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Nutrition and the ageing body
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Nutrition and the ageing bodyLecture 1: Introduction to ageing and the muscle
Right now, biggest part of our population is between 45 and 55 years old. However, by 2100 there
will be more people above 55 years compared to people younger than 55 years old.
Dependency ratio = ratio between the number of persons above 65 years old (economically inactive)
and the number of persons aged between 15 and 64 years old. The dependency ratio is expressed
per 100 persons of working age. It tells something about the number of older people who are
dependent on younger people. This will grow in the future.
Life expectancy increases
- Lifespan was increasing between 2000 and 2019: linear increase around +5,6 years.
- However, lifespan decreased -2,1 years between 2019 and 2021 (because of covid)
- But life expectancy will increase again
- 21% of Europeans are older than 65 years (n = 106 million)
- Projection for 2050
o 30% of Europeans will be older than 65 years old (n = 150 million)
- In the US! You see that the lifespan declined with 2,7 years. Now, it is the lowest since 1996.
The reasons for this are:
o Covid-19 50% of decrease in lifespan can be explained by covid
o Unintentional injuries 15,9% (drug- and substance abuse, this also has to do with
covid, because people used more during lockdown)
o Because of the lockdowns, the influenza and pneumonia numbers decreased, so less
deaths due to those reasons.
Map: the darker the colour, the more an event impacts life expectancy.
Covid-19 is the biggest event since WWII with this big of an impact on life expectancy.
When different countries are compared: Eastern Europe countries had a big decrease in lifespan
during covid, Western Europe countries had a big decrease in 2020, but increased again in 2021.
In the USA, also a difference is seen between origin and race.
AIAN people (already have a lower lifespan in the USA), were hit harder by covid compared to other
groups in the USA. The same applies for black people.
Maximum lifespan does not increase.
Despite increase in average life expectancy, there is no increase in max lifespan.
In 1997, a French lady (Jeanne Calment) died at the age of 122 years. After her, no one reached this
high age anymore.
Oldest person right now is also a French lady, she is 118.
Healthy lifespan:
Health span = how many years of your life do you spend in good health?
If the health span is 70, this means someone spends his/her life 70 years in good health.
However, there is some controversy regarding health span. It may be difficult to establish when
someone is healthy or unhealthy. It is hard to make definitions for these concepts. F.e. when
someone was born with DMI but lives very healthy.
But health span is a helpful concept for interventions preventing age-related deteriorations.
When you make 2 lines: lifespan and health span.
The gap with lifespan is increasing
, People live longer and longer, but also more years in poor health
Reasons for the gap:
o The quality of life is mostly impacted by cardiovascular diseases, DM, cancer, and
Alzheimer’s disease and dementia.
o During aging, more abdominal fat is gained, loss of kidney volume, loss of bone,
cartilage, muscle mass and strength. But also altered hormone levels, mechanical
and structural tissue changes, age-related diseases, frailty and multimorbidity.
Health gap variation
People with practical education and lower income and people with higher education and
higher income, have a big difference in lifespan and health span. These people don’t have
different genetics, but they live in different areas and have a different lifestyle.
o 7 years in lifespan
o 15 years in health span
There is a focus for this in the Dutch national prevention agreement (smoking, obesity,
alcohol) and in the coalition agreement (increased tax on sugar-containing beverages,
protection of children against child-marketing, plans for sugar levy and 0% tax on fruits and
vegetables)
Also, in other countries this is seen; in the UK no junk food advertising before 9pm and no
junk food advertising online.
What is more important for longevity?
A. Lifestyle and environment
B. Genetics
Blue zones = locations in the world with an exceptional longevity, in these areas people are highly
active have low levels of stress, a strong community, they have local produced food and non-
processed foods.
Examples are Loma Linda (religious population) in California. They are strict vegetarians. Besides this,
they have little chronic diseases and live 10 years longer than the normal American.
