Diet soda depletes calcium and may increase heart attack risk

The average American drinks 216 liters of soda each year.1 Soda drinking has previously been associated with lower bone mineral density in women and children,2,3 and one study in particular has focused specifically on the effects of diet soda on bone health.  The authors commented that this research was sparked by the observation that diet soda drinking behaviors are often different than regular soda drinking behaviors – women often use diet sodas in an effort to avoid weight gain – either to stave off hunger between meals or as a replacement for calorie-containing beverages.  Many women drink over 20 diet sodas per week.4

These researchers discovered that parathyroid hormone (PTH) concentrations rise strongly following diet soda consumption.  PTH functions to increase blood calcium concentrations by stimulating bone breakdown, and as a result release calcium from bone.

In the study, women aged 18-40 were given 24 ounces of either diet cola or water on two consecutive days, and urinary calcium content was measured for three hours. 

Women who drank diet cola excreted more calcium in their urine compared to women who drank water.  

The authors concluded that this calcium loss may underlie the observed connection between soda drinking and low bone mineral density.5

Although caffeine is known to increase calcium excretion and promote bone loss,6 caffeine is likely not the only bone-harming ingredient in sodas.  A 2006 study in the American Journal of Clinical Nutrition found consistent associations between low bone mineral density and caffeinated and non-caffeinated cola (both regular and diet), but not other carbonated beverages.7 One major difference between the two is the phosphoric acid in colas, absent from most other carbonated beverages. 

In the Western diet, phosphorus is commonly consumed in excess – at about 3 times the recommended levels, whereas dietary calcium often low.  Although phosphorus is an important component of bone mineral, a high dietary ratio of phosphorus to calcium can increase parathyroid hormone secretion, which is known to increase bone breakdown.   Studies in which women were given increasing quantities of dietary phosphorus found increases in markers of bone breakdown and decreases in markers of bone formation.8,9 Therefore it is likely that the phosphorus content of colas  triggers calcium loss.

There is nothing healthy about diet soda.  It is simply water with artificial sweeteners and other chemical additives, such as phosphoric acid. 

The safety of artificial sweeteners is questionable, and they provoke the release of insulin and other hormones that regulate blood glucose; their intense sweetness confuses the body, which naturally associates sweet taste with calories – over time, these mixed signals can lead to increased appetite and weight gain.10 

Diet sodas don’t just weaken our bones, they are linked to kidney dysfunction and promote obesity.

Furthermore, a study on older adults who drank diet soda daily had a 43% increased risk of heart attack or stroke compared to those that never drank diet soda.11



1. Nation Master.  Statistics: soft drinks.

2. McGartland C, Robson PJ, Murray L, et al. Carbonated soft drink consumption and bone mineral density in adolescence: the Northern Ireland Young Hearts project. J Bone Miner Res. 2003 Sep;18(9):1563-9.

Mahmood M, Saleh A, Al-Alawi F, Ahmed F. Health effects of soda drinking in adolescent girls in the United Arab Emirates. J Crit Care. 2008 Sep;23(3):434-40.

3. Tucker KL, Morita K, Qiao N, Hannan MT, Cupples LA, Kiel DP. Colas, but not other carbonated beverages, are associated with low bone mineral density in older women: The Framingham Osteoporosis Study. Am J Clin Nutr. 2006 Oct;84(4):936-42

4. Frieden J. ENDO: Diet Soft Drinks Deplete Urinary Calcium. Medpage Today.

5. NS Larson, et al "Effect of Diet Cola on urine calcium excretion" ENDO 2010; Abstract P2-198.

6. Vondracek SF, Hansen LB, McDermott MT. Osteoporosis risk in premenopausal women. Pharmacotherapy. 2009 Mar;29(3):305-17.

Massey LK, Whiting SJ. Caffeine, urinary cal- cium, calcium metabolism and bone. J. Nutr. 19923 Sep;123 (9): 1611-14

7. Tucker KL, Morita K, Qiao N, et al. Colas, but not other carbonated beverages, are associated with low bone mineral density in older women: The Framingham Osteoporosis Study. Am J Clin Nutr. 2006 Oct;84(4):936-42.

8. Kemi VE, Kärkkäinen MU, Karp HJ, et al. Increased calcium intake does not completely counteract the effects of increased phosphorus intake on bone: an acute dose-response study in healthy females. Br J Nutr. 2008 Apr;99(4):832-9.

9. Kemi VE, Kärkkäinen MU, Lamberg-Allardt CJ. High phosphorus intakes acutely and negatively affect Ca and bone metabolism in a dose-dependent manner in healthy young females. Br J Nutr. 2006 Sep;96(3):545-52.

10. Swithers SE, Martin AA, Davidson TL. High-intensity sweeteners and energy balance. Physiol Behav. 2010 Apr 26;100(1):55-62.

Ma J, Bellon M, Wishart JM, et al. Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects. Am J Physiol Gastrointest Liver Physiol. 2009 Apr;296(4):G735-9.

Liang Y, Steinbach G, Maier V, Pfeiffer EF. The effect of artificial sweetener on insulin secretion. 1. The effect of acesulfame K on insulin secretion in the rat (studies in vivo). Horm Metab Res. 1987 Jun;19(6):233-8.

11. Gardener H, Rundek T, Markert M, et al. Diet Soft Drink Consumption is Associated with an Increased Risk of Vascular Events in the Northern Manhattan Study. J Gen Intern Med. 2012 Jan 27. [Epub ahead of print]


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Comments (13) Read through and enter the discussion with the form at the end
mike rubino - April 24, 2012 10:29 AM

America's love affair with junk food is never ending .

jon schneider - April 24, 2012 11:32 AM

Would carbonated drinks such as Perrier and Pellegrino do the same damage as diet sodas?

