For many people today, the dietary laws regarding clean and unclean animals are among the most puzzling instructions found in the Bible. For thousands of years, these laws have been a striking mark of identity separating those who follow biblical guidelines from the rest of the world (Leviticus 20:25–26). Yet, for centuries, these same instructions have also been a source of controversy and confusion among various religious groups, even those who claim to get their beliefs from the same book—the Bible.

Perceptive scholars have recognized that these laws express God’s will and represent wise, reasonable, and beneficial measures revealing “God’s care for the health of His people.”¹ Sadly, most people today—including theologians—have little or no understanding of the sound medical reasons behind God’s instructions, because the scientific wisdom behind the biblical dietary laws is seldom taught or explained. Instead, these laws are commonly viewed as antiquated Old Testament regulations for the Jews that are no longer applicable for Christians or the general public. However, as Eerdmans Handbook to the Bible comments, “The lists of clean and unclean animals in Leviticus 11 and Deuteronomy 14… have a significance often ignored. Far from being a catalogue of food taboos based on fad or fancy, these lists emphasize a fact not discovered until late in the last century… that animals carry diseases dangerous to man.”² In fact, the same animals labeled unclean in Scripture still carry parasitic diseases that are dangerous to human beings today.

Despite these important scientific facts, many theologians and secular scholars have dismissively referred to the dietary guidelines in Leviticus and Deuteronomy as meaningless, repulsive, arbitrary, irrational ideas that originated in primitive superstitions—not in the mind of God. They have even asked, “What has all this to do with religion?”³

Scripture reveals several important reasons for the dietary laws. In Exodus, we learn that God chose the nation of Israel and set them apart for a special purpose (Exodus 19:5–6), and the dietary laws contributed to that divine purpose: “I am the Lord your God, who has separated you from the peoples. You shall therefore distinguish between clean beasts and unclean.… And you shall be holy to Me, for I the Lord am holy, and have separated you from the peoples, that you should be Mine” (Leviticus 20:24–26). Living according to God’s divine laws should have made Israel a model nation—a light and example to the world—as nations saw the blessings they enjoyed, including blessings of good health (Deuteronomy 7:15).

As we will see, not only would the dietary laws contribute to the Israelites’ good health, they would promote wise and efficient management of environmental resources. Understood this way, the distinction between clean and unclean animals plays a role in helping us “tend and keep” the land as good stewards of God’s creation (cf. Genesis 1:28; 2:15). Indeed, to fully grasp the significance of the biblical dietary laws, we must see them in the context of God’s overall purpose for mankind.

Certain Mammals are Good for Food

Leviticus 11 and Deuteronomy 14 are the primary passages in the Bible that describe the dietary laws. These chapters provide very specific information summarized in simple, easy-to-understand principles that could be applied long before the microscope was invented, and long before germ theory was proposed. Today, the discoveries of modern science are revealing just how important and practical these laws really are.

Beginning in Leviticus 11, we read that God told Moses and Aaron to inform the Israelites, “These are the animals which you may eat among all the animals that are on the earth: Among the animals, whatever divides the hoof, having cloven hooves and chewing the cud—that you may eat” (vv. 1–3). Plant-eating mammals (herbivores) that fit this description are called ruminants. These animals have four-chambered stomachs that convert grasses that are inedible to humans and other animals into nutritious, high-quality protein products (meat and milk) that people can then use for food. Examples of clean animals would be all cattle, sheep, goats, deer, bison, moose, antelope, gazelles, caribou, and giraffes. They are all divided-hoof herbivores that obtain their food by grazing or browsing on grasses and other plants.

From the standpoint of wise environmental management, these guidelines make a lot of sense. Vast areas of the globe are covered by rangelands (savannas, veldts, and pampas), which are often called “marginal lands” because they do not have enough rainfall to support the production of food crops like corn or wheat. “Cattle, sheep and goats have the ability to convert plant carbohydrates and proteins into available nutrients for human use, making otherwise unusable land productive.”⁴

The clean animals that God permitted His model nation to eat—easily discerned by split hooves and cud-chewing—were designed to produce nutritious food in an economical and ecologically sound manner. These guidelines were a key benefit that God wanted the world to see through the example of Israel.

