One key lesson from coping with COVID-19 is that high-quality scientific information matters. It’s as true for nutrition and food science as it is for virology.
As the scientific community has worked to figure out how to fight the virus, many of the classic truths about the connection between good nutrition and good health have been reaffirmed. It is consequently unsurprising that a healthy diet plays an important role in COVID-19 management and recovery. That makes it all the more unbelievable that the dietary guidelines issued by the U.S. government to promote a healthy diet are woefully out of step with current scientific understanding.
Given the significance of nutrition for health, one would think that the congressionally mandated dietary guidelines published every five years would be extremely accurate. That is to say that the guidelines would be reflective of the current scientific evidence. Yet, the dietary reference intakes, or DRIs, published by the National Academies of Science, Engineering, and Medicine, on which the dietary guidelines are heavily based, are not up to date. There’s simply no federal funding dedicated to keeping them in line with the continuously evolving body of scientific literature.
“Historically, DRIs were set to prevent deficiency diseases and toxic levels of intake, but as the field of nutrition has evolved, a focus on chronic disease risk reduction has emerged,” explained my good friend and research colleague Dr. Regan Bailey. A professor in the Department of Nutrition Science at Purdue University and a member of the 2020 Dietary Guidelines Advisory Committee, Bailey knows her stuff. If the dietary recommendations are to remain relevant, revising the DRIs and keeping them current is critical.
Indeed, the DRIs form a fundamental pillar of the guidelines by informing the Dietary Guidelines Advisory Committee how much of any one nutrient a healthy person of a specific gender and life stage needs, be it a macronutrient (protein, fat, and carbs), vitamin, or mineral. With the exception of sodium and potassium, none of the DRIs have been updated in the last 10 years, and some, such as magnesium and vitamin C (that have been thought to influence immune function significantly in response to infectious diseases) have not been updated since the late 1990s.
On closer look, the “new” 2020 dietary guidelines are in this regard old science with a new cover, not exactly a document that inspires us to “follow the science.”
In what should have been big news, shortly before they left office, then-Deputy Undersecretary for Food Nutrition and Consumer Services Brandon Lipps and his USDA team secured funding to revise energy requirements and macronutrients (i.e., protein, fat, and carbs) prior to the 2025 report. This is one of the biggest wins that nutrition science has seen in a decade. Unfortunately, there has been hardly any media coverage.
For the first time, the 2020 dietary guidelines included recommendations specific to young infants from birth to 2 years of age. However, the majority of nutrient DRIs for infants and young children were derived by extrapolating down from adult data by body weight, a common practice in the absence of data decades ago. Infants and young children are, of course, one of the most vulnerable subpopulations. The period from conception until the age of 2, otherwise known as “the first 1000 days,” is universally recognized as a critical period for brain development, in which the timing of nutrition is crucial and later compensation will not be able to retrieve all of the lost function.
Let’s consider magnesium, one of the many nutrients the DRI of which is desperately in need of an update. Certain foods such as dark, green, leafy vegetables, whole grains, nuts, and seeds are rich in this mineral. Magnesium matters because it is involved in over 600 enzymatic reactions in the body, including many that influence immune function. Recall all the hype around vitamin D during the height of the pandemic? Dr. Anthony Fauci recommended taking vitamin D supplements to prevent and decrease the severity of COVID-19. But it takes magnesium to activate vitamin D in the body.
That’s right — you can take vitamin D supplements all day long, but if you’re magnesium-deficient, it likely won’t do much for you.
Magnesium has what nutrition scientists know as a “calcium-channel blocking effect.” In other words, it prevents calcium from entering the cell. Blocking calcium matters because viruses such as COVID-19 love calcium and need lots of it inside the cell to replicate and spread. So, how much magnesium do you need every day for tip-top immunity? That’s a good question, and we don’t really know the answer since the last time the evidence was reviewed, I was in middle school! Needless to say, the magnesium DRI update, like many others, is long past due.
Furthermore, if all DRIs were kept up to date, future dietary guidelines advisory committees would be able to expand beyond traditional recommendations into new nutrition-relevant areas, such as immune function. Dietary guidelines should dig deeper on health issues as simple as dental caries (i.e., cavities), which is constantly on the back burner even though it remains a very significant diet-related chronic disease across the population. Large amounts of consistent clinical evidence demonstrate that something as simple as sugar-free gum improves oral health by dramatically increasing saliva production and discouraging snacking. And here is the best part: The costs associated with keeping all the DRIs up to date is less than the annual budget to plant grass on the National Mall.
Chew on that!
Dr. Taylor Wallace, Ph.D., CFS, FACN (www.drtaylorwallace.com) is the principal and CEO of the Think Healthy Group, Inc., an adjunct professor in the Department of Nutrition and Food Studies at George Mason University, and a member of Forbes Health Advisory Board.
