Are we really genetically similar to the paleo men and women? page

[paul900]

10,000 years ago agriculture was invented and we started ingesting grains that we had never had before. From 10,000 years to now we have ingested a lot of novel foods in comparison to 120,000 years ago.

Surely in that time the body has produced proteins and enzymes (which means altered genes as they are responsible for producing the proteins) to deal with the new foods.

Therefore we are not identical to the paleo people. This seems obvious but mark sisson and other paleo advocates gloss over this point and tell us we are absolutely identical to paleo men and women when we really are not.

Thoughts?

[Leida]

Sure, there is some adaptations.

1) Small amounts of unprocessed grains do not cause negative reaction in most people. However, processed grains, aka bread and pastas have an immediate and profound impact on the appetite because of the components added to it in the last 100 years (a far cry from 100,000 years ago). We are absolutely not adapted to deal with that.

2) Consuming unprocessed starch from grains and/or tubers leads to fast and significant weight gain when it is combined with fat

3) Grains contribute little to the palate and nutritional profile.

--> If you are trying to gain weight, consuming unprocessed grains is your choice. If that's not the case, dropping grains is a single easiest thing to do to control the weight and reduce it to the average weight range.

[Tribal Rob]

Surely in that time the body has produced proteins and enzymes (which means altered genes as they are responsible for producing the proteins) to deal with the new foods.

Surely you need to provide researched based evidence to back these claims up, why don't you read through all the references in the Primal Blueprint, do your own reseach to see if there is any evidence we have mutated to be able to digest grains better (note: that the presence of an emzyne that digest starch is not evidence that we should be eating half a pound of bread and pasta a day) then present a decent case.

I mean surely the ability to use a keyboard and log on to a forum dosn't mean you have to be an idiot

[jojohaligo]

Whether I am the same as a paleo person is really not affecting the dietary choices I make. How I feel is. In other words, not eating grains, not eating beans, not eating overly processed foods, avoiding most dairy (yogurt, butter and some cheeses don't bother me), all have done wonders for my IBS, arthritis, and bursitis.

[The Scientist]

I have been a fan of the site for a while, but have never joined in the forum. This topic left me unable to resist replying. I have a PhD in cell biology, so this is right up my alley.

Natural selection will only select changes that increase reproductive success (more children). The likely reason that humans have not evolved any mechanism to deal with the harmful effects of grains is that these effects take their greatest toll on people's health later in life. If all of the downsides of eating grains happen after reproductive age (which most paleolithic people did not even make it past due to infectious disease and violent death), there would be no reason (selection pressure) to favor genes/alleles that alleviate the problems grains pose. They are high in calories, and in the short term, people would have experienced a huge benefit (reproductively) from eating grains just to get more calories and not starve. This is the same reason that humans have not evolved defenses against most cancers of neurodegenerative diseases – natural selection does not care if you die after you are too old to reproduce.

Changes that have made their way into our genome in the last 10,000 years are a different story. For example, the lactose dehydrogenase (LDH) gene, which processes lactose in milk, was selected for expression into adulthood because people in their reproductive years clearly benefited from being able to get more calories from milk they collected from domesticated animals.

So, we are not identical to paleolithic people, but the changes that have taken place in our genome are due to the need to compete with other people for reproductive success in the short term, and have nothing to do with health and longevity past normal reproductive age. I hope this helps to answer your question.

[Tribal Rob]

^^^What that clever chap said^^^

Hovever, my understanding was that plenty of paleothic people live to a ripe old age, but the average age was low due to infant mortality, fighting tigers and other dumb stuff and disease, but if you made it past these hurdles you could be a right old codger and look after the young-un while the rest of the tribe are off fighting tigers for buffalo meat.

I'm not really qualified to explain it, but my understanding is there is a great differance in selecting for an exisiting variation (like being able to digest diary into adulthood) which can change a population quite quicky, compared to a new mutation occuring that inferes some benifit to this mutation being passed on and become a normal trait, which can take a veeeeerrry long time.

