Yes, nearly all whole foods are made of cells. Every piece of fruit, every vegetable, every cut of meat, and every fish fillet is composed of millions of individual cells, each with its own internal structures. This is true whether the food comes from a plant or an animal. The exceptions are a handful of items like table salt, water, and some heavily refined ingredients that have had their cellular structure completely destroyed during processing.
How Plant Cells Show Up on Your Plate
When you eat an apple, a carrot, or a stalk of celery, you’re eating plant cells. Each one is surrounded by a rigid cell wall made primarily of cellulose, a tough carbohydrate built from chains of glucose. That cell wall is what gives raw vegetables their crunch. Inside, the cell contains water-filled compartments called vacuoles, energy-producing structures, and, in green plants, tiny organelles that capture sunlight to produce sugars.
Plant cells store their carbohydrates, vitamins, and other nutrients inside these walled compartments. Tubers, fruits, leaves, and stems all keep their carbohydrates locked within living cells, which limits their carbohydrate density to a maximum of roughly 23% by mass. The rest of the cell’s weight is mostly water. This natural packaging is a key reason whole plant foods tend to be less calorie-dense than processed alternatives.
How Animal Cells Differ in Meat and Fish
A steak or a salmon fillet is also made of cells, but animal cells look different from plant cells. They lack the rigid cell wall, relying instead on a thin, flexible membrane to hold their contents together. That’s one reason raw meat feels soft rather than crunchy.
Skeletal muscle, which makes up the bulk of the meat we eat, consists of about 90% muscle fibers and 10% connective and fat tissues. Muscle fibers are elongated, spindle-shaped cells ranging from 10 to 100 micrometers in diameter. In fish, these fibers are just a few millimeters long; in land animals, they can stretch several centimeters. Each fiber is packed almost entirely with protein filaments that, in a living animal, allow the muscle to contract. Layers of connective tissue wrap around individual fibers, then around bundles of fibers, then around the whole muscle, creating the texture you feel when you chew.
What Cooking Does to Food Cells
Heat transforms the cellular structure of food in ways that affect both texture and nutrition. When you cook vegetables, the rigid cell walls soften and break apart. This is why steamed broccoli is tender compared to raw broccoli. That breakdown releases nutrients that were previously locked inside the cells. Carotenoids (the orange and red pigments in carrots and tomatoes) become easier for your body to absorb after cooking because heat softens plant walls and separates these compounds from the proteins they’re bound to. Vitamin K, stored inside the light-capturing organelles of green plants, also becomes more available once heat ruptures the cell walls.
Cooking also deactivates certain enzymes inside plant cells that would otherwise destroy nutrients. When you cut or crush raw vegetables, the collapse of cell compartments activates enzymes that break down vitamin E. Heat shuts those enzymes down, which is why cooked samples of some vegetables actually contain more detectable vitamin E than raw ones.
In meat, heat causes proteins inside muscle fibers to unfold and clump together, squeezing out water. That’s why overcooked chicken breast turns dry and tough. The connective tissue surrounding muscle fibers, on the other hand, slowly dissolves into gelatin with prolonged, gentle cooking, which is the principle behind braising and slow-roasting.
Fermented Foods Are Full of Microbial Cells
Yogurt, kimchi, sauerkraut, and sourdough bread all contain living microbial cells, or at least started with them. Yogurt is produced when bacteria ferment and acidify milk. The food industry generally aims for a minimum of one million viable bacterial cells per milliliter at the time you eat it. Some yogurts add extra strains of beneficial bacteria or even probiotic yeasts. When you eat a spoonful of yogurt, you’re consuming the original animal cells from the milk alongside enormous numbers of bacterial cells that transformed it.
Foods That Aren’t Cellular
Some things in your kitchen have no cellular structure at all. Table salt is a mineral crystal. Water is a simple molecule. Refined white sugar, extracted and purified from sugarcane or beet cells, no longer contains any intact cells. The same goes for refined oils and white flour. These ingredients once came from living cells, but processing stripped away the cell walls, membranes, and internal structures, leaving behind isolated chemical compounds.
This distinction matters more than you might think. A researcher at the London School of Hygiene and Tropical Medicine proposed that “acellular” carbohydrates, those found in flour, sugar, and processed starches, behave very differently in your gut than carbohydrates still sealed inside intact plant cells. When you eat whole foods, digestive processes have to breach each cell wall before accessing the carbohydrates inside, releasing them gradually. Flour and sugar, by contrast, flood the upper digestive tract with a concentration of carbohydrates that gut bacteria rarely encountered over the course of human evolution. The hypothesis suggests this promotes a more inflammatory mix of gut bacteria and may contribute to the appetite-regulation problems seen in populations eating heavily processed diets.
How Your Body Handles Cell Walls
Humans can’t directly digest cellulose, the main structural material in plant cell walls. We lack the enzymes to break its strong molecular bonds. This is why cellulose is classified as insoluble dietary fiber. Your stomach acid, which sits at a highly acidic pH of 1.5 to 2.0, kills most bacteria you swallow but does little to dissolve cellulose itself.
Your body has a workaround, though. Your large intestine hosts bacteria that can break down plant cell walls, many of the same species found in the guts of herbivores. These bacteria ferment cell wall components in your ascending and transverse colon, producing short-chain fatty acids that your colon absorbs and uses for energy. So while you can’t digest fiber on your own, your gut bacteria extract some nutritional value from it. Most of the nutrition from plant foods, however, comes from the cell contents, the starches, sugars, proteins, fats, and vitamins, released once chewing and digestion breach the cell walls.
Cultivated Meat: Cells Without the Animal
One of the newer developments in food technology takes the cellular nature of food to its logical extreme. Cultivated meat is produced by taking a small tissue sample from a living animal, isolating individual cells, and growing them in a bioreactor. The cells multiply outside the animal’s body, producing cell mass that can be shaped into unstructured products like ground meat. For something more like a steak, cells are grown on edible scaffolds that guide them into organizing into fibers, mimicking the layered muscle structure of conventional meat. The final product is still made of animal cells. It simply skipped the step of building an entire animal around them.