Is Our Food Becoming Less Nutritious? What the Evidence Actually Says

Have you ever heard someone say that fruits and vegetables today are less nutritious than they were decades ago?

The claim is often repeated in conversations about modern farming, soil health, hybrid seeds, and the food our grandparents ate. Sometimes it is presented as a simple explanation for why we need to eat more vegetables—or take more supplements.

But the evidence is more complicated.

Some studies have found declines in the concentration of certain nutrients in particular crops over time. Other nutrients have remained stable, and some have increased. The findings differ depending on the crop, nutrient, growing conditions, and how the comparison was made.

So, is our food becoming less nutritious? Let’s look at what research actually tells us.

1. What Does “Less Nutritious” Mean?

A food can be described as nutritious in several ways.

It may provide:

Protein, carbohydrates, and fats
Vitamins and minerals
Dietary fibre
Phytochemicals and other bioactive compounds
Energy that supports growth and daily activity

When researchers say a crop has become “less nutritious,” they are often referring to a change in the concentration of a particular nutrient—for example, the amount of iron or zinc in a given weight of grain.

That does not necessarily mean the food has lost all its nutritional value. It means one or more measured components may have changed.

It is also important to distinguish between:

Nutrient concentration: how much of a nutrient is present in a given amount of food
Nutrient intake: how much of that nutrient a person actually eats
Bioavailability: how much of the nutrient the body can absorb and use

These are related, but they are not interchangeable.

2. What Have Studies Found?

One of the better-known long-term studies examined wheat grown in the Broadbalk field experiment in the United Kingdom.

Researchers found that concentrations of some minerals in wheat grain declined over the later decades of the study. The decline coincided with the introduction of modern, higher-yielding wheat varieties.

One possible explanation is yield dilution: when a plant produces more grain, the amount of starch may increase faster than the amount of certain minerals, reducing their concentration in each unit of grain.

However, the findings from one crop and one location cannot automatically be applied to every fruit, vegetable, or grain grown around the world.

Research comparisons are difficult because nutrient levels can vary with:

Crop variety
Soil composition
Weather and climate
Fertiliser and irrigation practices
Crop maturity
Storage and transport
Laboratory methods used to measure nutrients

Researchers need carefully controlled comparisons to determine whether a change is caused by crop genetics, growing conditions, or another factor.

3. Are Modern Crop Varieties the Reason?

Modern crop breeding has helped increase yields, improve disease resistance, and make food production more reliable.

But breeding for one characteristic—such as higher yield—may sometimes affect other characteristics, including nutrient concentration.

This is not inevitable. Crop varieties differ in their nutrient profiles, and plant breeders can select for both yield and nutritional quality.

The challenge is that farmers need crops that are productive, resilient, affordable, and suitable for local conditions. Nutrient density is one important goal among several.

The idea that all modern varieties are nutritionally inferior to traditional varieties is therefore too broad. Some traditional varieties may contain more of particular nutrients, while some modern varieties may perform better in other ways.

4. What About Soil Health?

Soil matters. Plants need access to minerals and other nutrients to grow.

But the statement “modern food is less nutritious because our soil is depleted” is an oversimplification.

Nutrient levels in crops depend on several interacting factors. Soil nutrient availability, crop genetics, climate, farming practices, and the relationship between yield and nutrient uptake can all play a role.

Healthy soil is important for sustainable agriculture, but soil health alone cannot explain every reported change in crop nutrient composition.

5. Could Rising Carbon Dioxide Affect Nutrients?

Researchers are also studying how elevated atmospheric carbon dioxide affects crop composition.

Some experiments have found that increased carbon dioxide can reduce the concentration of certain nutrients—particularly protein and some minerals—in specific crops.

The effect is not identical across all plants or nutrients. Climate change also affects crops through heat, drought, rainfall patterns, and other stresses.

This is an active area of research, and the results need to be interpreted crop by crop rather than turned into a single claim about all food.

6. Does This Mean We Need to Eat More Vegetables?

Not necessarily.

A decline in the concentration of a nutrient in one crop does not tell us how much of that food a person should eat. Nutrient requirements depend on age, life stage, overall diet, and individual needs.

The most practical approach remains to eat a varied diet that includes different vegetables, fruits, pulses, whole grains, nuts, seeds, and suitable protein sources.

Variety matters because no single food provides every nutrient in the amounts we need.

7. Can Agriculture Improve Nutritional Quality?

Yes. Researchers and farmers are exploring several approaches:

Biofortification: breeding crops to contain higher levels of particular nutrients
Crop diversity: growing and using a wider range of crop varieties
Improved soil and nutrient management: supporting plant growth and nutrient uptake
Breeding for nutritional traits: selecting crops for both yield and nutrient composition
Dietary diversification: helping people access and consume a wider variety of foods

These approaches have different costs, benefits, and practical challenges. No single solution will work everywhere.

The Takeaway

The evidence does not support a simple conclusion that all food today is less nutritious than food in the past.

Research has found declines in some nutrients in certain crops, including evidence from long-term wheat studies. But nutrient composition varies widely, and the causes are complex.

The better question is not simply whether modern food is “worse.” It is:

How can we grow, produce, and eat food that is nutritious, accessible, sustainable, and diverse?

That is a more useful conversation than assuming every modern food is nutritionally inferior.