How healthy food and vitamin advice are failing us

Eat your vegetables. Choose whole grains. Get your nutrition from food.

You’ve heard that advice for years. And if you’ve taken it seriously, you deserve to know about something that gets far less attention: Some of those healthy foods are delivering less nutrition than they once did.

To me, that raises an uncomfortable question.

If the nutritional content of our food has changed, shouldn’t the advice we’re given change with it?

Especially the advice that dismisses vitamins as a waste of money.

I believe eating well and supplementing wisely can belong in the same health routine. And research gives us good reasons to take that position seriously.

What’s happening to the food we count on?

A British report called Hollow Harvests, produced by Deep Science Ventures with the Mark Leonard Trust, examines a problem hiding behind our increasingly productive harvests.

According to its public summary, decades of breeding and farming for yield have left many crops with 20 to 50 percent less of several key nutrients.

One example makes the issue easy to understand: If a carrot contains half as much potassium, you have to eat twice as much carrot to obtain the same amount of that mineral.

The carrot may look just as healthy. You may feel just as good about putting it on your plate. But its nutritional contribution has changed.

That doesn’t mean every vegetable has lost half its nutrients. It does mean we should pay attention to what “healthy food” actually delivers.

Coverage of the report highlights potassium, iron, selenium and zinc. These minerals help keep some of your body’s most essential functions running:

• Potassium supports your heart, muscles and nerves. Too little in your diet can contribute to high blood pressure.
• Iron helps your blood carry oxygen throughout your body and supplies oxygen to your muscles.
• Selenium supports thyroid function and helps protect your cells and maintain defenses against infection.
• Zinc supports immune function, wound healing and the production of DNA and proteins.

These are nutrients we depend on every day.

This isn’t just Britain’s problem

American research has been pointing to nutritional losses for years.

USDA researchers grew 14 American wheat varieties from different historical eras at two Kansas locations. Their findings linked higher yields with lower concentrations of iron and zinc, with a similar trend for selenium. The growing location influenced the results.

Another study compared USDA composition data for 43 crops, mostly vegetables, from 1950 and 1999.

Across the foods as a group, researchers found statistically reliable declines in protein, calcium, phosphorus, iron, riboflavin and vitamin C. Median declines ranged from 6 percent for protein to 38 percent for riboflavin, or vitamin B2.

Calcium declined 16 percent and iron approximately 15 percent. Seven other nutrients showed no statistically reliable change, and historical comparisons carry uncertainties, including changes in sampling and testing methods.

Still, the findings deserve attention. Vitamin B2 helps turn food into usable energy. Calcium supports bones, muscles and nerves. Vitamin C is needed to produce collagen and more.

When I look at that list, I see nutrients connected to functions we want to preserve as we get older.

More food doesn’t always mean more nutrition

One explanation is a dilution effect: A crop’s yield increases faster than its mineral content. We harvest more, but each serving can deliver less of certain nutrients.

The American wheat research supports that trade-off.

Then there’s the ground beneath those crops.

A 2021 study estimated that roughly one-third of the U.S. Corn Belt had completely lost its original organic-rich topsoil—the layer that helps retain water and nutrients. That study measured soil loss, rather than the nutritional content of harvested food.

Separate, preliminary research comparing regenerative and conventional American farms found differences in soil health and crop micronutrients and phytochemicals. It suggests that caring for soil can influence food quality.

And our food supply reaches well beyond American farms: Imports supplied nearly 60 percent of fresh fruit and about a third of fresh vegetables available in the U.S. in 2023, according to USDA—making soil health and nutritional quality in the countries supplying that produce relevant to our plates, too.

Improving crops and rebuilding soil deserve serious attention. But those changes will take time.

What do we do while we wait?

Keep eating nutritious foods, certainly. But I also think a daily multivitamin/mineral deserves a place in the conversation. NIH recognizes that these supplements can help people obtain recommended amounts when food alone falls short.

That makes the sweeping dismissal of supplements harder to accept.

The ‘waste of money’ message needs an update

Johns Hopkins Medicine still features an editorial titled “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements.”

Its accompanying discussion concludes that multivitamins don’t reduce cognitive decline and several other health risks.

But research has moved forward.

A 2024 analysis of three cognitive studies within the COSMOS randomized trial included 5,203 older adults. Daily multivitamin/mineral supplementation significantly benefited overall cognition and episodic memory—the ability to recall experiences and events.

Researchers estimated the overall cognitive benefit was equivalent to two years less cognitive aging.

For readers who want to preserve their memory and mental abilities, that deserves more than a dismissive shrug.

There’s encouraging evidence for illness recovery, too. In a small, 12-week Oregon State University trial, older adults taking a multivitamin/mineral containing zinc and high amounts of vitamin C experienced shorter and less severe self-reported illness than those taking a placebo. Their blood levels of vitamin C and zinc also improved.

These studies give us reasons to consider supplementation beyond correcting a diagnosed deficiency.

My concern is that a memorable “waste of money” message can outlive the evidence used to justify it.

Readers deserve advice that keeps up.

What I would keep in mind

Our food supply reaches well beyond American farms: Imports supplied nearly 60 percent of fresh fruit and about a third of fresh vegetables available in the U.S. in 2023, according to USDA—making soil health and nutritional quality in the countries supplying that produce relevant to our plates, too.

I have don’t the digging, but it’s not a leap to imagine those imported products are diluted to. But here’s the thing…

Continue choosing nutritious foods and eating a variety of them. A multivitamin can complement that effort.

Choose a basic multivitamin/mineral suited to your age and follow its directions. And, as I’m sure you already know, the NIH describes taking a basic multivitamin as unlikely to harm health. If you’re not sure how much you might need, or whether certain vitamins or minerals could interfere with medication, check with your doctor.

It’s time for a fuller conversation about nutrition—one that considers the food we’re actually eating, the nutrients our bodies need and what newer research tells us.

Sources:

Hollow Harvests — Deep Science Ventures

Historical shifts in the seed mineral micronutrient concentration of U.S. hard red winter wheat germplasm — USDA Agricultural Research Service

Changes in USDA food composition data for 43 garden crops, 1950 to 1999 — Journal of the American College of Nutrition

The extent of soil loss across the US Corn Belt — Proceedings of the National Academy of Sciences

Soil health and nutrient density: Preliminary comparison of regenerative and conventional farming — Proc Natl Acad Sci U S A

Is There Really Any Benefit to Multivitamins? — Johns Hopkins Medicine