Category Archives: Diet

Caffeine >330 mg/day Associated with Fractures in Swedish Women

Abstract

Coffee, tea and caffeine consumption in relation to osteoporotic fracture risk in a cohort of Swedish women.

Consumption of coffee and tea, and total intake of caffeine has been claimed to be associated with osteoporotic fracture risk. However, results of earlier studies lack consistency.
We examined this relation in a cohort of 31,527 Swedish women aged 40-76 years at baseline in 1988. The consumption of coffee, caffeinated tea and the intake of caffeine were estimated from a self-administered food frequency questionnaire (FFQ). Multivariate-adjusted hazards ratios (HRs) of fractures with 95% confidence intervals (95% CIs) were estimated by Cox proportional hazards models.
During a mean follow-up of 10.3 years, we observed 3,279 cases with osteoporotic fractures. The highest (>330 mg/day) compared with the lowest (<200 mg/day) quintile of caffeine intake was associated with a modestly increased risk of fracture: HR 1.20 (95% CI: 1.07-1.35). A high coffee consumption significantly increased the risk of fracture (p for trend 0.002), whereas tea drinking was not associated with risk. The increased risk of fracture with both a high caffeine intake and coffee consumption was confined to women with a low calcium intake (<700 mg/day): HR 1.33 (95% CI: 1.07-1.65) with > or =4 cups (600 ml)/day of coffee compared to <1 cup (150 ml)/day. The same comparison but risk estimated for women with a high propensity for fractures (> or =2 fracture types) revealed a HR of 1.88 (95% CI: 1.17-3.00).
In conclusion, our results indicate that a daily intake of 330 mg of caffeine, equivalent to 4 cups (600 ml) of coffee, or more may be associated with a modestly increased risk of osteoporotic fractures, especially in women with a low intake of calcium.

Hallström H, Wolk A, Glynn A, Michaëlsson K
Osteoporos Int 2006
PMID: 16758142

Coffee at ≥ 4 Cups Associated with Lower Bone Density, but Not Fractures

Abstract

Long-term coffee consumption in relation to fracture risk and bone mineral density in women.

High consumption of coffee has been suggested to reduce the risk of some late-onset diseases and death but also to contribute to the development of osteoporotic fractures. Results of previous fracture studies have been inconsistent, and a comprehensive study is needed. The longitudinal population-based Swedish Mammography Cohort, including 61,433 women born in 1914-1948, was followed up from 1987 through 2008. Coffee consumption was assessed with repeated food frequency questionnaires. During follow-up, 14,738 women experienced fracture of any type, and 3,871 had a hip fracture. In a subcohort (n = 5,022), bone density was measured and osteoporosis determined (n = 1,012). After multivariable adjustment, there was no evidence of a higher rate of any fracture (hazard ratio per 200 mL coffee = 0.99; 95% confidence interval: 0.98, 1.00) or hip fracture (hazard ratio per 200 mL coffee = 0.97, 95% confidence interval: 0.95, 1.00) with increasing coffee consumption. A high coffee intake (≥4 cups daily) versus a low intake (<1 cup daily) was associated with a 2%-4% lower bone density, depending on site (P < 0.001), but the odds ratio for osteoporosis was only 1.28 (95% confidence interval: 0.88, 1.87). Thus, high coffee consumption was associated with a small reduction in bone density that did not translate into an increased risk of fracture.

Hallström H, Byberg L, Glynn A, Lemming EW…
Am. J. Epidemiol. Sep 2013
PMID: 23880351

Moderate Caffeine May be Good for Bones

Abstract

Favorable effect of moderate dose caffeine on the skeletal system in ovariectomized rats.

Caffeine, a methylxanthine present in coffee, has been postulated to be responsible for an increased risk of osteoporosis in coffee drinkers; however, the data are inconsistent. The aim of the present study was to investigate the effects of a moderate dose of caffeine on the skeletal system of rats with normal and decreased estrogen level (developing osteoporosis due to estrogen deficiency).
The experiments were carried out on mature nonovariectomized and ovariectomized Wistar rats, divided into control rats and rats receiving caffeine once daily, 20 mg/kg p.o., for 4 wk. Serum bone turnover markers, bone mass, mass of bone mineral, calcium and phosphorus content, histomorphometric parameters, and bone mechanical properties were examined. Caffeine favorably affected the skeletal system of ovariectomized rats, slightly inhibiting the development of bone changes induced by estrogen deficiency (increasing bone mineralization, and improving the strength and structure of cancellous bone). Moreover, it favorably affected mechanical properties of compact bone. There were no significant effects of caffeine in rats with normal estrogen levels.
In conclusion, results of the present study indicate that low-to-moderate caffeine intake may exert some beneficial effects on the skeletal system of mature organisms.

