Excess linoleic acid consumption may adversely affect brain health

Increased intake of omega-6 rich plant oils such as soybean and corn oil over the past few decades has inadvertently tripled the amount of n-6 linoleic acid (LA) in the Western diet. Although LA is nutritionally “essential,” very little is known about how it affects the brain when present in excess. A review published in the Science of Food provides an overview of the metabolism of LA by the brain and the effects of excess dietary LA intake on brain function.

Preclinical and clinical studies dispel previous assumptions that LA is a benign fatty acid in the brain. The authors reported that when present in excess and chronically, LA induces ataxia in chickens, promotes neuroinflammation in rats, and is linked to abnormal neurodevelopment in humans.

From the review, the researchers found that chronic consumption of low-LA diets might protect the brain against inflammation. This conclusion was substantiated by studies that showed an anti-inflammatory lipidome in the brains of rats fed a low LA diet. In addition, studies showed that lowering LA consumption combined with a diet high in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduced headache frequency in patients with drug-resistant migraines.

The researchers concluded that there is evidence that excess LA in the food supply might adversely affect the brain. “The potential benefit of LA lowering merits detailed evaluation in well-designed and adequately powered clinical studies, to test whether this translates into tangible reductions in the risk of neurodegenerative disorders and neurodevelopmental abnormalities at a population level,” wrote the authors.

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