Animals living alongside humans produce amylase, enzyme that breaks down starch | Hacker News Reader

Animals living alongside humans produce amylase, enzyme that breaks down starch

elifesciences.org

98 points100c1p43r57 comments

Although I follow a ketogenic diet and benefit from it I have laughed about the claims that it's somehow aligned with the needs of Paleolithic people. SO I really enjoyed this: "Unlike Neanderthals and Denisovans, who had only two diploid copies, we carry up to 20 copies of the AMY1 gene, which produces salivary amylase. "

Isn't that the opposite of what you believe? Paleolithic people were not genetically adapted to high-starch diets like we are. Ergo, a low-carb diet like keto was more natural for them.

The "we" in the sentence is homo sapiens. Neanderthals and Denisovans were not the same species as us.

> "Unlike Neanderthals and Denisovans, who had only two diploid copies, [homo sapiens] carry up to 20 copies of the AMY1 gene, which produces salivary amylase. "

Doesn't that mean we've evolved to eat a lot of starch so the more natural thing for humans to eat is therefore starch, if you follow this line of reasoning? And therefore, we've "evolved beyond" the keto diet?

FWIW, I do not think this is good reasoning.

OP is not making a claim here, he is pointing out counter evidence to someone else's claim, which is that keto diets are optimal for homo sapiens because that is what our genetic ancestors evolved to eat. The presence of significantly more genes for amylase provides strong (although far from conclusive) evidence that homo sapiens have evolved to eat a much more varied diet than paleo proponents assert.

Paleo diet mainly prohibits wheat and refined carbs but allows for specific starches such as sweet potatoes. It's different than keto. At any rate, the existence of enzymes does not indicate that starches should make up a large portion of one's diet either, as we must admit the past century of relative plenty in the Western world has led to all sorts of dietary diseases.

I meant that I find a low fat ketogenic diet works well for me due to specific health issues of mine.

I see no reason why it might be good (or not!) for the population at large, so I laughed at people who thought it might be so based on fanciful evolutionary theories. Theories which appear to be confounded by the discoveries in the paper.

Apologies if I was too terse in my original comment.

I was just curious the reasoning, I feel that keto and also fasting would make the general population much healthier.

I think the keto / paleo things continued with “...and that’s why we modern humans should emulate a paleo diet.” So, parent poster doesn’t agree with this theory and it’s adherents.

Is it too much of a reach to make a claim that due to our high starch diet compared to other hominid species our brains developed at a faster rate due to our brains consuming a higher yield of the energy stored in polysaccharides.

Therefore isn’t it imperative for a majority of paleo and keto oriented diet people to consume complex polysaccharides for their brains to perform optimally? *with the exception of people who must follow it for serious health reasons

> This may suggest that our lineage has evolved specific adaptations to digest starch-rich foods, underlining the long and continuing importance of these staples in our diet

This reminds me of the interest in keto dieting and the frustrating misunderstanding that carbs are the cause of excess weight, diabetes etc. If that were true, the whole world would be diabetic and obese, since everywhere has a staple carb. It's only with excess calories and fat that carbs contribute to, but are not the cause of, the problem.

There are a few populations without (much) staple carbs, for example the Inuit and the Maasai. But I don't think many people solely blame carbs. It's processed carbs and sugar, hyper-palatable foods, lack of sleep, lack of sun exposure, microbiome damage from antibiotics, and a ton of other lifestyle factors.

But once you're in a compromised state (autoimmune, type 2 diabetes, hypertension, etc.), the ketogenic diet can be a very good way to treat or reverse those conditions. It doesn't mean that no one can eat carbs, it just means there are a lot of people who really do benefit from it.

Apparently Inuit people are actually fine on carbs because the meat they eat tends to retain its glycogen stores better because of the arctic conditions.

Inuits have mutated to adapt to that diet.

https://www.ucl.ac.uk/news/2015/sep/how-inuit-adapted-ice-ag...

As societies get richer and more sedentary they do get more diabetic and obese though. That’s not really due to carbs existing of course - but as we get easier access to luxury ultra rich foods it causes a lot of problems.

It's usually more of an issue with simple carbs, ie monosaccharides and disaccharides. Starch isn't one of them.

It is after amylase gets through with it. Amylase converts starch into disaccharides and trisaccharides. (Does that still count as simple?)

