be related to blood viscosity, essentially how thick it is. She postulates that a man who drinks five or more glasses of water per day will have much thinner blood than the average man who drinks only 2.8 glasses of water, the comparison figure.

"Higher blood viscosity increases damage to the inner lining of the blood vessels," Chan explains. "The more damaged the arteries, the narrower they become and the chance of clotting increases." Heart attacks are the result of clots that can block the flow of blood to the heart.

For women, the risk reduction from water was slightly less dramatic but still significant at 40 percent. That may be because women, whose blood cells bend more easily, generally have a lower blood viscosity than males, Chan says. "And we don't sweat as much as men so we don't lose water as quickly," she adds.

Valtin, who reviewed Chan's study favorably, says she and her colleagues offer a reasonable explanation for the correlation they found between water intake and heart problems, but points out that the benefits were seen with as few as five glasses a day, considerably less than the 8-by-8 rule.

But Chan believes that the protection would increase with even more water. Unfortunately, the low number of people drinking eight or more glasses of water among the 20,000 Adventists studied was not significant enough to provide statistically convincing results.

The two scientists also differ on the type of fluid that counts. "By and large, the six to seven glasses I speak of to maintain water balance can include beverages other than water, such as coffee, tea, soft drinks, even beer in moderation," Valtin concludes. But Chan's analysis showed that women who drank five or more glasses of fluids instead of water—milk, caffeinated beverages, juices or sodas—were more than twice as likely to suffer a fatal heart attack than those who stuck to water. So convincing were the results that Chan says, "I can't believe that water isn't in the food pyramid."

If you choose to follow the 8-by-8 rule, the challenge lies in how to succeed in filling up. "You have to do more than sip," Chan says. At the beginning of the work day, she fills a glass jug with 48 ounces of water and makes sure that she has finished drinking it by day's end. "I get distracted by my work and I won't take the time to walk down the hall to the water fountain." At home she makes sure that she adds a glass of water to the equation in the morning and evening.

In his survey of the literature, Valtin points to studies that correlate higher fluid intakes—six glasses and more— with lower incidences of bladder and colorectal cancer, urinary tract infections and kidney stones. He also stresses that strenuous physical activity, long airplane flights, hot weather and certain diseases increase the human body's need for water.

However, he argues that most of us "are probably drinking enough," and says that the burden of proof for the health benefits of drinking more than six glasses of fluid per day is now on those who recommend the 8-by-8 water regimen.

Chan, on the other hand, asserts that all those daylong water quaffers are making the right choice in replacing caffeinated, sweetened and alcoholic fluids with pure water.