ALA and Prostate Cancer
ALA and Prostate Cancer
The problem is the lack of data from randomized controlled trials to throw light on the
 ALA-prostate cancer issue. There is therefore a need to acquire evidence from a randomized
 controlled study to illustrate the effect of ALA on a surrogate marker for prostate cancer,
 namely prostate specific antigen (PSA). Demonstration that atrial fibrillation recurrence was
 reduced after cardioversion and that there was no adverse effect of 1 years of ALA feeding on
 PSA would go a considerable way to providing the required evidence that ALA in the human diet
 has no adverse effect on the prostate and so allow its use for cardiovascular risk reduction.
 hypothesis: The effect of ALA on PSA levels over time will be no different from the control,
 so providing supportive data for the view that ALA is not cancer promoting.
In addition disturbing news on alpha-linolenic acid (ALA) has recently been reviewed by
 Brouwer and colleagues (J Nutr:2004). Their analyses suggests that ALA, as found in canola
 oil and other healthy foods, may cause prostate cancer even though there is good evidence
 that canola oil will prevent heart disease. This issue urgently needs further research.

 In studies largely from the Harvard group, but suggested by additional studies from Uruguay
 and Spain, a link has been identified between ALA intake and prostate cancer. The Harvard
 studies are cohort studies where groups of approximately 40,000 doctors or health
 professionals have been followed up for periods of 10 years and the dietary intakes of ALA
 related to the subsequent development of aggressive prostate cancer. It must be stressed that
 these are not randomized crossover studies which are the currently accepted gold standard for
 evidence-based medicine and regulatory decision making. Nevertheless they raise concern over
 the health profile of a fatty acid with a growing reputation for cardiovascular disease
 prevention and a component of other healthy foods such as walnuts, flax, canola and soy.

 The same Harvard group identified the deleterious effects on cardiovascular health of trans
 fatty acids in their cohort studies and this has resulted in a major effort to remove trans
 fatty acids from the food supply. On the other hand their identification of the benefits of
 vitamin E in their cohort studies has not been confirmed by subsequent randomized controlled
 trials. Although Dr Willett, the senior member of the Harvard group, has drawn surprisingly
 little attention to the negative findings with ALA, it remains a sticking point with
 regulators in the current debate over the inclusion and use of ALA in the food supply. This
 concern has been sufficient for the Natural Health Products Directorate of Health Canada to
 ask for a full proposal from us before we start studies on ALA in the prevention of atrial
 fibrillation due the apparently negative impact of ALA consumption on prostate cancer.
Inclusion Criteria:

 -  Blood samples available from Bordeaux

 Exclusion Criteria:

 -  Blood samples not received from Bordeaux