Follow the Science, At Least on Nutrition

If we’ve learned anything from the Covid-19 pandemic, it’s the make-or-break importance of solid, up-to-date scientific information – and the regulatory flexibility necessary to respond to new information quickly. At least with some aspects of Covid prevention and treatment, “follow the science” became the guiding mantra, as sustained inquiry into the coronavirus progressed at warp-speed, leading to scientific breakthroughs and three vaccines in only months, rather than the normal years or even decades.

However, related research also confirmed the truth that a healthy diet is key to preventing, managing and recovering from Covid-19 (and other diseases).

That’s why it’s surprising, and exasperating, that many suggestions in the 2020 Dietary Guidelines for Americans – the official government recommendations for a healthy diet – were based on outdated data. Rather than following the science, they have too often lagged behind recent findings or been subjected to apparently politicized science. That needs to change.

Dietary Guidelines are more than advice on how to eat. They form the basis of federal food policies and programs, nutrition education, and various public and private disease prevention initiatives. Formulated in consultation with the Dietary Guidelines Advisory Committee, the Guidelines serve as a reference tool, influence what’s on food labels, and dictate what foods are allowed in school lunch programs.

Just as important, health-care professionals and policy makers determine nutritional recommendations for especially vulnerable groups – such as pregnant women, young children and adolescents. All these people depend on (and assume there is) sound science behind the Guidelines.

Given the link between nutrition and health, one would think the congressionally required dietary Guidelines would be of high scholarly quality, accurate and scientifically up-to-date, particularly since they are published just once every five years. Indeed, the statute that mandates publication specifically requires that they be based on “the preponderance of current scientific and medical knowledge.”

Unfortunately, updates that include Recommended Dietary Allowance (RDA) values for various nutrients receive less attention.

Part of the science behind the guidelines is Dietary Reference Intakes (DRIs) that tell us how much of any given nutrient a healthy person needs, from macronutrients (proteins, fats and carbohydrates) to vitamins and minerals. Surprisingly, except for sodium and potassium, none of the DRIs have been updated in the last ten years; others, like magnesium and vitamin C, have had no updates since the 1990s.

So, on closer look, the “new” 2020 dietary guidelines turn out to be the fifth consecutive congressionally-mandated iteration of old, often outdated science, packaged in a new cover. Not surprisingly, the 2020 Advisory Committee recommended urgent extensive updates to existing DRIs, for most nutrients, for all age and sex groups and life stages, to better characterize potential risks of dietary inadequacy and excess.

If these official dietary recommendations are to mean anything, the underlying science must be current and the DRIs must be updated – right now, and more regularly in the future.

The 2020 Advisory Committee report on that point is clear: “The DRIs are essential resources for evaluating the nutritional quality of current dietary patterns for the American public, and the Committee has identified where updates are needed for the DRIs to be relevant in the Dietary Guidelines process.”

That’s why it should have been big news when former Deputy Undersecretary of Agriculture for Food Nutrition and Consumer Services Brandon Lipps’ team secured DRI research funding before leaving office. For some reason, though, there was hardly any media coverage.

Instead, ahead of the 2020 Guidelines’ publication, misguided news reports announced an expected reduction in RDAs for alcoholic drinks and added sugars – in the midst of the Covid lockdowns, when millions of Americans were increasing their intakes, as a way to cope with their isolation and boredom. But without new studies to justify them, USDA and HHS made no changes to the 2015 recommendations.

By contrast, a big change that was introduced in the 2020 Guidelines involved recommendations for young infants from birth to two years of age. For example, they suggested that babies and toddlers shouldn’t have any sweets in their first 24 months, even though there is no new science to support that new guideline. Making that change even more troubling, the very young are probably more vulnerable to the effects of using outdated DRIs than any other age group.

In another example, it’s been a long time since the last DRI update for choline, a nutrient that particularly affects infants. Certain animal source foods – such as eggs – provide sufficient amounts of choline, which appears to improve cognitive development that begins during infancy and lasts into school-age years.

Researchers at Cornell University recently discovered that women who consume twice the recommended intake of choline during their third trimester of pregnancy – a time of rapid brain development – deliver lasting neuro-protective benefits to their babies. Enhanced cognitive effects observed in the children (increased attention, memory and problem-solving skills) were still maintained at age 7.

Surprisingly though, since choline was first granted a DRI in 1998, the DRI for infants across all domestic food policy has not been based on even one actual clinical trial. It’s been based on the average level of choline in breast milk. That certainly appears to make the choline-intake recommendation entirely random and inadequate, especially for parents who follow vegan diets

DRIs have to be kept up-to-date, and ongoing, relevant research on any nutrition-health nexus must be incorporated into them.

In yet another example, the Guidelines also mention tooth cavities as a significant diet-related chronic disease.  And yet the Guidelines ignore the large body of evidence showing the role that chewing sugar-free gum can play in improving oral health by increasing saliva production and discouraging snacking.

In fact, the Guidelines almost entirely overlooked the importance of oral health to overall health, even though wider health benefits linked to a healthy oral biome include the prevention of heart disease, pre-eclampsia and eclampsia (a pregnancy complication characterized by high blood pressure), periodontitis (a serious gum infection that can destroy gums and even jawbones) and diabetes.

Chewing sugar-free gum has been associated with faster post cesarean recovery. Researchers have even suggested a link between oral health and Covid: coronavirus may spread into the bloodstream through infected gums, causing a more severe disease in people with poor oral hygiene.

To restate the obvious, if the government is going to publish Dietary Guidelines for Americans every five years, agencies need to follow the science. Rather than regurgitating and reprinting old information, and expecting us to follow it on faith, these highly influential Guidelines need to be based on current scientific knowledge. Our health and the health of our children are too important for anything less.

Whether it’s nutrition, Covid or climate change, the last thing we need is more sloppy politicized science, and more policies, laws and regulations dictated by “woke” or “cancel culture” agendas that put our well-being way down on the list of government priorities.

<i>Via email from Paul Driessen</i>