Undoubtedly multi-factorial, but excessive omega-6 fats as a major driver is the most convincing theory I've heard. Interesting reading: https://www.breaknutrition.com/omega-6-fatty-acids-alternati...

Your link references the street lamp joke - love that one, referenced it in a comment yesterday.

My understanding is the omega-3 oils are problematic for humans too, they’re just not as acutely toxic as the omega-6 oils. I started avoiding seed oils in college. It was not the specific intervention I needed, but I believe avoiding this anti-food has helped keep me from deteriorating like people commonly do...

Which scientific journals have you read on the matter to form your opinion? Just curious -- always looking to learn.

Until recently, everyone has lived near the border of starvation, and not had an opportunity to get obese.

Since the agricultural revolution, carbs are what we have been able to mass produce, and therefore breed ourselves to greater numbers on. That it probably hasn't been the ideal diet for us is a distant secondary concern.

Now that we're finally overproducing food, we actually are getting obese on the carb diet. Coincidence? Maybe.

I think the Venus of Willendorf and her equally thicc cousins are, if you'll excuse the expression, ample proof that some people had an opportunity to get obese long before the agricultural revolution.

Sure. When I said "everybody" I really meant "almost everybody".

Of course, in preindustrial times, obesity was a sign of wealth, and that statue might be an ideal to strive for, made by paper thin worshippers.

The Venus is a fictional character. In the same era you would see statues of men with phalluses as big as their bodies. Obesity was probably rare before the agricultural revolution.

Didn't someone put a theory out that the Venus of Willendorf was not venerating the Fat Goddess, but rather what someone sees when they look straight down at their body?

(cuz cave people didn't have good mirrors and all)

Deeper explanation: https://steemit.com/science/@deeallen/self-portraits-of-fert...

There are all sorts of theories!

Olga Soffer points out that the woven clothing on the figurines is often incredibly detailed, and suggests they may have been some kind of fashion doll [1]. Mandy Weston speculates that they may be bobbins used for weaving [2]!

[1] https://www.researchgate.net/publication/235979951_The_Venus...

[2] https://www.academia.edu/31112020/Venus_Figurines_-_Evidence...

I believe that you're missing the point. We aren't getting obese on the carb diet. We are getting obese from excess calories and dietary fat. De novo lipogenesis (producing fat from only carbs) is inefficient and uncommon. Storing carbs as body fat via de novo lipogenesis is inefficient; storing dietary fat in body fat reserves is easy and efficient.

storing dietary fat works best when you eat carbs, because then your body will run on carbs and carbs will spike your insuline to signal the body to store the fat. Also the insuline spikes and drops make you crave more carbs...

That sounds like a very keto perspective. Meat can "spike" insulin, too.

> "In fact meat protein causes as much insulin release as pure sugar." and "Some of the protein-rich foods (beef, cheese, eggs) had larger insulin responses per gram than did many of the foods consisting predominately of carbohydrate." and "A low-fat diet based on less-refined, carbohydrate-rich foods with relatively low insulin scores may help enhance satiety and aid weight loss as well as improve blood glucose and lipid control" [1]

If you're not eating excess calories and are limiting fat intake, you won't get fat.

[1] http://ajcn.nutrition.org/content/66/5/1264.full.pdf

"The results of this study are preliminary but we hope they stimulate discussion and further research. Additional studies are needed to determine whether the IS concept is useful, reproducible around the world, predictable in a mixed-meal context, and cliii ically useful in the treatment of diabetes mellitus, hyperlipidemia, and overweight"

Interesting but ultimately a flawed concept.

Since i was born and for 45 years i was eating a typical mediterranean diet (i live in these parts) very high in complex carbs and fibers from legumes, whole grain breads, beans. what exactly did that to my health? Gradualy from my early teens years i become overweight and later on obese, my cholesterol levels skyrocket and from the age of 20 i became pre-diabetic

Since i started a low carb diet 3 years ago (48 yo now) not only i lost all that extra weght, but i'm no longer pre diabetic and the cholesterol levels went down to normal levels. most importantly, i feel and i'm as healthy as i've never felt in my whole life so far. and all this by eating mostly meat, fish, eggs, full fat dairy and a bit of vegetables/fruits

I know very well what these 45 years of eating low-fat high complex carbs actualy did to my health and how much i suffered all these years, and i'm not intend to return back to these eating habits, Ever!

