The strange endurance of consuming blood for health

The history of blood, as told by a hematologist

Since ancient times, blood has been seen as a semi-magical substance. Alchemists theorized it was a mixture of the four elements. Others proposed it was one of four bodily fluids whose balance dictated health. This 2019 essay by a hematologist reviews blood's reputation across cultures and centuries.

Blood has evolved many times over hundreds of millions of years, resulting in different blood colors and compositions—and there are even some organisms that don't need blood at all.

Seven things you might not know about blood

The red stuff currently pumping throughout your body is a type of connective tissue that is both a solid and a liquid. The liquid portion—plasma—acts as a carrier for the solid portion, which includes blood cells and their biological brethren. Your body is constantly refreshing its supply of blood, creating new cells to replace those that have expired or died. This article overviews some lesser-known facts about blood (and why it's not always red).

Without the option of modern blood transfusions, some doctors in the mid-1800s tried to help save cholera patients by injecting them with cow's milk, hoping it would boost their nutrition and hydration.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

Why don't we synthesize blood?

We're trying. Scientists are currently working on creating viable synthetic blood, an alternative to the presently relied-upon donations that manage to fall short of demand. More than half of the world's nations struggle to meet their population's need for blood. This article details current and historical efforts to develop synthetic blood, a venture that started more than 400 years ago.

What does blood do?

Blood's primary purpose is to ferry oxygen and nutrients to cells in need while collecting cell waste and byproducts for removal. It also enables the body's repair and immune systems to traverse our internal landscape to address cell damage or external invaders, such as viruses and parasites. Zooming out from the exact roles of blood's various cells, the fluid connective tissue also assists with maintaining homeostasis via temperature regulation and pH balance.

The economics of horseshoe crab blood

Horseshoe crabs are older than dinosaurs and have survived five mass extinctions that wiped most life from the planet. But it's only now that their future as a species is in danger. This blood, worth about $60,000 per gallon, is hyper-sensitized to certain bacteria that are fatal to humans. This 17-minute podcast dives into humanity's pursuit of horseshoe crab blood, a "somewhat magical" mixture heavily relied on by the pharmaceutical industry.

A brief history of human blood groups

The blood group that determines whether you have type A, B, AB, or O blood was discovered near the turn of the 20th century. This short academic article dives into three main theories about the evolution and emergence of blood groups, the exact nature of which remains unclear.

Each second, the human body produces 2 million to 3 million new red blood cells.

Explore the microscopic composition of blood.

An interactive explanation of blood transfusion

The antigens and Rh factors of blood cells (which determines your blood type) must be compatible with your immune system—which is why blood transfusions between patients must have matching types. In a mismatch, the immune system will attack and destroy donor blood cells, triggering a potentially fatal reaction.

Medical recognition of strokes stretches back to ancient Greece

Every minute, 750 milliliters of blood flows to the brain, supplying 20% of the body’s oxygen. A sudden disruption—whether from a clot (ischemic stroke) or a bleed (hemorrhagic stroke)—can be life-threatening. From ancient Greek theories to modern CT and MRI scans, here’s how stroke science has evolved over time.

Humans can have brain damage after four minutes without blood flow.

Englishmen in the 17th century mixed their blood into wine to show devotion

In order to demonstrate their love for a woman, some young Englishmen would stab themselves in the arm and mix the blood into their wine. They'd then toast the object of their affection and drink to their honor.

The plasma-selling industry is expected to reach $50B by the end of the decade

About 55% of your blood volume is plasma, the liquid part of blood created from water, proteins, minerals, and salts absorbed through the digestive tract. This 49-minute podcast episode explores the business of plasma—part of a global industry expected to be worth $50B by 2029.

Blood color differs across the animal kingdom, with some animals producing blood that appears green (a group of lizards in New Guinea) or blue (horseshoe crabs).

Explore this blood type interactive to learn more about how the 8 most common blood types are defined.

The earliest known cardiovascular system dates to 520 million years ago.

