Is there a science to healthy living?
Get the basics right with a science-backed, effective strategy
The 5 pillars
Good physical wellbeing is largely a result of 5 behaviours that underpin just about every aspect of health. Known as the “Five Pillars of Good Health” these include:
- Eat well
- Keep fit
- Manage stress
- Don't smoke
- Get adequate sleep
There’s a whole bunch of other stuff we could add in regarding routine medical screening (i.e. blood pressure, blood glucose/diabetes, blood cholesterol, bone densitometry, dental hygiene etc.), but for the most part, a long and healthy life awaits those who get the five pillars right.
No other health topic has generated more income for publishers and printers than nutrition. It seems everyone has an opinion on it, even those with no formal qualification in nutrition. The number of diets that have been rolled out over the past few decades is bewildering.
So how does one sort the good from the bad? It has to come down to the evidence - in well-designed studies. Which diet(s) deliver the best results?
We need one caveat here, the diet should be easy to follow and maintain. Back in the 1979, Nathan Pritikin published the worlds best selling diet book. The principles were sound and the evidence strong. The diet is nowhere to be seen today because only about 1 in every 1,000 people had the willpower to stick with it (we now believe those people were OCD).
The diet that shows the best combination of evidence base and stickability is the Mediterranean Diet. This diet, which not only boasts great cancer- and cardio-protective effects, also has very low attrition, meaning it is easy to stick with in the long term. It has been recently revamped into the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet which has now been shown to slow cognitive decline with ageing, as well as delivering the reduced cancer and CVD benefits.
How easy is it? A leading nutrition scientist, Professor Gary Wittert said, “Basically it goes like this – eat fresh food, mostly plants, and not too much”.
If nutrition has a reputation for being complex, then exercise is a recipe in simplicity. Quite simply, the health departments of almost every nation in the world give the same basic guideline – 150 minutes per week of moderate physical activity.
To understand exercise it’s useful to acquaint ourselves with the concept of a MET. A MET is a unit of energy expenditure that equates to the energy used by a human at rest. So I’m sitting down, resting (that’s 1 MET) and I stand up (1.5 METs). I walk slowly to the front door (2 METs) where I exit the house and begin my brisk walk (3.5 METs at 4.8 kph). The rush of fresh air is exhilarating and I break into an easy jog (7 METs). The neighbours dog chases me and I briefly sprint up the road (14 METs at 14 kph). In that final sprint to escape the rottweiler, I expended energy 14 times quicker than I did at rest. If I could sustain that I could burn through my entire 24-hour energy requirement in just 1.7 hours! Unfortunately most of us are not fit enough to sustain such a pace, nor do we have the time.
When we look at the relationship between exercise and life expectancy, we see some pretty impressive gains by the time we get to 10-15 MET hours per week, beyond which the benefits tend to plateau. So if I jogged for 2 hours (that’s a 7 MET activity – see pre canine experience above) over the course of a week, say 4 x 30 minutes, I’d get 2 hrs x 7 METs = 14 MET hours per week of activity, and, according to the graph below, 4 extra years of life expectancy.
And in the process, I would also avoid many debilitating conditions that would reduce my quality of life as I age.
Managing stress may seem a little out of place in this list, after all, stress is about mental rather than physical health, but the two are intimately connected via our immune system. Stress impairs immune function, which subsequently predisposes us to all manner of physical illness – all the way from colds and flu to cancer and cardiovascular diseases.
Stress management therefore, represents a crucial tool in the management of physical health and avoidance of preventable (lifestyle related) diseases.
18 minutes of life lost per cigarette smoked, what more can we say?
Get adequate sleep
Not so long ago, the main scientifically validated symptom of poor sleep was simply tiredness and/or fatigue. How things have changed!
We now know that too much or too little sleep can increase the risk of early death to three times the baseline level due to increased risk of diabetes, obesity, cardiovascular diseases and high blood pressure.
The majority of studies show the lowest risk sleep is around 7 hours duration. At 6 and 8 hours, the risk is slightly elevated (risk ratios around 1.05 meaning a 5% increase in the chance of premature death). The big impact comes when we move outside this 6-8 hour window. By the time we get to less than 5 or greater than 9 hours, risk can double or even triple.
Poor sleep is defined as either sleep deprivation (not enough sleep) or fragmented sleep (disruption of sleep cycle). These can result in excessive daytime sleepiness, with the obvious impact on concentration/attention and cognitive function which impairs performance and may even effect employability.
But it’s the cardio-metabolic effects that concern us most from a health perspective. Sleep deprivation can reduce insulin sensitivity by as much as 40%, resulting in an increased risk of type 2 diabetes¹.
Hormones that regulate appetite (leptin and ghrelin) are affected, leading to poor appetite control and a predisposition to obesity, which further increases diabetes risk. A meta-analysis of 17 studies covering more than 600,000 adults showed the risk of obesity increased by 55% in those who slept less than 5 hours per night².
Discounting clinical conditions which dramatically impact sleep (i.e. obstructive sleep apnoea and narcolepsy), most people can improve both quality and quantity of sleep by simply practicing good sleep hygiene.
In the SHAPE Survey, the five pillars of good health are assessed and recommendations are provided. SHAPE also calculates the ‘Health Age’ of the user. Health Age is a great way to understand whether health behaviours are impacting one’s life expectancy. If I’m 35 years old with a Health Age of a 45 old, I’m in trouble … I’m ten years closer to ‘the end’. A few changes to the 5 pillars and viola! … my Health Age drops to 30 years. Phew!
¹Knutson, Kristen L. 2007. Sleep Medicine Clinics 2 (2): 187-197. doi:10.1016/j.jsmc.2007.03.004.
²Mayer, Stephanie B., et al. 2016. Journal Of Clinical Sleep Medicine 12 (07): 997-1002. doi:10.5664/jcsm.5934.