Longevity Bloomington Newsletter #29 - Brain Health
How to reduce your risk of dementia and improve your cognitive function
Research Roundup - Brain Health
By now, most of you know that exercise has a significant positive impact on almost every part of the body. However, a body region that most people do not think of as benefiting from exercise is the brain.
Regular physical activity not only strengthens muscles and boosts energy but also enhances cognitive function, memory, and overall mental well-being. Most people are understandably concerned about losing their cognitive function as they age. Luckily, there are action steps you can take now to lessen your likelihood of this occurring. The sooner you take action, the better. Developing dementia is not inevitable. It is estimated that ~40% of dementia cases can be prevented with lifestyle changes.
In this post, we’ll explore the remarkable benefits of exercise on brain health, empowering you to embrace a more active lifestyle for both your body and mind.
What is the effect of exercise on brain health?
Before discussing exercise's impact on the brain, a very brief anatomy lesson is in order. The hippocampus (red structure in the image below) is a curved structure located deep in the brain that plays a major role in learning and memory. Damage to the hippocampus makes it much harder for someone to form new memories or learn new information. Hippocampal volume shrinks 1–2% annually in adults > 60 without dementia, and this loss of volume increases the risk of developing cognitive impairment.
A 2011 study randomly assigned 120 adults (average age = 67) to an aerobic walking group or to a control group that performed stretching exercises. The walking group started by walking for ten minutes and increased walking duration weekly by five-minute increments until a duration of forty minutes was achieved at week seven. They remained at forty minutes for the remainder of the one-year program.
What did they find? The aerobic walking group increased the size of their hippocampus by 2%. Two percent may not sound like much, but this is equal to reversing age-related brain loss by one to two years! THEIR BRAINS LITERALLY GOT BIGGER! BY WALKING! And importantly, their brains got bigger in the area where memories form (the hippocampus). The stretching group showed a 1.4% decline in hippocampus size. From the authors:
“We demonstrate that loss of hippocampal volume in late adulthood is not inevitable and can be reversed with moderate-intensity exercise. In sum, we found that the hippocampus remains plastic (can be changed) in late adulthood and that one year of aerobic exercise was sufficient for enhancing volume. Increased hippocampal volume translates to improved memory function. These results clearly indicate that aerobic exercise is neuroprotective and that starting an exercise regimen later in life is not futile for either enhancing cognition or augmenting brain volume.”
An additional study in The Journals of Gerontology randomly assigned 59 adults (aged 60-79) to an aerobic fitness or stretching control group. The aerobic fitness group initially began exercising at 40-50% of their heart rate reserve and then gradually increased to 60-70% over the course of the 6-month trial. They exercised three times per week.
The aerobic exercise group experienced significant increases in brain size in the very regions that are often reported to show substantial age-related deterioration! The areas of the brain that were enhanced the most with aerobic exercise play a central role in everyday functioning. From the authors:
“These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans. Furthermore, these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults. Our results suggest that brain volume loss is not an inevitable effect of advancing age and that relatively minor interventions can go a long way in offsetting and minimizing brain volume loss.”
To summarize the benefits of exercise on dementia prevention, a 2020 review in Practical Neurology summed it up this way:
“There is good evidence that increased levels of exercise and general physical activity in cognitively healthy adults are associated with reduced risk of dementia.
Dementia is not an inevitable part of aging. There is good evidence that older adults who are physically active, do not smoke, drink alcohol only in moderation, and eat a healthy diet have a lower risk of dementia. The highest levels of exercise seem to be the most protective.”
How Does Exercise Benefit Brain Health?
Now that we have established that exercise is good for the brain, let’s explore how exercise reduces the risk of dementia and improves cognition.
Increasing Blood Flow to the Brain
When you exercise, blood flow to the brain is increased. This increase in blood flow provides nourishment to the cells of your brain and helps remove metabolic waste. Typically, blood flow to the brain decreases with age but staying active can increase the amount of blood to the brain, help maintain cerebrovascular integrity, and prevent brain shrinkage.
Increasing the Size of Your Brain
As we discussed above, exercise can literally make your brain bigger! Importantly, it makes your brain bigger in the regions of the brain most important for memory. There is good evidence that demonstrates exercise training increases gray and white matter volume (two areas of the brain that are essential for brain function) as well as making your hippocampus larger. Exercise can guard against the gradual loss of brain cells including neurons.
