Healthy soil can be cultivated at scale, so if quality is the top priority that's not an issue. At least two major factors are at play:

- soil usually doesn't get time to recover and gets fertilized every year, nutrition can't build back up because of worsening chemical conditions due to monoculture and salts -> simply less nutrients are available to the plants with each cycle

- plants get bred to maximize yields, leading to first and foremost bigger plants, other factors (like nutritional value) are not priority #1

See https://www.scientificamerican.com/article/soil-depletion-an....

>Healthy soil can be cultivated at scale, so if quality is the top priority that's not an issue.

The larger issue is that consumers have no way of assessing the nutritional value of the items they're purchasing at the point of purchase. Cost is mediated on the basis of weight, which results in water-rich, nutrient poor, taste-poor produce. Saline injection into meat is another similar issue.

How do we make growing nutritional food profitable? Foods that can be sold on the basis of nutrient specific benefits, like Golden Rice or Vitamn D enriched milk can be marketed and sold on that basis, but comparing two beefsteak tomatoes grown in differing soils is not possible at present at the point of sale.

Typical food certification strategies, such as Organic, DOP, AOC, and other regional growth indicators don't seem to fit the bill. It's also unclear whether or not there is a market for inspections on the basis of nutritional value - from an organizational standpoint, it shouldn't be too difficult to have an inspector randomly audit crops and send samples to a lab to be HPLC or Mass Spec'd, but whether or not another certification mark changes buying patterns is unclear.

In Japan they have handheld machines that measure sugar content and acidity of fruits,[1] because fruits are used as gifts and you want to make sure it's a good one. How can we get fruit manufacturers to start sorting their fruit by sweetness?

They start around $1000 because it's a niche market. They appear to be infrared spectroscopy based which isn't too complicated, I was thinking about making an open source version. Should only be like $30 in parts. Would people buy this to test their produce before they buy?

[1] Called non destructive saccharimeters

Edit: actually it looks like they measure infrared polarization, not spectral absorption

Taste generally tracks with nutrition in non processed foods. If that could be validated, then we have a win win— and then needs new ways of marketing/branding higher taste options

I suspect that “if” will be more difficult than just measuring the vitamin and mineral content of random samples of the produce directly, but even if it isn’t, taste would rapidly be another flawed proxy: https://en.m.wikipedia.org/wiki/Goodhart%27s_law

(I’d argue that taste is already an example of Goodhart’s law, and that this is why fast food is popular despite being objectively bad).

That is interesting and relevant for me. A quick search only gave this, mainly about antioxidants. Do you know of more good literature?

https://www.nationalgeographic.com/culture/article/organic-f...

What about a handheld scanner using smell to distinguish good from bad. As long as food isn't bred to smell certain ways that can't be distinguished from good, it should work fine.

Saline-injected tomatoes... Coming soon!

It's a bit old and maybe they've learned more, but don't inject them with saline, just irrigate them with 10% sea water.

https://www.livescience.com/7194-healthier-tomatoes-grown-se...

Or tomatoes with a healthy corn syrup glaze.

>Healthy soil can be cultivated at scale, so if quality is the top priority that's not an issue.

Healthy soil can only be cultivated at scale with the aid of petrochemical byproduct fertilizers, which are not likely to be a long-term feature of our agricultural system.

The fertilizer that is derived from fossil fuels is ammonia (and nitrate made from ammonia by partial oxidation). More precisely, it's made from hydrogen derived from steam reforming of methane. But any source of hydrogen would do, including electrolysis with renewable electricity. There is nothing essential about fossil fuels for industrial agriculture.

It should also be noted that the total energy consumed in growing food in the US (ignoring sunlight absorbed by the plants) is less than the energy used to COOK food in the US. It's roughly 1% of the total energy used by the US.

The petrochemicals can be synthesised from CO2 and water with known methods. While nobody bothers with this right now, SpaceX basically has to make this economical as one sub-goal of their Mars colony, so I expect it in a decade or two, well before we run short of natural petroleum.

I’m more concerned with the long-term need to recover the potassium and phosphorus that washes into the ocean, which, despite still being theoretically solvable, is not currently economic enough to bother with even for the gold and uranium that’s also in the seawater.

Crop rotation doesn't improve the soil at scale?

It's never seemed to me that this whole "worse soil -> less nutrients" postulate makes sense on its face. There are, roughly, four categories of nutrients:

- organic macronutrients, which we'd definitely notice if they weren't there

- organic micronutrients, which are generally carbon compounds, but carbon doesn't come from soil, it comes from the air

- electrolytes, which do come from soil, but are always replenished with fertilizer, because plants need them too

- inorganic micronutrients, essentially transition metals plus selenium and iodine, which are present in utterly tiny quantities in food (you need about half a milligram of selenium per day), and could certainly be replaced by fertilizer if we even tried, or easily supplemented. Speculation: manure could work well.

