Thursday, July 18, 2013
Fluoride levels in Beers and Stouts sold in Ireland
Beer can contain significant levels of fluoride and can in themselves depending on consumption be a significant contribution to the dietary intake of fluoride. For many adults especially those with alcohol addictions or for individuals who consumer relatively large volumes of beers or stouts regularly, the dietary intake of fluorides from this source may significantly exceed that of consuming drinking water.
No accurate database is available providing comprehensive data on fluoride content of beverages, foodstuffs or medications in Ireland. Prior to 2011 no data was available from the Food Safety Authority of Ireland (FSAI) on fluoride levels in foods and beverages. This is despite the fact that the World Health Organisation recommend that prior to commencement of water fluoridation programmes the total dietary exposure of the population for all sectors must be accurately determined, so as to avoid over chronic exposure of the population to fluoride. The WHO Guidelines for Drinking Water recommend that “when setting national standards for fluoride that it is particularly important to consider volume of water intake and intake of fluoride from other sources.”[i]
The WHO has consistently and correctly stated that "in the assessment of the safety of a water supply with respect to the fluoride concentration, the total daily fluoride intake by the individual must be considered." Similarly the WHO have advised “that in countries with large water-ﬂuoridation programmes, ﬂuoridated water may be used in food processing, raising the ﬂuoride content of the processed food above that of products for which unﬂuoridated water has been used. This is particularly important when baby foods are prepared and means that details of the nutrients, including ﬂuoride, should be printed on the packages.”[ii]
It is deeply worrying that despite this recommendation from the WHO no proper dietary fluoride risk assessment has been undertaken in the ROI and that no database is readably available for the public to examine or calculate their fluoride exposure form foodstuffs and beverages. As with any foodstuff or beverage such as tea, any product produced in Ireland that uses public water supplies will have elevated fluoridated levels. This includes soft drinks, alcoholic beverages and fruit drinks. Despite the warning of the WHO no data on the fluoride content is provided on any packaging in Ireland.
The first attempt to measure the fluoride exposure of the Irish population was undertaken by the FSAI in 2011. The Total Diet Survey reported fluoride levels in beers sold in Ireland of less than 0.05mg per litre. No data was provided on the brands of beverages tested.
To check the accuracy of the data provided in the FSAI report independent scientific testing of forty two alcoholic beverages was undertaken following the American Society of Testing and Material (ASTM) and EPA standard methodologies for fluoride determination. The results conclusively demonstrated that the levels of fluoride reported by the FSAI were grossly inaccurate. A literature review of published data supported this observation.
In contrast to the data provided by the FSAI, Warnakulasuriya et al. (2002) reported mean fluoride concentrations of 0.08–0.71mg/L in beers available in Great Britain; with one Irish beer contained fluoride at 1.12mg/L.[iii]
The authors of the latter study concluded that beers brewed in locations with high fluoride water levels may contribute significantly to the daily fluoride intake, particularly in alcohol misusing subjects and this may contribute to alcohol-associated bone disease. Marier and Rose (1996) reported that the fluoride content of beer varies according to the fluoride content of process water.[iv] At 0-0.2 ppm fluoride in drinking/process water the fluoride content of beer has been measured at 0.3mg/L. For 1ppm process water 0.7ppm was recorded.
The U.S Department of Agriculture (2005) similarly published measured fluoride levels in beers and wines; the mean concentrations for beers was 0.45 mg/l, 1.05mg/l for red wine and 2.01mg/l for white wine respectively.[v]
The NRC scientific committee (2006) reported that the typical fluoride levels in beers ranged from 0.08 - 1 mg/L and wine 0.2 – 3.0 mg/L.[vi]
Similarly the WHO reported that Dabeka and Mckenzie (1995)[vii] measured fluoride level of beers in Canada with a range from 0.2mg/l to 0.96mg/L. [viii]
Independent testing of alcoholic beverages undertaken for this study measured the fluoride content in approximately 40 beers and stouts available on the Irish market. The highest fluoride levels in beers produced were as expected from fluoridated countries (Ireland and New Zealand) or countries
Fluoride content of all samples was determined by direct potentiometric methods using a fluoride ion selective electrode. The potentiometric technique is considered the simplest and most reliable for fluoride determination. This method utilizes a fluoride selective membrane (Europium doped lanthanum fluoride single crystal cell) immersed in the solutions after buffering with TISAB (Total Ionic Strength Adjustment Buffer) reagent. Readings on the ion analyzer (Extech EXFL700 fluoride meter) were recorded after 3 min of infusion.
The EXFL700 allows the users to follow the American Society of Testing and Material (ASTM) and EPA standard methodology using TISAB reagents and certified standard solutions. The accuracy of the instrument is ± 3% of reading or ± 0.1ppm (whichever is greater). Calibration standards were prepared using fluoride standard solution (certified 100ppm Eutech fluoride standard) added to plastic labware and diluted with deionized water. All samples and standards used were at the same temperature for precise measurement.
The results conclusively demonstrate that the fluoride levels in beers and stouts produced in Ireland vary between 0.4 and 0.8mg/l.
Similar levels were measured in New Zealand beers where fluoridated water was used in the production process.
This illustrates that the level of fluoride in beers reported by the FSAI was in the order of 16 times below the scientifically accurate measured level.
[i] The 1971-2003 World Health Organization International Standards for Drinking-water.
[ii] Fluorides And Oral Health, World Health Organization, Technical Report Series 846, 1994.
[iii] Warnakulasuriya S, Harris C, Gelbier S, Keating J, Peters T. 2002. Fluoride content of alcoholic beverages. Clin Chim Acta 320:1–4.
[iv] Marier, J.R. & Rose, D. (1966) The fluoride content of some foods and beverages - a brief survey using a modified Zr-SPADNS method. J. food Sci., 31: 941-946.
[v]USDA National Fluoride Database of Selected Beverages and Foods, Release 2, December 2005
[vi]] National Research Council of the National Academies, Fluoride in Drinking Water,2006, Page 40
[vii]Dabeka, R.W. and McKenzie, A.D. 1995 Survey of lead, cadmium, fluoride, nickel and cobalt in food composites and estimation of dietary intakes of these elements by Canadians in 1986–1988. J. Assoc. Off. Anal. Chem. Int., 78, 897–909.
[viii] J. Fawell et al. World Health Organisation Fluoride in Drinking Water, 2006