> 45 years of eating low-fat high complex carbs

Can you quantify how many grams per day "low fat" was for you? Were you consuming eggs, fish, dairy or olive oil? Were you consuming any processed foods?

Main source of my fat intake was from olive oil which was about 2 tablespoons per day (in salads). dairy, in the form of low fat yogurt (1-2 times per week) and eggs (max 2-3 eggs) was always on very limited quantities during the week, With the exception of (small fishes) fish which was only consumed durring the weekends and not more than 3 times per month, no other meat or poultry was consumed in my home. basically the majority of weekdays we were eating dishes with legumes (lentils, kidney beans, chickpea) green beans, peas, olive-oil based vegetable dishes, potatoes, brown rice, whole grain breads, salads which always were present in the table, and of course plenty of fruits. i was basically eating as vegetarian my entire life.

No processed foods, fast foods or sweets were allowed on my home, as a family, we were always very health conscious people.

I agree that you won't get fat if you're limiting calories intake, I was just saying all dietary fat isn't always stored and carbs do have an impact in fat absorption.

I'm currently losing the stubborn fat I've had for all my life, just a few pounds I couldn't get rid of: only a low carb higher fat diet has finally worked for me (my BMI is normal).

Also I'm 47 (not the killer)

That was one of the earliest GI measurement studies, though the term GI was invented later.

The problem with GI-based (or GL which takes quantity into account) is that insulin levels at 2 hours isn’t a good proxy for health. One really needs to measure the integral of the insulin level over 24 hours or more (which would involve lots of starving subjects). The best proxy we have for the overall insulin response over time is just net carbs.

The rise of obesity in the US tracks very closely with the massive increase in cheese & chicken consumption. Sugar consumption actually plateaued years earlier.

So if i switch to tofu and beef, i won't get fat?

I doubt you’d be able to stomach enough tofu to gain weight eating that alone. You’d have to eat 10 cups a day just to hit a maintenance level of about 2000 calories.

It would be a lot easier on fatty cuts of beef at 330 calories for 100g.

The number of carbs your body can tolerate without being converted and stored as fat is highly variable and may come down to specific genetic factors that are largely inherited from one's racial makeup. There's no doubt that carbs and sugars make a higher percentage of our diets than historical, traditional diets.

The argument for keto/carnivorous diet does not depend on human adaptation to digesting starches. I understood it as:

* Evolution works at the level of genes, not individuals. It will select for short-term reproductive success at the expense of longevity or quality of life.

* All living things evolve to avoid being eaten (at least while they have the potential to reproduce or aid the reproduction of their kin).

* Animals primarily defend against being eaten by fleeing or fighting. These defenses can be 100% neutralized by killing the animal.

* Plants primarily defend against being eaten by producing toxins. These defenses can be neutralized by metabolism, but evolution has no incentive to select for 100% neutralization. If 100% neutralization of plant toxins is difficult then dying young with a lot of children might be a better strategy.

However, there are plants that defend with spines/shells/hiding underground, and plants that produce fruit to attract animals for seed distribution, all of which change the selection pressure for toxin production, and any food may be healthful or harmful purely as a spandrel (a byproduct of evolution of some other characteristic). There are examples of human populations maintaining good health on a wide variety of different diets, so as is usually the case with nutrition, there are no clear answers.

These arguments are all interesting but I think most relevant is that the best nutrition science we have to date shows that a proper plant based diet is optimal for health & longevity. The plants and animals we eat now are radically different than the ones we were exposed to through most of our evolution so paleo proponents are chasing a lost world.

Actually, the representation of the ancestral diet being primarily meat is incorrect - outside of a few examples where there just weren’t many plants available. Largely, humans ate what they happened upon. Meat was a scarce byproduct of another predators meal. Ie we ate what the big cats left behind.

Furthermore, the ultra refined and concentrated foods we now eat didn’t exist until very recently. The amount of sugar cane needed to produce a single can of soda isn’t something any human would sit down to eat.

Edit-changed are to ate

>we ate what the big cats left behind.

humans can hunt

Humans evolved during the ice age. There were no vegetables in large enough quantities to feed the human brain's massive growth over the past million years. Every single paleolithic cave art depicts animals and hunting techniques. Fossil evidence from millions of years ago show bone scrapes on zebra and reindeer bones in human caves. We evolved to hunt wooly mammoths twice the size of elephants for goodness sake. We decimated whole populations of megafauna. You would have to go back 4-6 million years ago to find scavenger ancestors.

