Advice recommending the consumption of saturated fat, including from beef tallow, has been in the news lately.^1,2 I won’t go into the health issues associated with eating this, as I’m not a medical doctor. My concern focuses more on beef and other animal fats as delivery devices for fat-soluble, toxic chemicals like dioxins, organochlorine pesticides, and polychlorinated biphenyls. These chemicals are linked to health issues such as cancer, hormone disruption, reproductive impairment, and neurological toxicity.^3-5

Animal fats are repositories for these long-lasting chemicals and are accumulated over the animals’ lifetimes. Unlike water-soluble contaminants, like plasticizers that are excreted from your body within days, fat-soluble contaminants can take months to decades to metabolize or excrete, depending on their structure and other factors.^3,6,7 Therefore, the best approach to keeping your body burden of these chemicals low is to avoid them in the first place. Don’t forget full fat dairy (yes, sadly, that includes cheese) when reducing consumption of animal fats.

What about free-range or organic sources of beef and dairy products? I wrote about this issue previously – check out this post for more detail. In essence, switching from conventionally raised to grass-fed beef products may result in a healthier ratio of omega 3 to omega 6 fats. However, that will not reduce your exposure to the contaminants listed above because these chemicals are present in air pollution worldwide and are deposited on both grasses and grains that provide food for cattle. Because animals consume large quantities of these plants over their lifespan, they accumulate toxic chemicals into their fatty tissues, a process called bioaccumulation. With respect to organic products, conventionally raised cattle may be exposed to pesticides in their feed. Thus, consuming organic beef products may protect you from those toxicants but not those accumulated from the environment like dioxins and PCBs.

Bottom line, the best way to avoid these toxic chemicals is to include more plant-based sources of fats like avocadoes, olive oil, and nuts in your diet rather than animal-based sources.

References

1. Green, H. H. (October 25, 2025). RFK Jr to urge Americans to eat more saturated fats, alarming health experts. The Guardian.
2. Russel, L. (June 20, 2024). What is beef tallow? Is it good for me? Mayo Clinic Press.
3. ATSDR Case Studies in Environmental Medicine. Polychlorinated Biphenyls (PCBs) Toxicity (2014). U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry.
4. EPA (2023). Learn about Dioxin. https://www.epa.gov/dioxin/learn-about-dioxin#:~:text=Dioxins%20are%20called%20persistent%20organic,and%20can%20interfere%20with%20hormones.
5. EPA (2023). Health effects of exposures to mercury. https://www.epa.gov/mercury/health-effects-exposures-mercury
6. Idowu, I. G., et al. (2023). Polychlorinated biphenyl (PCB) half-lives in humans: A systematic review. Chemosphere, 345.
7. Milbrath, M. O’G. et al. (2009). Apparent half-lives of dioxins, furans, and polychlorinated biphenyls as a function of age, body fat, smoking status, and breast-feeding. Environ. Health Perspect. 117:417-425.