Abdulla study

Two studies (Abdulla et al, 1981 Lightowler and Davies, 1998) used the duplicate portion technique to assess the iodine content of the vegans diets. Usual restraints and influences identified with this technique, such as the possible influence on dietary habits of collecting the food samples and gaining adequate cooperation from the subjects, might have been reduced in the Abdulla study that was undertaken in a controlled environment. These individuals consumed a modified diet to which they were unaccustomed, their iodine intakes would therefore not be a true reflection of their habitual diet. 

Zinc intakes of 6 Swedish vegans (individuals who consume no food of animal origin at all) using chemical analyses of diets from a duplicate portion sampling technique approach were included in a study by Abdulla et al. (12). Dietary fiber Intake of male subjects was 62+9 g/day and that of female subjects was 43 9 g/day. Zinc Intake of male subjects was 13 2.3 mg/day and that of female subjects was 6.5 1.3 mg/day, so as in the study of lacto-ovo-vegetarians by Anderson et al., subjects were found to have relatively high Intakes of fiber and relatively low Intakes of zinc with the zinc that was supplied being from foods believed to exhibit low zinc bioavailability. 

Abdulla WA, Kadry H, Mahran SG, el-Raziky EH, el-Nakib S. Preliminary studies on the anti-schistosomal effect of Ammi majus L Egypt J BiUiarz 1978 4(l) 19-26. 

Fehling C, Abdulla M, Brun A, et al. 1975. Methylmercury poisoning in the rat A combined neurological, chemical, and histopathological study. Toxicol Appl Pharmacol 33 27-37. 

Several measurements require the collection of nervous tissue at necropsy and homogenization of the tissues prior to analysis simple tissue procedures and associated measurements often do not indicate the localization of effects. Assays using tissue microdissection and in vitro cell cultures can help in the understanding of neurotoxic mechanisms, and these are being used more widely (Abdulla and Campbell 1992 Costa 1998 Harry et al. 1998). The development of assays such as neural gold protein, amyloid precursor protein, neuron specific enolase, heat shock proteins, and amyloid precursor proteins to study nervous diseases may find applications in some toxicology studies where the assays can be adapted for laboratory animals (de la Monte et al. 1997 Fitzpatrick et al. 2000 Rajdev and Sharp 2000). 

In the study by Abdulla et al. (1981), subjects were asked to provide duplicate food samples by visual measurement rather than weighed records, thus increasing the likelihood of underestimation of iodine intake. However, in addition, the urinary excretion of sodium, potassium and nitrogen was compared with the corresponding intake values to test the validity of the duplicate portion collections. Results from their analysis indicated that, as in the Lightowler and Davies study, females, but not males, underestimated their duplicate food collections. 

We identified eight studies worldwide that evaluated iodine nutrition in vegetarians (Abdulla et al, 1981 Draper et al, 1993 Key et al, 1992 Krajcovicova-Kudlackova et al, 2003 Lightowler and Davies, 1998 Rauma et al., 1994 Remer et al., 1999 Waldmann et al, 2003). Those studies are summarized in Table 54.6. The informational value of these studies is limited by small sample size and methodological deficiencies. For example, only four studies included more than 40 vegetarians (Draper et al, 1993 ... 

A study performed in an iodine-deficient area of Sweden (Abdulla et al, 1981) found the vegan diet to be iodine-deficient, but did not consider the iodine content of an omnivore diet from that iodine-deficient region. 

These studies reflect the marked heterogeneity that can characterize vegetarian and vegan diets. In two studies, subjects were directed to avoid iodized salt, fish, seaweed and kelp, and iodine-containing processed foods, while only iodine-free beverages were provided (Abdulla et al, 1981 Remer et al., 1999). In these individuals, iodine... 

In addition to iodine measurements, three studies (Abdulla et al., 1981 Key et al., 1992 Raiuna et al., 1994) performed thyroid function tests as indirect measures of iodine sufficiency. Thyroid function was normal in two studies (Abdulla et al., 1981 Rauma et al., 1994). The third study reported elevated thyroid-stimulating hormone (TSH) levels in 5 of 48 vegans, but did not measure dietary or urinary iodine levels (Key et al., 1992). It is noteworthy that the three highest TSH levels were in vegans who usually took kelp it is possible that these three actually suffered iodine-induced hypothyroidism (Wiersinga and Braverman, 2003) secondary to the consumption of excessive iodine-rich kelp. 

The authors would like to thank Qatar Chemical Company for conducting this study and sharing of information. Special thanks to Mr. Saleh Abdulla (Technical Manager)for his great support. 

Abdulla MI, Barakat IE, Games DE, Ludgate P, Marraganis VG, Ratnayake VU, Jackson AH (1979) Studies of Erythrina Alkaloids Pt. III. GC-MS Investigations of Alkaloids in the seeds of a further fourteen species. Ann Mo Bot Gard 66 533-540... 

Barakat I, Jackson AH, Abdulla MI (1977) Further studies of Erythrina alkaloids. Lloydia 40 471-475... 

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