It is likely that you have heard of the term “phytonutrients” or “phytochemicals”; the multitude of chemicals found in plants that have health promoting abilities. However, I bet you have not heard of the term zoochemicals. This is not some group of chemicals that gets zoo animals to do tricks on command. Rather, the term zoochemcials is a general term for the many chemicals found in animal products that can have health promoting properties. (1) As you will see, it is regrettable that this term is not as commonly used as phytochemicals because there are a number of chemicals found in animal foods that have similar or maybe even greater potential for health benefits than do phytochemicals.
Before highlighting the zoochemicals, I will offer my two cents about why there is a lack of awareness or appreciation of zoochemcials. I think the current view or awareness is largely due to the ubiquitous myth that animal foods need to be consumed with great caution, particularly those that have higher fat amounts. Animal foods can be eaten, but there are often many caveats connected to the recommendation. The warnings usually have to do with the fat and cholesterol content of the food and the general view that eating higher amounts of animal products will cause many diseases, particularly heart disease and cancer. For example, the book The Encyclopedia of Healing Foods by two popular naturopathic doctors, Michael Murray and Joseph Pizzorno, have these types of warnings scattered throughout the book. For instance, they state “We suggest you limit your intake of red meat (beef, veal, or lamb) to no more two servings per month and choose the leanest cuts possible” (p.14) “Milk and cheese are often loaded with fat and cholesterol, which at elevated levels lead to obesity, heart disease, diabetes, and some forms of cancer” (p.569) and finally “While moderate consumption of meat and animal products may be health promoting, there is no question that overconsumption of these foods is spurring a global epidemic of lifestyle diseases, such as heart attack, strokes, and cancers…”(p.596).(2) Regrettably, in general, these types of statements are ever-present in the nutrition field. This is regrettable because the evidence for such caution is weak and, in fact, eating animal products is actually more likely to contribute to a more positive health effect than a negative one. (3,4,5,6,7,8) This will be considered heresy by many, but I really think that the evidence is clear on this topic. This does not mean that everyone needs to eat high amounts of animal products to be healthy. However, it is clear that humans, healthy ones, have subsisted on widely varying diets. But, there is not a single human culture/tribe etc. that purposefully avoided eating animal products and the general consensus is that animal products were hunted and eaten whenever possible. Additionally, there are a number of cultures that have been meticulously studied that eat close to a completely carnivorous diet (no plant products) and have been exceptionally healthy and typically lived a long life if they made it past infancy or avoided some type of infectious disease.(3,8)
I want to point out that there are legitimate ethical, moral and environmental concerns associated with many aspects of the typical animal production (factory farms) in the US and other countries. However, these concerns, in no way, take away from the fact that the human body should be eating animal products. The anatomical, evolutionary, cultural, and clinical evidence is clear that humans thrive when animal products are available. (3,4,5,7,8) Related to this aspect is the quality of animal products, i.e. grain-fed vs grass-fed, hormone use and so on. Yes there is a difference, but the difference is not usually huge. But, overall, it is best that the animal products that you ingest are high quality. That is all that will be said on this for now, as these subjects need their own post/discussion in order to clearly elaborate on the many points related to them.
The following are the nutrients/chemicals that are found only in animal products or found in relatively high amounts compared to most plant foods. There will be exceptions, such as seaweeds for iodine and so forth, but considering foods that are commonly consumed the animal foods will often have a greater nutrient density than plant foods (nutrient density refers to the amount of nutrients per serving size of foods). Also realize that the foods listed below are the foods that naturally have the nutrient in it. Therefore, foods that have been fortified/enriched with a certain nutrient are not listed.
The details of each nutrient will not be discussed here, but you can assume that each one of them can play an important role in promoting a high level of health. However, the amounts of accessory nutrients (the zoochemcials) that can be ingested from food itself will often not reach the amounts used for assisting in health problems or clinical trials. This does not mean that at these levels cannot help keep a person healthy. Besides containing these items, most animal foods are a very good source of many B-vitamins and high quality proteins. It is important to realize that many whole foods contain numerous substances that are beneficial and it is often misguided to reduce a complex food down to a specific nutrient. It has repeatedly been shown that the many nutrients found in foods work synergistically.(11) Therefore, it is usually best to get all of your nutrients from real, high-quality foods. However, there are situations, like food aversions, health conditions, seasons, athletic goals, and many others, when supplementing your diet with specific nutrients is needed and helpful.
As you can see from the above details, animal based products are a great source of vitamins, minerals, proteins, fats, and other accessory nutrients that are important for health. The ability to have a nutrient dense diet is not hindered, in fact it is usually improved, when quality animal products are included in the diet. For those following a smart low-carbohydrate diet or for those thinking about it, it should be clear that basing your diet around high-quality animal products is good for your health.
1 – Hasler, C. (2002). Functional foods: benefits, concerns and challenges – A position paper from the American Council on Science and Health. J Nutri; 132: 3772-3781.
2 – Murry M. et al (2005). The encyclopedia of healing foods. Atria Books. New York.
3 – Abrams, H.L. (1980). Vegetarianism: An anthropological/nutritional evaluation. J Appl Nutr; 32(2): 53-86.
4 – Cohen, M. (1989). Health and the rise of civilization. Yale University Press. New Haven, Conn.
5 – Cordain, L. et al (2000). Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr; 71: 682-692.
6 – Frassetto, LA. Et al (2009). Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr: 1-9.
7 – Mann, N. (2000). Dietary lean red meat and human evolution. Eur J Nutr; 39: 71-79.
8 – Price, W. (2000). Nutrition and physical degeneration. Price-Pottenger Nutrition Foundation. La Mesa, CA.
9 – Whitney, EN. & Rolfes, SR. (2002). Understanding Nutrition. Wadsworth. Belmont, CA.
10 – Zeisel, S. et al (2003). Concentrations of choline-containing compounds and betaine in common foods. J Nutr; 133: 1302-1307.
11 – Milner, J.A. (2004). Molecular targets for bioactive food components. J Nutr; 134: 2492S-2498S.