This article was originally published in the quarterly journal of the Weston A. Price Foundation, Wise Traditions.
All human cultures have a tradition of cooking. Claude Lévi-Strauss, considered the father of modern anthropology, emphasized the importance of cooking in defining the human state in his book “The Raw and the Cooked” from the 1960s. He suggested that cooking food is a cultural and psychological practice rather than a biological necessity. Similarly, anthropologist Edmund Leach believed that cooking was done for symbolic reasons, to distinguish humans from animals.
Contrary to the traditional view, recent scientific studies have shown that cooking makes food easier to digest. This suggests that cooking not only allows for more time and energy for cultural activities but also fuels the development of a larger brain.
The study of digestion of raw and cooked food dates back to the experiments conducted on Alexis St. Martin, who suffered a gunshot wound to the stomach. William Beaumont, the doctor who treated him, observed the process of digestion by conducting various experiments. He discovered that the stomach digested tender and finely divided foods more efficiently than large pieces of food. Cooked foods were also found to be more easily digestible than raw foods.
After leaving the stomach, food enters the small intestine where digestive enzymes break it down into basic components for absorption. Studies on patients with ileostomies have shown that humans digest cooked starch much more efficiently than raw starch.
Research on raw food diets, such as the Giessen Raw Food Study conducted in Germany in the 1990s, has provided further insights into the benefits of cooking food. The study involved a group of individuals consuming raw food diets predominantly consisting of fruits, vegetables, honey, oils, dried fruits, meats, fish, fermented vegetables, and nuts. Despite consuming high-caloric foods like honey and oils, the subjects on the diet lost weight and ended up with a body mass index (BMI) below the normal weight range.
Women lost an average of 26.5 pounds and men lost 21.8 pounds, which might be welcomed by an overweight person but not advisable for a hunter-gatherer who needs a robust physique for activities like hunting and gathering. The volunteers reported feeling hungry all the time.
Approximately 30% of women under 45 experienced partial to complete amenorrhea, with those consuming high amounts of raw food affected more frequently. Men reported a decreased interest in sex.
Researchers cautioned that a strict raw food diet may not provide sufficient energy and that it is associated with significant body weight loss. They warned against long-term adherence to a very strict raw food diet due to the risk of underweight and amenorrhea.
Other risks associated with an all-raw diet include low bone mass, low B12 levels, low HDL-cholesterol, and elevated homocysteine levels.
The Cooking Theory
The cooking hypothesis suggests that the practice of cooking our food led to various behaviors considered uniquely human. Richard Wrangham, the lead author, noted that cooking provided humans with more energy, allowing for the selection of a smaller digestive tract, smaller mouth and teeth, and a larger brain.
In his book “Catching Fire: How Cooking Made Us Human,” Wrangham expanded on the idea that cooking made digestion easier, providing humans with more energy for other activities. The reduced size of the human gut increases efficiency and saves energy that would otherwise be spent on digestion.
Another benefit of cooking is that it reduces the time needed for chewing, giving humans an energetic edge. Cooked food provides more calories and is easier to digest than raw food.
Why Cook?
Cooking starches breaks down their granules, making them more digestible and providing more energy. Vegetables and plant foods containing dietary fiber can be challenging to digest, but cooking helps break down the fiber into more easily digestible components.
Cooked meat is easier to digest than raw meat because cooking melts away the connective tissues around muscle fibers, making the meat softer and easier to break down during digestion. These are clearly difficult to chew and digest in their raw form, with ligaments and silverskin remaining tough even after cooking. However, the collagen found in tendons transforms into a broth-like consistency when cooked in liquid.
Collagen also wraps around individual muscle fibers and bundles, creating the “grain” of the meat. These collagen wrappings contribute to the chewiness and toughness of raw meat, but cooking, especially slow cooking in liquid, breaks down the collagen into soft gelatin.
Steaks and filets have little collagen and are best cooked quickly at around 140 degrees F to maintain tenderness. Cooking them longer or at higher temperatures can make the muscle fibers tough. Techniques like slicing thinly, grinding, or pounding raw meat make it easier to chew and digest.
As collagen melts during cooking, muscle fibers unwind, increasing the surface area for gastric juices and digestive enzymes to work. Cooking partially denatures meat proteins, aiding in the digestion process.
Enhancing the benefits of cooking involves reducing particle size, acidity, salt, and drying to promote protein denaturation. Aging meat converts glycogen to lactic acid, further aiding denaturation. Hunters like the Kalahari San tenderize meat by cooking it until it falls apart and then crushing it.
While raw food consumption exists in some human societies, almost all cook at least some of their food, including meat. Cooking helps break down proteins, making them easier to digest.
Although cooking can lead to vitamin and enzyme loss, consuming raw foods alongside cooked foods can provide essential nutrients. Lacto-fermented foods can enhance nutrient levels and compensate for enzyme loss during cooking.
Dr. William Beaumont’s observations on the gastric juice and digestion process shed light on the importance of proper food breakdown in the stomach. The temperature, quantity, and state of food all play a role in digestion, with raw foods often leaving the stomach undigested. Tough cuts of meat such as heart, tendon, and salt pork take approximately four hours for full digestion. Interestingly, soup also takes about four hours for full digestion. Beaumont observed that solid food is easier to digest than fluids, with soup taken with bread leaving the stomach after three to three and a half hours. Animal foods and farinaceous aliments are easier to digest than vegetables, while fats and oils leave the stomach unchanged.
Excesses in eating or drinking, fatigue, anger, excitement, illness, and damp weather can impair the quantity and quality of gastric juices. When St. Martin had a fever, the secretion of gastric juice was minimal, and when he was angry, digestion was greatly hampered.
The Expensive Tissue Hypothesis explains that humans have a relatively large brain compared to body size, leading to a smaller digestive tract. The hypothesis suggests that humans can manage with a smaller gut by consuming an easy-to-digest diet, primarily achieved through cooking food.
Milk products provide excellent nourishment in their raw form, with milk proteins being fragile and not requiring heat for digestion. Eggs increase in protein value when cooked, and traditional cooking methods include burying eggs in hot sand or ashes. Meat should be gently cooked to melt collagen and relax muscle fibers, while overcooking can make it tough and harder to digest.
Seafood can be consumed raw or cooked, with marinating in acid making raw fish easier to digest. Grains require cooking to soften them, but anti-nutrients in whole grains must be neutralized through soaking, sour leavening, or fermentation. Beans should be soaked and cooked for easier digestion, with some cultures fermenting legumes after cooking.
Vegetables are harder to digest than meat or starches, and most should be cooked until tender. High-pectin fruits like apples are best cooked, with Asian cultures always cooking these fruits. Citrus fruits should have membranes removed before consumption to reduce pectin intake. Interesantemente, en ratones diabéticos no obesos, comer pectina aumenta la incidencia de diabetes.22
Sopas – El sorprendente hallazgo de Beaumont – que la sopa tarda más en salir del estómago que la carne o almidones, a menos que se coma con pan – ¡indica que el pan o los crutones son un complemento natural para la sopa!
Sal – Los jugos digestivos – ácido clorhídrico (HCl) y cloruro de potasio (KCl) – requieren cloruro, que obtenemos de la sal (NaCl). El sodio en la sal activa enzimas que ayudan a descomponer almidones. ¡La sal es esencial para la digestión!
Caldo – El trabajo del Dr. Francis Pottenger indica que el caldo tomado con las comidas (en sopas, salsas, gravies y estofados) actúa como ayuda para la digestión de otros alimentos, especialmente si estos alimentos están procesados para reducir el tamaño de las partículas. Please rewrite the text so that it is more clear and concise.
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