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aerobic exercise

Aerobic exercise is good for the brain. METRO photo
Exercise may improve mild cognitive impairment

By David Dunaief, M.D.

Dr. David Dunaief

As we consider aging, many of us fear loss of our mental capability as much as loss of our physical capabilities. Yet, just as with physical capabilities, age is not the only determinant.

Mild cognitive impairment (MCI) is feared, not only for its own challenges but also because it may lead to dementia, with Alzheimer’s disease and vascular dementia being the more common forms. Prevalence of MCI may be as high as one-in-five in those over age 70 (1). It is thought that those with MCI may have a 10 percent chance of developing Alzheimer’s disease (2).

So, the most compelling questions are: What increases risk and what can we do to minimize the risk of developing cognitive impairment? Many chronic diseases and disorders contribute to MCI risk. These include diabetes, heart disease, Parkinson’s disease and strokes. If we can control these, we may reduce our risk of cognitive decline.

Heart disease creates substantial risk

In an observational study, results demonstrated that those suffering from years of heart disease are at a substantial risk of developing MCI (3). The study involved 1,450 participants who were between the ages of 70 and 89 and were not afflicted by cognitive decline at the beginning of the study. Patients with a history of cardiac disease had an almost two times greater risk of developing nonamnestic MCI, compared to those individuals without cardiac disease. Women with cardiac disease were affected even more, with a three times increased risk of cognitive impairment.

Nonamnestic MCI can affect executive functioning — decision-making abilities, spatial relations, problem-solving capabilities, judgments and language. It is a more subtle form of impairment that may be more frustrating because of its subtlety. It may lead to vascular dementia and may be a result of clots.

Strokes: where is more important than how many

Not surprisingly, stroke may have a role in cognitive impairment. Stroke is also referred to as a type of vascular brain injury. But what is surprising is that in a study, results showed that the location of the stroke was more relevant than the frequency or the multitude of strokes (4). If strokes occurred in the cortical and subcortical gray matter regions of the brain, executive functioning and memory were affected, respectively. Thus, the locations of strokes may be better predictors of subsequent cognitive decline than the number of strokes. Clinically silent strokes that were found incidentally by MRI scans had no direct effect on cognition, according to the authors.

Exercise benefits cognitive functioning

Exercise may play a significant role in preventing cognitive decline and possibly even improving MCI in patients who have the disorder. Interestingly, different types of exercise have different effects on the brain. Aerobic exercise may stimulate one type of neuronal development, while resistance training or weightlifting another.

In an animal study involving rats, researchers compared aerobic exercise to weightlifting (5). Weightlifting was simulated by attaching weights to the tails of rats while they climbed ladders. Both groups showed improvements in memory tests, however, there was an interesting divergence.

With aerobic exercise, the level of the protein BDNF (brain-derived neurotrophic factor) increased significantly. This is important, because BDNF is involved in neurons and the connections among them, called synapses, related mostly to the hippocampus, or memory center. The rats that “lifted weights” had an increase in another protein, IGF (insulin growth factor), that promotes the development of neurons in a different area of the brain. The authors stressed the most important thing is to exercise, regardless of the type.

In another study that complements the previous study, women were found to have improved spatial memory when they exercised — either aerobic or weightlifting (6). Interestingly, verbal memory was improved more by aerobic exercise than by weightlifting. Spatial memory is the ability to recall where items were arranged, and verbal memory is the ability to recall words. The authors suggest that aerobic exercise and weightlifting affect different parts of the brain.

This was a randomized controlled trial that was six months in duration and involved women, ages 70 to 80, who had MCI at the trial’s start. There were three groups in the study: aerobic, weightlifting and stretching and toning. Those who did stretches or toning alone experienced deterioration in memory skills over the same period.

A Centers for Disease Control and Prevention report claims the majority of the adult population is woefully deficient in exercise: Only about 1 in 5 Americans exercise regularly, both using weights and doing aerobic exercise (7).

Diet makes a difference

Several studies show that the Mediterranean diet helps prevent MCI and possibly prevents conversion from MCI to Alzheimer’s (8, 9). In addition, a study showed that high levels of carbohydrates and sugars, when compared to lower levels, increased the risk of cognitive decline by more than three times (5). The authors surmise that carbohydrates have a negative impact on insulin and glucose utilization in the brain.

