Our foods contain fewer and fewer nutrients

Soil depletion

Total agricultural output has increased considerably in recent years. Productivity has risen markedly — in the United States, for example, it has tripled since 1948 [1]. Innovations in the use of chemical products, genetic modifications, equipment and so on have all contributed to this increase. 

This increase in productivity comes at a devastating cost to the nutrient content of our foods. 

Farming practices aimed at increasing productivity lead to soil degradation and a loss of organic matter. Carbon concentrations have fallen by 43%, nitrogen by 42%, phosphorus by 27% and sulphur by 33%. These nutrients support plant growth through photosynthesis, enzymes, protein synthesis and so on [2]. The loss of these nutrients from soil has an impact on the nutritional quality of the foods that grow in those soils. 

Studies suggest that conventional farming practices involving intensive soil tillage, nitrogen fertilisation and the application of synthetic pesticides may have contributed to the decline in nutrient density by disrupting the symbioses between crops and soil life [3].

Pollution

All plants have photosynthetic pathways that allow them to absorb carbon dioxide from the atmosphere, break it down and use the carbon for growth. When carbon dioxide concentrations are higher, crops absorb less water, meaning they also absorb fewer micronutrients from the soil. A 2018 study confirmed that concentrations of protein, iron, zinc and several B vitamins decreased in 18 types of rice following exposure to higher levels of carbon dioxide [4].

Processed foods

Processing (including preparation) makes food healthier, safer, more flavoursome and easier to preserve. Whilst the benefits are numerous, processing can also be detrimental, affecting the nutritional quality of food. 

Blanching, for example, is a heat treatment lasting a few minutes at 70°C to 100°C, designed to destroy enzymes that could damage vegetables or fruit before further processing (freezing, drying, etc.). This technique leads to losses of vitamins and minerals. 

Similarly, milling and extrusion can result in the physical removal of minerals during processing. 

The nutritional quality of minerals found in food depends on their quantity and bioavailability. It is known that the bioavailability of key minerals such as iron, zinc and calcium is strongly influenced by the fibre, phytic acid and tannin content of foods. The concentrations of these constituents are modified by various processing methods, including milling, fermentation, germination, extrusion and heat treatment. Vitamins, in particular ascorbic acid (vitamin C), thiamine (vitamin B1) and folic acid (vitamin B9), are highly sensitive to the same processing methods. The duration and temperature of processing, product composition and storage all considerably influence the vitamin status of our foods [5].

For example, coarse wheat flour mills lose less vitamin E than fine mills. The vitamin E content of germinated wheat can be up to 30% lower than that of ungerminated wheat [6].

The more a food is processed, the fewer nutrients it will contain in the end. 

The findings of a recent 2024 study are based on 15 years of data. They show that adults are not consuming enough vitamins A, C, D, E and K, choline, magnesium, calcium or potassium. Meanwhile, they are consuming too much sodium! [17].
What is more, this study shows that even consuming dietary supplements may not be sufficient. This is particularly true for magnesium, potassium and calcium, which are required in very high quantities and can hardly be covered by a single capsule [17].

One of the most significant scientific studies to have drawn attention to this issue was published in the United States in 2004. Based on nutritional data published in 1950 and 1999, university researchers noted changes in 13 nutrients across 43 different garden crops, from asparagus to beans and from strawberries to watermelons [7].

These raw fruit and vegetables showed a significant decline in their protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C content. The declines range from 6% for protein to 38% for riboflavin [8].

A more recent study from 2021 found that certain vegetables showed notable declines in nutrient content. Sweetcorn, red-skinned potatoes, cauliflower, green beans, green peas and chickpeas saw their iron content fall by 30 to 50% [9].  

There is a wealth of evidence demonstrating this decline in the nutritional quality of foods. Grains have also experienced falls. The protein content of wheat dropped by 23% between 1955 and 2016, and there have also been notable reductions in manganese, iron, zinc and magnesium content [10].

If we take the specific example of magnesium, part of the problem stems from the soil used in agriculture, which is becoming increasingly depleted in essential minerals. Over the past 60 years, the magnesium content of fruit and vegetables has fallen by 20 to 30%. It is also estimated that 80 to 90% of magnesium is lost during food processing [11]. 

In particular, for potassium, one study showed that although average potassium concentrations in milk remained the same between 1999 and 2015, concentrations in beef, pork, turkey and most fruit and vegetables (including bananas, but not potatoes) were generally lower in 2015 than in 1999, and that the reported reductions in dietary potassium intake corresponded to these decreases in the food supply [17].

In other words, you could eat exactly the same foods as your parents or grandparents - the same foods in the same quantities - and obtain fewer nutrients.

Yes, organically sourced foods are also affected, but to a lesser extent. 

One study showed, for example, that organic crops contain significantly more vitamin C, iron, magnesium and phosphorus, and significantly fewer nitrates than conventional crops. Trends suggest that organic crops contain more nutritionally important minerals and fewer heavy metals than conventional crops. 

For example, when comparing organic and conventional lettuce, we find: 17% more for vitamin C, +17% iron and +29% magnesium [12]. For spinach, 52% more vitamin C is observed, and up to 69% more magnesium for organic carrots! 

This is thought to be due to better soil management and improved fertilisation practices for organic crops. 

According to forecasts, this depletion of nutrients is unlikely to resolve any time soon, and is instead tending to worsen. Using models based on projected atmospheric carbon dioxide concentrations by 2050, researchers estimate that the protein content of potatoes, rice, wheat and barley is likely to decrease by a further 6 to 14% [13]. 

It therefore seems difficult nowadays, even with a varied and balanced diet, to meet all your nutritional needs. In particular, during pregnancy and breastfeeding, when needs are significantly higher, it becomes truly challenging to provide all nutrients in sufficient quantities to support both your own needs and those of your baby. Supplementation with pregnancy vitamins and breastfeeding vitamins may become necessary. 

ANSES studies already show that, even with an optimised diet and an increase in calorie intake, it is not possible to cover 100% of the needs for certain essential nutrients [14].

A recent comprehensive review of nutrition in adolescent girls and women of reproductive age concluded that dietary deficiencies, particularly in iron, vitamin A, iodine and zinc, remain common [15]. 

The typical diet in developed countries, characterised by high consumption of red meat, refined grains, refined sugars and high-fat dairy products, also shows deficiencies in several important nutrients, particularly magnesium, iodine, and vitamin D [16].

One study even shows that vitamin D supplementation has been beneficial for the population. Positive changes in habitual dietary intake of vitamin D from foods, drinks and, in particular, food supplements, led to an improvement in the percentage of male and female adults meeting vitamin D recommendations [17].

We hope that in the future, it will no longer be necessary to supplement a natural diet. But in the meantime, we offer you supplements that will help you meet your nutritional needs during these particularly sensitive periods. 

Baby Bump, the pregnancy food supplement 3 in 1. It helps cover both the expectant mother's needs and those of her baby, combining a pregnancy multivitamin complex (with 14 nutrients in bioactive form, including vitamin D, iodine, zinc, etc.), DHA and choline. Baby Bump also covers the recommended daily intake of vitamin B9.

And to help meet your iron needs, we offer Iron Mama, which covers 100% of the recommended daily intake of iron in just 1 capsule. Say goodbye to the discomfort associated with iron capsules — with our Ferrochel™ iron bisglycinate, our capsules combine optimal absorption with digestive comfort. 

Our magnesium food supplement Mama-gnésium contains magnesium bisglycinate. To meet your needs with the best form available, without any discomfort. 

Discover our full range of food supplements for fatigue to help you stock up on nutrients. 

Take care mama.