God Commands Us Not to Eat Certain Creatures

The dietary laws regarding cud-chewing beasts also prohibit the consumption of all carnivorous animals for very logical reasons. God created unclean animals, unsuitable for human consumption, for many other purposes. Carnivores, as beasts of prey, play an important role in controlling the populations of other animals. As an example, wolves and mountain lions, which feed on herds of deer, not only control numbers, but also help maintain the herd’s health by culling out older, sick, or infirm animals. That is one reason why we should not eat carnivores—they may eat sick animals and transmit diseases to humans.

The pig or swine is specifically mentioned in Scripture as unclean and unfit to be human food (Leviticus 11:7–8; Deuteronomy 14:8). While some theologians have stated, “We do not know why the swine was forbidden,”⁵ others find numerous reasons related to ecology, economics, nutrition, and public health. In the wild, swine are often nocturnal animals that root for food. Their nighttime feeding habits would keep contact with humans at a minimum. Domesticated pigs, however, have been used for centuries as scavengers around human settlements. Having an omnivorous animal like the pig around that can put on weight rapidly by eating anything from simple grain to garbage, dead animals, and human waste products—and that can later be slaughtered and used for “food”—seemed like a pretty good arrangement to many peoples.

But is it? The similarities between human and pig digestive tracts make them ecological competitors for many of the same types of food, resulting in a great deal of corn and other grains to be diverted to feed hogs in order to satisfy society’s craving for pork, instead of feeding humans themselves more directly—and far more efficiently.⁶

But pigs are not the only animal the Bible warns us to avoid eating. Rabbits and rodents can transmit tularemia (also called rabbit fever, deerfly fever, and tick fever) to humans who come into contact with meat and body fluids from these animals. This bacterial disease is endemic in North America and across Europe, the Middle East, and Asia. It can also be transmitted by ticks or mosquitoes that bite an infected animal and then bite human beings.⁷

Biblical dietary guidelines also prohibit eating bats and monkeys—which have been implicated as the source of the Ebola virus that has emerged with devastating effects in equatorial Africa where both bats and primates are consumed as “bush meat.”⁸ Bats and camels have been implicated in Middle East Respiratory Syndrome (MERS). In fact, consuming unclean animals such as bats, pigs, civets, and various other “exotic” but unclean animals, has been implicated in the possible origins of many modern flu epidemics and pandemics of our times, such as Severe Acute Respiratory Syndrome (SARS), Swine Flu, and the coronavirus that gave the world COVID-19. Virologist Michael Lai has noted, “The fact that both SARS and most flu viruses originated in southern China is no surprise,” citing the custom of those in the region to eat such wild animals. Lai highlights that SARS is suspected by some to have moved from animals to humans after first mixing with a human virus that may have been “brewing” in another animal, such as a pig.⁹

There Are Dangerous Parasites within Pork and Other Meat

Trichinosis, caused by a small parasitic roundworm that gets into muscle tissue, is one of the major diseases transmitted by swine and other unclean animals. It is a global disease infesting approximately 11 million people.¹⁰ This is not surprising, considering that pork has long been the most popular meat in the world, only recently surpassed by poultry.¹¹ On average, each American consumes more than 50 pounds (23 kilograms) of pork every year.¹²

Pigs are not alone, however, and many carnivorous and omnivorous animals are infected with the parasite trichinella spiralis. In addition to pork, bear and walrus meat have both served as significant sources of infections in humans. The list of unclean animals that transmit this parasite to people in their meat includes squirrels, rats, cats, dogs, rabbits, foxes, panthers, lions, and horses.¹³ It is hardly an accident or coincidence that God prohibited the consumption of these animals.