Cognitive decline should be taken very seriously, and everything that can be done to prevent it should be utilized. Exercise has potentially positive effects on neuron growth and development, and controlling carbohydrate and sugar intake may reduce risk. Of course, if you have cardiovascular disease, making lifestyle changes to reverse or minimize its impact will reap both physical and cognitive rewards. Let’s not squander the opportunity to reduce the risk of MCI, a potentially life-altering disorder.

References:

(1) Ann Intern Med. 2008;148:427-434. (2) uptodate.com. (3) JAMA Neurol. 2013;70:374-382. (4) JAMA Neurol. 2013;70:488-495. (5) J Alzheimers Dis. 2012;32:329-339. (6) J Aging Res. 2013;2013:861893. (7) Morb Mortal Wkly Rep. 2013;62:326-330. (8) Neurology 2013;80:1684-1692. (9) Arch Neurol. 2009 Feb.;66:216-225.

Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com. 

Aerobic exercise and weight lifting may prevent cognitive decline, according to studies. Stock photo
Reducing carbohydrate and sugar intake may reduce risk

By David Dunaief, M.D.

Dr. David Dunaief

Mild cognitive impairment (MCI) is one of the more common disorders that occurs as we age. But age is not the only determinant. There are a number of modifiable risk factors. MCI is feared, not only for its own challenges but also because it may lead to dementia, with Alzheimer’s disease and vascular dementia being the more common forms. Prevalence of MCI may be as high as one in five in those over age 70 (1). It is thought that those with MCI may have a 10 percent chance of developing Alzheimer’s disease (2).

Since there are very few medications presently that help prevent cognitive decline, the most compelling questions are: What increases risk and what can we do to minimize the risk of developing cognitive impairment?

Many chronic diseases and disorders contribute to MCI risk. These include diabetes, heart disease, Parkinson’s disease and strokes. If we can control these maladies, we may reduce the risk of cognitive decline. We know that we can’t stop aging, but we can age gracefully.

Heart disease’s impact

In an observational study, results demonstrated that those suffering from years of heart disease are at a substantial risk of developing MCI (3). The study involved 1,450 participants who were between the ages of 70 and 89 and were not afflicted by cognitive decline at the beginning of the study. Patients with a history of cardiac disease had an almost two times greater risk of developing nonamnestic MCI, compared to those individuals without cardiac disease. Women with cardiac disease were affected even more, with a three times increased risk of cognitive impairment.

Nonamnestic MCI affects executive functioning — decision-making abilities, spatial relations, problem-solving capabilities, judgments and language. It is a more subtle form of impairment that may be more frustrating because of its subtlety. It may lead to vascular dementia and may be a result of clots.

Stroke location vs. frequency

Not surprisingly, stroke may have a role in cognitive impairment. Stroke is also referred to as a type of vascular brain injury. But what is surprising is that in a study, results showed that the location of the stroke was more relevant than the frequency or the multitude of strokes (4). If strokes occurred in the cortical and subcortical gray matter regions of the brain, executive functioning and memory were affected, respectively. Thus, the locations of strokes may be better predictors of subsequent cognitive decline than the number of strokes. Clinically silent strokes that were found incidentally by MRI scans had no direct effect on cognition, according to the authors.

Exercise’s effects

Stock photo

Exercise may play a significant role in preventing cognitive decline and possibly even improving MCI in patients who have the disorder. Interestingly, different types of exercise have different effects on the brain. Aerobic exercise may stimulate one type of neuronal development, while resistance training or weight lifting another.

In an animal study involving rats, researchers compared aerobic exercise to weight lifting (5). Weight lifting was simulated by attaching weights to the tails of rats while they climbed ladders. Both groups showed improvements in memory tests, however, there was an interesting divergence.

With aerobic exercise, the level of the protein BDNF (brain-derived neurotrophic factor) increased significantly. This is important because BDNF is involved in neurons and the connections among them, called synapses, related mostly to the hippocampus, or memory center. The rats that “lifted weights” had an increase in another protein, IGF (insulin growth factor), that promotes the development of neurons in a different area of the brain. The authors stressed the most important thing is to exercise, regardless of the type.

