- Excerpt
Like vitamins and minerals, poly-unsaturated fatty acids (PUFAs ) such as linoleic acid and the Omega-3’s form an essential part of the human diet. Some of these PUFA's are of vegetable, others are of animal origin. Vegetable oils mainly provide linoleic acid (LA) and relatively small amounts of alpha-linolenic acid (ALA), which is one of the omega-3's. These cooking oils are made from sources such as soybeans, sunflower seeds, linseeds, peanuts, etc. The important Omega-3's are of animal origin. Cold-water fish, oysters, clams and lobsters provide good amounts of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). You should be aware of the fact that you can only reap the benefits of PUFAs when your diet provides all of them. In this regard, the problem is that in the Western world we over-consume plant-based PUFA's (providing mainly LA) and under-consume Omega-3's from animal sources. This leads to an excessive intake of LA, which has dire consequences for human health.
Why is an excess of Linoleic Acid harmful?
The harmful effects of over-consumption and excessive intake of linoleic acid were described by Dr. Joe Mercola and Christopher R. D'Adamo in Linoleic Acid: A Narrative Review of the Effects of Increased Intake in the Standard American Diet and Associations with Chronic Disease, an article published in the scientific journal Nutrients. (i) "While LA is considered to be an essential fatty acid and supports health when consumed in modest amounts", the authors warn that an excessive intake of LA leads to the formation of oxidized linoleic acid metabolites. These so called OXLAMs "likely contribute to many chronic diseases that became an epidemic in the 20th century, and whose prevalence continues to increase". OXLAMs "have been associated with various illnesses, including cardiovascular disease, cancer, and Alzheimer’s disease, among others".
Lipid peroxidation and disease
That OXLAMs can cause so many seemingly unrelated diseases stems from the fact that they damage fundamental structures, including DNA, mitochondria, cell membranes, proteins, and stem cells. This is how the over-consumption of processed seed oils can lead to abnormal levels of inflammation and cardiovascular damage. In addition, so Mercola and D'Adamo, OXLAMs "deplete glutathione levels in the liver, thus, lowering antioxidant defenses, impairing immune function, and increasing mortality. Furthermore, oxidized species lead to fat cell insulin resistance [disturbed fat metabolism causing visceral fat deposits], as well as the inhibition of cardiolipin, an important fat located in the inner membrane of mitochondria." Impaired activity of the mitochondria ‒ the “compartments” in the cells that produce energy ‒ has been associated with cancer and neurological, cardiovascular, and metabolic disorders.
LA also harms gut bacteria and intestinal health
In addition to the problems caused by OXLAMs, a high-fat diet rich in LA may also impair the microbiome (bacteria) in your gut and lead to intestinal disorders. In n-6 High Fat Diet Induces Gut Microbiome Dysbiosis and Colonic Inflammation, an article published in the Journal of Molecular Science, O.I. Selmin and co-authors report that “diets rich in n-6 fatty acids [LA] increase the risk of intestinal inflammation, colon cancer, and obesity”. An excess of LA causes a shift from healthy to pathogenic bacteria in the gut microbiome. This effect “plays an important role in the development of Irritable Bowel Diseases” (IBD), which, in the U.S. alone afflict some 1.4 million adults. The authors attribute the increasing incidence of IBD to a marked increase in intake of vegetable oils rich in LA. (ii)
Moderating the consumption of LA
Over-consumption of LA isn't necessarily caused by one's individual dietary choices or preferences. Mercola and D'Adamo point out that dietary LA is practically unavoidable since the majority of processed foods, such as potato chips, cookies, pastries, and bread, contain one or more forms of industrially processed seed oils. "Less obvious and stealthy sources include most food establishments (e.g., restaurants), as they primarily use processed seed oils to prepare their food.” Lowering dietary LA intake by avoiding processed foods, LA-enriched food (margarine) and reducing the amount of vegetable oils used in cooking “can help reduce the production and accumulation of OXLAMs implicated in chronic diseases." But because it can take up to 2 years before LA is broken down in the body, "the damage can be far more persistent than other dietary factors, and the impact of reducing excessive LA intake takes time."
