This article was originally published in Never Too Late (PCOA News). View the original article here.
In my column last month, I talked about the benefits of following a “mediterranean diet” for brain health. Since the theme for this month’s edition of Never Too Late is nutrition, I thought I’d focus on one particular aspect of diet, and it’s an important one – dietary fat.
For decades, health experts have emphasized the importance of following a “low fat” diet. And in general, that’s good advice, especially as a way to maintain a healthy body weight. There are a lot of good reasons to maintain a healthy body weight. Being overweight or obese is associated with increased inflammation in multiple organ systems in the body, including the brain. Obesity is a major risk factor for type-2 diabetes, hypertension, and heart disease, three health conditions that increase risk for cognitive impairment and dementia in later life. In particular, obesity during mid-life (the 40’s and 50’s) has been identified consistently as a risk factor for Alzheimer’s disease in large epidemiological studies. In late life (typically the 70’s, 80’s, and beyond), however, the association between obesity and dementia isn’t so clear. Some studies have even identified late-life obesity as protective against dementia.
When it comes to the brain, however, some dietary fat is a good thing. In fact, it’s essential for maintaining a healthy brain. When you take out water weight, your brain is about 60 percent fat. Our primary brain cells – neurons – need fats to maintain their structure and to mediate processes involved in neurotransmission, or the communication between cells. Fats are also critically important for maintaining astrocytes, the cells that support many brain functions including provision of nutrients, maintenance of fluid balance, regulation of blood flow, and repairing the brain and spinal cord following infection or traumatic injury. When the brain does not have adequate supplies of dietary fat, it can have negative consequences for cognitive functions such as learning and memory, as well as emotional health.
But not all fats are equal.
This is a complicated topic, but in general, omega-3 fatty acids are always at the top of the list of fats that are needed to maintain brain health. Compared to other parts of the body, the brain has a higher concentration of omega-3 fatty acids, especially one called docosahexaenoic acid (DHA). Low levels of brain DHA result in damage to neurons and difficulties with learning and memory. In addition, low levels of DHA have been linked to mood disorders such as depression and bipolar disorder, and have been used as an effective supplement to drug treatments for these conditions.
Omega-3 fatty acids are found in a wide range of plant and animal foods. Cold water fish, like salmon, sea bass, tuna, mackerel, sardines and herring, as well as oysters, are rich in DHA as well as eicosapentaenoic acid (EPA), another omega-3 fatty acid important for brain health. Plants are also rich sources of omega-3s, including nuts and seeds (especially walnuts, flax, and chia seeds), as well as soy beans (edamame) and kidney beans. These plants are a good source of the third omega-3 fatty acid called alpha-linolenic acid (ALA).
Although some research indicates that ALA and ALA-containing foods are beneficial when it comes to brain health, most research has focused instead on the benefits of DHA and EPA.
The bottom line is that dietary fat isn’t always bad for your health, but it really depends on the type of fat. The omega-3 fatty acids are a critical component of a healthy diet that will help maintain brain health as we age. So the next time you’re enjoying a salmon steak or a tuna salad, know that you’re also feeding your brain.
If you’d like to hear more about our studies, or if you’d be interested in participating, send us an email at healthymindsforlife@email. arizona.edu. We’ll tell you about some great opportunities to get involved. I’ll look forward to hearing from you!