Public health seeks to prevent disease, prolong life and promote health. Sometimes this requires population-wide interventions that are meant to have benefits but also might cause harm to some. When a single-minded focus on anticipated benefits fails to consider potential risks, our well-meaning efforts may cause more harm than good. This critically important fact is often overlooked, especially when interventions seem safe.
So I was disappointed when the case of a 56-year-old man with a wobbly gait, presented in the New York Times, failed to consider the reasonable possibility that this man’s ultimate diagnosis of vitamin B-12 deficiency and the damage done by that deficiency may have been delayed because his “normal” blood levels were likely masked by his ingestion of folic acid—another common vitamin B supplement added to many foods.
Even though he was a free-living and competent adult, he was being fed these supplements without his consent (and quite possibly without his knowledge). This is because the U.S. food supply, through mandatory fortification of enriched grains, has been supplemented with folic acid for more than 15 years. Sure, this is a story about just one man, and anecdotes aren’t evidence—but I consider this a “proof of concept” that ought at least to raise the consideration that this well-meaning but aggressive intervention, intended to help unborn babies, might harm a 56-year-old man. (Full disclosure: this case probably caught my attention because I’m a 56-year-old man myself.)
To fully understand what happened, a brief history of dietary folic acid supplementation is in order. Folic acid deficiency in pregnant women can lead to devastating neural tube defects (NTDs), including spina bifida, in their babies. Because these problems develop during the first trimester, the damage may already be done by the time a woman knows she’s pregnant. So to prevent this rare but potentially devastating condition, folic acid has been added to all fortified grains in the U.S. since the late 1990s. This was accomplished by aggressive lobbying by interest groups that no doubt could pull the heartstrings of our congressional representatives with stories and photos of suffering and deformed babies.
I can only imagine the competing testimony from those arguing the need to consider unintended consequences, including the long-known fact that taking extra folate through supplements can impede diagnosis by masking a B-12 deficiency (often caused by the relatively common condition of pernicious anemia), thereby leading to irreversible and serious neurological damage in older adults.
It’s hard to picture a compelling and dramatic case being made for this. I imagine no moving testimony, just some dry statistics, such as pointing out that only 4,000 NTDs occur annually in the U.S., compared with between 500,000 and a million instances of Americans with pernicious anemia. (They’re even drier when the necessary caveat is added: NTD incidence [meaning newly diagnosed cases each year] is much easier to measure than that of pernicious anemia, so the latter figure is estimated prevalence [the number of individuals with a given condition at a given time].)
But here’s the real point raised by this wobbly patient: if indeed he suffered harm from ingesting supplement-type levels of folic acid from his food (because of a delayed diagnosis of the cause of his condition), he incurred that risk when he had absolutely no chance of benefitting from the vitamin “supplement” he was unwittingly ingesting. That’s simply because a 56-year-old man—like me—has a zero risk of becoming pregnant.
Indeed, this zero risk of pregnancy is shared by all boys and men, as well as all premenarchal girls and postmenopausal women. Looking at data from the 2010 census, this would mean about 250 million out of about 310 million Americans—about 80% of the population—are unwittingly ingesting a supplement that is not intended for their benefit. For some of them, mostly those over 40, this supplementation might lead to harm.
As an academic public health professional, I’m pleased to see that there’s some evidence that this activist intervention of our food supply has led to some benefit (reducing NTD incidence from 4,000 to 3,000 per year, with some people claiming even larger benefits).
But shouldn’t we at least acknowledge that this significant but relatively rare benefit may come at the cost of an arguably less significant but much more common harm? Buried deep in the discussion of the New York Times case were comments by readers JJL and Jennifer that raised this possibility, noticing that the patient’s normal blood counts delayed the diagnosis and might have been caused by folate fortification.
Disturbingly, this point was not raised by the expert diagnostician quoted in this case. Yet there are those who argue that we should increase the level of fortification, and fortify even more foods than we currently do, in spite of data showing that the current fortification standard has significantly raised blood levels of folate, as well as evidence that there may be harms from this intervention.
All in the name of preventing rare birth defects. Babies have their lobbyists; who out there is going to speak for the rest of us?
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