Why Your Sunday Roast May Be Less Nutritious Than It Was 80 Years Ago

New research suggests that many foods we eat today are less nutritious than the same foods were 80 years ago. A report from Deep Science Ventures (DSV) found that some fruits and vegetables contain 20 to 50 percent fewer nutrients than they did in 1940. Scientists say modern farming, damaged soil, and climate change may all be part of the problem. The findings raise big questions about what we are really getting from the food on our plates.

The DSV report looked at 29 fruits and vegetables and found some striking drops in key nutrients. Iron levels had fallen by 50 percent on average, copper was down 49 percent, and magnesium had dropped by 10 percent. Calcium and potassium levels had also decreased over the same period. Everyday vegetables like carrots, potatoes, peas, and cabbage were all included in the study.

A separate study compared beef sold in British supermarkets in 2024 with government data from 1992. Researchers found that today's beef has much lower levels of iodine and several B vitamins, including B1, B2, B6, B12, and folate. On a more positive note, the same study found that iron, selenium, calcium, magnesium, and potassium were all higher in today's beef than they were 34 years ago. Scientists say better lab testing may explain some of the changes.

These nutrients matter a great deal to our health. Iron helps carry oxygen around the body, and too little of it can make a person feel very tired or become anaemic. Magnesium keeps muscles and nerves working properly, and potassium helps control blood pressure. B vitamins help turn food into energy and support the nervous system.

One key explanation for falling nutrient levels in vegetables is called the 'dilution effect.' When crops are bred to grow bigger and faster, they can produce more carbohydrates without absorbing as many minerals from the soil. This means nutrients are spread more thinly through a larger vegetable, so each bite contains less. Scientists say this is a widely accepted idea among researchers.

Soil health is another important factor. When farmers grow the same crops repeatedly on the same land without letting the soil recover, it can lose its ability to support healthy plant growth. Intense ploughing can also harm the tiny organisms in the soil that help plants absorb nutrients. Fertilisers can replace some nutrients, but experts say they do not fully make up for what is lost.

Climate change complicates things further. Higher levels of carbon dioxide in the air help plants grow faster, but faster growth often means fewer nutrients packed into each plant. A 2014 study found that crops grown in high-CO2 conditions had more carbohydrates but less zinc, iron, and protein. As the climate keeps changing, scientists warn that the nutritional value of our food could continue to fall.

Will Summers of DSV said that farmers have focused on producing large amounts of food rather than nutritious food. He noted that over 2 billion people worldwide have at least one nutrient deficiency and most don't know it. In Britain, 14 percent of adults aged 19 to 64 have folate levels low enough to count as a clinical deficiency. People taking appetite-suppressing weight-loss drugs face extra risk because they eat less overall.

The good news is that solutions already exist. Farmers can use cover crops and crop rotation to restore soil health, and plant breeders can develop varieties that are naturally richer in nutrients. Food manufacturers already add vitamins and minerals to some everyday foods, like flour and breakfast cereals. Summers said it would be better to fix the problem at the farming level rather than adding nutrients back in afterwards.

Summers believes that farmers should be rewarded for the nutritional quality of their crops, not just for how much they produce. Eating a wide variety of fruits and vegetables remains the best everyday advice for staying healthy. We have become very good at growing food cheaply and making it last longer on store shelves. But experts say it is time we started paying closer attention to what that food actually contains.