I have been struck particularly by three key areas where the argument has moved on.

A Healthy Mind in a Healthy Body

I have flagged in several previous Newsletters the good news about dementia. The number of patients is increasing dramatically. Your chances of getting it are shrinking. There is evidence from all over the developed world that the incidence of dementia has declined. This came as a surprise to many researchers. New evidence continues to show that this is the case.

The explanation to date is that the overall reduction could be due to only one type of dementia. Vascular dementia is the second most common form after Alzheimer’s. It accounts for 20% of incidence and comes from the drop in blood to the brain. Damage to arteries from such things as stokes is the most common cause. The Western world has invested in reducing cardiovascular disease and has succeeded. It would seem logical that this has had its effect on vascular dementia.Improvements across all forms of dementia have favored men. This is the group where improved cardiovascular health has increased the most.

Evidence is now emerging that improved cardio-vascular health can improve other kinds of dementia. That includes Alzheimer’s disease. The findings are more exciting. It seems that cardio-vascular health prevents the onset of the symptoms of dementia. The indicators of plaque etc in the brain can remain. With good blood supply our system can prevent the symptoms from emerging.

The bad news is that the data is only demonstrated in the developed world. Worst still there is evidence that the rate of improvement is slowing or plateauing. Researchers suggest that interventions to improve cardio-vascular activity may have themselves plateaued. Medicine has “harvested the low hanging fruit”.

There are less studies in poorer nations, but the suspicion is that the effect will not be there. We know that dementia depends on the exposome. That is the wider environment in which people spend their lives. Even within the developed world there are huge differences across levels of deprivation. Those people that grow up in the most deprived areas have higher incidences of dementia.

“How Was Your Day?”

In Newsletter #095 I discussed the impact of loneliness and social isolation on health. They turn out to be more dangerous than smoking or excess alcohol intake. All the epidemiological studies show that separately and together they are bad for health. Social isolation is an objective “outside-in-measure”. It assesses the actual day-to-day contact of an individual. How many times do they talk to acquaintances, to friends, to family. How much contact do they have through everyday things like shopping. Loneliness by comparison is an “inward- looking” measure. It assesses how we feel about the level of our day-to-day contact compared to the amount we desire.

Past studies have always shown that these two are different. We can have high levels of social interaction but still feel lonely. We do not necessarily feel lonely if we have few contacts. More recent work has gone further. Both can affect health outcomes. It has now been shown that psychological loneliness has a bigger effect on our mental health. Social isolation is more associated with physical health. Researchers are now speculating on how this works. Their suggestion is that we all need somebody close enough to us with whom we can defuse at the end of the day. Those “how was your day?” conversations are stress reducing. Without them we live in a heightened world of stress. Stress is bad for your health. It is related to inflammation levels.

Researchers are also shedding light on initiatives around the world to reduce loneliness. In the Netherlands that have a large range of programs. The second largest supermarket chain, Jumbo, has launched “chatting checkouts”. These cashiers are given more time and encouraged to chat with their customers. Other programs aim to bring isolated people together. Interventions create events under a banner of “exercise”, art, or some other theme. Researchers have suggested that this may be a dangerous strategy. It may solve social isolation but make loneliness worse. In the wrong setting lonely people when brought together may reinforce each other’s loneliness. Loneliness can be contagious.

There are no Grandma Apes

In a very early Newsletter #002 I quoted from David Lieberman. He is an evolutionary biologist and anthropologist. He argues that evolution did not intend humans to retire. He asked a simple question:

“Why are humans uniquely allowed to live past their reproductive age?”

Most other species die after they pass the time when they reproduce. He argued that this even happens with our closest relatives, the great apes.

His argument is that this enables humans to reproduce at a faster rate. He looked at the few remaining hunter- gather communities. He argues that older members’ role is to continue to gather food for the whole group. This enables younger females to reproduce more often.

A recent study of wild apes suggests that apes may not be that far away from us. We are not unique in this regard. On average the females spend 20% of their lives post menopause. This is not the 40% of humans but still significant. They must still be adding value to the community. The researchers point out that this is a group of apes within a protective reserve. They may have developed different behaviors. The older members may be protected from predators.

The andromorphic idea of “Grandmothers” was introduced by the media when they saw the paper. It is certainly not the case. Young female chimpanzees leave their home groups. The remaining males are promiscuous. The result is that it would be impossible for any grandmother to know who their grandchildren are.

It still seems that evolution did not intend us to retire.