Cooking is very likely the reason humans suddenly had access to far more calories to support a larger brain. The idea that an organ like the brain that feeds directly on glucose was supported by animal fat and protein just doesn’t hold up to serious scrutiny.

The brain is incidentally 60% fat. And all the glucose the brain requires can be synthesized from lactic acid. There are entire societies that live off of 99% meat. They live their entire lives with almost no vegetable intake whatsoever, and their brains develop and function perfectly normal. In contrast, consuming too much glucose can wreak all sorts of havoc on the brain, spurring excessive consumption, type 2 diabetes, and has been linked with Alzheimer's.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3577529/

https://www.nih.gov/news-events/news-releases/higher-brain-g...

https://www.alzheimersanddementia.com/article/S1552-5260(17)...

“Studies have shown that type 2 diabetes can be a risk factor for Alzheimer’s disease, vascular dementia and other types of dementia because cardiovascular problems associated with diabetes are also associated with dementia. These include:

Obesity Heart disease or family history of heart disease Impaired blood vessels Circulation problems High cholesterol High blood pressure Research has also proved that, similar to diabetes, glucose is not used properly in the brains of people with Alzheimer’s disease. ”

https://alzheimer.ca/en/Home/About-dementia/Alzheimer-s-dise...

I'm not sure of your point, because the parent comment mentioned animal fats and protein not being a primary food source for paleolithic humans and their ancestors (which is not what the fossil evidence shows AT ALL, we created spears and bows and arrows and various hunting strategies and tools that are well documented, for millions of years).

But with regards to your type 2 diabetes comment, type 2 diabetes is strongly associated with diet intake of excessive carbohydrates. https://www.ncbi.nlm.nih.gov/pubmed/30289048 https://www.ncbi.nlm.nih.gov/books/NBK499830/

You don't need carbs in your dietary intake. Your body can synthesize carbs from fat, just as it can synthesize fat from carbs.

There is no such clinical evidence. For example, the Sami of North Scandinavia have a 40% lower cancer rate than Swedish people do (who are pretty healthy by Western standards), despite getting the bulk of their calories from reindeer meat.

https://www.ncbi.nlm.nih.gov/m/pubmed/19186763/

The modern cow is not fundamentally different from the ancient Aurochs, or reindeer or bison that used to be consumed in large quantities. Sure cows have been selectively bred for docile behavior and varying amounts of lean and fattyness but genetically speaking they're extremely similar. Meat doesn't vary a great deal (which is why a lot of things taste like chicken).

Diet has relatively little influence on cancer. Diseases much more closely correlated with diet like diabetes and atherosclerosis are most effectively prevented with a plant based diet. Tribes like Inuit and Masai that eat mostly wild meats show advanced atherosclerosis at early ages and suffer from short lifespans.

Of course if you're eating supermarket meat then your diet is nothing like any kind of ancestral hunter.

I'd love to see your clinical research cited sources.

Meanwhile meat has not changed much at the cellular level in tens of millions of years. The only fundamental difference between modern meat and ancient meat is that our ancestors ate the whole animal, organs and all, and that's relatively rare in modern American diet.

Hmm I wonder if it is just an adaptation (humans mean their staples are about and it gets selected for) - or if it is something mutagenic. The fact it is the same enzyme makes me wonder.

The wild animals have the genes, the ones associated with humans have multiple copies of it.

Ah I missed that aspect in my skim. The consistency excess copies seems to imply that losing them entirely would be extra bad for survival enough so that redundant copies would boost offspring survival and dominate for human adjacents but not their more wild counterparts.

The domestification might even imply reverse order - that the ones with the starch genes were more likely to wind up in "dog" pools - say because they were attracted to starch and got closer to humans - and thus plenty of extra copies among their descendants. Meanwhile ones without were more likely to stay away and their descendants more likely to wind up in "wolf" pools where prevalence was lower.

The image of the wolf with the deer leg in its mouth and the German shepard with the pizza slice in its mouth is basically the entire tl;dr.

Good quality dog food is closer to deer leg then to pizza. Unfortunately there are too much low quality made of unbelievable junk pet food around compare to which even pizza sounds good and healthy. That prompts a lot health problems to the dogs.

But specially made dog food has only existed for 100 years or so. Dogs evolved eating humans' food scraps.

Yes, they are opportunistic carb eaters as a result of that evolution. The business of the low quality dog food abuses that.

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