There are articles in the media referring to a Norwegian study and also various media insertions online with regards to a theoretical opinion. This latter abstract is taken only from a mathematical conclusion, not from actual studies, and has been taken out of proportion and structurally amended by the media to make it sound like it is a study. It isn't. Here is the actual abstract which related to media misinterpretation.... and also here…
So what is the truth? Is folic acid good for health, or a potential risk?
In most study reference agencies on and offline, there are, by far, more conclusions of folic acid helping as a chemopreventative rather than a cancer-cause.
There are more in-depth studies available, but from the point of view of what is available for public viewing, anyone can log into search engines such as PubMed, for example, amongst many others, and see abstracts of these types of studies quite easily to confirm the beneficial uses of folic acid. You will note that there are no actual instances of conclusive study data of folic acid causing cancer.
It is known that there are potential contradictions of folate's uses as a conclusive chemopreventative, and its cell proliferation effects, which is where the cancer-causing concerns have come from. I.E. suggesting that as well as helping to protect tissues, the cell mutation and proliferation effects that normally keep tissues intact, "could" in theory proliferate cancer cells also.
However, the only available data where this is discussed isn't concerning actual studies. It comes only from the mathematical opinion and the one Norwegian study group. This mathematical conclusion is where the majority of the media hype has spread from, not the Norway studies.
So in actual effect, there are no studies concluding that folate intake causes cancer....if used appropriately, in an appropriate form the body can metabolize, and without any interfering factors.
Regarding the Norway studies, there are many conflicts of data to consider within this. For example, the majority, if not all, of patients were heart disease patients. In these cases the doses and type of folate used isn't clear.
Too high a folate status in the body, of inadequate metabolistic type may increase the risk of certain chronic diseases among certain individuals (I.E. groups that are further susceptible, such as heart patients for example in this case), possibly by interfering with the homeostasis of carbon metabolism or through drug interaction, or even through non-related causes where folate has simply been blamed.
Other factors in the study are the stage of the start of treatment (it is known that beginning folic acid intake early in life enables it to help prevent disease and act as a chemopreventative, whereas starting high doses later in life can have a potential opposing effect), drug intervention (we don't know what medications the heart patients were on, which can effect both the cell proliferation and mutation issues, effecting how folic acid is metabolized in the body, and hence whether its beneficial effects were ever fully absorbed (concluding potentially that it wasn't the intake of folic acid causing the degeneration, but the actual lack of absorption of the ingested folic acid, and hence a LACK of folic acid in the body).
There are also factors of this being Norwegian-specific (as well as heart-patient specific), and any conclusions that may hold that wouldn't apply to the population in general, or to a conclusive study result.
Other factors to note are:
1. Studies indicate the importance of dosage, which is in line with general knowledge that any substance, natural or pharmaceutical, if used inappropriately, either in format or in excessive dosage, can always have the potential for opposing effect.
2. Following on from this, format is important, which is in line with the information we have previously confirmed to our customers in terms of the type of folic acid we use and why. The reason why we use the current form is because it is absorbed more efficiently than the 5-MTHF and 5-FTHF, and this may also be a factor in the result of, say, the Norwegian study for example, as cell mutation and proliferation effects will be directly affected by the type and hence metabolism of the folate type used. These other forms require an enzyme to convert them back to the usable form of folic acid. As I have personally discussed with customers before, many people potentially lack the enzymatic processes needed to make the necessary conversion.
So looking at the larger picture, the only comments on folic acid potentially causing cancer lay in the Norwegian study which has many questions and potential flaws, and in a mathematical opinion, which has no backing and even concludes actual study needs to be done to confirm or deny this potential.
Conversely, the conclusive studies showing the benefits of folic acid are many and open to public viewing, and the general consensus from actual study results is that a low folate body status has been shown to be a risk factor for cancer and cardiovascular disease.
Folate is needed to carry one-carbon groups for methylation reactions and nucleic acid synthesis (the most notable one being thymine, but also purine bases). Thus, folate deficiency hinders DNA synthesis and cell division, affecting hematopoietic cells and neoplasms the most because of rapid cell division, giving potential rise to degenerative disease through deficiency.
Here are just some study examples that I have taken from a public-viewable study source (Pubmed) so that our customers can easily follow them up. Many more like this are available on there, as well as other sources:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2593624/?report=abstract&tool=pmcentrez - important point here is that it confirms no increase of cancer risk
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657096/?report=abstract&tool=pmcentrez - note in this study aspirin was used in conjunction with folic acid, with many potential negative effects that may have effected the study outcome.
At the end of the day we have not the slightest doubt that low dose folic acid in conjunction with the other B vitamins is essential for your overall health. As you know we do not subscribe to high dose vitamins, but rather in moderation and in conjunction with other nutrients as nature intended.