Posts Tagged ‘Diet’
Studies reported in this week’s Journal of the American Medical Association (August 12, 2009) support the relation of physical activity and the Mediterranean diet to reduced risk for Alzheimer’s disease. The first study, by Scarmeas and his colleagues, showed that persons who report following the Mediterranean diet and who are more physically active were less likely to develop Alzheimer’s disease over several years. The average age of the participants was 77 years, so this group (called the Northern Manhattan cohort) would have been at higher risk than younger individuals.
The second study, by Feart and her colleagues, looked at adherence to the Mediterranean diet and risk for having problems on certain mental ability tests. Here again, the study suggests that following the Mediterranean diet was associated with a reduced risk of developing certain kinds of cognitive problems.
The study was discussed by Dr. Nancy Snyderman on the Today Show. You can find a link to a page that will let you see the segment from the show here. (Look for a link to “Study: Mediterranean diet cuts Alzheimer’s risk.” You also have to watch a commercial; that’s NBC, not me). I think that she may overstate the case based on the research; there’s a very nice editorial in this same issue of the Journal by well-known neurologist David Knopman. He points out a number of possible reasons for these findings that might affect the conclusion that the Mediterranean diet and exercise reduce the risk of Alzheimer’s. He suggests we should “nibble and savor” the results of these studies, not “swallow them whole.”
It’s still premature to be sure that following the Mediterranean diet or being physically activity will prevent Alzheimer’s disease. Given what we know about the relation of cardiovascular health and risk for Alzheimer’s, and what we know about diet and exercise and cardiovascular health, though, I think it’s a good idea to pay close attention to your diet and to exercise safely.
When you’re thinking about brain fitness, it’s easy to get preoccupied with things like computer training programs and exotic dietary supplements. It’s just as important, and probably more important, to remember the basics of brain fitness.
What are the basics? I think they start with essential health care that will make sure your brain is in a health body. Maybe the single most important basic is to take care of your blood pressure. Besides being a risk factor for heart attack, high blood pressure is a risk for stroke. Studies have suggested that high blood pressure is a risk factor memory problems. You should know your blood pressure, and if it’s high, you should discuss it with your doctor. A number of effective treatments are available for high blood pressure. You can find out more about high blood pressure on the web site of the American Heart Association by clicking here.
One risk for memory problems that seems to be more and more common is the metabolic syndrome. The metabolic syndrome is a group of characteristics that includes abdominal obesity (fat around the waist), problems with blood lipids (the special substances in the blood that carry fats around the blood stream), insulin resistance (your body doesn’t take care of sugar very well), and increases in the substances in your blood that cause blood clots. People with the metabolic syndrome may be at higher risk for diabetes and heart attacks. The American Heart Association also has a good page on metabolic syndrome here. It may be possible to reduce the effects of the metabolic syndrome by maintaining a health weight, getting regular exercise, and following a healthy diet.
We know that the basics include a lot of things we’ve been hearing for years. What has become more clear over the past few years is that there are clear reasons for the links among obesity, low physical activity, and several diseases. One of the most intriguing links is the fact that all these conditions are associated with markers of inflammation in the blood. Inflammatory markers have complicated names like cytokines and interleukins. You don’t have to know all the specific names to know that high levels of these markers go along with memory problems. More and more, then, there’s a clear link between your basic health and your brain’s fitness.
Dietary supplements for brain fitness are controversial. This is at least in part because of two important facts:
- Very little research shows that any supplement has a positive effect on brain fitness, and
- Many supplements are costly, and some may have negative side effects such as interactions with prescription medications.
The first fact means that it’s very hard to know whether any supplement measures up to the claims that some people at least make for it. The second means that you may have to make a substantial investment in something that may or may not help you, and that the makers of the supplements may have a lot of money to promote them.
Having said that, some dietary supplements have limited evidence to support their inclusion in a brain fitness program. Probably the best-supported supplement for heart health, omega-3 fish oils, is a likely candidate for brain health. The American Heart Association recommends that everyone get some omega-3 fish oils from their diet, and from supplements if they to lower their triglycerides.
Another supplement that has been touted as possibly effective in reducing your risk of getting Alzheimer’s disease is curcumin. It’s a substance that occurs in turmeric, a common spice. Consumption of turmeric in some parts of India, some researchers have suggested, may account for low rates of Alzheimer’s disease in those areas. In one study with mice, those fed curcumin seemed to have a reversal of amyloid plaque formation in their (those are one of the key things that happen in the brain in Alzheimer’s).
Large scale studies have shown that people who get more antioxidants in their diet, and possibly those who take supplements of antioxidants like vitamins C and E, may have lower risk for developing Alzheimer’s disease. A group of researchers in New York have shown that people who follow the antioxidant-rich Mediterranean diet more closely have a lower risk for Alzheimer’s disease.
At the moment, these are our best guesses for supplements that may help maintain brain fitness. As interest increases in brain fitness, we may know more about these and other supplements.
