What are essential fatty acids
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Essential Fatty Acids: Definition, Importance, and Health Implications
Definition and Discovery of Essential Fatty Acids
Essential fatty acids (EFAs) are a group of polyunsaturated fatty acids that are crucial for human health but cannot be synthesized by the body. The concept of EFAs was first introduced by George and Mildred Burr in 1929 when they discovered that certain fatty acids were necessary to prevent deficiency diseases in rats fed a fat-free diet. They identified linoleic acid and alpha-linolenic acid as essential fatty acids, marking a significant milestone in lipid research1.
Types and Sources of Essential Fatty Acids
EFAs are categorized into two main types: omega-6 fatty acids and omega-3 fatty acids. Linoleic acid (LA) is the primary omega-6 fatty acid, while alpha-linolenic acid (ALA) is the primary omega-3 fatty acid. These fatty acids are found in various dietary sources such as vegetable oils, nuts, seeds, and leafy green vegetables2 7.
Metabolism and Biological Functions
Once ingested, EFAs are metabolized into longer-chain derivatives. For instance, LA is converted into arachidonic acid (AA), and ALA is converted into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These metabolites play critical roles in the formation of eicosanoids, which are signaling molecules involved in inflammatory and immune responses3 9.
Health Benefits and Physiological Roles
EFAs and their metabolites have numerous health benefits. Omega-3 fatty acids, particularly EPA and DHA, are known for their anti-inflammatory properties and are beneficial in preventing cardiovascular diseases, hypertension, and certain chronic conditions like rheumatoid arthritis and type 2 diabetes6 7. Omega-6 fatty acids, while also essential, can promote inflammation if consumed in excess, highlighting the importance of a balanced intake of both types5 6.
Essential Fatty Acids and Skin Health
EFAs are vital for maintaining healthy skin. Linoleic acid, in particular, is abundant in the skin and is crucial for maintaining its barrier function and preventing dryness. Arachidonic acid, derived from linoleic acid, is also important for skin health as it serves as a precursor for prostaglandins, which are involved in skin repair and inflammation2.
Clinical Implications and Deficiency
EFA deficiency is rare due to their widespread availability in the diet. However, when it occurs, it can lead to symptoms such as dry skin, hair loss, and impaired wound healing. Deficiency is more likely in conditions where fat absorption is compromised or in diets extremely low in fat8 10.
Conclusion
Essential fatty acids are indispensable for human health, influencing a wide range of physiological processes from inflammation to cardiovascular health. Ensuring a balanced intake of omega-3 and omega-6 fatty acids is crucial for maintaining overall health and preventing chronic diseases. Further research is needed to fully understand the optimal dietary requirements and the broader implications of EFAs in human health.
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Most relevant research papers on this topic
Discovery of essential fatty acids
Essential fatty acids, such as linoleic acid and linolenic acid, are crucial nutrients for maintaining good health and preventing deficiency diseases in rats fed a fat-free diet.
Highly CitedESSENTIAL FATTY ACIDS AND THE SKIN
Essential fatty acids are essential to human diet, but skin cannot synthesize them independently.
Highly CitedEssential fatty acids: biochemistry, physiology and pathology
Essential fatty acids (EFAs) and their metabolites play diverse roles in various physiological and pathological processes, with altered metabolism linked to various diseases.
Highly CitedProblems with essential fatty acids: time for a new paradigm?
The term 'essential fatty acid' is ambiguous and should be replaced with less biased terminology like polyunsaturates, omega3 or omega6 polyunsaturates, or individual fatty acid names for improved clarity and broader exploration of their functional and health attributes.
Highly CitedConsequences of Essential Fatty Acids
Informed voluntary food choices can prevent imbalances in dietary n-3 and n-6 nutrients, potentially benefiting human health and reducing the negative effects of excessive tissue n-6 HUFA actions.
Rigorous JournalHighly CitedEssential fatty acids in the treatment of dry eye.
Essential fatty acid supplementation shows a potential relationship with improvement in dry eye disease, but more large-scale randomized clinical trials are needed to confirm their efficacy.
Systematic ReviewHighly CitedEssential fatty acids in health and chronic disease.
N-3 fatty acids, found in green leafy vegetables, flaxseed, rapeseed, and walnuts, have beneficial effects in preventing chronic diseases and promoting overall health.
Highly CitedHow essential are essential fatty acids?
Essential fatty acids are crucial for human and animal health, with dietary factors potentially causing deficiency or marginal deficiency states.
Essential Fatty acids - a review.
Essential fatty acids and their metabolites play crucial roles in maintaining health and preventing diseases like obesity, hypertension, diabetes, and cancer.
Literature ReviewHighly Cited