Folwarczna J, Pytlik M, Zych M, Cegieła U…
Mol Nutr Food Res Oct 2013
PMID: 23754597

Tea, but Not Coffee, Reduces Hip Fracture

Abstract

Coffee, tea, and the risk of hip fracture: a meta-analysis.

The present meta-analysis shows no clear association between coffee consumption and the risk of hip fractures. There was a nonlinear association between tea consumption and the risk of hip fracture. Compared to no tea consumption, drinking 1-4 cups of tea daily was associated with a lower risk of hip fracture.
Prospective cohort and case-control studies have suggested that coffee and tea consumption may be associated with the risk of hip fracture; the results have, however, been inconsistent. We conducted a meta-analysis to assess the association between coffee and tea consumption and the risk of hip fracture.
We performed systematic searches using MEDLINE, EMBASE, and OVID until February 20, 2013, without limits of language or publication year. Relative risks (RRs) with 95% confidence intervals (CI) were derived using random-effects models throughout all analyses. We conducted categorical, dose-response, heterogeneity, publication bias, and subgroup analyses.
Our study was based on 195,992 individuals with 9,958 cases of hip fractures from 14 studies, including six cohort and eight case-control studies. The pooled RRs of hip fractures for the highest vs. the lowest categories of coffee and tea consumption were 0.94 (95% CI 0.71-1.17) and 0.84 (95% CI 0.66-1.02), respectively. For the dose-response analysis, we found evidence of a nonlinear association between tea consumption and the risk of hip fracture (p(nonlinearity) < 0.01). Compared to no tea consumption, 1-4 cups of tea per day may reduce the risk of hip fracture by 28% (0.72; 95% CI 0.56-0.88 for 1-2 cups/day), 37% (0.63; 95% CI 0.32-0.94 for 2-3 cups/day), and 21% (0.79; 95% CI 0.62-0.96 for 3-4 cups/day).
We found no significant association between coffee consumption and the risk of hip fracture. A nonlinear association emerged between tea consumption and the risk of hip fracture; individuals drinking 1-4 cups of tea per day exhibited a lower risk of hip fractures than those who drank no tea. The association between 5 daily cups of tea, or more, and hip fracture risk should be investigated.

Sheng J, Qu X, Zhang X, Zhai Z…
Osteoporos Int Jan 2014
PMID: 24196722

Moderate Alcohol is Good; Caffeine with Low Calcium is Bad

Abstract

To drink or not to drink: how are alcohol, caffeine and past smoking related to bone mineral density in elderly women?

To determine relationship between alcohol, caffeine, past smoking and bone mineral density of different skeletal sites in elderly women, accounting for other biological and life-style variables.
A cross-sectional study in 136 Caucasian women, mean +/- SD age 68.6 +/- 7.1 years, all healthy and free of medications affecting bones, including estrogen. Bone mineral density (BMD) of multiple skeletal regions and body composition were measured by dual X-ray absorptiometry. Serum vitamin D (25-OHD) and parathyroid hormone (PTH) were analyzed and used as confounders. Calcium (Ca) intake was assessed by food frequency questionnaire. Alcohol and caffeine consumption was assessed by questionnaires determining frequency, amount and source of each. There were no current smokers, but the history of smoking was recorded, including number of years and packages smoked/day. Past physical activity was assessed by Allied Dunbar National Fitness Survey and used as confounder. Statistical significance was considered at p <or= 0.05.
In the correlational analysis, alcohol was positively associated with spine BMD (r = 0.197, p = 0.02), 25-OHD and negatively with PTH. Smoking was negatively related to Ca intake, 25(OH)D and number of reproductive years. In subgroup (stratified by Ca intake) and multiple regression analyses, alcohol (average approximately 0.5-1 drinks/day or approximately 8 g alcohol/day) was favorably associated with BMD of spine and total body. Caffeine (average approximately 2.5 6-fl oz cups/day or 200-300 mg caffeine/day) had negative association with most of the skeletal sites, which was attenuated with higher Ca intake (>or=median, 750 mg/day). The past smokers who smoked on average 24 years of approximately 1 pack cigarettes/day had lower BMD in total body, spine and femur than never-smokers when evaluated in subgroup analyses, and the association was attenuated in participants with >or=median Ca intake. There was no significant association between past smoking and BMD of any skeletal site in multiple regression analyses.
The results support the notion that consumption of small/moderate amount of alcohol is positively, while caffeine and past smoking are negatively associated with most of the skeletal sites, which might be attenuated with Ca intake above 750 mg/day.