- (extra) that wacky little devil cobalamin, which is both organic and a transition metal (cobalt), but doesn't come from plants anyway

Now, I could certainly see some kinds of farming techniques impacting the nutritional quality of plants. If you can increase the water content of your broccoli ceteris paribus, you sell more broccoli but the concentration of vitamin C goes down. I could also see impacts on the physical properties (compaction, grinding) of soil leading to worse long-term crop yields. But in order to convince me that soil changes are going to impact the vitamin C content of orange juice, when the constituents of vitamin C come entirely from water and air, you need pretty strong evidence.

Fairly easy answer to this. If I took a orange tree and only fed it water and air. Would it produce oranges with vitamin c? The answer. No. Because the plant requires far more than just water and air in order to run all the other systems within itself to make that vitamin c production happen. If you take away certain elements in your soil, your going to affect aspects of that plants health that in turn affect its production capacity. If you provide most nutrients for a plant sure it will produce fruit. Will that fruit be as good as fruit from a plant with all the nutrients? No, no it will not.

As far as I remember from the last discussion on the matter the effect is overblown. Nutrient decline for modern techniques and soils is around 7% from baseline.

Is that 7% one-time or 7% compounding? The latter has a pretty deleterious effect over time...

One-time, or rather total decrease over time. I'll see if I can dig up a source.

EDIT - old but seems like a decent review: https://www.scientificamerican.com/article/soil-depletion-an...

To recap, there are declines up to 30% in certain nutrients for certain vegetables. This seems to be mostly down to farmers choosing varietals that grow faster and handle transport better over time.

Personally it's still my opinion that this is no big deal. Even if, say, oranges are lower-quality than a century ago, they are now cheap, easy to obtain and available year-round. You might have to eat four oranges instead of one for whatever nutrient allotment you desire but...that's a heck of a lot easier than it was for our grandparents. As long as people aren't eating mainly combinations of flour and oil, they'll be fine.

That article is quite odd. It does not misrepresent the studies that it references. This [1][2] is the primary one, the 2004 paper from Davis et al. But the paper makes it very clear, as does the article in its discussion of the paper, that the main culprit is believed to largely come down to breed selection. It does consider soil quality and ultimately dismisses it as the main variable:

"The apparent overall decreases for some nutrients are interesting and potentially of concern, but like Mayer and Johnson, we urge caution about their interpretation. Mineral decreases are popularly predicted for, or blamed on, mineral deficiencies in soil and fertilizer [5], but without sufficient consideration of contrary evidence and other possibilities.

[Snipping various scientific evidence they mention]

Factors other than soil mineral concentrations seem to have primary control of food mineral contents for the foods and minerals studied here. (The minerals I and Se are well known exceptions to this rule.) In the case of Fe, depletion is never an issue; instead, the issue is the ability of the plant to acquire the Fe that it needs. The fraction of soluble Fe in soils may be only about 10^-13 of total soil Fe."

In general, there seems to be an inverse relationship between nutrition and yield: higher nutrition + lower yield, or lower nutrition + higher yield. It's not hard to guess which we pick. But then the article (similar to another published in Discover magazine) focuses entirely and exclusively on soil quality as the primary issue.

[1] - https://pubmed.ncbi.nlm.nih.gov/15637215/

[2] (SciHubbed) - https://sci-hub.st/https://pubmed.ncbi.nlm.nih.gov/15637215/

Eating more food eventually means obesity issues.

I don’t think we are at the point where it’s either nutritional deficiency or obesity, but that seems like the ultimate risk here.

My man, no one is becoming fat because they eat too many oranges for the vitamin C.

I'd strongly argue against that. A lot of people somewhat mindlessly consumer fruit and fruit juice 'because it's good for you' which is a reasonable proxy for high levels of things like Vitamin C.

And fruit is in general very good for you, but of course it's also quite high in calories. A single navel orange has upwards of 70 calories [1]. So 2 oranges ~= 1 can of Coke. And fruit juice is even worse. A plain cup of orange juice has 112 calories. If somebody buys some form of it that's been sweetened or otherwise mixed, you can easily end up with your OJ having more calories than a Coke.

People can easily speed their way to obesity by eating things that they think (and are) 'good for them' without really appreciating how many calories they're consuming. Similar to how things like vegans can easily end up consuming way too many calories when doing things like using peanuts as a protein source. An 80kg man needs around 64 grams of protein a day. 64 grams of protein from peanuts (to take things to an extreme) would be more than 1400 calories. And that's from raw unseasoned peanuts, which have the best nutrition:calorie ratio.

[1] - https://www.verywellfit.com/oranges-nutrition-facts-calories...

All other things being equal, eating more oranges (even salad) can very much result in being fatter.

Roughly speaking, 100 extra calories a day means 1 added pound of fat per month.

Yet, give it 100 years and see what’s going on.

I've heard it's highly dependent on the nutrient

BBC Radio investigated it in 2019: https://www.bbc.co.uk/programmes/w3csz3ry

The next year they did the same for soil degradation, and found it a similarly complex topic: https://www.bbc.co.uk/programmes/p08dx986

Both are <10 minute MP3 downloads

was the baseline also under monoculture?

If I remember correctly, yes. The comparison was made between normally grown vegetables from the 60s and now.

