AGE and Western Diet
Essential fatty acids (AGE) are two lipids that must necessarily be introduced with food. Specifically, it is:
- Linoleic acid (AL or LA), progenitor of the omega 6 fatty acids
- Alpha linolenic acid (AaL or ALA), progenitor of the omega 3 series.
These derived fatty acids have specific properties, both from a functional and structural point of view.
The fatty acids derived from LA and ALA are, respectively
- Omega 6: gamma linolenic acid (GLA), diomogamma linolenic acid (DGLA) and arachidonic acid (AA).
- Omega 3: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Arachidonic acid, although not really essential, can become it with a lack of linoleic acid or due to the inability to convert it to a metabolic level.
The most used foods in the western diet are richer in omega 6 than omega 3.
Despite the only fatty acids considered "really" essential are ALA and LA, research institutes suggest a minimum level of intake also for EPA and DHA (omega 3). By virtue of the great importance they have for human health, the safety contribution for EPA and DHA serves to prevent their deficiency.
The national reference body is the SINU - Italian Society of Human Nutrition - which established the Recommended Levels of Nutrients and Energy for the Italian population (LARN).
Omega 3 in food
As we have seen, the omega 3 group consists of: ALA (essential), DHA (derivative) and EPA (derivative).
Alpha linoleic acid is typical of vegetables, while eicosapentaenoic acid and docosahexaenoic acid are mainly found in foods of animal origin.
Alpha Linolenic Acid
ALA is very abundant in oil seeds and in the germ or embryo of other seeds (even starchy ones).
From oilseeds and germ (sometimes including bran) it is possible to obtain an even more concentrated oil than ALA (but also vitamin E, other vitamins, antioxidant minerals, etc.).
The table below summarizes some of the richest sources of alpha linolenic acid known today.
| Amount of Alpha Linolenic Acid Contained in the Oil Extracted from the Seeds of Certain Plants | |||
| Common name | Alternative Name | Linnea nomenclature | % ALA † |
| Chia | Salvia chia | Salvia hispanica | 64% |
| Kiwi | Chinese gooseberry | Actinidia chinensis | 62% |
| Perilla | Shiso | Perilla frutescens | 58% |
| Linen | / | Linum usitatissimum | 55% |
| Cranberry | / | Vaccinium vitis-idaea | 49% |
| Camellia | Camelina | Camelina sativa | 35-45% |
| Porcelain | Portulaca | Portulaca oleracea | 35% |
| Sea buckthorn | Sea berries | Hippophae rhamnoides L. | 32% |
| Hemp | Cannabis | Cannabis sativa | 20% |
| wot | English or Persian nuts | Juglans regia | 10.4% |
| Canola | Turnip from seed | Brassica napus | 10% |
| Soy | / | Glycine max | 8% |
| † average value | |||
Bibliography:
- Beare-Rogers (2001). "IUPAC Lexicon of Lipid Nutrition" (pdf). Archived (PDF) from the original on 12 February 2006. Retrieved 22 February 2006.
- Seed Oil Fatty Acids - SOFA Database Retrieval
- Li, Thomas SC (1999). "Sea buckthorn: New crop opportunity". Perspectives on new crops and new uses. Alexandria, VA: ASHS Press. pp. 335-337. Archived from the original on 22 September 2006. Retrieved 2006-10-28.
- "Omega-3 fatty acids". University of Maryland Medical Center.
Docosahexaenoic acid and Eicosapentaenoic acid in food
Good sources of EPA and DHA are:
- Mono and multicellular algae, and relative extraction oil.
- Krill of the cold waters in the northern hemisphere, and extraction oil.
- Blue fish, especially the species that inhabit cold salty or brackish waters: meat, liver, eggs and extraction oils.
In fish: cooked salmon (average of species) contains 500-1, 500 mg of docosahexaenoic acid and 300-1, 000 mg of eicosapentaenoic acid per 100 g of edible portion (salmon oil is even more concentrated).
