Soda is Bad, But What About Carbonated Water?
In our latest newsletter, we suggested carbonating water as one way to kick a sugary soda habit. Yesterday, we received an inquiry as to the safety of drinking carbonated water, in particular the possible effects of drinking carbonated water as it might rob bones of calcium and minerals.
Through a string of correspondences, our new friend Holly and I exchanged emails about the truth behind this oft shared bit of misinformation surrounding carbonated water. I passed along numerous articles and studies that show that the INGREDIENTS in soda, not the carbonation, lead to osteopathic problems like bone density and loss of calcium.
After writing Holly, I realized that she may not be the only one that may have been given wrong information on this topic, so in light of our company's mission to share the best information we have, here is the email with the associated studies, articles, references, etc.:
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Hi Holly,
Thanks for your input. In speaking and attending global water conferences around the world, working alongside Nobel laureates, professors emeritus, leading material scientists, doctors, scholars and researchers there has not been found any significant or deleterious effects of carbonation on the body or studies showing thusly. This is the consensus of researchers and doctors in the study of natural or holistic medicine, too. Below is some preliminary research supporting our findings. If you have scientific studies or clinical trials that say otherwise, please let us know. Please be assured that we do not disseminate information without secure and proper research.
Here are some references from Dr. Andrew Weil, Harvard Women's Health Watch, a Tufts University Study (on 2,500 participants) medical journals, etc. These studies identify the ingredients in soda/cola (particularly the caffeine), not the carbonation, that has negative effects on the bone density of the participants.
Dr. Weil Don’t worry about carbonation. Scare stories about its purported detrimental effects continue to pop up, but a number of studies have shown that there’s really no danger. The notion that the carbonation in sodas is bad for bones comes from studies performed in the early 1990s, which suggested that drinking soda, specifically cola, raises the risk of bone fractures among adolescent girls and older women who were former college athletes. No such association was found for non-cola drinks. On its website, the National Osteoporosis Foundation (NOF) states that there is no connection between the carbonation in soft drinks and bone loss and that certain carbonated mineral waters (the ones rich in calcium and those that are more alkaline) have actually been shown to improve bone health. Soft drinks are bad for teeth, especially in children. But the carbonation isn’t to blame; it’s the high sugar content of these beverages that is responsible for tooth decay, which is now the most common childhood disease – five times more common than asthma, according to the American Dental Association. The latest study on this comes from the School of Dentistry at the University of Birmingham in the UK. A research team there reported that extracted human teeth exposed to flavored sparkling waters showed surface changes indicative of erosion. The researchers note that unflavored sparkling water is unlikely to cause this. There are no known negative effects of carbonation on the digestive system, and some studies have found that it helps relieve indigestion and constipation. In an Italian study, researchers randomly assigned 21 individuals with both of these complaints to drink at least 1.5 liters daily of either carbonated or tap water for at least 15 days or until the end of a 30-day trial. At the beginning and end of the trial all the participants filled out questionnaires and were given tests to evaluate stomach fullness after eating, gastric emptying (movement of food out of the stomach), gallbladder emptying, and intestinal transit time (how long it takes for what you’ve eaten to travel out of the body). The results showed that drinking the carbonated water improved indigestion, reduced symptoms of constipation and aided gallbladder emptying. While I’m concerned about the unhealthy amounts of sugar, artificial sweeteners and caffeine found in sodas, I have no concerns about the carbonation itself. You can use your new device with no health worries, and you can also feel good that by getting your fizzy water this way, you’re helping to cut back on the environmental impact of all the bottles and cans you might otherwise use. Another bonus: homemade sparkling water costs much less than what you would pay for it at a market.
Study 1
Abstract
Background: Soft drink consumption may have adverse effects on bone mineral density (BMD), but studies have shown mixed results. In addition to displacing healthier beverages, colas contain caffeine and phosphoric acid (H3PO4), which may adversely affect bone.
Objective: We hypothesized that consumption of cola is associated with lower BMD.
Design: BMD was measured at the spine and 3 hip sites in 1413 women and 1125 men in the Framingham Osteoporosis Study by using dual-energy X-ray absorptiometry. Dietary intake was assessed by food-frequency questionnaire. We regressed each BMD measure on the frequency of soft drink consumption for men and women after adjustment for body mass index, height, age, energy intake, physical activity score, smoking, alcohol use, total calcium intake, total vitamin D intake, caffeine from noncola sources, season of measurement, and, for women, menopausal status and estrogen use.
