Alzheimer’s disease. Two words that can strike fear in anyone’s heart. There’s no cure at this time for this progressive form of dementia that slowly but steadily destroys memory and thinking skills, and eventually, the ability to carry out the simplest of tasks. First, the bad news: People who have Type 2 diabetes appear to be at higher risk for developing Alzheimer’s disease (AD) than people without diabetes. Now the good news: There are signs of progress in fighting this disease.
The lowdown on Alzheimer’s disease
Most of us know someone who has Alzheimer’s disease — a parent, an aunt or uncle or a neighbor, perhaps. Affecting roughly 5.7 million Americans, Alzheimer’s disease is the most common form of dementia and sixth leading cause of death in the U.S. According to the Alzheimer’s Association, someone in the U.S. develops Alzheimer’s disease every 66 seconds. On average, a person who has Alzheimer’s lives four to eight years after diagnosis, although he or she may live as long as 20 years.
This condition can set in years before symptoms appear. Abnormal deposits of protein form “amyloid plaques” and “tau tangles” in the brain, affecting neurons (nerve cells). The damage occurs primarily in a part of the brain called the hippocampus. As more neurons die, more parts of the brain are affected. In early stages, memory loss is mild, but as it progresses, a person loses the ability to have a conversation and respond to his or her environment. There’s no cure for Alzheimer’s, although treatment can slow the progression and improve quality of life.
The link between Alzheimer’s disease and diabetes
While the cause of Alzheimer’s disease isn’t known, scientists do know that high blood sugar levels can damage blood vessels. Damaged blood vessels in the brain may raise the risk of Alzheimer’s disease. High blood sugar levels may also lead to inflammation, which damages brain cells. And high levels of insulin, which can occur in Type 2 diabetes, may trigger the onset of Alzheimer’s disease. For these reasons, Alzheimer’s is sometimes dubbed “Type 3 diabetes.”
It’s important to know your risk factors for Alzheimer’s disease. As with diabetes, some of these risk factors can’t be changed, but others can.
Age is the greatest risk factor for Alzheimer’s disease. Most people with the condition are 65 and older. However, about 200,000 Americans who are under the age of 65 have early-onset Alzheimer’s.
Your risk for Alzheimer’s increases if you have a parent or sibling with the disease. Your risk also increases if more than one family member has it.
Having certain genes for Alzheimer’s disease increases the risk, although having these “risk” genes doesn’t mean that you will develop the condition. (“Deterministic genes” directly cause Alzheimer’s disease, which will develop in anyone who has them.) According to researchers at Mayo Clinic, one gene in particular called APOE4 is linked with more than 50 percent of Alzheimer’s cases. APOE4 can interfere with the brain’s ability to use insulin, causing brain cells to starve and eventually die.
Head trauma or loss of consciousness as a result of head injury raises the risk. Always wear your seatbelt and wear a protective helmet when playing sports. If you are older, make your home fall-proof to limit the chances of falling and suffering a head injury.
Poor heart health
High blood pressure, heart and vascular disease and stroke can raise your risk. Focus on getting your heart health numbers (blood pressure, cholesterol, triglycerides) into a healthy range. A nutritious eating plan, regular physical activity and medication can help you get your heart health numbers on track.
Uncontrolled Type 2 diabetes
Diabetes control and heart health go hand in hand. It’s not always easy, but getting and keeping your blood sugars and A1C levels within your target range can lower your risk of getting Alzheimer’s disease.
An unhealthy diet, being overweight, not getting regular physical activity and smoking can worsen heart health and diabetes, thereby increasing your risk of Alzheimer’s disease.
Promising new treatments for Alzheimer’s disease
Researchers are racing against the clock to find ways to either prevent or cure Alzheimer’s disease. So far, there’s no cure. Medications are available, but they work to help slow memory loss, not to prevent or cure the condition. However, some newer approaches are promising.
Research is currently underway to test a therapy called an anti-amyloid antibody drug. The goal is to see if administering a monthly infusion of this drug can decrease amyloid buildup in the brain, helping to slow memory loss. The study investigating this treatment is called the A4 Study and it involves adults ages 65–85 who have normal thinking and memory function but who may be at risk for memory loss due to Alzheimer’s disease. (This study is not for people who have already have the disease.) The A4 Study is expected to last four-and-a-half years, and is funded by the National Institute on Aging/NIH, Eli Lilly and Company and other organizations.