Other fish considered a good source of docosahexaenoic acid are: salmon oil, tuna, mackerel, swordfish, anchovies, herring, sardines, caviar, bottarga, cod liver and oil, lanzardo, alaccia, needlefish, bonito, alletterato etc.
The benefits of fish consumption as a source of AGE can be overcome by brain damage caused by toxic pollutants such as heavy metals (mercury, etc.). For this there are security levels to be respected.
Algae and Krill
Algae and krill are also considered as fishery products or aquatic products.
They are not part of the food group but have an incomparable DHA and EPA content. For this reason they are considered excellent raw materials for supplements.
In algae: in the early 1980s NASA sponsored a search for the discovery of plant organisms that could be used as a food and oxygen source in space flights.
The researchers identified some species of algae rich in nutrients, from which it is possible to obtain an oil with high levels of DHA.
In krill: krill, a part of plankton made up of tiny crustaceans, has also begun to be used more recently.
Krill has a high concentration of DHA and EPA and low levels of pollutants.
However, as we will see later, its withdrawal is not considered completely sustainable.
Omega 6 In Foods
The omega 6 group is composed of: LA (essential), GLA (derivative), GGLA (derivative) and AA (derivative).
Most omega 6 is more abundant in plant foods than in animals (containing mainly arachidonic acid).
The richest meats of omega 6 are those of herbivorous or omnivorous animals fed with foods rich in these fatty acids.
You should read the article: Omega 6 in pork.
Linoleic Acid in Foods
The table below summarizes some of the richest sources of linoleic acid known today.
| Quantity of Linoleic Acid Contained in the Oil Extracted from: Seeds (or parts) of Certe Piante | |
| Common name | % LA † |
| Salicornia | 75% |
| Safflower | 74.6% |
| Evening primrose | 73% |
| Poppy | 70% |
| Grape (grapeseed) | 69.6% |
| Sunflower | 65.7% |
| Prickly Pear | 65% |
| Hemp | 54.3% |
| Corn | 59% |
| Wheat germ | 55% |
| Cotton | 54% |
| Soy | 51% |
| wot | 51% |
| Sesame | 45% |
| Rice bran | 39% |
| Argan | 37% |
| Pistachio | 32.7% |
| peanuts | 32% |
| Peach | 29% |
| Almond | 24% |
| Rapeseed and rape | 21% |
| Linen | 15% |
| olive | 10% |
| Palm tree | 10% |
| Cocoa (Butter) | 3% |
| Macadamia | 2% |
| Coconut | 2% |
| Quantity of Linoleic Acid Contained in Food of Animal Origin | |
| Chicken fat | 18-23% |
| Egg yolk | 16% |
| Lard | 10% |
| Butter | 2% |
| † average value | |
Bibliography:
- Oomah, B. Dave; Busson, Muriel; Godfrey, David V; Drover, John C. G (2002-01-01). "Characteristics of hemp (Cannabis sativa L.) seed oil". Food Chemistry. 76 (1): 33–43. doi: 10.1016 / S0308-8146 (01) 00245-X ..
- Oil, peanut, salad or cooking: search for peanut oil on //www.nal.usda.gov/fnic/foodcomp/search/.
- "Essential oil extracted from peach (Prunus persica) kernel and its physicochemical and antioxidant properties". LWT - Food Science and Technology. 44: 2032–2039. doi: 10.1016 / j.lwt.2011.05.012.
- MK Nutter, EE Lockhart and RS Harris (1943). "The chemical composition of depot fats in chickens and turkeys". Journal of the American Oil Chemists' Society. 20 (11): 231–234. doi: 10.1007 / BF02630880.
- "Olive Oil: Chemical Characteristics".
- Beltran; Del Rio, C; Sánchez, S; Martínez, L (2004). "Influence of Harvest Date and Crop Yield on the Fatty Acid Composition of Virgin Olive Oils from Cv. Picual" (PDF). J. Agric. Food Chem. 52 (11): 3434–3440. doi: 10.1021 / jf049894n. PMID 15161211.