Improving Cardiovascular and Metabolic Health
Cardiovascular risk factors, such as diabetes, high blood pressure, high cholesterol, and obesity, cause hardening of blood vessels in your brain. These changes can lead to cognitive decline and increase your risk of having a stroke.
Regular physical activity can prevent these risk factors, thereby reducing the risk of reduced cognition through improvement in general cardiovascular health. A 2023 review in Brain Sciences summed it up this way: “Reducing cardiovascular risk factors through physical activity may be one of the most effective strategies for preventing age-related cognitive decline and dementia.”
Preventing and Treating Depression
Depression is a known risk factor for dementia. A 2023 article in JAMA found that depression in mid-life increases your risk of dementia. Luckily, as we have discussed in a previous newsletter, exercise is an effective way to reduce symptoms of depression in some individuals. A 2016 review concluded: “Our results provide robust evidence that exercise can be considered an evidence-based treatment for the management of depression.” In addition to exercise, counseling and medication may also be helpful. Discuss your options with your healthcare provider.
Improving Sleep Quality
Poor sleep may increase your risk of cognitive decline. When you sleep, many vital bodily functions occur that are important for your health. Think of your brain as taking on the role of a housekeeper when you sleep. Recent research has shown that sleep removes toxins from your brain via a recently discovered series of channels called the glymphatic system. The glymphatic system is a waste-clearance system for your brain. It is responsible for replenishing as well as cleansing the brain as you sleep. Regular physical activity can improve your sleep quality and can improve sleep disorders like insomnia.
For more information on improving your sleep, read our previous sleep newsletter.
What Types of Exercise Are Most Effective at Improving Brain Health?
The vast majority of research looking at the effects of exercise on brain health have studied aerobic exercise as their modality of choice. As a result, the strongest amount of evidence supports the use of aerobic exercise in improving your brain function. Aerobic exercise can take many forms such as walking, jogging, cycling, and swimming.
In recent years, there has been growing interest in using resistance training to improve cognition and prevent brain volume loss. A 2022 review found that resistance training improved cognitive function and helped prevent cognitive deterioration.
As we have discussed in other newsletters, you shouldn’t pick between aerobic exercise and resistance training. Everyone needs both. Regularly lift weights and elevate your heart rate, and you will have all of your bases covered.
Bonus points if you exercise in a group: this 2023 study found improvements in cognition when exercising alone, but the benefits were DOUBLED with group exercise. The group provides an added social interaction element, which can significantly contribute to cognitive health by reducing isolation and enhancing motivation.
How Much Exercise Do I Need to Improve Brain Health?
A good rule of thumb for almost any health condition is 150 minutes of moderate aerobic exercise per week plus at least two days of resistance training. If you consistently hit these numbers, you can rest assured that you will be making a big improvement in your health. This amount of physical activity was enough to be cognitively protective and was associated with an increase in hippocampus size and improved spatial memory.
If you are currently inactive and 150 minutes of physical activity per week seems daunting, just get started doing something. Anything. Go for a walk with a neighbor (bonus points if you are wearing a weighted backpack or a weighted vest). The biggest benefits are seen in the folks that go from doing nothing to doing something.
A 2018 systematic review found that: “The minimum level of physical activity to have a positive effect against dementia is >1 hour per week performed over the course of two sessions per week. From these findings, the current meta-analysis suggests that participation in these amounts of physical activity helps prevent all-cause dementia, Alzheimer’s disease, and vascular disease. “
If you are already active, there is still added benefit and disease protection from further improving your fitness. Some is good. More is better.
What else can I do outside of exercise to improve my brain health?
Although exercise has the most evidence to support its use in protecting against cognitive decline, there are many things you can do to protect your brain as you age. A few things other than exercise that also can help to improve brain health:
cognitive activity
social engagement
blood pressure control
feeling a sense of purpose
eating a healthy diet
reducing depression
reducing alcohol intake
avoiding smoking
In conclusion, while the link between exercise and brain health is powerful, the message here is not to alarm you, but to empower you. Dementia is not an inevitable fate, and there are actionable steps you can take to reduce your risk. By incorporating regular physical activity into your routine, you’re not only improving your body’s health, but also protecting your mind for the future. You have the ability to make a positive impact on your brain health, and it’s never too early—or too late—to start.
