BACKGROUND: The genetic variation which underlies the thermolability and low enzyme activity of 5,10-methylenetetrahydrofolate reductase (MTHFR; C677T) has been extensively studied in many populations, including the Irish population. AIM: To describe the examination of the C677T substitution in two new control samples drawn from the Irish population. METHODS: A collection of 487 serum samples was obtained through the blood transfusion services of both the Republic of Ireland and Northern Ireland and a further 115 samples from volunteers. RESULTS: In both samples, the frequency of the thermolabile/low enzyme activity allele (T) was higher than that previously reported for the Irish population. CONCLUSION: This finding thus supports the need for a greater use of internal control/family-based association studies, as opposed to the classic case control study design, when assessing the contribution of the MTHFR T allele to disease processes.

Adult↗

PubMedDate not supplied

Haemostatic function and polyunsaturated fatty acids.

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Coronary Disease↗

PubMedDate not supplied

Estimation of food additive intake: methodology overview.

Any attempt to estimate food additive intake will require some level of screening to reduce the scale of the problem to a manageable level. Even then the process should always begin with crude estimates of food intake and of food additive usage level. The starting point for the latter may be the maximum permitted levels as laid down in the relevant regulations. If at that point the data are deemed acceptable, the process ends. If further requirements are needed they can be for both food intake data and food additive usage levels. Refinement may involve disaggregation of gross categories into more precise categories but research needs to be done to establish the true value of highly refined data. It remains possible that the distribution of the intakes of refined categories is similar to that of the crude categories. Intake data should relate to the population who consume the foods containing the additive in question and even then at some higher level such as the 97.5th percentile. Whether the use of this extreme is acceptable as numbers of subjects diminish in any age and sex breakdown of data remains to be seen. We also need to know something of the dietary habits and sociodemographic characteristics of high consumers and to devise ways of obtaining data for consumers-only from household budget data. Finally we need to know more of how to increase the precision of estimating the percentage of consumers, perhaps combining food frequency questionnaires with 3-day records.

Diet Surveys↗