Ilich JZ, Brownbill RA, Tamborini L, Crncevic-Orlic Z
J Am Coll Nutr Dec 2002
PMID: 12480799

It is interesting how many things are bad when calcium is low. There is some evidence that high protein, caffeine, and sodium are all bad for bones only when calcium is low. Otherwise, they all may be moderately good for bones when calcium is high.

 

Review: Caffeine, Calcium, and Bones – 2002

Abstract

Effects of caffeine on bone and the calcium economy.

Caffeine-containing beverage consumption has been reported to be associated with reduced bone mass and increased fracture risk in some, but not most, observational studies. Human physiological studies and controlled balance studies show a clear but only a very small depressant effect of caffeine itself on intestinal calcium absorption, and no effect on total 24-h urinary calcium excretion. The epidemiologic studies showing a negative effect may be explained in part by an inverse relationship between consumption of milk and caffeine-containing beverages. Low calcium intake is clearly linked to skeletal fragility, and it is likely that a high caffeine intake is often a marker for a low calcium intake. The negative effect of caffeine on calcium absorption is small enough to be fully offset by as little as 1-2 tablespoons of milk. All of the observations implicating caffeine-containing beverages as a risk factor for osteoporosis have been made in populations consuming substantially less than optimal calcium intakes. There is no evidence that caffeine has any harmful effect on bone status or on the calcium economy in individuals who ingest the currently recommended daily allowances of calcium.

Heaney RP
Food Chem. Toxicol. Sep 2002
PMID: 12204390

Caffeine Not Associated with Bone Loss in Postmenopausal Women

Abstract

Dietary caffeine intake and bone status of postmenopausal women.

Dietary caffeine intake has been suggested as a risk factor for bone loss in postmenopausal women. We measured the bone density of both hips and the total body in 138 healthy, postmenopausal women aged 55-70 y who had either never used hormone replacement therapy (HRT) or had used HRT for < 1 y. In this cross-sectional study, participants were stratified according to their reported current and long-time caffeinated beverage use into one of three groups: low [0-2 cups (180 mL, or 6 oz per cup) caffeinated coffee per day], moderate (3-4 cups caffeinated coffee per day), or high (> or = 5 cups caffeinated coffee per day). Caffeine intake was measured from diet records and by gas chromatography of each subject’s brewed, caffeinated beverages. No association between caffeine intake and any bone measurement was observed. The anthropometric and nutrient intakes of the three groups were similar. Compared with caffeine intake based on chemical analysis of brewed beverages, 3-d prospective food records and computer-assisted analysis overestimated caffeine intake by nearly two-thirds. In conclusion, the habitual dietary caffeine intake of this cohort of 138 postmenopausal women ranged from 0-1400 mg/d and was not associated with total body or hip bone mineral density measurements. This study does not support the notion that caffeine is a risk factor for bone loss in healthy postmenopausal women.

Lloyd T, Rollings N, Eggli DF, Kieselhorst K…
Am. J. Clin. Nutr. Jun 1997
PMID: 9174479 | Free Full Text

Caffeine with < 800mg Calcium May Accelerate Bone Loss

Abstract

Caffeine and bone loss in healthy postmenopausal women.