[The Scientist]

The math on this is tricky. It is not necessarily that "plenty of paleolithic people live to a ripe old age". What we know is that once you subtract out external causes of death, like infection and trauma, people live to a ripe old age on average. The problem here is that most people did die from external causes before they got very old.

As far as selecting for old age because you can assist in rearing children/grandchildren – that is one hypothesis. On the flip side, you could say that having an old person around used up food and other resources that could have been given to children. The question is: in a paleolithic setting, at what age do you start becoming more of a burden than a help to your offspring (as far as their reproductive success goes)? I think it is obvious that staying alive until your children are into adolescence is a big deal, but what about beyond that? This is all speculation, and don't let anyone tell you they know the answer, because there is no way to prove it one way or the other.

[paul900]

I have been a fan of the site for a while, but have never joined in the forum. This topic left me unable to resist replying. I have a PhD in cell biology, so this is right up my alley.

Natural selection will only select changes that increase reproductive success (more children). The likely reason that humans have not evolved any mechanism to deal with the harmful effects of grains is that these effects take their greatest toll on people's health later in life. If all of the downsides of eating grains happen after reproductive age (which most paleolithic people did not even make it past due to infectious disease and violent death), there would be no reason (selection pressure) to favor genes/alleles that alleviate the problems grains pose. They are high in calories, and in the short term, people would have experienced a huge benefit (reproductively) from eating grains just to get more calories and not starve. This is the same reason that humans have not evolved defenses against most cancers of neurodegenerative diseases – natural selection does not care if you die after you are too old to reproduce.

Changes that have made their way into our genome in the last 10,000 years are a different story. For example, the lactose dehydrogenase (LDH) gene, which processes lactose in milk, was selected for expression into adulthood because people in their reproductive years clearly benefited from being able to get more calories from milk they collected from domesticated animals.

So, we are not identical to paleolithic people, but the changes that have taken place in our genome are due to the need to compete with other people for reproductive success in the short term, and have nothing to do with health and longevity past normal reproductive age. I hope this helps to answer your question.

This makes sense. The negative effect of grains is not seen until later in life, as disease takes hold. And you rightly make the comparison with cancer, which is the same thing. Humans obviously developed mechanisms to prevent cancer taking place (by and large) until we have aged quite a bit.

However, the difference is that these grains have been introduced and the body has had to deal with them for 10,000 years. As such, you would expect the body to have developed novel proteins in order to be able to deal with them, (so that they don't cause harm until we reach reproductive age and beyond). So lets take a case study of a child born today. The child will eat grains from Day 1 and probably live to the age of 70 when he or she will die of health related issues (we can't say for sure these are grain related health issues but I would concede that dietary choices most likely lead to the death of the person). So essentially the body has coped with daily consumption of grains for 70 years. Could paleolithic people have done that? WELL THEY ACTUALLY DID! Neanderthals ate grains. But we are very different to the paleolithic man.

As an aside, the paleolithic man was all over the world so his diet depended on the environment. Paleo asians ate differently to paleo africans and paleo europeans and paleo americans etc. So do we look at our genetic heritage to look at what our particular paleo ancestors ate and then replicate that?

And another thing about dairy, do you really think paleo people didn't drink milk? I mean seriously, of course they drank milk. This is another con that the paleo gurus try to pull.

The fact of the matter is, NEANDERTHALS ATE GRAINS, THIS IS A FACT

So people should think for themselves about paleo and have some common sense.

[paul900]

So I am actually wrong about grains being introduced in the last 10,000 years. It seems we have been eating grains for 40,000 years

[sbhikes]

I think the age thing was touched upon a little bit in the book Born to Run. It appears that when it comes to marathon running, a man at age 64 is every bit as capable as a youth at 17. In other words, there is a steep rise in ability after 17 that then tapers off very slowly, returning to the same capacity by age 64. So the idea that being old means you are shriveled and incapable is more an artifact of our modern degenerative disease conditions than our actual innate capability. An older person in paleolithic times would have been fully capable of providing value to his or her group for a very long time.