Tapeworms (taenia), which afflict about 100 million people worldwide, are another serious health problem. While beef and fish can contain tapeworms that will colonize the human digestive tract and cause discomfort, the pork tapeworm is much more dangerous. The larva of the pork parasite, once inside the human intestine, can migrate through the tissues to the heart, eyes, and brain—and can eventually cause death.¹⁴ Pork tapeworm infections “are more prevalent in under-developed communities with poor sanitation where people eat raw or undercooked pork… in Latin America, eastern Europe, sub-Saharan Africa and Asia.”¹⁵

Although the general medical advice for avoiding parasitic infections from animals is to adequately cook the meat, the most effective way to avoid these diseases is to avoid eating unclean animals that do not have cloven hooves and do not chew the cud—as God instructed Moses and the Israelites 3,500 years ago. If this portion alone of the biblical dietary code were applied today, the global burden of parasitic disease could be dramatically reduced within a generation.

Certain Aquatic Creatures Were Designed to Clean the Environment

After dealing with edible land animals, the second major set of divine dietary instructions concerned aquatic creatures. Scripture instructs, “These you may eat of all that are in the water: whatever in the water has fins and scales, whether in the seas or in the rivers—that you may eat.… Whatever in the water does not have fins or scales—that shall be an abomination to you” (Leviticus 11:9, 12).

These divinely ordained biblical guidelines were designed to point people to the safest kinds of fish to eat.

Biblically clean fish generally swim free in bodies of water. Most unclean fish are either bottom-dwellers or predatory scavengers. The prohibition against eating fish that have no scales protects against the consumption of fish that often produce poisonous substances in their bodies. A U.S. Army survival manual comments, “Most poisonous fish have many similar physical characteristics. Generally, they are odd-shaped—box-like or almost round—and have hard skin (often covered with bony plates or spines), tiny mouths, small gills, and small or absent belly fins.”¹⁶ Many sea creatures noted for being venomous (e.g. four sharks, 58 stingrays, 47 catfish, 57 scorpion fish, 15 toadfish) do not have true scales.¹⁷ Eels—nocturnal predatory scavengers that eat “almost any animal food, dead or alive”—would also be considered unclean because they lack scales.¹⁸ Eel blood contains a toxic substance “which can be dangerous” if it comes “into contact with eyes or another mucous membrane.”¹⁹

Shellfish, lacking both fins and scales, are clearly excluded by the biblical dietary laws. But why would lobsters, crabs, crayfish, and shrimp—considered delicacies in much of the world—be prohibited? The answer lies in understanding the role they were designed to play in nature.

Lobsters are nocturnal foragers. They are bottom-dwelling predatory scavengers that eat dead creatures and other bottom-dwelling organisms and debris.²⁰ They are usually caught in lobster pots baited with dead fish. Lobsters have long antennae and tiny hair-like sensors all over their bodies “that can detect specific chemical molecules in the environment (released by decaying organisms), which can help the lobster identify and locate food”—even in the dark! Lobsters have also been observed to bury a dead fish and then dig it up later, at intervals, to eat a bit more of it.²¹

Crabs have been called “professional garbage hunters” as they are scavengers that eat almost anything. The crab prefers dead fish but will eat any carrion. Common shrimp live by day in the mud or sandy bottoms of bays and estuaries, but by night become active as predatory scavengers and are “bottom dwelling detritus feeders.”²²

These organisms were all created for a very important ecological purpose. They are, in essence, the “garbage collectors” or the “clean-up crew” for the bottoms of lakes, rivers, bays, and oceans. They were neither designed nor intended to be food for human beings.

There Is Threat of Disease from Shellfish

There are also important and logical reasons why God created clams, oysters, mussels, and scallops, and then labeled them unclean and inappropriate for human consumption. These creatures are found in lakes, streams, and coastal areas where they perform specialized roles. As stationary filter-feeding mollusks, they pump large amounts of water over their mucus-covered gills, trapping tiny pieces of food (e.g. silt, plant debris, bacteria, viruses) which they then eat. As a result, some consider mussels and similar organisms the sea’s ultimate scavengers. Filter-feeding organisms are the “vacuum cleaners” for aquatic environments. Their role is to purify the water.

