Healthy habits strengthen your heart and your head
January 1, 2022 | View PDF
Most Americans over age 60 are fearful of age-related health decline and disease. According to one survey, the fears of dementia and Alzheimer's disease top the list. These fears are not without cause - the most recent statistics estimate that 6.2 million older Americans are living with Alzheimer's dementia which accounts for 60 to 70% of dementia cases.
Dementia is a general term for cognitive problems that interfere with daily living. It can result from or with other conditions such as Parkinson's disease, stroke or head trauma. The most common types of dementia are Alzheimer's disease and vascular dementia.
In 2019, Alzheimer's disease was the sixth-leading cause of death in the United States, significantly behind heart disease and cancer. Though rates of death due to heart disease and cancer are higher, their rates are decreasing while Alzheimer's disease rates have increased more than 145% since 2000. Currently, 11.3 % or one in nine people age 65 and older has Alzheimer's dementia.
Just as with most chronic diseases in older individuals, advanced age is the single greatest risk factor for developing dementia or Alzheimer's disease. Given that this is not a risk factor most of us want to change, it's time to plan for not just a longer lifespan but a longer healthspan with healthy brains.
Lifestyle over genetics?
Individual genetics certainly play a role - if no one in your family had dementia, you've leaped past one hurdle. But the majority of cases do not have an identifiable, single genetic cause. This may mean that researchers have not identified the genes responsible, but it may also mean that predisposing genes are potentially modifiable through lifestyle. In 2020, it was suggested by the Lancet Commission on Dementia Prevention, Intervention and Care, that up to 40% of dementia cases could be prevented or delayed through modifiable risk factors. The commission suggests a focus on the following: Physical activity, smoking, education, staying mentally and socially active, blood pressure and diet.
Looking at the list, it is easy to see that heart-healthy habits are likely to impact brain health. There are a few others that have emerged as promising for delaying or preventing Alzheimer's disease and dementia. Research points to healthy habits in middle adult years (ages in the 50s and 60s) as most effective for delaying or preventing dementia. So, where to start?
Get cataract surgery (if needed) and address poor hearing. Poor hearing, poor sense of smell and poor vision have all been associated with increased risk of dementia. It has been unclear whether these are causes of dementia or whether they occur as a result of dementia-caused brain changes.
Hot off the press in December 2021, published research showed that cataract surgery (lens replacement) reduced risk of developing dementia by 30%. This effect persisted for at least a decade after surgery. The study didn't investigate the mechanism by which the risk was reduced but suggested that higher quality sensory input after lens replacement may be responsible.
One investigator hypothesized that, after surgery, retinal cells receive more blue light stimulation which helps to regulate sleep and cognition.
Hearing loss is associated with cognitive decline, depression and increased risk of falls. Just as with vision, it appears that poor sensory input affects parts of the brain involved with hearing and individuals with greater hearing loss seem to have greater risk of developing dementia.
Hearing is considered a modifiable risk factor for dementia and hearing loss should be addressed to stop cognitive decline, social isolation and falls, which can lead to traumatic brain injuries and other serious injuries.
Exercise more. Regular physical exercise is one of the best things that you can do to prevent dementia. Aerobic physical activity can increase brain-derived neurotropic factor supporting formation of new neurons and protects existing ones. Increased blood flow and oxygen delivery to the hippocampus, one of the brain's memory centers, has been shown to decrease hippocampus decline. Even small amounts of physical activity can be helpful and can improve cognitive test performance for individuals with or without dementia.
The amount of physical activity recommended is the same as for general population fitness – a goal of 30 minutes per day of moderate intensity aerobic physical activity. This level improves brain health and heart health. Resistance exercise at least twice per week can help increase mobility, reduce blood sugar and improve sleep, all of which are important for heart and brain health. Standing more and moving at least every 30 minutes are necessary to maintain best health.
Lower blood pressure, blood cholesterol and blood sugar levels. The brain relies on a healthy heart to provide the very high levels of oxygen needed for the brain's energy production. Researchers sum it up this way: "A healthy heart ensures that enough blood is pumped to the brain, while healthy blood vessels enable the oxygen- and nutrient-rich blood to reach the brain so it can function normally".
