The Impact of Shift Work On

Health and Diet

ShiftworkShiftwork

Any work regularly undertaken outside “normal” Any work regularly undertaken outside “normal” working hoursworking hours

07:00 – 18:0007:00 – 18:00

NightsNightsEarly amEarly amEveningEvening

FixedFixedRotatingRotating

Eight hourEight hourTwelve hourTwelve hour

StatisticsStatistics

Approx 3.6m UK Approx 3.6m UK (1-7 of workforce)(1-7 of workforce)

men > womenmen > women

↑ ↑ Transport & Communication Transport & Communication sector (26%)sector (26%)

Most common occupational Most common occupational group of women working group of women working shifts is nursesshifts is nurses

UK employees UK employees work longer work longer hours than other hours than other European European workersworkers

UK mean for UK mean for males in FT males in FT employ is 45.8 employ is 45.8 hours per week hours per week (EU mean 41.3)(EU mean 41.3)

UK mean for UK mean for females is 40.6 females is 40.6 hours per week hours per week (EU mean 39.0) (EU mean 39.0)

Approx 2.7 million UK Approx 2.7 million UK workers usually work > 48 workers usually work > 48 hours per week hours per week (mean 56 hours). (mean 56 hours).

Shift Work

Health Specifics

Circadian RhythmsCircadian Rhythms

EffectsEffects

• Circadian disruptionCircadian disruption

• Sleep loss/debtSleep loss/debt

• FatigueFatigue

• Social disruptionSocial disruption

• Health implicationsHealth implications

Adjustment to shiftworkingAdjustment to shiftworking

Stress

Strain

Organisational

Implications

Sleep Disturbance

Mood changes

Functionality Reduced

Adjustment to shiftworkingAdjustment to shiftworking

stress strain organisational effects

Phase-shifting of waking and sleeping hours

Impaired performanceImpaired healthDisturbed relationships

> Absenteeism> Accidents> Labour turnover< Productivitymodifying

factors

Individual characteristicsJob-related factorsEnvironmentDomestic

Colquhoun & Rutenfranz 1980Colquhoun & Rutenfranz 1980

Studies show that staff can be prone to:

•Serious illness•Stress•Sleep disorders •Accidents

The evidence points to:

The ‘phase shift’ experienced in night and rotating shift work

Involves desynchronization at the molecular level in the circadian oscillators

in the central nervous tissue and in most peripheral tissues of the body

Desynchronization

There is a change in the coordination between oscillators

with transient loss of control by the master-oscillator

‘The Suprachiasmatic Nucleus’

(SCN) Located in the hypothalamus

Critical

The body’s various Circadian Rhythms are

“reset”

every 24 hours by environmental cues

e.g. light and darkness & melatonin

PositivesPositives

FlexibilityFlexibility FinancialFinancial Free timeFree time FamilyFamily

PositivesPositives NegativesNegatives

FlexibilityFlexibility FinancialFinancial Free timeFree time FamilyFamily

Sleep deprivationSleep deprivation AcknowledgementAcknowledgement Society still 9-5Society still 9-5 SpacedSpaced

Extraneous Supports

“The ability to effectively manage the juggling act between paid work and the other activities that are important to shift workers”

– Family/Friends– Recreation– Spiritual– Health and Wellness– Finances– Work & colleagues

Potential effectsPotential effects

StressStress

FatigueFatigue

ExposureExposure

cardiovascularcardiovascular

mental healthmental health

immune systemimmune system

gastrointestinalgastrointestinal

musculoskeletalmusculoskeletal

social effectssocial effects

performance impairmentperformance impairment

safety problemssafety problems

over-exposureover-exposure

Gastrointestinal disorders and shiftworkGastrointestinal disorders and shiftwork

IndigestionIndigestion (Chan (Chan et al.et al. 1987) 1987)(Poole (Poole et al.et al. 1992) 1992)

RefluxReflux

Peptic UlcerationPeptic Ulceration (Waterhouse (Waterhouse et al.et al. 1992) 1992)

Related to:Related to:

irregular hoursirregular hourscircadian dysrhythmiacircadian dysrhythmiapoor catering facilitiespoor catering facilitiesinequality in GP accessinequality in GP access

