Nutrition impacts all facets of brain function: executive reasoning, attention, language, visuospatial skills, and global cognitive abilities. For optimal brain health, you need adequate B vitamins and the right ratio of Omega-3 and Omega-6 fatty acids. Let’s learn more.
This is obviously a difficult area to study in humans for ethical reasons. Scientists approach the subject obliquely by trying to find ways to improve brain function in those in the midst of cognitive decline. The area of study is also clouded because researchers do not always follow the same protocols, which makes it difficult to make comparisons. With all that said, let’s see what can be learned and how we can best use that information.
Researchers generally divide this field of study into the following areas: memory, executive function, attention, language, visuospatial skill, and global cognitive function. These areas are not treated equally in the study of how nutrition affects each of them. The primary focus among brain health researchers has been memory, so let’s start there.
Studies have identified specific nutrients and foods that have been shown to improve memory in those with cognitive decline.
- Vitamin B12
- Folic acid
- Fish oil
- DHA (docosahexaenoic acid)
- Vitamin E
- Cocoa flavonoids
- Concord grape juice
- Wild blueberry juice
In studies, these nutrients were able to influence a person with declining mental ability, specifically in the area of memory. Could they do the same for a healthy person?
Let’s turn our attention to oils and the types of fat they contain. There are two primary dietary fats (out of roughly 30) that we should be most interested in: Omega-3 and Omega-6. Both are polyunsaturated fatty acids. The most relevant Omega-3s are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). As for the Omega-6 group, we are most interested in linoleic acid (LA), gamma-linoleic acid (GLA), and arachidonic acid (AA).
Omega-3 PUFAs positively impact our thinking and behavior. They also affect the composition of the microbiota as well as gut inflammation. This is how the gut-brain axis functions.
The ratio of Omega-3 to Omega-6 is a biomarker for chronic disease. Western diets are low in fish and fish oil, which skews this ratio in favor of the inflammatory Omega-6s. As a side note, this imbalance is linked to an increased risk of breast cancer.
Omega-3 PUFAs have an anti-inflammatory effect, which may explain their neuroprotective benefits. Omega-6 PUFAs—through intermediaries—have just the opposite effect. Thus, the correct ratio is important for brain health. Numerous studies have shown a correlation between low Omega-3 levels and brain health issues like schizophrenia, ADHD, PTSD, dementia, and Parkinson’s disease.
You can help yourself by reducing the plant oils (n-6 PUFAs) in your diet and eating more fatty fish or supplementing with fish oil.
The use of supplemental vitamin E has positive effects on executive function for up to six months; thereafter the results were similar to placebo.
With vitamin E supplementation, there was a significant difference during the initial 18 months of a three-year study.
Folic acid was found to be useful in restoring visuospatial skills.
Global Cognitive Function
Available research in this area found no improvement in global cognitive function from the interventions tested.
Non-traditional medicine makes use of many herbs and other natural substances not typically relied upon in traditional medicine. The list below servers as an example and it contains some commonly accepted substances.
Ginkgo biloba has the potential to improve cognitive function in patients with Alzheimer’s disease, but there is insufficient scientific evidence at this time.
St. John’s Wort has some interesting effects on the brain in experimental animals, but it has not been studied enough to recommend at this moment.
Bacopa monnieri is used in Ayurvedic medicine. Some interesting studies have been conducted, but more is needed before a recommendation can be made. Some of the findings for Bacopa monnieri include: inhibition of inflammatory pathways in the brain, alleviation of cognitive decline, and increased learning ability.
Taurine is a key amino acid for brain function and is found in non-traditional medicinal treatments. When the data from one review were summarized with a focus on different types of brain damage (Alzheimer’s disease, mental diseases, cognitive injuries), the conclusions suggest that taurine can improve cognitive function in many ways.
Acetyl carnitine is also commonly used in non-traditional medicine. Dietary supplementation of acetyl carnitine has a neuroprotective, neurotrophic, anti-depressive, and analgesic effect in painful neuropathies. It also has antioxidant and anti-cellular death activity.
L-glutamine is an essential precursor for the biosynthesis of amino acid neurotransmitters and is also found in non-traditional medicine.
The Biggest Takeaway
The strongest evidence linking diet to brain health centers on vitamin B12, folic acid, and an Omega-3/Omega-6 ratio of between 1:1 and 3:1. If you’re concerned about memory loss and other areas of cognitive function, increase your consumption of foods rich in B vitamins (cruciferous vegetables, leafy greens, meat, fish, eggs) and eat more fish. Alternatively, consider supplementation.