How beer became a part of medieval culture

This history of beer's evolution during the Middle Ages unpacks how the brewing process, which killed harmful bacteria, made beer a safe alternative to water. That fact, along with the Catholic church condoning (and, in some cases, producing) the beverage, helped it evolve into a major commodity.

US labs drain an estimated 500,000 horseshoe crabs of blood each year to harvest a compound that screens vaccines and medical devices for bacterial toxins.

Vampire bats are the only mammal to feed exclusively on blood

Scientists believe their ancestors may have eaten parasites and insects off larger animals until vampire bats started feeding directly from those animals. Colonies work together to stay fed, as a vampire bat can die without just two days of eating.

One doctor argued vampires were based on a real disease

At a conference in 1985, Canadian biochemist David H. Dolphin posited that stories of vampires and werewolves had a real-world origin. He argued that porphyria could have caused sufferers to seek out blood, as well as experience light sensitivity and an aversion to garlic. More than one article in the 1990s discredited this take.

Blood clotting is critical to maintaining life, but dysfunctional clots can be fatal.

How did segregation in the US affect blood donations?

When the US established its first nationwide network of blood banks in 1941 with the hopes of restoring the dwindling reserves of military members, it was quick to emphasize blood donated by Black Americans wouldn't coat the veins of white servicemen. Historians say this policy was meant to appease white Southerners who believed Black blood was inferior to their own.This policy was leaked to the press that same year.

New blood cells are created by hematopoietic stem cells

Blood is made up of several cells with various functions and short lifespans, so the body must have a constant supply of replacements. These replacements are created by hematopoietic stem cells, rare cells that live in bone marrow and can regenerate themselves and blood cells.

Gladiators followed a mostly vegetarian, high-calcium diet

Analysis of skeletons from a gladiator cemetery at Ephesus by researchers at the Medical University of Vienna found little meat consumption but unusually high calcium levels—likely from drinking wood ash mixed with water to promote weight gain and protect vital organs.

Ten things to know about your heart

Your heart does amazing things day in and day out. Its main job is crucial: It keeps oxygenated blood circulating throughout your body. Did you know that, other than your cornea, every cell in your body gets blood from your heart? You may not think...

The Hungarian countess rumored to have bathed in blood

According to legend, Hungarian countess Elizabeth Báthory killed up to 600 women to bathe in their blood and preserve her youth. Such allegations have been challenged since the 1980s when Slovakian archivist Josef Kocis published a book detailing new aspects of Báthory's life and included possible evidence of a conspiracy meant to undermine her power as part of Transylvania's ruling dynasty.

Snake venoms are repurposed proteins responsible for other bodily functions

Just as saliva aids digestion in humans, proteins responsible for bioactivities such as digestion and blood clotting were eventually secreted in the glands and fangs of snakes across evolutionary history. Organisms that could not withstand the effects of these molecules (e.g., excessive bloodstream clotting) became ideal prey for snakes.

The quest to find natural ways to extend lifespan

Tales of searching for the Fountain of Youth persist. Our modern-day version is marked by promises of pharmaceutical miracles and a proliferation of viral "biohacking" routines. One doctor’s quest to unlock the keys to longevity stimulated much of this renewed fervor, though his ideas are often taken out of context.

Bone marrow generates roughly 500 billion new blood cells each day.

Why hibernating bears don't get blood clots

For mammals, long periods of inactivity can lead to health problems—blood flow slows and pools, veins kink and distort, and clots potentially form. Hibernation takes this risk to the extreme, yet for decades why animals like bears did not exhibit...

A history of Rome and wine

Wine and winemaking were integral parts of everyday Roman life. Wine was used medicinally and for religious rites, as well as for pleasure. It also contributed to the expansion of the Roman empire as wine and grapes were traded throughout the Mediterranean. Roman winemaking practices spread as the empire grew. Without Rome, wine may never have grown into what it became, and vice versa.

Mosquitoes drink a maximum of 0.01 milliliters of blood in a single meal.

