Findings open new avenue of research in memory loss
A new Northwestern Medicine study showed cognitive SuperAgers have resistance to the development of fibrous tangles in a brain region related to memory and which are known to be markers of Alzheimer’s disease.
The tangles are made of the tau protein which forms structures that transport nutrients within the nerve cell. These tangles disrupt the cell’s transport system, hampering communication within the neuron and preventing nutrients from performing their particular job within the cell. The end result of tangle formation is cell death.
“The results suggest resistance to age-related tau degeneration in the cortex may be one factor contributing to preserved memory in SuperAgers,” said lead study author Tamar Gefen, an assistant professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.
Many people develop Alzheimer’s or other forms of dementia as they get older. However, others remain sharp well into old age, even if their brains show underlying signs of neurodegeneration.
Among these cognitively resilient people, researchers have identified education level and amount of time spent on intellectually stimulating activities as factors that help prevent dementia. A new study by MIT researchers shows that this kind of enrichment appears to activate a gene family called MEF2, which controls a genetic program in the brain that promotes resistance to cognitive decline.
The researchers observed this link between MEF2 and cognitive resilience in both humans and mice. The findings suggest that enhancing the activity of MEF2 or its targets might protect against age-related dementia.
“It’s increasingly understood that there are resilience factors that can protect the function of the brain,” says Li-Huei Tsai, director of MIT’s Picower Institute for Learning and Memory. “Understanding this resilience mechanism could be helpful when we think about therapeutic interventions or prevention of cognitive decline and neurodegeneration-associated dementia.”
Tsai is the senior author of the study, which appears today in Science Translational Medicine. The lead authors are recent MIT PhD recipient Scarlett Barker and MIT postdoctoral fellow and Boston Children’s Hospital physician Ravikiran (Ravi) Raju.
A large body of research suggests that environmental stimulation offers some protection against the effects of neurodegeneration. Studies have linked education level, type of job, number of languages spoken, and amount of time spent on activities such as reading and doing crossword puzzles to higher degrees of cognitive resilience.
When it comes to healthy aging and your diet, there are plenty of mixed up “facts” that need to be unraveled, says Johns Hopkins registered dietitian Kathleen Johnson, M.A., R.D., L.D.N. Here, she separates nutrition fact from fiction.
Myth: You should avoid dairy as you get older.
Truth: Only if it aggravates your stomach or digestive system.
Our bodies often become less tolerant of certain foods as we get older, says Johnson. Dairy is one of them because production of the enzyme lactase, which aids in the digestion of dairy, decreases as we age.
But unless you’re not feeling well after having dairy products (symptoms such as gas and bloating), there’s no need to start shunning dairy.
Myth: You can only get calcium from dairy.
Truth: Many other foods are surprisingly good sources.
If you can’t tolerate dairy anymore (see above), you can still meet the daily recommended amount (1,300 milligrams to help prevent osteoporosis) by eating foods such as bok choy (79 milligrams per serving) and white beans (96 milligrams). Other foods with calcium: spinach (146 milligrams), salmon (181 milligrams) and sardines (325 milligrams).
Myth: You should switch to a low-carb, high-protein diet.
Truth: It’s better to follow a well-balanced eating plan that helps you maintain a healthy weight.
Protein does help build muscle mass — something our body naturally loses after the age of 50 (thus the importance of resistance training). However, Johnson says, what’s most important for those over 50 is achieving and maintaining a healthy weight.
For that goal, she says, “practicing moderation, and making sure the largest food on your plate is a vegetable, followed by whole grains and protein” is important. One eating plan that most medical experts support for healthy aging is the Mediterranean diet.
Myth: You should avoid saturated fats.
Truth: Some can be good for you. Instead, focus on eating more healthy fats.
“There is good nutrition science supporting the benefits of good monounsaturated and polyunsaturated fats,” Johnson says — fats found in foods such as nuts and fatty fish.
“Just don’t make fats — of any type — the largest part of your diet,” she says. Bear in mind that fats help our bodies absorb many key vitamins and minerals for healthy aging.
Hydration is essential for health, especially with outdoor temperatures high. Since water is necessary to deliver nutrients and oxygen to cells, aid digestion, control blood pressure, and regulate body temperature, getting enough fluids every day is essential to helping the body function properly.
Hydrate! While all kinds of beverages and many foods provide us with fluids, water is the best drink to keep us hydrated. There is no recommended daily intake level for water, as needs vary with many factors, including ambient temperature, activity level, and types of foods in the diet. Be aware that older adults are at an increased risk for dehydration because they may not sense the need for fluids in response to their bodies’ hydration state as well as they did when they were younger.
The commonly stated goal of drinking eight (eight-ounce) cups of water a day has no firm scientific basis, but it is generally considered a reasonable goal. One way to tell if you’re getting enough fluid is to pay attention to your urine: dark urine indicates inadequate hydration.
Water Choices: Bottled waters are now the number one beverage in the U.S. These products come at a cost—both financial and environmental—so knowing what you’re getting and weighing your options carefully is important.
Tap water from public water systems is regulated by the Environmental Protection Agency (EPA). Routine testing of public water is required, and test results must be made available to the public. If your water comes from a well, the Centers for Disease Control and Prevention recommends having it tested once a year. Although U.S. drinking water is among the safest and most reliable in the world, it is not without controversy. Many people choose to use a whole house, under-sink, refrigerator, or pitcher-based filter system at home.