I found this interesting
youtu.be/cnTHgRJi0mM?si=ApW...
From chatgpt
Fats and oils are composed of fatty acids, which can vary in the length of their carbon chains. The length of the carbon chain influences the properties, metabolism, and health effects of the fat. Fatty acids are generally categorized as short-chain, medium-chain, long-chain, and very-long-chain, depending on the number of carbon atoms they contain.
Here’s a breakdown of the different carbon chain lengths found in various fats and oils, along with their common names:
Short-Chain Fatty Acids (SCFAs): 2-6 Carbon Atoms
Acetic acid (2 carbons): Found in vinegar and produced by gut bacteria during fiber fermentation.
Propionic acid (3 carbons): Found in dairy products and produced by gut bacteria.
Butyric acid (4 carbons): Found in butter and animal fats; also produced in the gut during fiber digestion.
Medium-Chain Fatty Acids (MCFAs): 6-12 Carbon Atoms
Caproic acid (6 carbons): Found in goat milk, butterfat, and coconut oil.
Caprylic acid (8 carbons): Found in coconut oil, palm kernel oil, and goat milk.
Capric acid (10 carbons): Found in coconut oil, palm kernel oil, and goat milk.
Lauric acid (12 carbons): Found in coconut oil (nearly 50%) and palm kernel oil; also present in breast milk and cow’s milk.
Long-Chain Fatty Acids (LCFAs): 13-21 Carbon Atoms
Myristic acid (14 carbons): Found in coconut oil, palm kernel oil, butter, and animal fats.
Palmitic acid (16 carbons): Found in palm oil, butter, lard, and meat products.
Stearic acid (18 carbons): Found in beef tallow, cocoa butter, and lard.
Oleic acid (18 carbons, monounsaturated): Found in olive oil, avocado oil, and canola oil.
Linoleic acid (18 carbons, polyunsaturated omega-6): Found in vegetable oils like sunflower, safflower, and corn oils.
Alpha-linolenic acid (ALA) (18 carbons, polyunsaturated omega-3): Found in flaxseed oil, chia seeds, walnuts, and canola oil.
Very Long-Chain Fatty Acids (VLCFAs): 22+ Carbon Atoms
Arachidic acid (20 carbons): Found in peanut oil and corn oil.
Eicosapentaenoic acid (EPA) (20 carbons, polyunsaturated omega-3): Found in fatty fish like salmon, mackerel, and sardines.
Docosanoic acid (Behenic acid) (22 carbons): Found in peanut oil and rapeseed oil.
Docosahexaenoic acid (DHA) (22 carbons, polyunsaturated omega-3): Found in fatty fish and algae oils.
Lignoceric acid (24 carbons): Found in peanut oil and certain animal fats.
Summary Table: Carbon Chain Length and Common Fatty Acids
Carbon Atoms Fatty Acid Name Common Sources
2 Acetic acid Vinegar, gut fermentation
4 Butyric acid Butter, gut fermentation
6 Caproic acid Coconut oil, goat milk
8 Caprylic acid Coconut oil, palm kernel oil
10 Capric acid Coconut oil, palm kernel oil
12 Lauric acid Coconut oil, breast milk
14 Myristic acid Coconut oil, butter
16 Palmitic acid Palm oil, butter, meat fats
18 Stearic acid Beef tallow, cocoa butter
18 Oleic acid (omega-9) Olive oil, avocado oil, nuts
18 Linoleic acid (omega-6) Vegetable oils (sunflower, safflower)
18 Alpha-linolenic (ALA) Flaxseed, chia seeds, walnuts
20 Arachidic acid Peanut oil, corn oil
20 Eicosapentaenoic (EPA) Fatty fish (salmon, sardines)
22 Behenic acid Peanut oil, rapeseed oil
22 Docosahexaenoic (DHA) Fatty fish, algae oil
24 Lignoceric acid Peanut oil, animal fats
Notes:
Saturated fatty acids: These fatty acids are typically found in animal fats, butter, and coconut oil, and they tend to be solid at room temperature.
Unsaturated fatty acids: These include monounsaturated and polyunsaturated fatty acids, which are often found in plant oils and fish oils and are liquid at room temperature.
This range of fatty acids, categorized by their carbon length, provides various nutritional benefits and characteristics, influencing how they are absorbed and used by the body.
Why are the odd numbers missing?
