Eating Fear: The cortisol connection in animal consumption


Eating Fear: The cortisol connection in animal consumption

Vegan Society of Canada News
July 19th 2024

There’s a lot of ground to cover to investigate the various detrimental effects to humans from eating meat due to the fear those animals experience in slaughterhouses, but as is often the case, there is still much we don’t know. Fear itself is hard to measure, so to quantify fear in animals perhaps the best proxy is cortisol.

Cortisol is a hormone produced by many animals, including human animals. Like cholesterol, this is something the body naturally produces and is necessary for the proper functioning of human animals. One particularity of this hormone is that it is a stress hormone; animals release this hormone in response to various stressful situations and it plays an important role in the fight or flight response. Also like cholesterol, too much of it can become a problem.

For human animals, it is widely known that chronic stress is highly detrimental to our health. Since most of our cells have glucocorticoid receptors to which cortisol can bind, it has a broad impact on our health, including, but not limited to, heart disease, stroke, depression, anxiety, sleep problems, and weight gain.

An overwhelming amount of research discusses the impact of stress as a source of cortisol increase in our bodies, but another vector that is much less often discussed is ingesting it via the eating of animals.

Most animals that are killed for food live in horrendous conditions and none of them, including those that are free-range, organic or humane, experience the transport to slaughterhouses and their death calmly. Many studies look at various aspects of animal agriculture and their impact on the cortisol levels of the resulting meat. For example, transport time has been shown to stress animals and affect cortisol levels. This stress response affects not only cows, pigs, chickens and other animals farmed for food but also fish.

Slaughterhouses are an aberration with tremendous costs to our society both for the killers and the killed. However, their negative effects do not stop there; the stress and fear of these animals are scientifically measurable. In a study looking at the lifeless bodies of 448 animals that were going to be butchered for food, 67 percent of them had high or extremely high levels of cortisol, above 74.7 ng/mL and 108.8 ng/mL respectively.

The relationship between cortisol levels and ill-health is complex and there are many things we do not understand. We know that cortisol levels play a role in cardiovascular diseases like stroke and heart disease, as well as diabetes, inflammation and autoimmune diseases. The impacts could be far-reaching, for example, there is research looking at the role of inflammation in cognitive diseases like Alzheimer’s.

The impact of cortisol levels from food ingestion is still unclear. Common sense would dictate that this should be fairly straightforward to investigate. Many agree that a high-protein meal increases cortisol levels more than a low-protein meal, but not everyone is in agreement. The strong influence of various lobbies may be muddying results. For example, in the test design of the conflicting research results, both meals contained animal protein; we have seen these issues with dairy where experiment designs contained dairy in all groups, even the control group, affecting the result. But we know dairy can be linked to cancer even in small amounts.

An interesting area of research would be to study whether all forms of protein raise cortisol or specifically animal protein. None of the research considered this, and it was widely assumed that protein in general raises cortisol levels more than carbohydrates. However, it would stand to reason that if one eats a piece of meat full of cortisol due to the horrendous stress experienced by that animal, this ingestion of cortisol is what raises cortisol levels and not protein itself.

It is highly unlikely that animal agriculture or governments in countries with strong animal agriculture lobbies—like much of the Western world—will fund this type of research. Vegan organizations may one day have to conduct this type of research themselves to get to the bottom of things. If you are interested in getting involved, please contact us.

While there are a lot of things we do not understand, one thing is clear: ingesting cortisol does not provide health benefits. In the best-case scenario, ingested cortisol via the extreme stress experienced by animals has no negative impact on human-animal health. In the worst case, it contributes greatly to the societal burden of various diseases that are now attributed to animal protein in general.

Ongoing research should help us understand the role that elevated cortisol levels play in human animals. Nevertheless, we advise people not to wait and hope for the best-case scenario.

A change of lifestyle offers individuals a powerful means to combat a range of issues, including personal health problems, climate change, loss of biodiversity, global acidification, eutrophication, freshwater shortages, pandemic prevention, antibiotic resistance, save countless lives and much more. We know of no other efficient way for individuals to address these critical challenges simultaneously without waiting for government, corporate, or technological interventions. By changing lifestyle, people can take immediate and impactful action. We encourage you to embrace this lifestyle change today. Contact us for support and to connect with local communities in your area.

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