Food: Healthy foods are less nutritious than before

Intensive farming practices have reduced the micronutrient content of many foods considered healthy. Nutritionists remind us that a diverse diet remains the best protection against chronic diseases.

Eating fruits, vegetables, and whole grains: the advice is well-known. But do these foods still live up to all their nutritional promises? Not necessarily, according to David Montgomery, a geologist in the Department of Earth and Space Sciences at the University of Washington.

Montgomery reviewed nearly 1,000 scientific studies on nutrient levels in food for his book What Your Food AteHis observation: while the content of macronutrients (carbohydrates, proteins, lipids) has not changed significantly in recent decades, that of micronutrients, vitamins and minerals such as iron or zinc, has indeed decreased in a wide range of foods.

The phenomenon is partly explained by what specialists call the dilution effect. When a wheat variety is selected to produce twice as many grains, the amount of minerals absorbed from the soil remains the same, but is spread over a much larger harvest volume. As a result, each ear contains proportionally fewer nutrients.

Modern agricultural techniques exacerbate the problem. Intensive tilling, the use of synthetic fertilizers and pesticides disrupt the balance of fungi and microorganisms in the soil. This balance determines the plants' ability to absorb not only minerals, but also phytochemicals—compounds with anti-inflammatory and antioxidant properties that protect cells against environmental toxins and neutralize free radicals that can damage DNA.

Montgomery advocates for regenerative agricultural practices: limiting physical and chemical disturbances to the soil, maintaining living roots at all times, and diversifying crops. These methods promote nutrient cycling and increase the production of phytochemicals in food.

Nutritionists offer a more nuanced perspective. Astrid Donalies, a nutrition specialist at the German Federal Food Center, believes the priority is not so much the intrinsic quality of each food as the variety of what we eat. She points out that today's consumers have access to a much wider range of fruits and vegetables than their grandparents, who had to make do with beets, potatoes, and a few pieces of fruit in winter. However, she recommends favoring regional and seasonal produce: it's fresher, and its shorter transport distances are better for the environment.

Silke Restemeyer, a nutritionist at the German Nutrition Society, an independent non-governmental organization, emphasizes the benefits of a varied diet rich in plant-based foods. "People who eat plenty of fruits and vegetables suffer less often from high blood pressure, heart disease, and strokes," she says. Data also suggests that certain cancers and dementia are less common in these individuals.

Restemeyer also recommends legumes, especially beans and lentils, for their high fiber and micronutrient content: vitamins B1 and B6, iron, zinc, and magnesium. Their low glycemic index provides lasting satiety, unlike a pastry or a burger. A handful of nuts a day provides essential fatty acids that are beneficial for the heart. As for grain products, choosing whole-grain versions reduces the risk of type 2 diabetes, lipid metabolism disorders, colon cancer, and cardiovascular disease. The general principle remains simple: more vegetables and whole grains, less meat and soda.