Gamma Linolenic Acid and Diologamma Linolenic Acid in Foods
Gamma linolenic acid
It is mainly found in vegetable based oils. The plants that contain the most are: evening primrose ( Oenothera biennis ), black currant, borage and hemp.
GLA is also found in varying amounts in oat seeds, barley and spirulina algae.
Borage oil contains 20% of GLA, that of evening primrose varies from 8% to 10% and blackcurrant oil from 15 to 20%.
The common safflower oil ( Carthamus tinctorius ) does not naturally contain GLA, but since 2011 a genetically modified variety is available from which an oil is obtained which contains up to 40%.
Diologamma linolenic acid
It is the essential less present in foods and is mainly synthesized starting from the GLA.
It has been observed that the concentration of DGLA in the body increases significantly with high concentrations of ALA.
This correlation is apparently "strange", since the two lipids do not belong to the same group. However, omega 3 and omega 6 exploit the same enzymes.
As ALA increases, a saturation of the enzymes present in the common metabolic pathway is created, blocking the production of arachidonic acid (which, as we shall see, is the derivative that tends to be produced more significantly).
Arachidonic acid in foods
In the human diet, arachidonic acid (AA) is supplied mainly by meat.
An alternative source of AA recently discovered is the Mortierella alpina mushroom.
For some animals such as cats, AA is a totally essential fatty acid. This is because their organism is not capable of producing it alone.
Also for this reason they are obliged carnivores and must constantly consume the meat to reach satisfactory nutritional levels of arachidonic acid (vegetables contain little and felines do not have the enzymes necessary to digest them).
| Food sources of arachidonic acid, listed in decreasing order of percentages for their contribution to the intake, based on data from the "National Health and Nutrition Examination Survey 2005-2006" | ||
| First name | Assumption contribution% | Cumulative Contribution% |
| Chicken and various recipes | 26.9% | 26.9% |
| Eggs and dishes that contain them | 17.8% | 44.7% |
| Beef and various recipes | 7.3% | 52.0% |
| Sausage, bacon, ribs | 6.7% | 58.7% |
| Fish and dishes that contain them | 5.8% | 64.5% |
| Burgers | 4.6% | 69.1% |
| Cured meat | 3.3% | 72.4% |
| Pork meat and various recipes | 3.1% | 75.5% |
| Mexican dishes | 3.1% | 78.7% |
| Pizza | 2.8% | 81.5% |
| Turkey and various recipes | 2.7% | 84.2% |
| Pasta and dishes that contain it | 2.3% | 86.5% |
| Cereal based dessert | 2.0% | 88.5% |
- Taken from: //epi.grants.cancer.gov/diet/foodsources/fatty_acids/table4.html
Importance of AGEs
Functions
The functions of the AGEs are many and to deepen them I recommend reading the dedicated article.
In short, we could define that:
- Constitute cell membranes
- They regulate various metabolic parameters (arterial pressure, triglyceridemia, cholesterolemia, damage to chronic hyperglycemia, etc.)
- In the right balance, they improve the elasticity of the blood vessels, balance inflammation, regulate the fluidity of the plasma
- As a consequence of the two previous points, they can lower the cardiovascular risk (probably also for the brain)
- They are necessary for fetal development and growth
- They play a structural role in the formation of central and ocular nerve tissue
- They could protect the brain from degeneration with old age
- They help to reduce certain forms of depression etc.
Heart, Brain and Sight: Recent Developments
We have anticipated that AGEs can contribute to heart, brain and vision health.
In reality, the most involved molecules are omega 3s.
In particular, docosahexaenoic acid (DHA) represents:
- A structural element necessary for the formation and maintenance of nervous and ocular tissue.
- The direct precursor of type 3 anti-inflammatory prostaglandins (PG3) - although in the body it is derived from the EPA, which in turn could be synthesized by the ALA.
Circulation, Heart and Brain : omega 3 positively intervenes by decreasing arterial pressure in hypertensive and normal subjects.
Moreover, these molecules seem to induce a circulatory benefit and decrease the density, as well as the aggregation, of the blood.
Significantly lower triglycerides in plasma, especially when in excess, and some (but not all) studies indicate a mild positive effect on cholesterolemia.