The absence of odd-numbered fatty acids (such as 5, 7, 9, 11, 13, etc.) in common fats and oils is due to the way fatty acids are synthesized in nature. Here's why:
1. Fatty Acid Synthesis in Nature:
Fatty acids are primarily synthesized through a process called fatty acid biosynthesis. This process occurs in both plants and animals and involves adding two-carbon units at a time, starting with acetyl-CoA, which is a two-carbon molecule. This stepwise addition of two-carbon units results in fatty acids that typically have even numbers of carbon atoms (e.g., 12, 14, 16, 18, 20 carbons).
Even-numbered fatty acids dominate because the synthesis pathway is highly efficient with two-carbon units, leading to fatty acids with carbon lengths of 4, 6, 8, 10, and so on.
2. Odd-Numbered Fatty Acids Are Less Common:
Odd-numbered fatty acids do exist, but they are much less common in nature and usually found in small quantities.
These are typically produced via alternative metabolic pathways. For instance, some odd-chain fatty acids are synthesized by certain bacteria and can be found in trace amounts in dairy products and ruminant fats (e.g., butter, milk, and cheese).
Propionyl-CoA (a three-carbon molecule) can be a starting point in the synthesis of odd-numbered fatty acids. However, this process is less efficient and less common than the two-carbon addition method that leads to even-numbered chains.
3. Sources of Odd-Chain Fatty Acids:
Although rare, odd-numbered fatty acids can be found in certain foods:
Pentadecanoic acid (15 carbons) and heptadecanoic acid (17 carbons) are odd-numbered fatty acids that can be found in small amounts in dairy fat and the meat of ruminants (like cows and sheep).
These odd-chain fatty acids are also sometimes found in marine organisms and certain bacterial or microbial sources.
4. Function and Importance of Odd-Chain Fatty Acids:
Though less common, odd-chain fatty acids, especially pentadecanoic acid (C15) and heptadecanoic acid (C17), are gaining interest in nutrition science. Recent studies suggest they may have beneficial effects on metabolic health, such as improving insulin sensitivity and reducing inflammation, but these findings are still being researched.
Summary of Key Points:
Even-numbered fatty acids dominate because of the biosynthetic process that adds two-carbon units during fatty acid synthesis.
Odd-numbered fatty acids do exist but are rare and typically arise from alternative pathways involving bacterial metabolism or specific animal tissues.
Foods like dairy and ruminant meat contain small amounts of odd-chain fatty acids, such as pentadecanoic and heptadecanoic acids.
This biochemical explanation accounts for the scarcity of odd-chain fatty acids in common fats and oils and their predominant presence in specialized or microbial sources.
How much should we be eating?
The optimal intake of C15:0 (pentadecanoic acid) is still an emerging area of research, and there is no formal dietary guideline or established recommended daily intake for it yet. However, some recent studies and emerging science have suggested potential intake ranges based on observed health benefits in populations with higher circulating levels of C15:0.
Current Research Insights:
Association with Health Benefits:
Studies observing populations with higher levels of C15:0 in their blood (through the consumption of whole-fat dairy and ruminant meats) suggest that these people may have better metabolic health, improved insulin sensitivity, and lower risks of heart disease and inflammation.
Based on these observations, some researchers have proposed that an optimal daily intake could be around 20-50 mg per day of C15:0 from natural sources like dairy and meat.
Practical Dietary Sources: To get approximately 20-50 mg of C15:0 per day from food, you might consume:
1-2 servings of full-fat dairy (e.g., a glass of whole milk, a serving of butter, or cheese).
1-2 servings of grass-fed ruminant meat (e.g., beef or lamb).
For example:
Whole milk (1 cup) contains around 3-4 mg of C15:0.
Butter (1 tablespoon) provides around 1-2 mg.
Grass-fed beef (3 oz) may contain 20-25 mg of C15:0.
Supplementation:
Some companies are beginning to offer C15:0 supplements based on the idea that increasing levels of this fatty acid could offer health benefits, particularly for those who do not consume much dairy or ruminant meats. These supplements typically provide a controlled dosage of around 100-200 mg of C15:0 per day.
Moderation in Diet:
While C15:0 appears to have potential health benefits, it’s important to consume it as part of a balanced diet rich in whole, unprocessed foods. Over-consuming high-fat dairy or meats may carry other risks (such as excess calories, saturated fat, and cholesterol), so balancing your intake of C15:0 with a diet that includes plenty of vegetables, fruits, and whole grains is crucial.
Final Thoughts:
While no official guidelines exist yet for C15:0 intake, aiming for around 20-50 mg per day through natural food sources like full-fat dairy and grass-fed meat seems like a reasonable target based on current research. Keep an eye on this evolving area of nutritional science for more concrete recommendations in the future.