Results: Cola intake was associated with significantly lower (P < 0.001–0.05) BMD at each hip site, but not the spine, in women but not in men. The mean BMD of those with daily cola intake was 3.7% lower at the femoral neck and 5.4% lower at Ward’s area than of those who consumed <1 serving cola/mo. Similar results were seen for diet cola and, although weaker, for decaffeinated cola. No significant relations between noncola carbonated beverage consumption and BMD were observed. Total phosphorus intake was not significantly higher in daily cola consumers than in nonconsumers; however, the calcium-to-phosphorus ratios were lower.
Conclusions: Intake of cola, but not of other carbonated soft drinks, is associated with low BMD in women. Additional research is needed to confirm these findings.
Harvard Women's Health Watch
Warnings about the harmful effects of carbonated beverages on bone emerge from time to time. The theory is that the phosphoric acid (phosphate) used to enhance flavor in some carbonated beverages can interfere with calcium absorption and result in the loss of calcium from bone. Fortunately, there's no good evidence that a high phosphate intake affects bone metabolism or bone density.
Still, carbonated beverages have long been associated with low bone density and fractures in adolescent girls. To investigate this association in adults, researchers at Tufts University examined data from 2,500 women and men (ages 49 to 69) involved in the Framingham Osteoporosis Study. They assessed dietary intake and measured bone mineral density (BMD) at the spine and hip.
Non-cola carbonated drinks were not associated with low BMD, but cola intake was associated with lower BMD at the hip (though not the spine) in the women, but not in the men. The more cola a woman drank, the lower her BMD. Women who drank more cola didn't drink less milk, but they did have a lower intake of calcium.
In 2005, the British Journal of Nutrition published the results of a small clinical trial comparing healthy postmenopausal women who drank about one quart of noncarbonated mineral water daily with those who drank the same amount of carbonated mineral water. After eight weeks, blood and urine tests for bone turnover showed no difference between the two groups.
It looks as though drinking seltzer water doesn't contribute to osteoporosis or increase fracture risk in women. The authors of the cola study suggested that the caffeine in the colas may account for the cola-drinkers' lower BMD. Other studies have also reported an association between caffeine and lower BMD. In some cases, soft drinks displace calcium-rich beverages, such as milk, and experts think that this, rather than any direct effect of soft drinks on bone, may explain the effect on BMD in adolescent girls.
So feel free to enjoy seltzer water without worrying, but don't overdo the caffeinated beverages, whether carbonated or not. And if you suspect that by drinking seltzer water, coffee, colas, or other soft drinks you may be reducing your intake of healthy beverages — such as calcium-fortified juices or vitamin D–fortified low-fat or skim milk — make sure you get enough calcium (1,200 to 1,500 mg per day) from other sources to compensate.
— Celeste Robb-Nicholson, M.D. Editor in Chief, Harvard Women's Health Watch
Study 2
Abstract
Background: Soft drink consumption may have adverse effects on bone mineral density (BMD), but studies have shown mixed results. In addition to displacing healthier beverages, colas contain caffeine and phosphoric acid (H3PO4), which may adversely affect bone.
Objective: We hypothesized that consumption of cola is associated with lower BMD.
Design: BMD was measured at the spine and 3 hip sites in 1413 women and 1125 men in the Framingham Osteoporosis Study by using dual-energy X-ray absorptiometry. Dietary intake was assessed by food-frequency questionnaire. We regressed each BMD measure on the frequency of soft drink consumption for men and women after adjustment for body mass index, height, age, energy intake, physical activity score, smoking, alcohol use, total calcium intake, total vitamin D intake, caffeine from noncola sources, season of measurement, and, for women, menopausal status and estrogen use.
Results: Cola intake was associated with significantly lower (P < 0.001-0.05) BMD at each hip site, but not the spine, in women but not in men. The mean BMD of those with daily cola intake was 3.7% lower at the femoral neck and 5.4% lower at Ward's area than of those who consumed <1 serving cola/mo. Similar results were seen for diet cola and, although weaker, for decaffeinated cola. No significant relations between noncola carbonated beverage consumption and BMD were observed. Total phosphorus intake was not significantly higher in daily cola consumers than in nonconsumers; however, the calcium-to-phosphorus ratios were lower.
Conclusions: Intake of cola, but not of other carbonated soft drinks, is associated with low BMD in women. Additional research is needed to confirm these findings.
Other references:
https://onlinelibrary.wiley.com/doi/full/10.1359/jbmr.2003.18.9.1563
https://onlinelibrary.wiley.com/doi/full/10.1359/jbmr.2003.18.9.1570
https://academic.oup.com/jn/article-abstract/123/9/1611/4724584
https://www.ncbi.nlm.nih.gov/pubmed/11684540
https://www.ncbi.nlm.nih.gov/pubmed/9763881
