The food we eat today is not the same as the food our grandmothers ate. Research points to a concerning decline in the nutritional value of food and reveals what this actually means for our health.
Imagine eating a balanced diet every day, including fruit, vegetables, whole grains, protein sources and healthy fats. It would seem logical to assume that your body is getting everything it needs. Yet a growing body of research points to an uncomfortable truth that cannot simply be dismissed: the nutritional value of the food on our plates today is significantly lower than it was several decades ago.
This is neither a conspiracy theory nor a marketing story created by supplement manufacturers. These are measurable, documented changes in soil composition and in the way food is grown and processed. They directly affect what our bodies receive, or fail to receive, from the meals we eat every day.
A nutritional crisis on our plates: what does the research say?
A 2004 study published in the Journal of the American College of Nutrition analysed 43 different types of fruit and vegetables and compared their nutritional composition with data from 1950. The results were concerning: the researchers recorded declines in protein content by an average of 6%, calcium by 16%, iron by 15%, riboflavin by 38% and vitamin C by 20%. [1]
A study conducted for the UK Department of Health reached a similar conclusion after tracking the composition of 50 types of vegetables over several decades. Spinach today contains approximately one third of the iron found in spinach in 1940, even though it looks exactly the same on the plate. [2]
| –38% Riboflavin (B2) in vegetables since 1950 | –16% Calcium in fruit and vegetables | –15% Iron in vegetables | –20% Vitamin C in fruit |
Decline in the nutritional value of fruit and vegetables between 1950 and 1999. Davis et al., J Am Coll Nutr, 2004.
Why is this happening? Soil is the foundation of everything
Food cannot contain more nutrients than the soil in which it is grown. This is a simple but frequently overlooked fact. Intensive farming, monocultures and the excessive use of chemical fertilisers deplete the soil of minerals that are no longer naturally replenished. [3] A plant grown in depleted soil cannot absorb nutrients that are simply not there.
The Food and Agriculture Organization of the United Nations warns that soil degradation is one of the greatest global challenges affecting our food supply. It is estimated that more than 33% of the world’s agricultural land is currently degraded. [4] This is not an abstract environmental issue. It affects every meal we eat.
You may eat the same meal your grandmother ate, but your body may receive significantly fewer vitamins and minerals from it than hers did.
Modern food: processed, convenient and nutritionally poor
Beyond the condition of the soil, food processing presents another major problem. According to research using the NOVA food classification system, ultra-processed foods now account for between 50% and 60% of total calorie intake in developed countries. [5] High-temperature processing, refined sugars and industrial oils remove many of the micronutrients that were still present in the original ingredients.
A study published in The BMJ in 2019 followed almost 20,000 participants. It found that every 10% increase in the consumption of ultra-processed foods was associated with a 12% higher risk of cardiovascular disease and a 14% higher risk of all-cause mortality. [6]
The issue is not only how many calories these foods contain. It is also what those calories fail to provide.
Chronic deficiencies: what are we actually missing?
The consequences are visible in public health statistics. The World Health Organization estimates that more than two billion people worldwide experience some form of micronutrient deficiency. This condition is often described as hidden hunger because it does not necessarily cause dramatic symptoms. Instead, it develops gradually and may present as fatigue, weakened immunity and poorer recovery. [7]
European studies also report concerning figures. Vitamin D deficiency has been identified in as much as 40% of the European population. Magnesium deficiency affects almost 15% of adults, while vitamin B12 deficiency is particularly relevant among people over the age of 50 and those following plant-based diets. [8]
These are not isolated cases. They represent millions of people functioning below their full potential without understanding why.
A separate but important issue: probiotics and gut health
One of the fastest-growing areas of nutritional research is the gut microbiome, the community of trillions of microorganisms living within our digestive system. These microorganisms influence immunity, mood, metabolism and many other aspects of health.
Modern diets, which are often high in sugar and low in fibre and fermented foods, can disrupt the balance of the gut microbiome in several well-documented ways. [9]
A meta-analysis published in the American Journal of Gastroenterology reviewed more than 30 randomised clinical trials. It concluded that probiotic supplementation can have measurable beneficial effects on symptoms of irritable bowel syndrome, infection frequency and inflammatory markers. [10]
The effects varied between studies and depended on the strains used, the dose and the population being studied. Overall, however, the evidence supports probiotic supplementation for specific indications.
| Supplement | Main role | Particularly relevant for |
| Vitamin D3 | Immunity, bone health and mood | People living in northern countries, particularly during autumn and winter |
| Magnesium | Muscles, nervous system and sleep | People experiencing stress, athletes and older adults |
| Omega-3 fatty acids | Heart and brain health, and regulation of inflammation | People who rarely eat oily fish |
| Vitamin B12 | Nervous system and red blood cell production | People over 50, vegans and vegetarians |
| Probiotics | Gut microbiome, immunity and digestion | People who have taken antibiotics and those with IBS |
Always consult a doctor or qualified nutrition professional before introducing supplements, ideally after appropriate blood testing.
Is supplementation the answer for everyone?
Honesty is important here because this subject attracts both excessive enthusiasm and excessive scepticism.
Dietary supplements are not a substitute for a healthy diet, nor are they a miracle cure. A varied, high-quality diet remains the foundation of good health, and no capsule can replace it.
However, when food no longer meets basic nutritional needs because of depleted soil, intensive processing or modern lifestyle factors, supplementation can become a reasonable, evidence-based strategy for filling specific gaps. [11] This is not a sign of weakness or failure. It is a practical response to the reality in which we live.
Three factors are essential: choosing evidence-based supplements, adapting supplementation to individual needs, ideally with prior blood testing, and purchasing products from reputable manufacturers that undergo independent quality testing.
We cannot correct nutrient depletion caused by degraded soil through good intentions alone. We can, however, stay informed and make decisions that support our long-term health.
Scientific references
[1] Davis DR, Epp MD, Riordan HD. Changes in USDA Food Composition Data for 43 Garden
Crops, 1950 to 1999. J Am Coll Nutr. 2004;23(6):669-682.
[2] Mayer AM. Historical changes in the mineral content of fruits and vegetables. British
Food Journal. 1997;99(6):207-211.
[3] Amundson R et al. Soil and human security in the 21st century. Science. 2015;348(6235).
[4] FAO. Status of the World’s Soil Resources. Rome: Food and Agriculture Organization of
the United Nations; 2015.
[5] Monteiro CA et al. Ultra-processed foods: what they are and how to identify them. Public
Health Nutr. 2019;22(5):936-941.
[6] Rico-Campà A et al. Association between consumption of ultra-processed foods and all
cause mortality. BMJ. 2019;365:l1949.
[7] WHO. Micronutrient deficiencies. World Health Organization; 2023.
[8] Cashman KD et al. Vitamin D deficiency in Europe: pandemic? Am J Clin Nutr.
2016;103(4):1033-1044.
[8] Cashman KD et al. Vitamin D deficiency in Europe: pandemic? Am J Clin Nutr.
2016;103(4):1033-1044.
[9] Sonnenburg JL, Backhed F. Diet-microbiota interactions as moderators of human
metabolism. Nature. 2016;535:56-64.
[10] Ford AC et al. Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel
syndrome and chronic idiopathic constipation. Am J Gastroenterol. 2014;109(10):1547-
1561.
[11] Blumberg JB et al. Impact of Frequency of Multi-Vitamin/Multi-Mineral Supplement
Intake on Nutritional Adequacy. Nutrients. 2017;9(8):849