It's the extra CO2 in the air that makes the nutritional value decline. Plants grow larger with more CO2, but the nutritional content stays the same.

>This has been primarily attributed, from what I remember, to the condition of the soil

Perhaps not

https://www.rothamsted.ac.uk/articles/fact-or-fake-news-our-...

Besides, the measured reduction in nutritional content is a fraction compared to our yield increases over the years.

If you:

live in a developed country

have a reasonable income

live near a supermarket

and eat a varied diet,

then you most likely do not have any nutrient deficiencies

How do we square declining nutritional value with people living longer __and__ spending more years in a healthy state?

The biggest factor is likely just reduced infant mortality. Today when we say today that somebody has a life expectancy of e.g. 80 years, then it does mean you can expect people to start dropping of various causes around that age, give or take a bit because infant mortality is approaching zero.

In the past infant mortality was extremely high, with frail infants invariably ending up as dead infants. And so in the past if you looked at somebody who was 15 years old, it's very likely that he'd live to roughly the same age as somebody today. It's not like he'd just start dropping around age 40. It was more a mix of people living to 5 years old and people living to 80 years old. Take the founding fathers as a random example:

==========

John Adams - 91

Benjamin Franklin - 84

Alexander Hamilton - 49 (killed in a duel)

John Jay - 84

Thomas Jefferson - 83

James Madison - 85

George Washington - 67 (speculation he may have been killed by a common medical practice of the time - bloodletting)

==========

Interestingly enough this goes all the way back to Ancient Greek times where you may be surprised upon some brief research to see how long any Greek you know of likely lived to, in spite of having effectively zero medical knowledge and hygienic practices such as shared butt sponges (in lieu of toilet paper) at the various public toilets. The reason I more contemporary samples is because one can reasonably argue a survivorship bias in the Ancient Greeks. Would you know of Philosophartes today if he had died when he was 40? Probably, but I can't prove that. The founding fathers though were all relatively young when their names were inscribed into history.

So how do you explain that life expectancy at for instance 50 years old keep increasing? For instance in my country (CH) life expectancy at 50 years old for a man was 26y in 1980, 29.5y in 2000 and 32.5y in 2020. People keep saying that infant mortality is the explanation but this is only valide for life expectancy at birth. Life expectancy at all ages as been increasing.

Infant life expectancy describes the huge changes. We went from life expectancies in the 30s not that long ago, to life expectancies in the 70s, largely due to it. The smaller changes since are going to be from many reasons that will also often vary heavily between regions. Unfortunately I lack the knowledge to even begin to intelligently speculate about the reasons for China's improvements.

Antibiotics, vaccines, improved cancer treatment, and smoking bans have all done wonders.

Declining nutritional and increasing caloric value is probably one of many contributors to rising diabetes rates though.

No great mystery, less nutritional value per unit produce just means you have to eat more produce, it doesn't force you to be malnourished.

More doesn’t account for nutritional deficiency. If zinc is missing in a foodstuff, it requires supplementing with other foodstuffs, not eating more of the same foodstuffs.

Nutritional drops have been minimal (see other comment references 7%) and considering most Americans don’t even get the minimal servicing of fruits and vegetables I’d worry about that first.

"nutritional value" isn't a scientific term so you're going to have to define what you mean by that. Crops have been in fact getting more and more energy dense over time.

Density of various micronutrients per lb.

They aren’t talking about macronutrients like calorie content.

And with nutritional value, the taste.

I was astonished when I first visited California how full of flavor the vegetables are. Just a whole different level.

In the extreme case, this is something we’ll need to figure out for space exploration too. Hopefully people are working on it!

It's not just space, global warming could lead to a complete ecosystem collapse (think Mars). We may need to move everything into climate controlled environments.

Nutritional decline of actual fruit and vegetables or the nutritional decline of food as is consumed by humans?

I don't think we are seeing the former while the later is how you use the former for the production of actual food that is consumed. Converting fruits into smoothies makes them retain mostly only sugar, while vegetables (and fruits) under thermal treatment loose a lot of nutrients like fiber and vitamins.

> Converting fruits into smoothies makes them retain mostly only sugar.

Wait. So where does the potassium go in my banana when I blend it up?!

The blender chops up potassium atoms into sucrose molecules via Nutri Bullet fission

That's why the blender motor gets hot when you run it. It's fissioning.

If it's fissioning then why do I have to plug in my blender? There's something they're not telling us.

Mostly for 5g signals.

I always learn so much on HN!

I think the parent might be slightly off the mark or simply is lacking detail.

One concern in nutrition is separating fruit juice from fruit pulp. You probably wouldn't eat three oranges in a sitting without feeling full but you can certainly drink three oranges' juice. That's the number of fruit needed to make a cup of orange juice.

If you're adding juice to a kale smoothy it's more complicated. At a certain point of extortion, refinement, and concentration that juice can become a proxy for simply adding cane sugar.

If you're blending your fruit and eating the pulp then there is no change.

Who can't eat 3 oranges without feeling full? How big are these oranges?

Is that true regarding smoothies? I mean, I get it for juicers, you lose the fiber. But smoothies?