All these features, combined with the anti-inflammatory ability, can decrease the probability of atherosclerosis, heart attack and stroke.
The research carried out in this regard favors the role of the diet and does not reveal a decisive importance of INDEPENDENT dietary supplementation from general nutrition.
However, in case of nutritional deficiency, it is likely to think that integration can play a positive role.
Degeneration of the Brain and Sight : the omega 3 seem to have a positive effect on the prevention of brain degeneration, protecting mental health from minor cognitive discomforts.
As far as the eyesight is concerned, in Canada good results have been observed in children's eye development thanks to the integration with seal oil.
In Europe this product is not allowed, but can be replaced with fish oil, seaweed or krill (rich in DHA).
No significant effects on the protection of sight in old age are known.
Quality and Sustainable Foods
Sustainability
Not all fishery products are able to cope with massive human withdrawal.
Some species are undergoing intensive fishing and this is especially true for: certain types of salmon, certain types of cod, bluefin tuna and bigeye tuna.
On the other hand, using krill-based feed (the basic link in the marine food chain), breeding can also be poorly sustainable.
Quality
Food quality is assessed in terms of the concentration of omega 3 active at the time of consumption.
This is lower in farmed products, for the use of feed, and in those badly preserved (even wild).
Another factor that affects quality is the presence of environmental pollutants. In most cases, this is NOT a modifiable factor.
The only tricks to follow are:
- Prefer small creatures.
- Limit the frequency of consumption to 3-4 times weekly.
Is it different for Integrators?
No, the same applies to supplements.
This is why there are two certification bodies that guarantee quality and sustainability.
IFOS ™ (International Fish Oil Standards): an independent body that analyzes and assesses the quality, contamination and stability of fish oil; if suitable, the evaluated products gain certification.
FOS (Friend of the Sea): is a non-governmental non-profit organization (NGO) that aims to preserve and protect the marine ecosystem; certifies the products obtained by means of fishing and aquaculture that comply with the criteria established by the FAO (Food and Agriculture Organization of the United Nations).
AGE and Inflammation
Every essential fatty acid performs fundamental tasks to maintain the health of the organism.
The interest in these metabolic products is justified by their ability to generate lipid mediators with pro- and anti-inflammatory action (prostaglandins, prostacyclines, thromboxanes, etc.).
The balance of these factors is very important; when pro-inflammatory factors prevail, the appearance of chronic degenerative inflammatory diseases and vice versa is favored.
It is hypothesized that these alterations, favored by the modern Western diet, are partially responsible for the increased incidence of so-called "wellness diseases".
The problems, for a change, begin when the normal body balance is disturbed by incorrect dietary habits.
With the improvement of socio-economic conditions, an increase in the intake of food of animal origin (rich in saturated fatty acids, cholesterol and AA) and of seed oils (in which the omega 6 are represented) has occurred.
At the same time, there was a decrease in the intake of omega 3 fatty acids, which are characteristic of fish caught.
The result is an alteration of the ideal ratio between omega 3 and omega 6 (1: 8 or 1: 4) until a relationship of about 20: 1 is obtained.
Excess of Omega 6
While the linolenic gamma, the linolenic diomogam and the eicosapentaenoic are immediate precursors of the prostaglandins with anti-inflammatory action (PGE - type 1 for GLA and DGLA and type 3 for EPA), some omega 6 play an opposite role (PGE type 2).
Arachidonic acid, in addition to being a fundamental component of cell membranes, determines the production of factors from which the whole "arachidonic acid cascade" derives. Simplifying the concept to the maximum:
" Omega 6 fats are precursors of both good substances (with anti-inflammatory activity) and bad ones (with proinflammatory activity), while omega 3s only give rise to eicosanoids that are positive for human health" .
Through the sequential activity of the elongases and desaturases, in the organism it is possible to obtain arachidonic acid from linoleic acid.
It is therefore logical to think that:
- Because of the pro-inflammatory role
- Considering the hypothetical tendency of the organism to favor its synthesis over other derivatives
- Assessing their significant presence in food
AA should be the least present AGE in the diet.
