Topics 1-5
Part 1: The Ground Floor
One part of the Spiral Staircase reference library, the research behind the book: the topics it holds, the recommendations they grade, and the terms they define.
The chapters
- Topic 1Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
The 200-Million-Year Warm-Up
- Expects.
- High energy costs paid for by effortful foraging; real darkness at night; changing temperatures; food judged by color and smell.
- Gets.
- Abundant calories, climate-controlled rooms, bright evenings, engineered food colors.
0 graded recommendations · 68 sources
- Topic 2Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
Standing Up
- Expects.
- Kilometers of walking most days, some running, carrying and throwing, and warm air that sweat can cool.
- Gets.
- Chairs, cars and desks; nearly a third of adults worldwide below minimum activity.
4 graded recommendations · 69 sources
- Topic 3Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
The Expensive Organ
- Expects.
- Cooked, varied food; sleep; a band of about 30 people inside a wider network; daily physical and mental challenge.
- Gets.
- Long hours seated (Chapter 6), isolation for some, and prices, deadlines and risks its defaults never met.
7 graded recommendations · 79 sources
- Topic 4Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.
The Last Ice Age and the Birth of Agriculture
- Expects.
- A varied diet of wild plants and animals, daily walking and carrying, small mobile groups, seasonal variety.
- Gets.
- Cereals supplying 42% of the world's dietary energy, sedentary work, and dense settlements shared with animals and strangers.
0 graded recommendations · 83 sources
- Topic 5
The Idea of Mismatch
In 1983 Randolph Nesse, a psychiatrist at the University of Michigan, finally got up the nerve to tell some evolutionary biologists his theory of aging.
0 graded recommendations · 42 sources
The handrail for this part
All 11 graded recommendations in these 5 chapters, sorted by how strong the evidence behind each one is. How the grades work.
Probable evidence
8 recommendationsGood observational evidence with a plausible mechanism, or small or few trials.
- Walk most days, especially after back pain
In the WalkBack trial, 701 adults recently recovered from non-specific low back pain had six sessions with a physical therapist spread over 6 months.
Topic 2
- Run a little, if you can
Any running was associated with a 27% lower risk of death from any cause, with no clear extra benefit from more.
Topic 2
- Respect the heat
Your body adapts to heat with repeated exposures. But in a laboratory study, 24 young, healthy adults doing light activity in humid heat could no longer shed heat fast enough...
Topic 2
- Sleep 7 or more hours a night on a regular basis
the consensus of American sleep medicine. ●●○ Loud snoring, gasping or daytime sleepiness warrant a sleep assessment. See Chapters 23 and 41.
Topic 3
- Keep people in your week
Social isolation is one of 14 modifiable risk factors; addressing all of them might prevent about 45% of dementia. ●●○ (observational) See Chapters 29 and 42.
Topic 3
- Walk briskly, and build up gradually
In a trial of 120 older adults, walking 40 minutes three times a week for a year, after building up from 10 minutes over seven weeks, enlarged the anterior (front) hippocampus by...
Topic 3
- Get DHA from fish, not pills
Adults: at least 225 g (8 ounces) of seafood a week. If pregnant or breastfeeding, eat 225-340 g (8-12 ounces) of lower-mercury choices and avoid king mackerel, marlin, orange...
Topic 3
- Cook
Strict raw-food diets are associated with underweight and lost periods. ●●○
Topic 3
Emerging evidence
3 recommendationsEarly, small, animal-only, or actively contested.
- Throw and carry, for play
No health trials exist. ●○○ The shoulder's reliance on stored elastic energy may help explain common throwing injuries, so build volume slowly.
Topic 2
- Learn something hard and new
Adults aged 60-90 who spent 15 or more hours a week (16.5 on average) for three months learning digital photography or quilting improved episodic memory more than those doing...
Topic 3
- Put worries on trial
Write a worry down, then check what happened. ●○○ It complements care rather than replacing it: persistent anxiety is treatable (Chapter 31).
Topic 3