In another study that complements the previous study, women were found to have improved spatial memory when they exercised — either aerobic or weight lifting (6). Interestingly, verbal memory was improved more by aerobic exercise than by weight lifting. Spatial memory is the ability to recall where items were arranged, and verbal memory is the ability to recall words. The authors suggest that aerobic exercise and weight lifting affect different parts of the brain.

This was a randomized controlled trial that was six months in duration and involved women, ages 70 to 80, who had MCI at the trial’s start. There were three groups in the study: aerobic, weight lifting and stretching and toning. Those who did stretches or toning alone experienced deterioration in memory skills over the same period.

A Centers for Disease Control and Prevention report claims the majority of the adult population is woefully deficient in exercise: Only about one in five Americans exercise regularly, both using weights and doing aerobic exercise (7).

Diet’s effects

Several studies show that the Mediterranean diet helps prevent MCI and possibly prevents conversion from MCI to Alzheimer’s (8, 9). In addition, a study showed that high levels of carbohydrates and sugars, when compared to lower levels, increased the risk of cognitive decline by more than three times (5). The authors surmise that carbohydrates have a negative impact on insulin and glucose utilization in the brain.

Cognitive decline is a disorder that should be taken very seriously, and everything that can be done to prevent it should be utilized. Exercise has potentially positive effects on neuron growth and development, and controlling carbohydrate and sugar intake may reduce risk. Let’s not squander the opportunity to reduce the risk of MCI, a potentially life-altering disorder.

References:

(1) Ann Intern Med. 2008;148:427-434. (2) uptodate.com. (3) JAMA Neurol. 2013;70:374-382. (4) JAMA Neurol. 2013;70:488-495. (5) J Alzheimers Dis. 2012;32:329-339. (6) J Aging Res. 2013;2013:861893. (7) Morb Mortal Wkly Rep. 2013;62:326-330. (8) Neurology 2013;80:1684-1692. (9) Arch Neurol. 2009 Feb.;66:216-225.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician. 

Exercising 30 minutes four to five times a week is best. Stock photo
It is possible to overdo exercise for weight loss purposes

By David Dunaief, M.D.

Dr. David Dunaief

When we make a New Year’s resolution to exercise regularly, the goal is often either to change body composition, to lose weight, or at least to maintain weight. How much exercise is best for these purposes? It is a hotly debated topic. You would think the answer would be straightforward, since exercise helps us prevent and resolve a great many diseases.

At the same time, we hope exercise impacts our weight. Does it? It is important to manage our expectations, before we start exercising. There are some intriguing studies that address whether exercise has an impact on weight management. The short answer is yes; however, not always in ways we might expect.

Then the questions become: What type of exercise should we be doing? How frequently and for how long? Let’s look at the evidence.

Duration

It makes sense that the more we exercise to lose weight, the better, or at least that is what we thought. In a small randomized controlled trial (RCT), the gold standard of studies, results showed that the moderate group in terms of duration saw the most benefit for weight loss (1). 

There were three groups in the study — a sedentary group (low), a group that did 30 minutes per day of aerobic exercise (moderate) and a group that did 60 minutes per day of aerobic exercise (high).

Perhaps obviously, the sedentary group did not see a change in weight. Surprisingly, though, the group that did 30 minutes of exercise per day experienced not only significantly more weight loss than the sedentary group, but also more than the 60-minute exercise group. The aerobic exercises involved biking, jogging or other perspiring activities. These were healthy young men that were overweight, but not obese, and the study duration was three months.

The authors surmise that the reason for these results is that the moderate group may have garnered more energy and moved around more during the remainder of the day, as sensors showed. The highest exercise group was sedentary through most of the rest of day, probably due to fatigue. Also, it seemed that the highest exercise group ate more than the moderate group, though the difference was not statistically significant. While this study is of impressive quality, it is small and of short duration. Nonetheless, its results are encouraging.

