Healthy ageing: what measurably changes with the years, what a 30 year Dutch cohort puts at the top and what a lifestyle scan measures

In this article you read what changes measurably in the body as the years pass, what a thirty-year Dutch cohort found most important for healthy ageing, and what a lifestyle scan can and cannot tell you about where you stand. That matters, because most of what people notice over the years is ordinary and measurable, while a small set of named signals belongs with a doctor, and those two ask something different of you. Many people notice the same handful of things: less strength than ten years ago, a memory that needs a second longer, a waist that grows while the plate stays the same. The BioProfile lifestyle scan measures how much you suffer from these complaints, and gives you an indication of where you stand today in this area, as the first of the 11 health areas that the full scan assesses. This is not a diagnosis. It is insight, to see where you stand today. And to help you make better choices in your food and your lifestyle. What this scan does not do: name a condition, or tell you why a change is happening.

What changes over the years, and how fast

The slowdown that people in their forties expect from their metabolism is hard to find in the data. Energy expenditure was measured with the doubly labelled water method in 6,421 people (64 per cent women) from 29 countries, aged 8 days to 95 years. Total energy expenditure and fat free mass were stable from age 20 to 60, and corrected for body composition total energy expenditure only starts to fall from a turning point of 63.0 years (95 per cent confidence interval 60.1 to 65.9 years), after that by about 0.7 plus or minus 0.1 per cent a year, so that people of 90 and older sit about 26 per cent below middle age.⁠¹ In plain words: the engine holds up through the decades in which most people say it does not.

Strength is a different story. In 1,880 older adults followed for three years, leg strength fell by 3.4 per cent a year in white men, 4.1 per cent in black men, 2.6 per cent in white women and 3.0 per cent in black women, while lean mass in the legs fell by about 1 per cent a year, so strength was lost roughly three times as fast as mass.⁠² Muscle strength and muscle mass go down as soon as breakdown outpaces building, a process that begins in young adulthood and only becomes noticeable after decades.⁠⁴ That is why you can look almost the same and still find the stairs harder going.

Why your waist grows while your plate stays the same

After the turning point around age 63, energy use corrected for body composition falls by about 0.7 per cent a year,⁠¹ and the muscles that use much of that energy have been quietly shrinking for decades.⁠⁴ Neither source measured the waist itself; what was measured is the energy side and the muscle side, and both move in the same direction. So a plate that has not changed since you were forty meets a body that has.

In a Dutch cohort in Doetinchem, 2,815 participants aged 46 to 85 at the last measurement were followed for 30 years, in six rounds five years apart. Eight of the ten strongest predictors of healthy physiological ageing came from the biological domain, with measures around body weight (BMI, waist circumference, waist to hip ratio) and cholesterol at the top, and diet and education level also in the top ten; the pattern was the same across the generations in the cohort.⁠⁵ For you that means: what research into healthy ageing in the Netherlands puts first is what you can actually see on a scale, a measurement and a lab result.

Memory, thinking, and when to call your GP

As you get older, your memory works a little more slowly, and that is true for many people: not coming up with a name, walking to the kitchen and forgetting what for, a phone number that is no longer at your fingertips.⁠⁶ A review of cognition in adults who are ageing healthily sorts out which parts move and which do not. Working memory, processing speed and cognitive plasticity go steadily down from middle age, perceptual speed mainly after 65, while the crystallised abilities go the other way: knowledge and vocabulary stay the same or even rise, and verbal knowledge climbs until middle age and then stays stable until about age 81. In longitudinal research most abilities held up at least until middle age, with large differences between people.⁠⁷ So the slower search for a word sits in one column and what you know in the other, and the second column is not the column that shrinks.

Some things make your memory work less well for a while: stress and life-changing events, certain medicines (among them sleeping pills and medicines for the bladder or the prostate), alcohol and drugs.⁠⁶ Contact your GP on a working day if one or more of these four apply: you think your memory is getting worse quickly; your symptoms get in the way of the ordinary things you do in a day; your symptoms keep getting worse and things are no longer the way they were; you think you have more trouble with your memory than other people do.⁠⁶

What the studies put behind healthy active ageing

The Dutch physical activity guideline for adults and older adults reads: be moderately active for at least 150 minutes a week, such as walking and cycling, spread over several days, and longer, more often and more intensively gives extra health benefit. Do muscle and bone strengthening activities at least twice a week, for older adults combined with balance exercises, the only addition the guideline makes for older adults. And avoid sitting still a lot. In that same advice, 44 per cent of people aged 18 and over met the guideline.⁠⁸

How much this weighs has been measured in 8 studies with 36,383 participants, average age 62.6 years, followed for 6.7 years on average, in which 2,149 participants (5.9 per cent) died. Against the quarter that moved least, the chance of dying was 0.48 (95 per cent confidence interval 0.43 to 0.54) in the second quarter, 0.34 (0.26 to 0.45) in the third and 0.27 (0.23 to 0.32) in the most active quarter; the quarter that sat most came out at 2.63 (1.94 to 3.56), and the quarter with the most light activity at 0.38 (0.28 to 0.51).⁠³ The steep part of that curve sits at the bottom: most of the difference is between doing almost nothing and doing a little, and light activity already counts.

Strength training has evidence of its own. Across 121 randomised trials with 6,700 older participants, training two to three times a week at high intensity, muscle strength showed a large effect, standardised mean difference 0.84 (0.67 to 1.00) across 73 trials with 3,059 participants. Walking speed was 0.08 metres per second higher (0.04 to 0.12) across 24 trials with 1,179 participants, and standing up from a chair came out at minus 0.94 (minus 1.49 to minus 0.38) across 11 trials with 384 participants.⁠⁹ Walking speed and getting out of a chair decide whether a day stays yours, so that is what healthy and fit ageing looks like in practice.

On the plate, the Dutch advice from the age of 70 reads: a daily supplement with 20 micrograms of vitamin D, for everyone of 70 and over, alongside meals built on at least 25 grams of protein.⁠⁴ And the people around you are not a soft factor: in 148 studies with 308,849 participants, average age 63.9 years at the first measurement and 7.5 years of follow-up, stronger social ties went together with an odds ratio of 1.50 (1.42 to 1.59) for surviving the study period, 50 per cent more chance, and that link held up across age, sex, health at the start, cause of death and length of follow-up. The link was strongest for composite measures of social integration (1.91; 1.63 to 2.23) and weakest for the single question of whether someone lives alone or not (1.19; 0.99 to 1.44).⁠¹⁰ In plain words: how you live counts, and who you live with counts too.

What a lifestyle scan does and does not measure about healthy ageing

The scan asks about your habits and about the signals above, scores your answers and places the score for this area in a reading band, so that you hold a starting value instead of an impression. Repeat the scan later and you have two values.

What a set of answers cannot do is say where a change comes from. A slow month of sleep, a slower search for words and a shrinking muscle all read the same in a questionnaire. Blood values and the assessment of a doctor are the layers that take a picture of symptoms to an explained picture, and that is a question for a doctor.

In summary

Energy use holds steady for decades and only begins to fall around sixty, while strength goes faster than muscle mass, and so an unchanged plate and an unchanged routine slowly fit you less well. Memory works a little slower over the years, knowledge and vocabulary do not, and four named signals are the reason to call your GP. What the studies put behind healthy ageing is a short list that keeps repeating: moderate activity on most days, strength training with balance twice a week, less sitting still, enough protein and vitamin D after 70, and people around you. A lifestyle scan tells you where that list finds you today.