Despite a wildly different rationale and back-story, the practical everyday dietary reality of doing the Paleo diet is very similar to the Atkins diet. The weight-loss, then, should not be surprising.
And many of the "criticisms and concerns" levied against Atkins ought to be considered relative to the Paleo diet as well. There are unfortunately no conclusive long-term studies on either diet, and the long-term effects of low-carb diets are not truly understood. All the positive evidence for Paleo is first-person and anecdotal, but we're left to wonder how something that feels so healthy, and make so much historical sense, could be wrong.
There are plenty of unresolved criticisms of Paleo that need to be examined. First and foremost is that while Paleolithic-era humans may have been fit and trim, their average life expectancy was in the neighborhood of 35 years. The standard response to this is that average life expectancy fluctuated throughout history, and after the advent of farming was sometimes even lower than It's only in recent modern history, with the advent of nutrition, that life expectancy has soared.
The contemporary Paleo diet, we are told, is the best of both worlds. But the jump in life expectancy occurred not over the last decade of two, in the age of food science.
It happened over about a hundred years. It was the result of advances in agriculture that increased the world-wide supply of food, eliminating malnutrition. While the specific estimates vary, none of these estimates come close to 25 as the typical age at death.
Also interesting are the causes of death among modern hunter-gatherer populations. Few people suffer from diabetes, heart disease, and other degenerative diseases of the modern world; the most common killers are diseases that modern medicine has rendered much less dangerous, especially gastrointestinal and respiratory diseases.
The basic pattern of Paleolithic mortality was probably close to these observed patterns in modern hunter-gatherer societies: a shockingly high infant mortality rate, but a relatively high life expectancy for those who survived to reach puberty, with most deaths caused by diseases that pose relatively little threat to people in modern societies.
This argument is not simply a set of statistics derived from studies on modern hunter-gatherers and extrapolated to the Paleolithic on the assumption that living conditions would be essentially similar.
It also has a basis in human biology, specifically reproductive biology. This means that children would have been spaced at least 3 years apart: 2 years of breastfeeding plus 9 months of pregnancy. Studies on modern hunter-gatherers show women reaching menarche at an average age of 16, and giving birth to their first child around 19 Hoggan uses 13, but this age is common only among modern industrial societies, where increased food intake and better nutrition have been steadily lowering the age of menarche since the 19th century.
The average age at menarche for modern hunter-gatherers seems a much more accurate estimation for a Paleolithic woman. But this is a completely unsustainable population pattern. Say that child is Child 1. The woman is now left with 2 children, but if she dies when Child 3 is a newborn, Child 3 will never get the benefits of her breast milk and nurture, and is therefore very unlikely to survive.
Going back to the discussion on average, the high infant mortality rate brings down the average lifespan age, and diet during that time is not a defining factor. Deaths from infectious diseases led to a much higher mortality rate than we see today. Unfortunately, the lack of immunizations, antibiotics, and modern medical procedures led to a large number of infant deaths, which creates a much lower average lifespan statistically.
We obviously have the resources and technological advancements to protect ourselves in the wild against other animals. Firearms, explosives, protective gear, and other weaponry was not readily available for cavemen, so their ability to be the dominant force in nature was hindered.
Predators were a real threat and were a common cause of death for cavemen. Today, we have the luxury of having 4 walls, a roof, heating, and shelter from the elements. Anyone who has lived in the northeast for any stretch of time between the months of November and April knows that it gets cold with the likely chance of terrible driving conditions. Behavior may not fossilize, but bodies do, and we can infer a surprising amount about behavior from those remains.
Species with more male competition, and more polygamy — where males have more than one female mate at a time — are likely to show a greater difference in body size between the sexes. Humans, along with chimps and bonobos, have much more modest size differences between the sexes, which has led many researchers to conclude that our ancestors were only moderately to slightly polygamous.
Monogamous marriage as we now know it was thought to have become more prevalent once societies became more complex and agricultural and less nomadic. Science weighs in: Undeniably, human infants and their mothers form a close bond. In other words, a harried mom seeking help from anyone who is available is not unusual, or a product of a 21st-century life. That helper could have been the father, but fathers, just like today, were not always available.
Anthropologist Sarah Blaffer Hrdy suggests that women evolved to be opportunistic in their use of others as alloparents — or people who help out with child care. Studies of children reared with multiple caregivers — not in an atmosphere where babysitters come and go, but one with two parents and a grandmother, or a mother, a couple of aunts, and an older sibling — support this idea.
Paleofantasy: Cancer is a modern scourge. Paleos often believe that agriculture leads to illness, by promoting a diet of grains and other processed foods, and that cancer is a recent aberration. Science weighs in: Not just our lives but also our genes have changed in the 10, years since agriculture, making us different in many ways from our Paleolithic ancestors. The truth, though, is that diseases have always been with us, modern only in the sense that some of them accompanied our evolution into human beings.
Searches for cancer in ancient remains are plagued no pun intended by sampling errors — the signature of cancer can be detected in bones, but many skeletons are incomplete, and of course cancers do not always spread to bone after they originate in soft tissue.
0コメント