Postmenopausal women

As a group, postmenopausal women have considerable difficulty losing weight and maintaining weight loss. In a secondary analysis of a randomized controlled trial, there were three aerobic exercise groups differentiated by the number of kcal/kg per week they burned: 4, 8 and 12 (2). All of the groups saw significant reductions in waist circumference. Interestingly, however, a greater number of steps per day outside of the training, measured by pedometer, were primarily responsible for improved waistline circumference, regardless of the intensity of the workouts.

But it gets more intriguing, because the group that exercised with the lowest intensity was the only one to see significant weight loss. More is not always better, and in the case of exercise for weight loss, less may be more. This study reinforces the suppositions made by the authors of the previous men’s study: We should exercise to a point where it is energy inducing and not beyond.

Premenopausal women

Not to ignore younger women, those who were premenopausal also saw a significant benefit with weight maintenance and exercise after having intentionally lost weight.

In a prospective (forward-looking) study, young women who did at least 30 minutes of exercise four to five days per week were significantly less likely to regain weight that they had lost, compared to those who were sedentary after losing weight (3).

Some of the strengths of this study were its substantially long six-year follow-up period and its large size, involving over 4,000 women between the ages of 26 and 45. Running and jogging were more impactful in preventing weight gain than walking with alacrity. However, all forms of exercise were superior to the sedentary group.

Aerobic exercise and resistance training

In another RCT with 119 overweight or obese adults, aerobic exercise four to five times a week for about 30 minutes each was most effective for weight loss and fat reduction, while resistance training added lean body mass. Lean body mass is very important. It does not cause weight reduction, but rather increased fitness (4).

With weight loss, it’s important to delineate between thin and fit. Fitness includes a body composition of decreased body fat and increased lean muscle mass. To help achieve fit level, it’s probably best to have a combination of aerobic and anaerobic exercise (resistance training). Both contribute to achieving this goal.

In conclusion, exercise can play a significant role in weight, whether with weight reduction, weight maintenance or increasing lean body mass. It appears that 30 minutes of exercise four to five times a week is best. Longer is not necessarily better.

What is most important, however, is to exercise to the point where it energizes you, but doesn’t cause fatigue. This is because it is important not to be sedentary the rest of the day, but to remain active. We should also include a complete package of lifestyle modifications in general — diet, exercise and stress reduction — to get the most compelling results.

References:

(1) Am J Physiol Regul Integr Comp Physiol. 2012 Sep 15;303(6):R571-R579. (2) Am J Prev Med. 2012;43(6):629-635. (3) Obesity 2010;18(1):167-174. (4) J Appl Physiol. 2012 Dec;113(12):1831-1837.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician. 

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Different types of exercise have different impacts

By David Dunaief, M.D.

Dr. David Dunaief

Mild cognitive impairment (MCI) is one of the more common disorders that occurs as we age. But age is not the only determinant. There are a number of modifiable risk factors. MCI is feared, not only for its own challenges but also because it may lead to dementia, with Alzheimer’s disease and vascular dementia being the more common forms. Prevalence of MCI may be as high as one-in-five in those over age 70 (1). It is thought that those with MCI may have a 10 percent chance of developing Alzheimer’s disease (2).

Since there are very few medications presently that help prevent cognitive decline, the most compelling questions are: What increases risk and what can we do to minimize the risk of developing cognitive impairment? These are the important questions.

Many chronic diseases and disorders contribute to MCI risk. These include diabetes, heart disease, Parkinson’s disease and strokes. If we can control these maladies, we may reduce the risk of cognitive decline. This involves making lifestyle modifications such as exercise and diet. We know that we can’t stop aging, but we can age gracefully.

Heart disease’s impact

Although we have made great strides, heart disease continues to be prevalent in America. In an observational study, results demonstrated that those suffering from years of heart disease are at a substantial risk of developing MCI (3). The study involved 1,450 participants who were between the ages of 70 and 89 and were not afflicted by cognitive decline at the beginning of the study. Patients with a history of cardiac disease had an almost two times greater risk of developing nonamnestic MCI, compared to those individuals without cardiac disease. Women with cardiac disease were affected even more, with a three times increased risk of cognitive impairment.