Antisense oligonucleotides (ASOs)
These DNA-like molecules may prevent the formation of tau and reduce existing levels, as well. Tau protein in the brain forms “tangles” in Alzheimer’s, and these tangles disrupt the brain cells’ ability to communicate with each other. ASO treatment in mice and monkeys has been effective; however, more studies are needed to see if this approach is both safe and effective in humans.
The drug memantine (brand name Namenda) is currently used in people who already have Alzheimer’s in an attempt to slow the progression. However, researchers are hoping that it might be used to prevent or slow the progression of the disease — before symptoms appear. A clinical trial at the University of Virginia is currently in the process of being designed to study if memantine might play a role in Alzheimer’s prevention.
Metformin, one of the most commonly used drugs to help manage diabetes, may be a promising way to help prevent Alzheimer’s disease. Newer studies have shown that the longer metformin is taken, the lower the chances of developing Alzheimer’s disease and other types of dementia. And people with early Alzheimer’s disease who were given metformin for eight weeks had significant improvements in memory and cognitive function. One researcher, Nir Barzilai, MD, plans to launch a large-scale study called TAME (Targeting Aging with Metformin) to further study the potential of metformin. Note: A study conducted by Taiwanese researchers found that long-term use of metformin increased the incidence of Parkinson’s and dementia. Large-scale studies are needed to clarify these results.
Another diabetes medicine, liraglutide (brand name Victoza) has reduced amyloid plaque in the brain and improved Alzheimer’s symptoms. A phase 2 study is being conducted at Imperial College London’s Memory Research Centre on patients with mild to moderate Alzheimer’s. If this next phase is successful, the hope is that liraglutide could be available to patients within the next five to ten years.
Extra-virgin olive oil, or EVOO, seems to protect memory and learning ability and to reduce the formation of amyloid plaques in mice fed an EVOO-enriched diet, according to researchers at Temple University. Mice that were genetically modified to have characteristics of Alzheimer’s were fed chow enriched with EVOO; at 9 and 12 months, they performed much better in cognitive tests compared to mice fed regular chow. The researchers are planning to study the effect of adding EVOO at a later stage of Alzheimer’s in mice to see if it can stop or reverse the disease.
Speaking of olive oil, a review of studies that looked at the effect of the Mediterranean diet on long-term cognitive function established that people who adhered to this way of eating had less cognitive decline, had improvements in cognitive function, or were less likely to develop Alzheimer’s disease compared to people who did not stick to this diet. The Mediterranean diet emphasizes fruits, vegetables, whole grains, beans, nuts, fish and olive oil, with lesser amounts of poultry and cheese and limited amounts of red meat and sweets.
You probably saw this one coming! Here’s yet another reason to lace up your sneakers. Researchers at the University of Southern California in Los Angeles found that as many as one in three cases of Alzheimer’s disease were preventable through lifestyle changes. Furthermore, after reviewing existing research, they concluded that cognitive function in seniors who did only aerobic exercise was three times better than seniors who did a combination of aerobic and resistance exercise. (This doesn’t mean you should give up your resistance exercise, however!).
If sleep eludes you, it’s time to focus on what steps you can take to get some serious shut-eye. That’s because a good night’s sleep helps the brain to clear away beta-amyloid in the brain. Beta-amyloid is a harmful plaque that can lead to brain cell death. Older adults who experience excessive daytime sleepiness are thought to be at higher risk of Alzheimer’s, according to researchers at Mayo Clinic.
New studies presented at the Alzheimer’s Association International Conference in 2018 examined how the digestive system may play a role in Alzheimer’s and other types of dementia. Research has already indicated that changes in gut bacteria are linked to inflammatory and autoimmune conditions. In studies with mice, changing their diet in order to change the bacterial profile in their gut may reduce amyloid buildup, decrease inflammation and improve memory. Aim to include probiotic-rich foods (such as yogurt with active cultures, miso and kimchi), as well as foods rich in omega-3 fatty acids (such as salmon, tuna, flaxseeds and chia seeds) in your eating plan.
To learn more about Alzheimer’s disease, contact the following organizations:
• Alzheimer’s Association: www.alz.org or (800) 272-3900
• ADEAR (Alzheimer’s and related Dementias Education & Referral Center): www.alzheimers.gov or (800) 438-4380
• BrightFocus Foundation: www.brightfocus.org/alzheimers/organizations or (800) 437-2423
Want to learn more about keeping your mind sharp? Read “Memory Fitness: How to Get It, How to Keep It” and “Nine Tips to Keep Your Memory With Diabetes.”