Another blue zone is Sardinia in Italy, here is a relaxed lifestyle, a lot of red wine is drunk here, which
consists of anti-oxidants.
Another blue zone is Okinawa in Japan. People who moved from the USA to Okinawa got a lower risk
of cardiovascular diseases, and the other way around people who moved to the USA increased the
risk of cardiovascular diseases. This shows the importance of lifestyle, it is more important than
genetics.
What these areas have in common: family is important, they don’t smoke, whole grains, a lot of
social engagement, constant moderate physically active, semi-vegetarian, a lot of legumes.
,Effect of lifestyle on lifespan:
- Large multi-cohort study in high income countries
o Smoking leads to – 4,8 years
o Physical inactivity leads to - 2,4 years
o Alcohol abuse leads to – 0,5 years
- Impact of diet was not assessed, but intermediates:
o Diabetes leads to – 3,9 years
o High BMI leads to – 0,7 years
o And hypertension leads to – 1,6 years
In conclusion, lifestyle is more important compared to genes.
Genetics
If you have a sibling of >100 years old, you have a 4-8x higher chance to reach 100 years yourself.
This has to do with genetics.
Long-lived sibling increases change to reach high age
Parents and offspring of long-lived persons also reach higher ages
However, also spouses/partners of long-lived persons reach higher ages no shared
genetics, but shared environment, behaviour, food, traits etc.
So, longevity families: combination of genetics, environment and cultural factors
Twin studies = used to unravel the true genetics determinants from environmental determinants. In
twin studies you compare monozygotic (eeneiig) to dizygotic twins.
The largest estimation of true hereditary of lifespan is 25%, most recent estimates are around 12%.
So, genetics only accounts for 12% (to max. 25%).
, However, if you have a genetic disorder/defect, you can have a very healthy lifestyle, you still won’t
reach a high age.
Genes that play a role in longevity:
Many studies have explored associations between variations in the genome and longevity.
But only 2 gene locations (loci) have been identified:
- APOE gene = apolipoprotein E; a cholesterol carrier in peripheral tissues and the brain. It is
susceptibility linked to Alzheimer and cardiovascular disease
- FOXO3A gene = trigger for apoptosis (programmed cell death)
There are many other genes found in specific studies, but these genes occur in specific families.
However, APOE and FOXO3A occur in the general population.
So, in conclusion
Lifestyle and environment are more important for longevity than genes. At least 75% vs 25%.
Evolution of ageing
Why does ageing exist? Is there an evolutionary benefit?
o Human species experience ageing mainly after reproductive fitness.
o ELS = essential life span period of survival of the body until reproduction (main
goal of life), for which evolutionary forces and natural selection have resulted
maintenance mechanisms protecting structural and functional designs of the
organism. After reproduction, we don’t have a function anymore.
What is the ELS?
What is the average lifespan? Around 45 years old.
What is the maximum lifespan? Reached by French lady; 122.
For lowest age to highest age, sort average lifespan, essential lifespan and maximum lifespan:
essential lifespan average lifespan maximum lifespan (122 by French lady)
Evolution of ageing.
- There is no evolutionary advantage of ageing and limited lifespan.
- Under natural conditions: death will occur before old age (by accidents, diseases, predation)
- No mechanisms were ever needed to make more room for newborns.
- Only the last 200 years we reach higher ages. So, ageing is the result of absence of natural
selection pressures.
- After you have reproduced, there are no evolutionary pressures selecting genes that
promote lifespan and health at later age.
Alternatively, ageing can be the result of
- Deleterious effects at later age of genes with advantageous effects during development
Why is there a menopause?
Two possibilities:
1. Adaptive: selective advantage of female reproductive cessation. More energy into helping
existing children instead of having more children themselves.
2. Nonadaptive: artifact of the dramatic increase in human life expectancy, non-existent in any
other mammals, except for whales.
Grandmother hypothesis:
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