Once you understand the purpose for which God created shellfish, the reason they are considered unclean should become obvious. Most of us would be reluctant to make a meal from the contents of our vacuum cleaner bag, or from the material that collects on our furnace filter or septic tank. This well describes the role of shellfish: “Because shellfish feed by filtering the water that washes over the shellfish bed, they can accumulate disease-causing bacteria and viruses that are harmful to people.”²³

How serious is the threat of disease from shellfish? The U.S. Food and Drug Administration has stated that “raw oysters, clams and mussels—so savored by gourmets—account for 85 percent of all the illnesses caused by eating seafood.”²⁴ Outbreaks of cholera, typhoid, hepatitis A, Norwalk virus, salmonella, and paralytic shellfish poisoning are just some of the health problems frequently linked to the consumption of these mollusks. Perhaps this is why Norwalk virus breaks out from time to time on cruise ships where these mollusks are commonly served. Public health authorities have recommended that pregnant women, the elderly and “individuals with immune systems weakened by certain diseases (cancer, diabetes, and AIDS) should… avoid eating or handling uncooked shellfish.”²⁵ Dangerous and potentially life-threatening consequences can be avoided by understanding and following the biblical dietary laws that prohibit eating marine organisms lacking fins and scales.

Locusts and Grasshoppers Are Good for Food

The final groups of organisms covered by the biblical code are birds, insects, and reptiles. Essentially all the unclean fowl are either birds of prey or scavengers, like vultures and seagulls (Leviticus 11:13–19). Carnivorous birds are important in controlling populations of other animals. Their habit of eating the flesh and blood of their prey make these birds potential agents for transmitting disease. Predatory, fish-eating birds (e.g. eagles) tend to accumulate high levels of toxic chemicals in their bodies. Most of these birds are not important “food” sources for humans.

Reptiles are also among the animals listed as unfit for human food (Leviticus 11:29–30; 42–43). Regarding insects, only those from the locust and grasshopper family are permissible as food (vv. 21–23). These creatures are distinguished by having “strong hind legs for springing”²⁶ and historically have been a food source in the Middle East.

Eating Blood Is Forbidden

The consumption of blood as food is also forbidden by the biblical dietary laws (Leviticus 3:7; 7:26-27). Yet, depending on your culture, it might come as a surprise to learn that animal blood is used in preparing many traditional foods—from black pudding in the United Kingdom and blood sausage (blutwurst) in Germany and other parts of Europe, to tiê’t canh in Asia, which is a pudding made from the raw blood of animals such as pigs or ducks.

Some in the nutrition industry even advocate for the use of blood as a food, seeing it as a “wasted product” of slaughterhouses²⁷—a potential “super food” and another way to profit off of the meat industry.²⁸ However , most advocates make little mention of the health risks involved in making and consuming these blood products. In a report detailing the deaths of a number of people who had eaten tiê’t canh in celebration of Vietnamese Lunar New Year, Dr. Tran Van Ky of the Vietnam Association of Science, Technology, and Food Safety noted the deadly nature of the practice: “The blood carries many diseases from the animals. People eating raw blood from sick pigs can get swine bacteria, worms, and other digestive diseases, while those having blood from sick chicken can be infected with H5N1 or H1N1 viruses.”²⁹

While many theologians believe the Old Testament commands about not eating blood were only for the Jews and were done away with by Jesus Christ, first-century apostles were still instructing New Testament Christians, including Gentiles, that they should not eat blood (Acts 15:20, 28–29). As Dr. Ky noted, obeying this biblical health principle can mean the difference between life and death.

Jesus Did Not Abolish the Dietary Laws

As we have seen, God revealed profound principles that would protect the environment, provide safe, healthful food, and reduce the risk of disease for individuals and societies who would follow these instructions. In fact, in the case of flu viruses and pandemics such as COVID-19 that originate in unclean animals, we see that obeying or disobeying God’s health laws in one part of the globe can affect the entire world!

So, if these laws are so logical and beneficial for us, why do so-called “Bible-believing” Christians so often seem to be at the forefront of rejecting them?

Broader theological and doctrinal mistakes aside, many have misunderstood and misinterpreted some biblical passages to their own harm. A closer look at these passages reveals the truth behind some of these mistaken interpretations.