Jean Myers - April 24, 2012 12:25 PM

What about home-made carbonated water, such as the Soda Stream? I like to drink fizzy water with a little pomegranate juice just to color it, but I wonder if there are any issues for bones with that. Thanks!

mgm - April 24, 2012 1:29 PM

The women where I work drink this stuff like an alcoholic sailor on leave - every single day. They have their own little refrigerator in their wing of the building for nothing but sodas - mostly diet colas. The sad thing is - they have all heard this information, and they just don't care. It's that incomphrensible logic of your average teenager who plays with fireworks - 'it won't happen to me'. Next thing he knows he's in an emergency room with three missing fingers. Our bodies are so wonderfully forgiving in the short term, then you're 60, fall and break a hip, and wish you hadn't had all those sodas. It's so frustrating to watch these beautiful, otherwise smart women turn their bones to chalk. I have about three sips off a soda about twice a month, and throw the rest away. It's the smallest of treats. These women drink gallons. It seems to really be the downfall of the office worker - diet sodas are a cornerstone of that culture.

Laura Prestien - April 24, 2012 2:57 PM

It's also because soda (in addition to coffee, animal products, and salt) makes your blood acidic. Your body leaches calcium from your bones in an effort to alkalize your blood and restore blood pH. People who consume these food in excess are mineral deficient and their blood acidity increases their risk of developing cancer. The answer is to minimize your intake of acidic foods; increase your intake of alkaline foods (like dark green veggies, lemons, limes) and take an absorbable mineral supplement.

kat - April 24, 2012 3:04 PM

What about zevia, a soda made with natural stevia.

Diane Shirley - April 24, 2012 7:59 PM

I love your eating plan on Eat to Live. Eventhough I might cheat a little, eating 16oz of raw and cooked vegetables and staying away from processed foods like wheat helps me. I agree on not drinking diet sodas and avoiding artifical sweeteners too for most of the time I noticed they increased my appetite.

Nancy Taylor - April 25, 2012 1:21 AM

I used to drink diet soda in the amounts you are describing. I also have hyperparathyroidism and hypercalcemia (one of these is termed "secondary" -- can't recall which. I also have RA and have been taking low dose prednisone on and off for the last year. Now I am getting repeated stress fractures in my left foot -- three in the last two years. I have changed my diet some--no processed food, no red meat, increased fruit, veggies and nuts/seeds/beans to the tune of about 8-10 servings a day. Is the bone loss you are describing to be secondary to excessive diet coke use reversible? Until now, I have thought that the low does prednisone may be causing the loss of bone integrity. I am scheduled for a bone density test but no actual data yet...just a foot that appears to be on the verge of fracturing again. I stave it off by wearing a surgical boot and taking 2000 mg of Vit D daily.

Suzy - April 25, 2012 9:17 AM

Excellent article! I wish this message would get out to everyone. I have tried to tell my grown kids about drinking soda, particularly diet soda, but they aren't listening! The stuff is just too addictive, and in the case of diet soda, they think it is a "free" beverage. (i.e. no calories)

I wondered also about sparkling mineral waters. Any research on those?

Deana Ferreri, Ph.D. - April 25, 2012 9:25 AM

Carbonated waters without additives and artificial sweeteners are not likely to be harmful. Stevia leaf, although it is likely safer than other artificial sweeteners still has the action of delivering sweet taste without calories, which can disrupt the body's appetite signals.

Esther - April 26, 2012 1:43 PM

mgm said: "The women where I work drink this stuff like an alcoholic sailor on leave - every single day. They have their own little refrigerator in their wing of the building for nothing but sodas - mostly diet colas."

YES! As I former teacher, I have seen this kind of thing firsthand. Many of my colleagues lived and breathed on diet (mostly caffeinated) colas, with their classroom mini-fridges stocked full of them. Like your experience, although they were well aware of the consequences, many of them had resigned themselves to their "addiction" (claiming it's a relatively "safe" one to have).

Thankfully, I never developed a taste for them, diet or regular. Now, coffee did become my drug of choice back then (1-2 cups/day), but since then, I've given it up entirely.

Larry Uelk - April 27, 2012 10:28 PM

Superb article on calcium. As an adviser to the animal-feeding industry for 35 years, I saw many similar situations with dairy animals and hogs with other nutrients. I also experienced a loss of oxygen during a 5-mile run just after drinking a carbonated beverage. I now know better.

Thank you!

Dan Altic - June 16, 2012 6:35 PM

This article confirms what nutritionists assert since a few decades that soft drinks may bring a series of chronic diseases. Science has shown that human body is slightly alkaline by design. If any the body becomes acidic the situation will correspond to a disease referred to in medicine as acidosis. This disorder is mainly due to our modern acidic diet. The food we eat may be divided into two groups: acidic-forming foods (cereals, sugar and animal products) that leave in our body an excess of acid, and alkaline-producing foods (vegetables and fruits) of which digestion end-products are alkaline. Soft drinks are considered as being highly acidic-producing foods. Their excessive and regular consumption may therefore cause acidosis, which is generally blamed by nutritionists to be the leading cause of most chronic diseases, including osteoporosis, obesity, heart and kidney disorders. On the other side alkaline water seems to be the best drink as it helps our body prevent and fight chronic diseases.

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