L1: Evolution and development of health behaviour Flashcards
evolution and depression paradox
why did natural selection not eliminate depression from the population?
lifetime prevalence of depression in NL
18%
heritability of depression
40%
Genome-wide Association Study about depression
No SNPs achieved significance
fecundity =
fertility
resultaten van studie over fertility bij mental disorders
Except for women with depression, affected patients had significantly fewer children. But males did have significantly fewer children.
Dus waarom niet bij depressie?
Vulnerability to depression, and perhaps substance abuse, may be preserved by balancing selection, suggesting the involvement of common genetic variants in ways that depend on other genes and on environment.
balancing selection=
Balancing selection is an evolutionary process that maintains genetic diversity within a population by favoring the persistence of multiple alleles (gene variants) at a specific locus. Instead of driving one allele to fixation (where only one variant remains), balancing selection helps keep different alleles in the gene pool. It plays a crucial role in maintaining genetic variation, which can be beneficial for a population’s ability to adapt to changing environments.
why do humans get depressed?
- cry for help
- reaction to losses
- seasonal (no activity in winter)
- energy conservation
- rumination, solving problems
- association with inflammation/infections
- mismatch
relatie inflammation and depression
Crosstalk between inflammatory pathways and neurocircuits in the brain can lead to behavioural responses, such as avoidance and alarm, that are likely to have provided early humans with an evolutionary advantage in their interactions with pathogens and predators. However, in modern times, such interactions between inflammation and the brain appear to drive the development of depression and may contribute to non-responsiveness to current antidepressant therapies. Recent data have elucidated the mechanisms by which the innate and adaptive immune systems interact with neurotransmitters and neurocircuits to influence the risk for depression.
evolutionairy pressure (conspecifics, predators, pathogens) -> inflammatory bias -> alarm, avoidance in the brain & wound healing, fighting infection in cells -> more infectious mortality, less inflammtory conditions and less autoimmunity & immunoregulatory system upregulated -> less infectious mortality, more inflammatory conditions and more autoimmunity & environmental, social and medical stress -> depression
kijken naar unified model of depression in schrift
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mismatch hypothesis=
we are not adapted to modern environments, but to ancestral environments. this results in a mismatch
what was the environment of evolutionary adaptedness
- savannah-like environment
- hunter-gatherer society
- nomadic lifestyle
- physical dangers
- high infant mortality
- food scarcity
mismatches we currently have:
- diet
- physical activity
- childrearing
- sunlight
- sleep
- social interactions
Hadza =
protected hunter-gatherer tribe in tanzania
evidence for mismatch hypothesis
- developing countries have less mismatches regarding mood disorders than rich countries
- rural areas have less mismatch than urban areas
- more mismatch in modern societies than traditional societies
- more physical activity is less mismatch, less physical activity is more mismatch
- more mismatches is more depression, less mismatches is less depression
diseases that occur more in urban areas
- depression
- anxiety
- diabetes
- hypertension
- asthma
- copd
association between urbanization and depression is confounded by…
- poverty
- immigration
- availability of green spaces in the city
more mismatch in modern societies than mismatch societies: voorbeelden
- nothing like depression in Kaluli, a hunter-gatherer society in new guinea
- more depression after modernization in china
physical activity patterns and biomarkers of cardiovascular disease risk in hunter-gatherers
Time spent in moderate-to-vigorous physical activity (MVPA) is a strong predictor of cardiovascular health, yet few humans living in industrialized societies meet current recommendations (150 min/week). Researchers have long suggested that human physiological requirements for aerobic exercise reflect an evolutionary shift to a hunting and gathering foraging strategy, and a recent transition to more sedentary lifestyles likely represents a mismatch with our past in terms of physical activity. The goal of this study is to explore this mismatch by characterizing MVPA and cardiovascular health in the Hadza, a modern hunting and gathering population living in Northern Tanzania.
These results provide evidence that the hunting and gathering foraging strategy involves high levels of physical activity, supporting the evolutionary medicine model for the relationship between physical activity and cardiovascular health.
results physical activity and depression
Depressive symptoms decrease with more physical activity; moderate exercise and high intensity both work
mismatch questionnaire is based on these factors:
- Deviant sleep rhythm
- Lack of exercise
- Processed food
- Lack of daylight / being outside / green environment
- Lack of contact with family, friends, partner
- Materialism
-Perfectionism / focus on achievement
Lack of time
Worrying (deadlines, finances, job
security, climate change)
Lack of freedom
Lack of joy (dancing, singing)
Social media addiction
Deviant youth (no siblings,
breastfeeding, warmth)
Unhealthy habits (smoking,
alcohol, drugs, coffee, medicines)
correlations between depression and sensitivity and mismatch factors
correlation depression and mismatch factors
controlling for sensitivity:
r(103) = .38, p < .001 (without controlling: .50)
correlation sensitivity and depression
controlling for mismatch factors:
r(103) = .22, p < .025 (without controlling: .37)
best predictors of depression:
- Lack of freedom
- Lack of time
- Worrying
- Processed food
- Sleep rhythm
- Perfectionism
- sensitivity is a moderator
oplossing voor deze mismatches:
- less grains and dairy
- raw foods (less processed foods)
- calorie restriction
- intermittend fasting
- barefoot running
- more exercise/weight training
- better sleep rhythm
- more music/singing/dancing
- greener environment
- more sunlight
- less social media
- less shopping
- more close interactions (tribe)
- less individualism
- less perfectionism
- less worrying