High blood pressure or prehypertension, high cholesterol, diabetes and prediabetes can damage and block blood vessels and impair blood flow to the brain and all are associated with higher risk of dementia. Clinical trials show that medical treatment to reduce blood pressure can safely decrease the occurrence of mild cognitive impairment and dementia. Keeping track of and lowering blood sugar and blood pressure with medication and lifestyle changes should be part of your heart and brain health plan.
Drink more water. Dehydration, often-documented in older Americans with dementia, may play a part in the development of dementia, though this is not well established. We know that dehydrated adults experience fatigue, depression and poorer cognitive function. In one study, chronically dehydrated adults were more likely to develop Alzheimer's disease and vascular dementia. It has been hypothesized but not proven that low cell and tissue fluid levels may cause brain proteins to become misshapen and may contribute to poor brain functioning and neurodegenerative disease.
Recommendations from longevity researchers suggest that women should drink between 8 and 11 cups daily and men should drink 10 to 15 cups. Some medical conditions and medications require restricting water; if you have been told to limit water, follow your medical provider's advice.
Get more and better sleep. Sleep has lots of benefits including lower blood pressure and healthier blood sugar levels and lower body weight – these may all improve heart health and brain health.
Sleep is also essential for the normal removal of toxins from the brain. Research in 2019 showed the effect of deep sleep "slow" brain waves accompanying cerebrospinal fluid washing toxins out of the brain. These slow waves are known to be important in memory and brain disease. People with Alzheimer's dementia often have sleep disturbances decreasing the number of "slow brain wave wash cycles" which result in accumulation of beta-amyloid (a toxin associated with Alzheimer's disease). This seems to perpetuate poor sleep, creating a vicious cycle.
Study findings released in early 2021 showed that people in their 50s and 60s who got less than six hours of sleep per night were 30% more likely to develop dementia than those who got at least seven hours of sleep per night.
According to the CDC, about 70 million Americans have chronic sleep problems.
If you have sleep apnea or frequently have poor sleep, put correcting these on your to-do list for better heart and better brain health. The amount of sleep needed for most adults is between seven and nine hours per night.
Reevaluate your food choices. Eating well and maintaining a healthy body weight during mid-life are likely to help prevent and delay dementia. This is another area in which "what is good for the heart is good, is good for the brain".
The current U.S. dietary recommendations and eating patterns are effective for improving heart health. The MIND Diet (Mediterranean-DASH Intervention for Neurodegenerative Delay) combines elements from the recommended Mediterranean and the DASH diets and focuses on berries, leafy greens and other vegetables, nuts, beans, whole grains, olive oil, seafood, poultry and wine. The diet is also very low in processed and red meat, sugar and fatty foods. A prospective study published in 2021 showed that older adults who adhered most closely to the MIND diet had slower cognitive decline and a 53% reduced risk of developing Alzheimer's dementia.
The differences in the MIND pattern from earlier heart healthy patterns is incorporation of foods that have demonstrated brain protective and antioxidant effects, such as berries. As you plan your revised heart health and brain health diet, consider a few other tweaks such as including naturally fermented food, more spices like turmeric, cardamom and basil, high-nutrient leafy greens like arugula and watercress, broccoli and other cruciferous vegetables. Stick to whole natural foods instead of processed foods.
Stay in touch. The brain and heart are connected in ways that have not been described here. And, staying socially engaged and challenging the brain with new experiences has always been considered important for brain and heart health. The past two years of COVID-19 has interfered with healthy levels of human interaction. Reach out to others and take care of yourself, your family and your community in whatever ways you are able for better brain and heart health.
No matter who we are, aging comes with some inevitable changes. Research on aging contains many contradictions and controversies. But, slowly, theories are being tested and can lead us to a better understanding of the controllable factors contributing to a longer life with good brain health. Dementia does not have to be one of the inevitable changes.
For more information about these recommendations, call or email Leslie Shallcross at 907-242-6138 or firstname.lastname@example.org.
Leslie Shallcross is a registered dietitian and professor at the University of Alaska Fairbanks Institute of Agriculture, Natural Resources and Extension.