Our food has too many toxins and not enough nutrients – but we already have the tools to fix it

I sometimes joke that my pets eat better than my children. It’s not for lack of trying – kids turn their noses up at vegetables, fish and pulses, while dogs will never turn down their specially formulated feed, complete with all the vitamins and minerals they need to thrive. The results are plain to see: a healthy, shiny coat, high energy levels, and good health.

While comparing kids to pets might seem a bit much, it does reflect a serious truth. Nutritionally speaking, food products made for animals, whether domestic or farmed, are more complete than those made for humans.

Mighty micronutrients

Microminerals or trace elements – such as iron, zinc, copper, selenium, iodine, and manganese – are essential. Although we need them in tiny amounts, they play a role in hundreds of metabolic reactions. Iron transports oxygen in the blood, zinc and copper are part of the enzymes that protect against oxidative stress, iodine is essential for thyroid function, and selenium helps the immune system to function properly.

When these nutrients are lacking, even slightly, the body notices: fatigue increases, defences are lowered, and the onset of chronic diseases, including cancer, becomes more likely.

The World Health Organization estimates that over 2 billion people suffer from some form of micronutrient deficiency. This is known as “hidden hunger”: there is food on the plate, but these invisible nutrients that ensure healthy development and ageing are missing.

Leer más: Hidden hunger affects nearly 2 billion worldwide – are solutions in plain sight?

Too many toxins

An additional problem is exposure to toxic elements such as arsenic, lead, mercury and cadmium, which we come into contact with through certain foods or our surroundings. Even in small amounts, they accumulate in the body and affect the nervous system and fertility, and increase cancer risk.

The big challenge is that both essential mineral deficiencies and exposure to toxins often go unnoticed. They do not show obvious signs until the problem is already serious.

A global, multifaceted problem

Micronutrient deficiency is a universal problem, but it manifests differently in different parts of the world.

In low-income countries, deficiencies are often due to a diet based almost exclusively on cereals or tubers, and the limited availability of animal-based foods rich in iron, zinc and selenium. This means combined deficiencies of iron, zinc and iodine affect millions of women and children, with serious consequences for physical and cognitive development.

Two contrasting realities coexist in middle-income countries. While rural areas continue to suffer from a lack of access to varied foods, large cities experience “hidden” deficiencies linked to ultra-processed diets and excessive calorie consumption that lacks micronutrients.

In more developed societies, deficiencies tend to be more subtle. It is not a question of visible hunger, but rather of subclinical deficiencies associated with ageing, and with vegan diets or poorly planned diets low in meat and fish.

In Europe, for example, several countries in the north and centre of the continent suffer from low levels of selenium and iodine. This is likely linked to soils that lack these elements.

At the same time, exposure to toxic metals such as mercury or cadmium remains a concern, particularly through the consumption of certain fish or smoking.

This diversity of causes reflects the fact that “hidden hunger” takes many forms, and that ensuring a balanced intake of essential minerals is a global challenge that knows no borders or income levels.

Targeted nutrition

In veterinary medicine, we have been ahead of the curve in this area for some time, and not just with household pets. In dairy cows, for example, serum (the liquid part of blood) is routinely analysed to adjust diet and prevent deficiencies that could affect both the animal’s health and milk production.

The same applies to horses, pigs, and poultry; their nutrition is precisely adjusted to prevent problems and optimise results.

In human medicine, we continue to rely primarily on dietary surveys and general recommendations, as there are no universally accepted reference values. We calculate how much iron, zinc, or iodine the average population should consume and, based on that, we design nutritional guidelines.

This approach is useful for guiding public health policies, but it is limited as it does not reflect individual circumstances. A person may be at risk of deficiency even if they follow the theoretical recommendations, or they may be unwittingly accumulating toxins.

The contradiction is obvious: if we take such good care of a cow’s or a dog’s diet, why don’t we apply the same principles to our own health?

Leer más: Only political will can end world hunger: Food isn't scarce, but many people can't access it

Serum: a window to our health

The good news is that we already have a simple tool to make the leap to personalised nutrition: serum analysis.

Serum allows both essential and toxic minerals to be measured at the same time. Just as we now receive cholesterol or glucose values in routine blood tests, we could also detect deficiencies in zinc or selenium, or whether we are accumulating lead or cadmium.

Current analytical technology allows us to obtain these profiles quickly and accurately from just a small sample. This opens the door to more effective public health programmes that are not based solely on dietary estimates, and to truly personalised nutrition.

Taking better care of cows than humans

If we know that a cow with selenium deficiency produces less milk and is less fertile, we act immediately to correct it. If a dog needs zinc to keep its coat shiny, we give it without hesitation. Why don’t we do the same with humans?

Targeted nutrition should not be limited to farm animals or pets. It can and should also be applied to human health. A simple serum analysis could help us live healthier lives, prevent disease and age with a better quality of life.

Perhaps it is time to learn from what veterinary medicine has been doing well for years: taking care of nutrition down to the last detail.

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This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Marta López Alonso, Universidade de Santiago de Compostela

Read more:

• The ultra-processed foods problem is driven by commercial interests, not individual weakness. Here’s how to fix it
• The A to K of vitamins: what you need and where to get it
• Food insecurity is on the rise: a look at the world’s ‘hunger hotspots’

Marta López Alonso receives funding for competitive research projects financed with national and European public funds which are not directly related to the content of this article.