For example, in Mark 7, Jesus explained to critics why His disciples ate without following the Pharisees’ ceremonial hand-washing tradition. Some Bible translations add words to Jesus’ answer in verse 19, suggesting that He did away with the dietary laws—for example, the Revised Standard Version translates this phrase, “Thus he declared all foods clean.” However, this translation is misleading and puts words into Jesus’ mouth that He did not say. Jesus’ point was that orally ingested dirt, which is eventually eliminated, does not spiritually defile a person, since it does not enter the “heart” and influence attitudes (vv. 18–23). Dirt passes through the digestive tract and is eliminated. Some translations treat this phrase far more accurately, such as the Jubilee Bible 2000, which reads verse 19 as saying, “Because it enters not into his heart, but into the belly, and the man goes out to the privy and purges all foods.”

The dietary laws regarding clean and unclean animals are simply not being discussed in this chapter of Mark—nor in Matthew 15:10–20, which discusses the same event but without the misleading translation. In fact, Matthew 15:20 plainly sums up Jesus’ teaching: “These are the things which defile a man, but to eat with unwashed hands does not defile a man.”

Some will also cite Peter’s vision recorded in Acts 10. In that vision, God showed Peter a collection of unclean animals and told him three times to “eat.” Peter declined, each time, because he believed eating those animals would be wrong (vv. 13–16). Remember, this was the same Peter, trained by Christ for three-and-a-half years, who heard Jesus’ statements regarding eating with hands unwashed in the manner of the Pharisees’ man-made traditions—yet he still believed years later that eating meat from unclean animals was wrong. Peter puzzled over the meaning of his vision (Acts 10:17) until three Gentile men came knocking at his door with a request to hear the Gospel explained (vv. 21–27). Peter would not previously have associated with these men who were outside the covenant community, because the Jews considered the Gentiles “unclean.”

When Peter put the pieces of this puzzle together, he concluded, “God has shown me that I should not call any man common or unclean” (v. 28). He perceived that God wanted the Gospel to go also to the Gentiles, and that these Gentiles were to come into God’s Church as equal to those coming from a Jewish background. Peter does not conclude here, or anywhere else in the New Testament, that the dietary laws have been abolished. To draw a different conclusion is to interpret Peter’s vision differently than Peter did, himself.

Not “Every Creature” Is Good to Eat

Some theologians try to use 1 Timothy 4:1–5 to suggest that the dietary laws are no longer valid for Christians. Yet, in these verses, the Apostle Paul was discussing false teachers who were promoting the idea that Christians could be “more spiritual” by practicing asceticism and vegetarianism, abstaining from foods that God had made for us to eat. When Paul states that “every creature of God is good, and nothing is to be refused if it is received with thanksgiving; for it is sanctified by the word of God and prayer,” we need to ask, Where in the Bible are any creatures “sanctified” or “set apart” by God for human consumption? The answer is found in Leviticus 11 and Deuteronomy 14, in the lists of clean animals. And where in the “word of God” would Paul have seen unclean animals “sanctified” or “set apart” by God for human consumption? Nowhere.

Paul was not setting God’s commands aside to declare unclean animals permissible to eat. Quite the contrary: He used the word of God to correct those who were condemning believers for eating meat based on the “commandments and doctrines of men”—not based on God’s commandments (Colossians 2:21–22).

To cite these passages as an excuse to get around the biblical dietary laws is to ignore both God’s instructions and the public health benefits they bring!

Furthermore, several Old Testament passages that discuss the coming Kingdom of God make no sense if Jesus did away with the dietary laws. For example, Isaiah records a prophecy of Christ’s attitude on this subject upon His return: “For behold, the Lord will come with fire and with His chariots, like a whirlwind, to render His anger with fury…. For by fire and by His sword the Lord will judge all flesh…. Those who sanctify themselves and purify themselves, to go to the gardens after an idol in the midst, eating swine’s flesh and the abomination and the mouse, shall be consumed together” (Isaiah 66:15–17).

Isaiah is plainly stating that the judgment of God will fall on those who ignore and reject His divinely inspired laws—including the biblical dietary laws of clean and unclean animals.

