The most nutritious food
Bivalves such as scallops and oysters are arguably the most reliably nutritious foods. I eat them every week
This is a summary of the most bioavailable nutrient-dense foods I’ve found. The terms macronutrient (protein, fat, carbohydrate) and micronutrient (everything else of use in real food) are used throughout.
Four investigations of amino acids and micronutrients (Table 1) are described as follows:
Food and Agriculture Organisation indispensable amino acids [1,2]
Priority micronutrients [3]
Commonly lacking micronutrients [4]
Micronutrients in decline [5]
Table 1: Amino acids, minerals, and vitamins described in this report
Indispensable amino acids
This is a new paper from scientists at the University of Illinois about sources of protein and muscle building associated with age-related muscle loss [1]. It ranks several sources of amino acids (protein building blocks) according to a UN Food and Agriculture Organisation (FAO) approved method. I added to that list using Wikipedia [2] and ended up with 53 records comprised of 19 animal-sources and 34 plant-sourced whole and processed foods.
The protein availability scores for the top animal-based and plant-based foods are listed in Tables 2 and 3, respectively. Note that the higher the protein availability number, the more likely we are to absorb the amino acids.
Table 2: Top 10 animal-based bioavailable sources of protein. Higher scores represent greater bioavailability
Table 3: Top 10 plant-based bioavailable sources of protein. Higher scores represent greater bioavailability
The obvious thing to note is that the top nine most bioavailable foods are animal-based. Only soy flour and potato come close to matching the lowest ranked animal-based foods.
The same paper [1] also presented data showing a measure of amino acid synthesis in muscle after a meal. They express the data as a fold-increase over pre-meal. I reproduce this data in Table 4. Note that I combined duplicate entries for whey and beef, show their data as ranges, and list according to the higher value.
What we see here is that ingesting whey (for example) produces two- to three-times more muscle synthesis than was measured before a meal. This contrasts with wheat and soy products which resulted in only 1.4 times increase post meal. Overall, of the 10 types of food tested, the animal-based comprise the top eight followed by wheat and soy products.
Table 4: Production of muscle protein from a range of animal- and plant-based foods
Thus, however you look at the data [1], protein from animal-based food is more likely to be absorbed by our body and then more likely to be involved in creating muscle than protein from plant-based foods.
Priority micronutrients
I previously discussed these in an article about food nutrient density [3]. Scientists from UC Davis and the Global Alliance for Improved Nutrition, Geneva looked at six priority minerals and vitamins and calculated how much of certain foods would need to be eaten to get enough of those nutrients.
I ranked the foods showing how little of highly nutrient-dense foods are needed compared to how much of less nutrient dense foods are needed to get enough of the six priority nutrients. I’ve restricted the list to the 10 most nutrient-dense foods in Figure 1.
As can be seen, liver is the most nutrient-dense and needs only 3g to get the proscribed amount of micronutrients. Next is small dried fish (22g) and the top10 is completed with dark green leafy vegetables (239g). Another way to consider this data is that liver contains 80x more bioavailable nutrition (represented by the six micronutrients) than dark green leafy vegetables.
Figure 1: Weight (g) of food type required to provide an average 1/3 of recommended intakes of “priority micronutrients”
The most commonly lacking micronutrients
I’ve previously highlighted the presentation by Alice Stanton, Professor, Royal College of Surgeons in Ireland and Director Human Health, Devenish Nutrition to a summit hosted by Teagasc, the Irish Agriculture and Food Development Authority entitled “The Importance of Transparent Evidence-Based Health Metrics” [4].
Professor Stanton focused on what she described as the most commonly lacking nutrients, namely iron, zinc, Vitamin D, and calcium and makes the following points:
18 of the 20 most bioavailable sources of those vitamins come from animal-based food
Human vitamin and mineral deficiencies are more likely in countries in which the percentage of calories from animal-based foods is low
Childhood stunting is highest in those countries where meat, milk, and seafood consumption is low, and results in:
Small stature
Less well-developed brains
Less able to engage in education
Less academic achievement
Less career success
Fewer opportunities in life
Less able to support families
A vicious cycle of poor nutrition in the next generation
In sub-Saharan Africa and SE Asia, more than 30% of children are stunted
Too little animal-sourced food is also not good for the elderly and leads to shorter lives
Nutrients in decline
I described how Scientists in the UK and Australia summarized data from the UK, Australia, America, and Finland on changes in eight minerals found in fruit, vegetables and various meat and dairy sources [5].
