The next time you're at the mall, supermarket, sporting event or park, take a look around. According to the Centers for Disease Control and Prevention, more than 1 in 10 (or about 11.3%) of the individuals you see have received a type 2 diabetes diagnosis. And a staggering 1 in almost 4 U.S. adults (38.0%) meet the criteria for prediabetes, the CDC adds.
Related: What Is Prediabetes—and 6 Steps to Help You Manage It
So this is no isolated issue, and the ripple effects of chronically elevated blood sugar levels—as experienced among those with prediabetes and type 2 diabetes—go far beyond your hunger levels, increased thirst and frequent trips to pee. All of these are symptoms of high blood sugar, or hyperglycemia, by the way.
Your focus, memory and overall brain health can also take a hit, according to The Lancet. But the cognitive collateral impact of diabetes is not necessarily inevitable. Even if you have or may be at risk for type 2 diabetes, it's possible to take steps to mind your, well, mind.
Ahead is your complete guide to the brain and blood sugar connection, plus how to eat, move and shift your lifestyle to benefit your brain.
Researchers are still searching for the exact reason(s) why this is true, admits Roxana Ehsani, RD, CSSD, a registered dietitian nutritionist in Miami and a national media spokesperson for the Academy of Nutrition and Dietetics.
"It could be due to aging or other chronic conditions, like having high blood pressure, as well as the diabetes itself," Ehsani says. "Also, people with diabetes are more at risk for developing chronic conditions, and if it's poorly managed or not controlled via medication, diet and exercise, it could impact all other organs, eyes, heart, kidneys and brain."
The most likely link between diabetes and dementia is the same reason why people with diabetes are at risk for challenges with their limbs.
"The brain depends on sugar as its main energy source. However, having high sugar levels in the blood, as in the case of diabetes, can cause stress and damage to the brain. Similar to how diabetes can lead to nerve damage to the heart, eyes and extremities, it can also affect the nerves and blood vessels of the brain," explains Diana Licalzi, RD, a registered dietitian and co-founder of Reversing T2D in Boulder, Colorado.
Consider the fact that blood vessels deliver oxygen-rich blood to the brain. If these blood vessels are impaired, it can affect the blood flow delivered to the brain and, over time, lead to impaired cognitive function. Moreover, insulin plays an important role in the brain's functions, and brain insulin resistance can negatively affect our cognition, per a 2020 publication in The Lancet Diabetes & Endocrinology.
"This damage can worsen memory and cognitive function and increase risk for more serious neurodegenerative disorders like dementia, Alzheimer's disease and vascular dementia," Licalzi says.
Just like inadequate blood flow to one's toes can lead to a need for amputation, for instance, decreased blood flow to the brain can lead to nerve damage that triggers problems with memory and learning, changes in mood and, in the long run, conditions like Alzheimer's disease, the CDC confirms. The CDC notes that this can occur with blood sugar that's too high or too low, so the happy medium is what we're all shooting for.
Related: 9 Items to Add to Your Grocery List for Better Blood Sugar Stability
Even if you have a family history of type 2 diabetes or have received a diagnosis already, it's not too late to shift your lifestyle and take smarter steps to maintain your brainpower.
"If you can establish healthy habits early on, you can help protect your brain from cognitive decline," Licalzi says.
Try these five strategies that the dietitians we spoke to recommend.
"A lot of people don't even know they have prediabetes or even diabetes. It's more common than you think that people are unaware of their elevated blood sugar levels," Ehsani says.
The American Diabetes Association confirms that more than 8 million Americans meet the criteria as we speak, yet are living undiagnosed. It's tough to receive a diagnosis or even know that something might be "off" if you don't visit your health care provider regularly.
"One way to be better informed about your health is to get yearly physicals with your doctor, complete with blood work. If diabetes runs in your family, it would also be important that you regularly check your blood sugar levels and A1C," Ehsani says. "A1C looks at what your blood sugar has been for the previous three months. Prediabetes can be prevented. If you do have elevated blood sugar levels or your levels are in the prediabetes range, it can be reversed."
If you have been diagnosed with type 2, it's vital to follow your doctor's treatment plan carefully and monitor your blood sugar levels between doctor's appointments as well.
"Poor blood sugar control is associated with worsening cognitive function. So one of the best ways to protect your brain if you have diabetes is to monitor your blood sugar levels and keep them as close to your target range as possible. This is key for managing diabetes and preventing diabetes complications, including cognitive decline," Licalzi says.
As you consume carbs, pairing them with foods containing protein and fiber can help balance blood sugar, Ehsani says.
Instead of plain white pasta with Alfredo, scoop up a serving of whole-wheat noodles with chicken and marinara sauce. Or during your 3 p.m. vending machine run, choose the bag of almonds rather than the pack of sour gummies.
If you're curious about an overall meal plan, the Mediterranean diet, a plant-based diet and the DASH diet are among the best for diabetes, Licalzi says.
An overall brain-sharp meal plan includes these healthy fats and cell protectors.
"Foods rich in omega-3s are going to be your best protector for brain health. They reduce inflammation in the body, and foods high in healthy fats are the brain's preferred source of fuel since the brain is composed mainly of fats," Ehsani says. "Omega-3s have been shown to reduce cognitive decline and help prevent Alzheimer's disease as well."
Omega-3-rich foods include fatty fish like salmon, herring, tuna and mackerel, and nuts and seeds, including walnuts, chia seeds, flaxseeds, flaxseed oil and hemp seeds.
Antioxidants are notable for their ability to act as "armor" for cells to reduce the chances of damage from external forces. Plus, research published in 2022 hints that some antioxidant-rich foods may lower the risk for dementia.
"You find your antioxidants in your fruits, veggies, spices and herbs. A lot of people don't know but spices are a powerful source of antioxidants you can just sprinkle on your food and can add antioxidants to your plate very easily," Ehsani adds, like by adding a dash of cinnamon to your oatmeal or some turmeric to your grain bowl.
"Research shows that you can prevent or delay the progression of type 2 diabetes by achieving a healthy body weight and engaging in regular physical activity," Licalzi says. "This will help protect your brain from very high blood sugar levels that come along with type 2 diabetes." Additionally, a 2020 review published in Physical Exercise for Human Health notes that exercise can positively impact insulin sensitivity, blood pressure and A1C levels.
If physical activity is not part of your regular routine, begin with small and realistic steps. Walking is a great way to start and one of the best exercises for people living with prediabetes and diabetes.
Having type 2 diabetes or prediabetes has been proven to increase the risk for cognitive decline later in life, but certain healthy habits can act like a "helmet" to protect your mind and its abilities.
Beyond these top five tips, other chronic disease risk-reducers like managing stress, stopping smoking (if you currently smoke) and keeping your alcohol consumption moderate can also help ameliorate the ancillary impacts of prediabetes and diabetes, Licalzi says. An overall healthy lifestyle can support your brain and body—and help you live sharper longer.
Related: What Is Healthy Eating for Diabetes, Exactly?