The effects of caffeine consumption on rates of change in bone mineral density (BMD) were examined in 205 healthy, nonsmoking, postmenopausal women. BMD of the spine and total body were measured by dual-energy x-ray absorptiometry, and dietary intakes by food-frequency questionnaire. Among women with calcium intakes above the median (744 mg/d), 1-y rates of bone change–adjusted for years since menopause, body mass index, physical activity, and baseline BMD–did not differ by caffeine intake. However, among women consuming less calcium, those with the highest caffeine intakes (> 450 mg/d) had significantly more bone loss (ANCOVA, P < 0.05) than did women consuming less caffeine (0-171 and 182-419 mg/d). Percent change in BMD by lowest to highest tertile of caffeine consumption was 0.26 +/- 2.74, 0.70 +/- 2.70, and -1.36 +/- 2.70 at the spine and -0.19 +/- 1.24, 0.23 +/- 1.23, and -0.68 +/- 1.25 at the total body. Daily consumption of caffeine in amounts equal to or greater than that obtained from about two to three servings of brewed coffee may accelerate bone loss from the spine and total body in women with calcium intakes below the recommended dietary allowance of 800 mg.

Harris SS, Dawson-Hughes B
Am. J. Clin. Nutr. Oct 1994
PMID: 8092093 | Free Full Text

Caffeine > 2.5 Cups of Coffee Increases Fracture in Framingham Study

Abstract

Caffeine and the risk of hip fracture: the Framingham Study.

Caffeine increases urinary calcium output and has been implicated as a risk factor for osteoporosis. The authors examined the effect of caffeine on hip fracture risk in 3,170 individuals attending the 12th (1971-1973) Framingham Study examination. Coffee and tea consumption, age, Framingham examination number, weight, smoking, alcohol consumption, and estrogen use were used to evaluate hip fracture risk according to caffeine intake. Hip fractures occurred in 135 subjects during 12 years of follow-up. Fracture risk over each 2-year period increased with increasing caffeine intake (one cup of coffee = one unit of caffeine, one cup of tea = 1/2 unit of caffeine). For intake of 1.5-2.0 units per day, the adjusted relative risk (RR) of fracture was not significantly elevated compared with intake of one or less units per day. Consumption of greater than or equal to 2.5 units per day significantly increased the risk of fracture. Overall, intake of greater than two cups of coffee per day (four cups of tea) increased the risk of fracture. In summary, hip fracture risk was modestly increased with heavy caffeine use, but not for intake equivalent to one cup of coffee per day. Since caffeine use may be associated with other behaviors that are, themselves, risk factors for fracture, the association may be indirect. Further studies should be performed to confirm these findings.

Kiel DP, Felson DT, Hannan MT, Anderson JJ…
Am. J. Epidemiol. Oct 1990
PMID: 2403108

Caffeine Not an Important Risk in Young Women

Abstract

Is caffeine associated with bone mineral density in young adult women?

By increasing the urinary excretion of calcium, caffeine consumption may reduce bone mineral density (BMD) and subsequently increase the risk for osteoporotic fracture. Although negative associations between caffeine consumption and BMD have been reported for postmenopausal women, in particular for those who consume low amounts of dietary calcium, the relation between caffeine and BMD in younger women is unclear. Therefore, we evaluated the association between caffeine consumption and BMD in a cross-sectional study of 177 healthy white women, age 19-26 years, who attended a Midwestern university.
Average caffeine intake (milligrams per day) was calculated from self-reports of the consumption of coffee, decaffeinated coffee, tea, colas, chocolate products, and select medications during the previous 12 months (mean caffeine intake = 99. 9 mg/day). BMD (grams per square centimeter) at the femoral neck and the lumbar spine was measured by dual-energy X-ray absorptiometry.
After adjusting in linear regression models for potential confounders, including height, body mass index, age at menarche, calcium intake, protein consumption, alcohol consumption, and tobacco use, caffeine consumption was not a significant predictor of BMD. For every 100 mg of caffeine consumed, femoral neck BMD decreased 0.0069 g/cm(2) (95% confidence in terval [CI] = -0.0215, 0. 0076) and lumbar spine BMD decreased 0.0119 g/cm(2) (95% CI = -0. 0271, 0.0033). No single source of caffeine was significantly associated with a decrease in BMD. Furthermore, the association between caffeine consumption and BMD at either site did not differ significantly between those who consumed low levels of calcium (< or =836 mg/day) and those who consumed high levels of calcium (>836 mg/day).
Caffeine intake in the range consumed by young adult women is not an important risk factor for low BMD.

Conlisk AJ, Galuska DA
Prev Med Nov 2000
PMID: 11071837