Cardiovascular problems of shiftworkCardiovascular problems of shiftwork

Liu & Tanaka 2002Liu & Tanaka 2002

Working hours related to Acute Myocardial Infarction:Working hours related to Acute Myocardial Infarction:

•increased risk in year prior to AMIincreased risk in year prior to AMI

•increased risk in month prior to AMIincreased risk in month prior to AMI

•x 2 increase in risk for overtimex 2 increase in risk for overtime (>61 hours) (>61 hours)

•x 2-3 increase in risk forx 2-3 increase in risk for <5 hours sleep <5 hours sleep

•x 2-3 increase for lack of sleepx 2-3 increase for lack of sleep (2 or more days with <5 hours sleep) (2 or more days with <5 hours sleep)

Overtime work and lack of sleep may be related to AMIOvertime work and lack of sleep may be related to AMI

PsychologicalNeurological

Energy Slump

ChocolateAlcoholCigarettesCoffeeDrugs

DopamineSerotoninGABAAdrenalin

PsychologicalBoostRelaxedCalmFeels good

Physiological

NauseousIrritatedDrunkDepressedHostile

GuiltyAshamedFailureAngry

Exhausting Fix it

Energy & Fatigue Cycle

Blood Sugar levels Serotonin ß-Endorphins

Tired

Fuzzy

Edgy

Irritable

Sleep Problems

Faint

Poor concentration

Depressed

Isolated

Lost

Suicidal

Stressed

Sleep problems

Poor Concentration

Lethargic

Run Down

Tearful

Reactive

Hopeless

Craves Sugars

Low pain threshold

Neurotransmitters

Neurotransmitters are made from essential amino acids.

There are hundreds of neurotransmitters: 6 main ones:

•Adrenalin•Dopamine (Noradrenalin)•Endorphins•Serotonin•Acetylcholine•GABA

Adrenalin

Has the opposite effect of insulin – 1st messenger hormone and will be released when the glucose levelin blood is low.

As neurotransmitter it has an effect on the sympathetic nervous system. (heart, lungs, blood vessels, bladder & gut)

Dopamine

Associated with:• Pleasure

• Alertness

• Concentration

• Euphoria

-ve = PD & Sc

all proteins (meat, milk products, fish, beans, nuts, soy products). 

Endorphins

The brains natural opiates

They bind to specific opiate receptors in the brain and induce pain relief.

Also known as the runners ‘high’

SerotoninAssociated with:

• Moods

• Sleep

• Dreams

• Bp

• Digestion

• Body temperature

pasta, starchy vegetables, potatoes, cereals, breads. 

Acetylcholine

Associated with:

• Memory

• Alertness

• Learning ability

• Concentration

• -ve Alz• Egg yolks, peanuts, wheat germ, liver, meat, fish, milk, cheese and vegetables (especially broccoli, cabbage and cauliflower)

EssentialsEssentials

Niacin BNiacin B33 Folic acidFolic acid Pyridoxine BPyridoxine B66 Vitamin CVitamin C ZincZinc MagnesiumMagnesium EFA’sEFA’s Tryptophan & tyrosineTryptophan & tyrosine

LunchesLunches

Core base of green saladCore base of green salad

Walnuts & pecan nutsWalnuts & pecan nuts

PeppersPeppers

TomatoesTomatoes

Fresh lemonFresh lemon

Mood Enhancing FoodsMood Enhancing Foods

EggsEggsFish & meatFish & meatCottage cheese Cottage cheese Rice pasta Rice pasta Crustacean vegetablesCrustacean vegetablesShort grain brown organic riceShort grain brown organic riceQuinoaQuinoaAvocadoAvocadoLegumesLegumes

Nutrient Food sources NT Proposed effect

Protein Meat, Milk, Eggs, Cheese, Fish, Beans

Dopamine, Norepinephrine

Increased alertness, concentration

Carbohydrate (CHO)

Grains, Fruits, Sugars

Serotonin Increased calmness, relaxation

Calories All Foods Reduced blood flow to the brain

Excess calories in a meal is associated with decreased alertness and concentration after the meal