Even in recent history, adaptations to the environment drove human evolution

Through genetics, environmental pressures, and cultural influences, humans have evolved to tolerate lactose, develop varying skin pigmentation, and acquire genetic resistance to diseases like bubonic plague. The metabolic and digestive systems of Indigenous peoples have adapted to their diet, which is influenced by the availability of food and water.

An interactive guide to the cardiovascular system

The cardiovascular or circulatory system moves blood throughout the body, ensuring cells have necessary nutrients and removing any waste. Click through this interactive 3D guide to explore the system as it crisscrosses the body via arteries, veins, and capillaries. This guide also includes similar breakdowns of the body and its other processes.

The evolution of the human diet

Could eating like our ancestors make us healthier? One estimate suggests prehistoric hunter-gatherer communities obtained 75% of their calories from meat and fish.

Interest in intermittent fasting outpaces the science

The public interest in fasting diets has outpaced the science behind related health claims. This article details how the science of fasting diets is mainly exploratory and focused on longevity and disease prevention. Current findings suggest fasting kick-starts regenerative processes in the body, decreases inflammation, and improves health outcomes overall. However, much of this research focuses on the short-term impact of fasting.

The word 'vampire' appeared in the English-speaking world in the 1730s

However, earlier mentions of creatures with similar characteristics existed throughout Medieval Europe. For example, people often spoke of revenants—restless dead creatures who tormented the living. Historians believe these stories grew in popularity in part because of influence from the Catholic Church, which was emphasizing the idea of purgatory. These older revenant stories eventually influenced modern vampire folklore.

What did it take to eat like a gladiator?

If you think gladiators were all rippling muscle, think again. Evidence suggests fighters weren't as cut as we've been led to believe. This article dives into the diets of ancient Roman gladiators, who may have eaten mostly vegetarian. Archaeological evidence gathered from the skeletons of 68 gladiators found in a 2,000-year-old Turkish grave suggests the fighters' diets mainly relied on barley and legumes, with little animal protein.

'Golden blood' is the rarest blood type in the world—fewer than 50 people are known to have it.

Explore the abundance of different types of cells in the human body

Lacking a nucleus and other organelles to maximize space for oxygen-carrying hemoglobin and enhance maneuverability through narrow capillaries, there are about four times as many red blood cells and platelets as all other cell types in the body combined. However, about half of the body's cell biomass consists of skeletal myocytes, or muscle fibers.

'1440 Explores,' Episode 2: Why We Drink and What It Does to US

Alcohol is the world's most popular drug—a molecule that can calm or excite and bond communities or tear them apart. We trace alcohol's journey from ancient rituals to modern hangovers, uncover how it shaped civilizations, and dive into the neuroscience of how it affects your brain and body. With insights from leading experts, we ask: Given all that we know, why do humans continue to drink?

The proteins and sugars on the surface of your blood cells determine your blood type.

Explore the current landscape for patient consent with this 1440 Original video tied to Henrietta Lacks' legacy.

How much your blood really costs

In the US, donating plasma twice a week can earn you $400 a month. But this system only works by targeting people who need the money most. Plasma clinics are placed in low-income zip codes, and frequent donation may increase health risks.

The dark side of modern sugar production

Humanity's ancestors evolved to wring more calories from sugary fruits by storing excess sugar as fat, an adaption that's culminated in many peoples' palettes preferring calorie-rich sweet. Now, the desire for sugar has both contributed to a widespread health crisis and been at the center of atrocities around the world.

How winemaking has changed throughout history

Winemaking is an ancient practice, and researchers continue to find evidence that this ritual came even earlier than previously estimated. This article outlines five key turning points in wine’s history, from the fermentation of fruit by our primate ancestors to today’s increasingly popular “New World” wine. Discover the fascinating scientific and cultural factors that led to wine’s changes in flavor and increased symbolic importance.

It is recommended that humans consume 2.0 to 3.7 liters (about 4.2 to 7.8 pint glasses) of water daily to replace water lost through breathing, sweating, urination, and bowel movements.