The case for eating more organ meat

As a matter of pragmatism and genuine preference, cultures across the globe have long and storied histories of cooking with offal—a catch-all term for every part of an animal that isn’t a slab of muscle meat. Yet for all that history, over the last few decades, offal consumption has declined worldwide, says food scientist Carlos Álvarez, especially in developed countries like the United States. 

As the “mild” flavor (compared to other parts of the animal) and sanitized packaging of factory farmed muscle becomes the norm, explains Amy Bentley, a professor of food studies at New York University, eaters find the distinctive form, flavors, and textures of recognizable brains, tangy livers, and mushy glands increasing unnerving.

But the disappearance of offal from modern foodways plays a part in food waste. Reports vary based on what their authors consider edible offal versus inedible items (some exclude bone, although much of it is edible), and which animal they examine. But most livestock is between 12 to 44 percent offal by weight; a cow’s liver alone can account for up to 4.5 percent of its mass.

(The scientific case for eating more bones.)

This impulse to do anything with offal but eat it directly is especially galling in light of a growing body of research that confirms it is often the most nutrient-dense portion of an animal’s body. Here's what the experts have to say.

What we know about the health benefits of organ meat

Offal lovers have long made vague claims of nutritional value, citing popular wisdom about how, for example, predators supposedly always go for the organs in a fresh kill first. But hard data on the properties of offal was historically hard to come by, says Fidel Toldrá, a food scientist who co-authored a reference guide to research on edible animal by-products in 2011. The topic isn’t profitable or popular enough to attract attention at well-funded Western research institutions, Álvarez argues. And academics in countries with vibrant offal-eating traditions tend to focus their research projects on hyperlocal livestock breeds, farming practices, and cultural dishes.

However, over the last few years, international research teams have attempted to collate and synthesize this “scattered and limited” body of scientific work. In doing so, they’ve identified serious gaps in global offal studies. We don’t know much about the properties of poultry guts, for example, or how different processing, storage, and preparation techniques might affect an offal product’s nutritional value. But these scholars have given us a sense of the beneficial role offal can play in our diets.   

Generally speaking, the research suggests that offal is not as protein dense as skeletal muscle—but it is packed with far more vitamins and minerals per gram. Beyond their head-to-head comparison with conventional meats, adds Wesley McWhorter of the Academy of Nutrition and Dietetics, "organs are among the most nutrient-dense foods available."

The exact ratios vary by species, and with the age, upbringing, and health of the animal in question. But across categories, livers top the nutrient charts, with massive concentrations of iron, copper, selenium, and zinc, as well as vitamin A, B vitamins, and choline. Each of these compounds facilitates a slew of vital bodily functions, but iron and vitamin B6 deficiency are fairly common even in developed nations, and associated with symptoms such as fatigue, weakness, and "mental status changes" like anxiety. Recent research on choline, which facilitates numerous metabolic functions, has likewise put a spotlight on its underappreciated potential role in our moods and mental functions.

Other “red offal” items, like kidneys, hearts, and spleens, contain similar nutrients, albeit mostly in lesser concentrations. At least one USDA review cites hearts and kidneys as uniquely good sources of niacin and vitamin B2, though, and food scientist Flaminia Ortenzi argues that spleen gives liver a run for its money on mineral density. She refers to both livers and spleens as “natural multivitamins,” while McWhorter stresses that red offal items in general are “among the most micronutrient-dense foods available, with particularly high levels of vitamin A, vitamin B12, iron, copper, zinc, and other bioactive compounds compared with typical muscle meats.”

We know a lot less about the nutritional profile of “white offal” items, like brains, lungs, and various forms of stomach and intestine. Álvarez explains that researchers are “more focused on developing methods to extract their collagen” for industrial uses, as what we do know suggests they are especially low in protein and not as rich in nutrients as red offal. Most are still rich in vitamin B12, though, which play a major role in the health of our nerves, blood cells, and DNA, and brains and glands tend to pack in vitamin C and polyunsaturated fats like omega-3, which help fight inflammation and improve brain and heart health. And, of course, blood is rich in iron, while bones are rich in minerals like calcium.

(Omega-3s are great for your health—but supplements may not be.)

Can everyone consume organ meat?

In truth, Álvarez explains, “we know very little about digestibility, bioavailability, or how these products may interact with other components of our diet.” But we can certainly say that organs are not the only nutrient-rich foods available to most consumers. One of the reasons it’s so easy to discard them is that, in a developed world of nutritional abundance, we don’t need them specifically. In fact, we know some people should avoid offal, explains Ty Beal, a global nutrition scientist at the Global Alliance for Improved Nutrition.

“Pregnant women, especially during the first trimester, should limit liver intake due to its high vitamin A content,” Beal says. Excessive vitamin A consumption can make anyone sick, but it may also lead to fetal development or pregnancy complications, he explains.

(How these two vitamin supplements could do more harm than good.)

"People with iron overload conditions may need to limit organ meats because of their high iron content," adds McWhorter. Additionally, those with "Individuals with gout or hyperuricemia should consume offal due to its purine content, which plays a vital role in the production of DNA and metabolism. “People with advanced kidney disease or specific lipid disorders may also need individualized guidance."

But most forms of offal rival or exceed the nutritional quality of other famously nutrient-dense foods like eggs, leafy greens, and small fish. Their compact value makes them a great option for groups with high nutritional needs, like young children, Beal and McWhorter argue. And Álvarez believes that they’d do more good offsetting the nutritional needs of a growing global population than they do going into the slurries we use to raise ever more livestock or literally greasing the wheels of industry.  

However, a few small studies suggest that arguments based on sustainability and food systems aren’t great at getting people to embrace offal—because they don’t address the ick factor of unfamiliar textures and flavors. If food scientists and nutritionists want people to explore the potential of organ meats, Bently explains, they have to make offal seem cool and approachable. That may mean hiding, at least initially, their distinctive shapes, textures, and flavors within mashes or sauces, or connecting them to haute cuisine or rustic food trends.

It is getting easier and easier to find simple offal recipes tuned to a modern Western palate, though. Think finely chopped bits of organ mixed through a salad or smothered within a soup. It’s also getting easier to find offal in the developed world, thanks to helpful butchers at farmers markets and specialized groceries catering to non-Western communities. So if you’re open to exploring the wonderful nutritional potential of offal—and pushing back against a climate of waste—consider looking into a new liver or other organ to incorporate into your next meal.