From various reports lately, I don't have links handy but I've seen them shared here on HN, it is generally accepted that the nutritional value of the food is declining. This has been primarily attributed, from what I remember, to the condition of the soil. So, if we start producing everything in a greenhouse, won't that impact nutritional value as well.
- 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....
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.
(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).
https://www.livescience.com/7194-healthier-tomatoes-grown-se...
https://www.nationalgeographic.com/culture/article/organic-f...
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
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.
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.
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.
- 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.
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.
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.
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...
Roughly speaking, 100 extra calories a day means 1 added pound of fat per month.
"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/
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
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
Declining nutritional and increasing caloric value is probably one of many contributors to rising diabetes rates though.
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.
They aren’t talking about macronutrients like calorie content.
I was astonished when I first visited California how full of flavor the vegetables are. Just a whole different level.
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.
Wait. So where does the potassium go in my banana when I blend it up?!
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.