The concern about eating animal-based meat is not only about the saturated fat, the trans fat, the cholesterol, but also how it might impact our stress hormone called cortisol. Cortisol has so many functions in our body, but usually, it is known as the stress hormone. Cortisol helps you to cope with stress. We need it in certain situations.
When cortisol level rises, it will help your liver to make more glucose through the process of gluconeogenesis (1), so you have the energy to respond to the stress you are facing. Cortisol raises your blood pressure too. So you can be more alert. Does cortisol level increase when one eats meat?
A study done in 1981 showed that when one eats 4 grams of protein/kg body weight, cortisol rises higher compared to those who eat 1 gram of protein/kg body weight. It seems when someone increases the protein intake way more than it is recommended, especially animal-based protein, it can increase cortisol levels at 30 and 60 minutes after the meal. (2)
A 2003 study looked at pregnant women who eat a high animal protein and low carbs diet in late pregnancy. They saw a rise in the blood pressure of their offspring. Why? “Because high-protein diets stimulate the hypothalamic-pituitary-adrenal axis, we hypothesized that an unbalanced maternal diet might increase maternal cortisol levels, exposing the fetus to excess cortisol and programming lifelong hypersecretion of cortisol.” (3) High animal protein intake and low carbs diet in late pregnancy might put your child at a higher risk of hypertension because of its link with cortisol, the stress hormone.
What animal went through and its possible impact on our health
Eating meat might increase cortisol in our bloodstream. Is it because the animal experienced stress before they were killed? Because of limited data, we still can’t make a solid conclusion. However, we can see the glimpse of light we have so far. Many studies have noticed how animals experience stress before being slaughtered or even from the way they were being raised. Cortisol levels in these animals increased as well.
They “may experience fear, dehydration, and hunger; increased fatigue” (4), and it impacts the meat quality itself. “Severe meat quality defects, bruises, and hemorrhages, and the increased spread of pathogens have been linked with severe pre-slaughter stress.” (5) And talking about food safety, there are pathogens found in meat that can have negative health impacts on humans.
Those pathogens are “Salmonella spp., Staphylococcus aureus, Escherichia coli, ...” (6) So there is a risk of eating meat from animals who experienced stress before being killed. Therefore choosing plant protein over animal-based protein can be a much safer option.
