Recently at a couple of conferences ( European Human Genetics conference and Consumer Genetics Conf ) there have been various speakers questioning DTC genetics and calling for all health related personal genetics to be delivered through medical practitioners. I argued in the past that unregulated tests delivered through practitioners actually have the potential for more harm, not less. By coincidence last week some discrepancies in a DTC and a via MD test were pointed out to me – and they seem topical. Breast feeding has many benefits one of which appears to be increased IQ scores – however not all studies agree, some indicating that results may be confounded by maternal intelligence (see Wikipedia ). Sometimes inconsistencies in associating an action with an outcome can be resolved by looking at genetic variation (which tends to increase the error bars when not accounted for). So in 2007 some headlines were made when a study was published by Caspi’s group ( PNAS, open access )
Travelling on a train to Scotland, all for the first time: Clinical researcher says: "Look the cows in Scotland are black!". Physicist replies: "No. Some of the cows in Scotland are black" Mathematician says: "No, actually in Scotland there is at least one cow black on one side" I’ve written about folic acid, homocysteine and various clinical trials of nutrients in the past. I just want to revisit it briefly because I think there are some seriously wrong messages emerging from the conclusions. For an excellent comment on evidence based recommendations see Colby Vorland . Homocysteine (Hcy) is associated with CVD, may or may not be causal but the evidence is good (Wald et al , BMJ, 2002). Folic acid (Vitamin B9) in reasonable amounts will lower homocysteine but clinical trials have been carried out, mostly showing not much benefit as far a CVD is concerned. A recent meta-analysis of 8 trials (total 37,485 individuals) seems t