Healthy Bites: The Power of Fiber
Maintaining a healthy diet becomes increasingly important as we age, and one key player in that diet is fiber. Fiber is essential for digestive health, helping to regulate bowel movements and prevent constipation. It also aids in weight management, lowers cholesterol levels, and can even reduce the risk of chronic diseases like heart disease and cancer. Increasing fiber intake can lead to better overall health and enhanced well-being.
Benefits of Fiber
Digestive Health: Fiber helps keep our digestive system running smoothly, reducing the risk of constipation and promoting regularity.
Heart Health: Soluble fiber can lower cholesterol levels, which is crucial for heart health.
Blood Sugar Control: Fiber helps slow the absorption of sugar, contributing to more stable blood sugar levels.
Weight Management: High-fiber foods are often more filling, helping you feel satisfied and reducing overall calorie intake.
Cancer: A high-fiber diet may reduce the risk of several types of cancer, including breast, colon, esophageal, gastric, and ovarian cancer.
Actionable Tips to Increase Fiber Intake
Start Your Day with Fiber: Choose a high-fiber breakfast cereal or oatmeal. Look for options with at least 5 grams of fiber per serving.
Snack Smart: Replace chips and cookies with snacks like raw vegetables, whole fruit, or popcorn. These choices are not only tasty but also rich in fiber.
Incorporate Beans and Legumes: Add beans, lentils, or chickpeas to soups, salads, or stews. They’re not only high in fiber but also packed with protein.
Choose Whole Grains: Opt for whole-grain bread, pasta, and brown rice instead of refined versions. They provide significantly more fiber.
Add Fruits and Vegetables: Aim for at least five servings of fruits and vegetables each day. Berries, pears, apples, and leafy greens are all fiber-rich options.
High-Fiber Foods to Include in Your Diet
Fruits: Raspberries, pears, apples (with skin), bananas, and oranges.
Vegetables: Carrots, broccoli, Brussels sprouts, and sweet potatoes.
Legumes: Lentils, black beans, chickpeas, and kidney beans.
Whole Grains: Quinoa, barley, oatmeal, and whole-grain bread or pasta.
Nuts and Seeds: Chia seeds, flaxseeds, almonds, and walnuts.
Increasing fiber intake doesn’t have to be overwhelming. By incorporating these simple strategies into your daily routine, you can enjoy the numerous health benefits that fiber provides. Remember to increase your fiber intake gradually and drink plenty of water to help your digestive system adjust.
Member Spotlight - Sandi Clark
This month’s member spotlight is on Sandi Clark!
How long have you been a member of Longevity and what are some of your favorite exercises in class?
I started exercising with Longevity four months ago and surprisingly love both the rower and ski machines. They make me feel like an Olympian!
Where are you from originally and what brought you to Bloomington?
I grew up on the northside of Indy and moved to Bloomington to finish graduate school after falling in love with the vibe of the town in the 70's. My daughter was raised here and – fortunately for me – came back to Bloomington with her family after law school. Ever since, I’ve been an involved grandmother of three lovely and active young people. One of the many gifts this offers is learning a lot about the confusing rules of gymnastics, football, and hockey, and having a firsthand perspective on what it's like to be growing up in today's world.
What do you do for work?
Workwise, I’m a counselor and consultant in private practice, now part-time. I offer strategies, coaching, and support for career, health, and personal transitions to adults of all ages.
What do you do outside of work?
Outside of work I spend time with family and friends, read, put my just adequate cooking skills to use, support and attend all sorts of arts and cultural activities, and enjoy traveling. (The photo is from a recent trip to Croatia, a beautiful country.)
What is your favorite restaurant in Bloomington?
My favorite Bloomington restaurant is the Uptown for both its food and atmosphere. It’s like Cheers for me.
If you had to eat one meal every day for the rest of your life, what would it be?
If you forced me to choose only one meal to eat every day for the rest of my life, (this is torture!) it would probably be either fruit, yogurt, and granola or a pasta dish with a Caesar salad.
Well Attended
We would like to recognize the Longevity Bloomington members who made it to > 80% of the classes since our most recent newsletter. Special shoutout to Dean, Dee, Lisa & Terry for 100% attendance! Well done!
Celebrating Our Day-One Members
Big thanks to Judy, Janet, Elsie, Tom & Pat. These five incredible members have been with us since day one – 3 years strong! Your commitment and support have helped make our fitness community what it is today. We’re beyond grateful for you all!
New Members
Welcome to Longevity Bloomington! It has been great having you all in class.