The Potential Role of Statins
Dr. Mills speculated that there may be “neuroprotective benefits for some of the statins which appear to be related to cardiovascular benefits. But at this point, we don’t have any clear data whether statins actually directly impact brain cholesterol, since it’s a separate pool.”
They could help “by increasing blood flow and reducing narrowing of the arteries, but any direct impact on the brain is still under investigation.”
Dr. Hansen pointed to research suggesting statins taken at midlife appear to be cardioprotective and may be protective of brain health as well, whereas statins initiated in older age do not appear to have these benefits.
He speculated that one reason statins seem less helpful when initiated later in life is that the BBB has already been damaged by systemic inflammation in the periphery, and the neuroinflammatory process resulting in neuronal destruction is already underway. “I think statins aren’t going to fix that problem, so although lowering cholesterol can be helpful in some respects, it might be too late to affect cognition because the nerves have already died and won’t grow back.”
Can Dietary Approaches Help?
Dr. Naidoo said that when looking at neurologic and psychiatric disease, “it’s important to think about the ‘long game’ — how can we improve our blood and cardiovascular health earlier in life to help potentiate healthy aging?”
From a nutritional psychiatry standpoint, Dr. Naidoo focuses on nourishing the gut microbiome and decreasing inflammation. “A healthy and balanced microbiome supports cognition, while the composition of gut bacteria is actually drastically different in patients with neurological diseases, such as AD.”
She recommends a nutrient-dense, anti-inflammatory diet including probiotic-rich foods (such as kimchi, sauerkraut, plain yogurt, and miso). Moreover, “the quality and structure of our fatty acids may be relevant as well: Increasing our intake of polyunsaturated fatty acids and avoiding processed fats like trans fats and hydrogenated oils may benefit our overall brain health.”
Dr. Naidoo recommends extra-virgin olive oil as a source of healthy fat. Its consumption is linked to lower incidence of AD by way of encouraging autophagy, which she calls “our own process of “cellular cleanup.’”
Dr. Naidoo believes that clinicians’ guidance to patients should “focus on healthy nutrition and other lifestyle practices, such as exercise, outdoor time, good sleep, and stress reduction.”
Dr. Mills notes the importance of omega-3 fatty acids, such as docosahexaenoic acid (DHA) , for brain health. “DHA is a major lipid component of neuronal membranes,” she said. “Because of inefficiencies in metabolism with APOE4, people tend to metabolize more of the lipids on the membranes themselves, so they have higher lipid membrane turnover and a greater need to supplement. Supplementing particularly through diet, with foods such as fatty fish rich in omega-3, can help boost the levels to help keep neuronal membranes intact.”
What This Means for the Clinician
“At this point, we see all of these associations between lipids and dementia, but we haven’t worked out exactly what it means on the individual level for an individual patient,” said Dr. Mills. Certainly, the picture is complex, and the understanding is growing and shifting. “The clinical applications remain unclear.”
One potential clinical take-home is that clinicians might consider tracking lipid levels over time. “If you follow a patient and see an increase or decrease [in lipid levels], that can be informative.” Looking at ratios of lipids might be more useful than looking only at a change in a single measure. “If you see trends in a variety of measures that track with one another, it might be more of a sign that something is potentially wrong.”
Whether the patient should first try a lifestyle intervention or might need medication is a “personalized clinical decision, depending on the individual, their risk factors, and how their levels are going,” said Dr. Mills.
Dr. Mills, Dr. Hansen, and Dr. Naidoo declared no relevant financial relationships.
A version of this article appeared on Medscape.com.