The results for fruit and vegetables for the period 1940-2019 show that, in the UK, the levels of sodium, iron, zinc, and magnesium decreased by 52%, 50%, 49%, and 10% respectively (Table 5).
The UK meat and dairy product data collected for the period 1940 – 2002 (Table 5) show averaged declines in micronutrients from large at 52% (iron), through a mid-range group at 19% to 24% (potassium, calcium, magnesium, phosphorous, and zinc) to small at 4% (sodium).
Table 5: Changes in micronutrient concentrations in Europe, USA and Australia. Green = increase, Amber = no change, Red = decline
“…we have relatively limited ability, compared to our great ape ancestors and ruminant animals, to ferment plants and extract their full complement of nutrition.”
Food Matrix
The food matrix [6], in my opinion, is the most important, and yet least understood, aspect of human nutrition. In the context of this presentation it probably explains the relative benefits of animal- versus plant-based foods. To state the case simply, the complex three-dimensional structures of fibre in plant cells walls limit the bioavailability of plant-based foods to humans. This is because we have relatively limited ability, compared to our great ape ancestors and ruminant animals, to ferment plants and extract their full complement of nutrition.
I will in future posts return to the subject of the food matrix because I believe it has profound effects on the uptake and metabolism of nutrients by our body and our microbiome.
Until then, I like a quote from reference six. The author speaks only to the importance to human metabolism but I think his words speak equally to that of our microbiome:
“Foods have complex structures which can be modified during processing, storage, ingestion and digestion. They interact with each other within the food system and within the gastrointestinal tract during digestion. It should be appreciated that all foods ultimately come from living organisms, where the components interact to support specific biological roles. Fibrous muscle structures are involved in animal movement, dense fat structures in energy storage in animals; fleshy starch-rich structures in energy storage in plants; encapsulated embryos in grains are involved in plant reproduction, the complex fluid, milk, is a biological fluid for nourishment of the newborn. These complex biological structures contain nutrients which provide sustenance for humans, but the bioaccessability of the nutrients is highly dependent upon the structures themselves”
Summary
The data I’ve described here show that a range of amino acids and micronutrients from animal-based foods are more available to humans and more likely to be used metabolically than is the case for plant-based foods. Matrix effects explain why animal-based foods appear more nutritious for our body.
Population studies remind me how important sources of readily available are to people in the poorer parts of the world. This isn’t a surprise given what is evident from examining the links between nutrition and the health of our agricultural ancestors and Victorian predecessors.
We should never lose sight of the nutritional benefit to and of our microbiome in the great three-way interaction of food-body-microbiome. The nutritional principles highlighted here for our body apply equally to our microbiome.
Finally, our knowledge of the food matrix, human metabolism and the interaction with our microbiome is still woefully inadequate. Under the circumstances, I try to apply the broad principles in play. The studies I’ve highlighted here point me in the right direction and reminded me why I strive for optimum nutrition using animal- and plant-based nutrient-dense foods. I try to remember how we evolved and to feed my body and microbiome to the best of my ability.
References
Burd NA, Beals JW, Martinez IG, Salvador AF, Skinner SK. Food-First Approach to Enhance the Regulation of Post-exercise Skeletal Muscle Protein Synthesis and Remodeling. Sports Med. 2019 Feb;49(Suppl 1):59-68. doi: 10.1007/s40279-018-1009-y. PMID: 30671904; PMCID: PMC6445816
Wikipedia – Digestible Indispensible Amino Acid Score https://en.wikipedia.org/wiki/Digestible_Indispensable_Amino_Acid_Score
Beal T, Ortenzi F. Priority Micronutrient Density in Foods. Front Nutr. 2022 Mar 7;9:806566. doi: 10.3389/fnut.2022.806566. Erratum in: Front Nutr. 2022 Apr 25;9:908592. PMID: 35321287; PMCID: PMC8936507
https://www.eatingmyselfhealthy.co.uk/articles/how-much-red-meat
https://www.eatingmyselfhealthy.co.uk/articles/declining-nutrition-in-food
Moughan PJ. Holistic properties of foods: a changing paradigm in human nutrition. J Sci Food Agric. 2020 Nov;100(14):5056-5063. doi: 10.1002/jsfa.8997. Epub 2018 Apr 30. PMID: 29532937
Appendix
Digestible Indispensable Amino Acid Score (DIAAS)
DIAAS is a protein quality measurement method used by the UN Food and Agriculture Organization (FAO). The method employs animal models (pig and rat) to measure amino acid digestibility at the end of the small intestine. That measure is used to represent protein's contribution to human amino acid requirements.