Nonamnestic MCI affects executive functioning — decision-making abilities, spatial relations, problem-solving capabilities, judgments and language. It is a more subtle form of impairment that may be more frustrating because of its subtlety. It may lead to vascular dementia and may be a result of clots. This gives us yet another reason to treat and prevent cardiac disease.

Stroke location vs. frequency

Not surprisingly, stroke may have a role in cognitive impairment. Stroke is also referred to as a type of vascular brain injury. But what is surprising is that in a study, results showed that the location of the stroke was more relevant than the frequency or the multitude of strokes (4). If strokes occurred in the cortical and subcortical gray matter regions of the brain, executive functioning and memory were affected, respectively. Thus, the locations of strokes may be better predictors of subsequent cognitive decline than the number of strokes. Clinically silent strokes that were found incidentally by MRI scans had no direct effect on cognition, according to the authors.

Exercise’s effects

Studies have shown that aerobic exercise improves brain function. Stock photo

Exercise may play a significant role in potentially preventing cognitive decline and possibly even improving MCI in patients who have the disorder. Interestingly, different types of exercise have different effects on the brain. Aerobic exercise may stimulate one type of neuronal development, while resistance training or weight lifting another.

In an animal study involving rats, researchers compared aerobic exercise to weight lifting (5). Weight lifting was simulated by attaching weights to the tails of rats while they climbed ladders. Both groups showed improvements in memory tests, however, there was an interesting divergence.

With aerobic exercise, the level of the protein BDNF (brain-derived neurotrophic factor) increased significantly. This is important, because BDNF is involved in neurons and the connections among them, called synapses, related mostly to the hippocampus, or memory center. The rats that “lifted weights” had an increase in another protein, IGF (insulin growth factor), that promotes the development of neurons in a different area of the brain. The authors stressed the most important thing is to exercise, regardless of the type.

In another study that complements the previous study, women were found to have improved spatial memory when they exercised — either aerobic or weight lifting (6). Interestingly, verbal memory was improved more by aerobic exercise than by weight lifting. Spatial memory is the ability to recall where items were arranged, and verbal memory is the ability to recall words. The authors suggest that aerobic exercise and weight lifting affect different parts of the brain, which corroborates the animal study findings above.

This was a randomized controlled trial that was six months in duration and involved women, ages 70 to 80, who had MCI at the trial’s start. There were three groups in the study: aerobic, weight lifting and stretching and toning. Those who did stretches or toning alone experienced deterioration in memory skills over the same period.

Here is the catch with exercise: We know exercise is valuable in preventing disorders like cardiovascular disease and cognitive decline, but are Americans doing enough? A Centers for Disease Control and Prevention report claims the majority of the adult population is woefully deficient in exercise: Only about 1 in 5 Americans exercise regularly, both using weights and doing aerobic exercise (7).

Diet’s effects

Several studies show that the Mediterranean diet helps prevent MCI and possibly prevents conversion from MCI to Alzheimer’s (8, 9). In addition, a study showed that high levels of carbohydrates and sugars, when compared to lower levels, increased the risk of cognitive decline by more than three times (5). The authors surmise that carbohydrates have a negative impact on insulin and glucose utilization in the brain.

Cognitive decline is a disorder that should be taken very seriously, and everything that can be done to prevent it should be utilized. Though the number of Americans exercising regularly is woefully deficient, the silver lining is that there is substantial room for improvement. Exercise has potentially positive effects on neuron growth and development. We need more campaigns like the NFL’s Play 60, which entices children to be active at least 60 minutes every day, but we also need to target adults of all ages. Let’s not squander the opportunity to reduce the risk of MCI, a potentially life-altering disorder.

References: (1) Ann Intern Med. 2008;148:427-434. (2) uptodate.com. (3) JAMA Neurol. 2013;70:374-382. (4) JAMA Neurol. 2013;70:488-495. (5) J Alzheimers Dis. 2012;32:329-339. (6) J Aging Res. 2013;2013:861893. (7) Morb Mortal Wkly Rep. 2013;62:326-330. (8) Neurology 2013;80:1684-1692. (9) Arch Neurol. 2009 Feb.;66:216-225.

Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.