The Dietary Laws Will Be Restored

One of the most regrettable consequences of professing Christianity’s aversion to the dietary laws, spawned in the turmoil of the second century AD, is that millions have suffered and died from diseases they contracted by eating food that God never intended them to eat. Somehow, the Bible’s plain, simple statement that Satan would deceive the whole world (Revelation 12:9) has been overlooked or conveniently forgotten. This deception has included the belief that simple, practical, rational, and beneficial instructions about diet have been abolished and are no longer valid.

However, this will soon change. When Jesus Christ returns to the earth, there will be a restoration of “all things” (Acts 3:20–21)—and “all things” would include the Creator’s biblical dietary laws.

Works Cited

¹ Frank Gaebelein et al., eds., The Expositor’s Bible Commentary, vol. 2 (Grand Rapids: Zondervan, 1990), 530.
² David Alexander and Pat Alexander, eds., Eerdmans Handbook to the Bible (Grand Rapids: William B. Eerdmans Publishing Company, 1973), 176.
³ “Leviticus 11–14,” The Interpreter’s Bible (Abingdon-Cokesbury Press, 1954), 52.
⁴ “Ruminant Nutrition for Graziers,” ATTRA Sustainable Agriculture, 2008, accessed March 31, 2020.
⁵ The Interpreter’s Bible, 56.
⁶ Jonathan Foley, “It’s Time to Rethink America’s Corn System,” Scientific American, March 5, 2013.
⁷ “Epidemiology of Tularemia,” Balkan Medical Journal 31, iss. 1 (March 2014): 3–10.
⁸ “Ebola (Ebola Virus Disease),” Centers for Disease Control and Prevention, November 5, 2019; and “Ebola Virus Disease,” World Health Organization, February 10, 2020, https://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease
⁹ Joanne Lee-Young, “SARS: Where Did It Come From?,” Popular Science, July 2, 2003.
¹⁰ “Parasites - Trichanellosis,” Centers for Disease Control and Prevention, November 15, 2019.
¹¹ “Meat and Dairy Production,” Our World in Data, November 2019, https://ourworldindata.org/meat-production.
¹² “Per capita consumption of pork in the United States from 2015 to 2029,” Statista.com, March 24, 2020.
¹³ “Pork,” World Book Encyclopedia, vol. 15 (World Book, Inc., 1995), 679.
¹⁴ Ralph Muller and John Baker, Medical Parasitology (J.B. Lippincott, 1990), 83–84.
¹⁵ “Parasites - Taeniasis,” Centers for Disease Control and Prevention, January 10, 2013.
¹⁶ John Boswell, ed., U. S. Armed Forces Survival Guide (MacMillan, 2007), 244.
¹⁷ Roger A. Caras, Venomous Animals of the World (Prentice-Hall, 1974), 103.
¹⁸ “Eel,” International Wildlife Encyclopedia, vol. 7 (Marshall Cavendish, 1990), 824.
¹⁹ Keith Banister and Andrew Campbell, The Encyclopedia of Aquatic Life (Facts on File, 1988), 26.
²⁰ “Lobster,” Encyclopædia Britannica, vol. 7 (Encyclopædia Britannica, 1995), 430.
²¹ “Lobster,” International Wildlife Encyclopedia, vol. 13 (Marshall Cavendish, 1990), 1464.
²² Banister et al., 235.
²³ “Shellfish Harvesting,” United States Environmental Protection Agency, March 2018.
²⁴ Roger W. Miller, “Get Hooked on Seafood Safety,” FDA Consumer 25, iss. 5 (June 1991): 7, https://quackwatch.org/wp-content/uploads/sites/33/quackwatch/casewatch/fda/fda_consumer/1991-june.pdf.
²⁵ Guy Murdoch, “Consumer Tips,” Consumer Research (July 1993): 2.
²⁶ Gaebelein et al., 572.
²⁷ Jack A. Ofori and Yun-Hwa P. Hsieh, “Issues Related to the Use of Blood in Food and Animal Feed,” Critical Reviews in Food Science and Nutrition 54, no. 5 (January 2014): 687-97.
²⁸ Jenny L. Cook, “Is black pudding the latest health food du jour?,” NetDoctor.co.uk, March 17, 2016.
²⁹ “Say no to pig blood pudding, doctors advise as swine bacteria kill 4,” ThanhNienNews.com, March 1, 2013.