Oxidative stress is the real problem
Over-consumption of LA-rich vegetable oils may contribute to minor and major intestinal disturbances. This problem can be tackled by reducing their intake. Oxidized forms of LA may contribute to disruption of cells, tissues and organs throughout the entire body. While Mercola and D’Adamo attribute the presence of OXLAMs to the excessive intake of LA, reducing intake may not prevent its oxidation all by itself. This is because, irrespective of the consumed amount of LA and other essential fatty acids, their oxidized forms are caused by reactive oxygen species, i.e. free radical forms of oxygen. In 1990, Dr. Masquelier explained this process in the simplest of terms. “Let's look at an everyday example, such as a container of fat going rancid. It all starts on the surface, where the fat comes into contact with the air, and therefore with oxygen. But the oxygen in question is not present in its usual molecular form, O2.”
Reactive forms of oxygen
“It has been discovered,” so Dr. Masquelier, “that cold and darkness slow down the process, whereas heat and light speed it up. This suggests that an initial input of energy (thermal, light) is required. This energy ‘boost’ is used to expel one of the electrons orbiting the oxygen nuclei. This loss of charge creates the intensely aggressive radical state that biochemists refer to as ‘the dark side of oxygen’. If you don't act quickly, the entire container of fat will go rancid. Oxidation takes place little by little; once it starts, there's no stopping it - it's a self-sustaining chain reaction. Oxygenated Free Radicals last for microseconds but, despite their transient nature, generate other radicals before disappearing. In fats, polyunsaturated fatty acids (PUFAs) are the target of choice for oxygen radicals. The oils richest in PUFAs are therefore the most vulnerable.”
Reliable captors of free radicals
Masquelier was well aware of the fact that the popularity of cooking oils containing PUFAs is fully justified, if only because they are considered particularly useful in preventing atherosclerosis and inflammation. But he warned that “any dietary recommendation to consume PUFAs will trigger an influx of Oxygenated Free Radicals.” His solution was simple and straightforward. “A reliable captor [antioxidant] must therefore be administered at the same time. By doing this, we are imitating nature, which only stores PUFAs alongside an antioxidant. Most often, it is a proanthocyanidin that performs this function, as is the case in peanuts, grape seeds, hazelnuts, etc.” According to Masquelier, dietary antioxidants must be harmless, their effect must have been demonstrated and, absorbed through the digestive tract, they must be able to spread throughout the body to be present whenever and wherever a radical attack occurs. While the vitamins E and C, and the trace element selenium fit the bill, Masquelier was convinced that in the realm of botanicals, it is especially his OPCs that meet these criteria. ”We have long been aware of their safety and bioavailability. As Oxygenated Free Radical captors, their efficacy far exceeds that of the other substances I have tested comparatively in vitro.”
The PUFA-balancing act
While Masquelier’s OPCs protect all PUFAs against oxidation, enjoying the latters’ benefits involves carefully balancing their respective intakes. As Mercola and D’Adamo suggest, minimizing the intake of LA-rich vegetable oils is the most essential step to take. Furthermore, “it is important to consume sufficient amounts of omega-3 fatty acids to sustain optimal health, with the recommended daily serving being between 500 and 1000 milligrams of omega-3 fatty acids.” Omega-3’s (EPA and DHA) are so important because they have anti-inflammatory properties, especially when they’re derived from animal sources. Do not try to “balance” a real or presumed excess of dietary LA with larger servings of omega-3 fatty acids, as this “does not support an ideal ratio. Instead, excessive quantities of omega-3s may cause additional metabolic damage—similar to that which occurs due to the conversion of elevated LA levels.” When you stick to these rules of thumb and protect all the PUFAs against oxidation by accompanying it with Masquelier’s OPCs and the vitamins E and C, you increase the chance that your balancing act will be successful.
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[i] Mercola, J.; D’Adamo, C.R.; Linoleic Acid: A Narrative Review of the Effects of Increased Intake in the Standard American Diet and Associations with Chronic Disease. Nutrients 2023, 15, 3129; [ii] Selmin, O.I.; Papoutsis, A.J.; Hazan, S.; Smith, C.; Greenfield, N.; Donovan, M.G.;Wren, S.N.; Doetschman, T.C.; Snider, J.M.; Snider, A.J.; et al. n-6 High Fat Diet Induces Gut Microbiome Dysbiosis and Colonic Inflammation. Int. J. Mol. Sci. 2021, 22, 6919.