However, the most recent data show that in vivo this conversion is quite inefficient and that arachidonic acid levels are subject to a fine regulation that largely ignores the dietary intake of linoleic acid.
This gives more importance to the dietary intake of AA, however abundant in most Western diets.
For a long time it was assumed that arachidonic acid could be deficient in vegetarian and vegan diets. Not enough evidence was found to defend this hypothesis, even if the concern of a possible deficit in pregnancy and lactation is still the subject of reflection.
The enzymes responsible for the metabolism of essential fatty acids (desaturase and elongase) are common to both series (omega 3 and omega 6).
It follows that an excess of linoleic acid, typical of industrialized societies, can "slow down" the metabolism of the already small quantities of alpha linolenic acid (removing the enzyme Δ-6-desaturase).
The result could be an excessive production of proinflammatory factors in the face of a modest synthesis of substances with opposite activity.
It should be noted that this argument falls if we take foods or supplements which are already naturally rich in EPA and DHA (which represent the active metabolites of alpha linolenic acid and which as such do not require any enzymatic conversion).
Although the existence of a correlation between the content of certain essential fatty acids in foods and the reduction of some cardiovascular risk factors is now proven, exceeding the intake of omega 6 with omega-3s could increase the risk of developing chronic or autoimmune inflammatory diseases.
| FOOD (100 g) | ω-3 | ω-6 | ω-6: ω-3 | |||
| DHA (g) | EPA (g) | LNA (g) * | totals (g) | totals (g) | - | |
| Salmon oil | 18.232 | 13, 023 | 1, 061 | 35.311 | 1, 543 | 0.04: 1 |
| Cod liver oil | 10, 968 | 6, 898 | 0, 935 | 19.736 | 0, 935 | 0.05: 1 |
| Sardine oil | 10.656 | 10, 137 | 1, 327 | 24.093 | 2, 014 | 0.08: 1 |
| Caviar | 3, 801 | 2, 741 | 0, 017 | 6, 789 | 0.081 | 0.01: 1 |
| Mackerel | 1, 401 | 0, 898 | 0 | 2, 670 | 0.219 | 0.08: 1 |
| Coho salmon (wild) | 0.656 | 0, 429 | 0, 157 | 1, 474 | 0.206 | 0.14: 1 |
| Coho salmon (breeding) | 0.821 | 0, 385 | 0.075 | 1, 281 | 0.349 | 0.27: 1 |
| Anchovy or alice | 0, 911 | 0.538 | 0 | 1, 478 | 0, 097 | 0.07: 1 |
| Tuna | 0, 890 | 0.283 | 0 | 1, 298 | 0.053 | 0.04: 1 |
| Herring | 0.862 | 0.709 | 0, 103 | 1, 729 | 0, 130 | 0.08: 1 |
| Flax seed | 0 | 0 | 22.813 | 22.813 | 5, 911 | 0.26: 1 |
| Linseed oil | 0 | 0 | 53.304 | 53.304 | 12, 701 | 0.24: 1 |
| Walnut oil | 0 | 0 | 10, 400 | 10, 040 | 52.890 | 5.27: 1 |
| Dried walnuts | 0 | 0 | 8, 718 | 8, 718 | 33.717 | 3.87: 1 |
| Dried almonds | 0 | 0 | 0 | 0 | 12.648 | - |
| peanuts | 0 | 0 | 0, 170 | 0, 170 | 10.535 | 61.97: 1 |
| Dry salted pistachios | 0 | 0 | 0, 263 | 0, 263 | 13.636 | 51.85: 1 |
| Soy lecithin | 0 | 0 | 5, 135 | 5, 135 | 40.178 | 7.82: 1 |
| Olive oil | 0 | 0 | 0761 | 0.761 | 9, 763 | 12.83: 1 |
| * LNA = undifferentiated alpha-linolenic acid SOURCE: "essential fatty acids in food" has been prepared based on data provided by the US Department of Agriculture | ||||||
