The reason we have more illness than would be expected. is as follows:
We are Great Apes, in other words , we are primates, our mammalian line evolved in Africa. That evolution took many millions of years , we adapted to the environment in Africa. When an environmental change occurs , then the organism either adapts to become better suited to that new environment , or it goes extinct , as generally it cannot compete for the resources within that environment.
We , as a species , have changed our environment quite dramatically, in the last few thousand years. At a pace that far outstrips our ability to fully evolve adaptations. In other words we are still mostly suited to running around naked on the plains of East Africa. I say mostly suited , because there is one at least adaptation that has ocurred within the last 10,000 years which would hinder our survivability. That is white skin. The reason we evolved white skin was because our environment changed , such that in Northern Europe , at lattitudes above say 40 degrees N , UVB in sunlight progressively diminishes , reducing the manufature of a vital hormone. That is vitamin D , when processed by the body , it becomes the hormone form. Lack of it results in many diseases. In the UK, at our latitude of 50 degrees , we cannot make Vitamin D in the skin for 6 months of the year , mid_Oct to mid-April. On the plains of East Africa , we can make it every day, because sunlight is much stronger, and contains UVB radiation every day. (It's just a matter of physics ..! )
Luckily , we can obtain some vitamin D , from food , in that winter period. Unluckily , it is not nearly enough. Only people like Inuit , etc, who are eating fish every day get a reasonable amount. You can of course take supplements , to help with the lack.
Scientific advances over the last 50 years , and more specifically over the last 20 years gives us a better understanding of Vit D physiology. We now know that every cell in your body ( almost ) has a receptor , we now know that it is not just useful for bone health, about 2000 of you your genes out of a total of about 23,000 have vitamin D response elements. i.e Vit D hormone form either up regulates or down regulates those genes in conjuction with other signalling elements within the body.
Now , when exposed to East African sun, modern humans , and our forefathers , have blood levels of around 120 - 140 of Vitamin D. In this country , we have levels commonly 1/2 to 1/3 of that. i.e. 30 - 70. There are consequences. Most of us don't reach the age of 85, in rude health. We should really. With a natural variation of plus or minus 5 years. . . ( obviously that is a statistical view, - some may suffer accident, disease, genetic variability etc etc. some are outliers etc. )
That would be our expected lifespan , if well nourished by all required nutrients. Vitamin D is a micro nutrient, there are other nutrients which we are low in.
Modern farming and food habits mean that many people are low in magnesium and probably quite a few others. Modern science does not yet have all the answers. We have however found out quite a lot concerning Vitamin D. It is one of the factors contributing to many major western diseases. Have a look here , for a good idea , many research papers etc etc. vitamindwiki.com/VitaminDWiki
Maybe this will prompt some people to check their Vitamin D level, I hope so. If you are in the UK , it will almost certainly be well below your forefathers ancestral level of 120 -140. That is why when many people go to the doctors , they will say .... "We are all low."
I have posted quite a bit here on mumsnet about Vitamin D, search my username , if you seek more info .
best of luck.
BTBH.
PS. you can get a test posted to you from this NHS lab . www.vitamindtest.org.uk
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