A recent study provides a clue into the exercise-brain fitness relation. A paper reported in the December 2008 issue of the journal Neurology shows that high levels of blood glucose (the kind that can happen in people with diabetes) may directly affect the hippocampus. Since the hippocampus is a part of the brain that is essential for memory, this study helps us understand one way in which physical fitness can affect brain function. What’s the link? We know that physical fitness improves the body’s ability to regulate blood sugar levels, so being physically fit may decrease the damage that high blood sugar levels can cause to the hippocampus.
The story is a little more complicated, though (isn’t it always)? Blood sugar is regulated by a hormone called insulin. People who have type II diabetes (the kind that people usually get later in life) have a condition called insulin resistance. This means that the body makes enough, and sometimes too much, insulin. The problem is that the insulin doesn’t have a strong enough effect. This means that the body keeps making higher levels of insulin. Exposing the body to high levels of insulin can cause problems.
In the case of the brain, insulin is very important for its function. Insulin has to cross into the brain from the blood by way of a special mechanism called a transporter protein. When insulin levels are high all the time, the body decreases the number of these transporter proteins, and the brain may not get enough insulin. Some studies have shown that insulin is important in memory function, so a decrease in the number of these transporter proteins may be yet another way that high blood sugar levels can affect memory. While all of these studies are preliminary, they add to what we know about high blood sugar, insulin resistance, and mental functioning.
There are two effective ways of keeping your blood sugar under control: diet and exercise. Following the Mediterranean diet can help, because it emphasizes the kinds of food that will help keep your blood sugar stable. Exercise has been shown to help your body be more sensitive to the effects of insulin. When your body is more sensitive to insulin’s effects, blood sugar levels will be lower and more stable. We know that following the Mediterranean diet and regular exercise can help your memory – their link to blood sugar and blood sugar’s effects on the brain may be why.
The Mediterranean diet is an important part of any brain health program. A number of studies have shown that people who follow the Mediterranean diet have less chance of having a heart attack, and that changing to the diet can reduce risk for another heart attack. Consistent with our increasing appreciation of the relation of heart and brain risk factors, at least one study has shown that people who follow the Mediterranean diet more closely have a lower risk of being diagnosed with Alzheimer’s disease.
Just that may be enough to have you ready to try the diet, but you might wonder what it is and what you’re supposed to eat. That’s where Dr. Michael Ozner’s book comes in. Dr. Ozner is a cardiologist in Miami, Florida, and says that he has been using the diet to treat his patients for more than 25 years. The book includes clinical vignettes in which patients describe their experiences with the diet and how it has helped them. Although Dr. Ozner recommends the often-unpopular practice of counting calories, people who follow the diet may find that they can eat more and still lose weight because of the diet’s emphasis on low-glycemic index foods, fresh fruit and vegetables, and whole-grain breads and pastas.
In clear language Dr. Ozner lays out the reasons why you should be interested in the diet. He gives you an overview of the studies that have shown that people who follow the diet have lower risk for heart disease, and explains why. You may note that many of the elements of the Mediterranean diet have anti-inflammatory and anti-oxidant effects, making it similar in this respect to Dr. Andrew Weil’s anti-inflammatory diet.
But the book has lots more than just a description of the why the diet is important. It also has a complete 14-day diet plan and a wide selection of recipes that any cook can use to make the diet not just healthy but delicious. My favorite section of recipes is the one for pizzas. There is also a section with a number of recipes for desserts that are high in flavor and low in fat.
Overall, this is a very useful book that will help you understand the importance of the Mediterranean diet and will help you get started in following it.
The Miami Mediterranean Diet: Lose Weight and Lower Your Risk of Heart Disease with 300 Delicious Recipes
Hardcover, 432 pages, ISBN 978-1933771502, $25.95.
Click here to order the book from Amazon.
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Mindfulness meditation as practiced over a long period by experts makes clear changes in someone’s brain function. But what about those of us who don’t have a few years to sit in a monastery in the Himalayas? A new study shows that even brief meditation practice can improve attention.
I saw an interesting blog post yesterday evening on the site of the Huffington Post about the potential benefits of meditation – or at least about what one woman thinks might be the benefits. (more…)
Although many people are excited about the potential for using computers to train their brains, we shouldn’t forget that other techniques have been used to the train the brain for many centuries. I’m thinking about the large number of techniques for meditation. While free computer software still requires an investment in a computer, meditation only asks you to sit or lie quietly and focus your mind.
A recently-published study shows parts of the brain in long-term meditators are larger than the same parts of the brain in people who don’t meditate. The article by Eileen Luders and her colleagues appeared in a recent issue of the journal Neuroimage (Vol. 45, No. 3, pp. 672-678, April 15, 2009). The study showed that portions of the orbitofrontal cortex and the hippocampus were larger in persons who had been regular meditators for 5 or more years. The study is interesting because the parts of the brain that were larger are often thought to be important in helping people keep themselves emotionally balanced.
A number of strategies are likely to be helpful for meditators. There has been a great deal of interest over the last several years in mindfulness meditation. Researchers have studied how it can be used in reducing anxiety and depression. Mindfulness is based on Buddhist meditation (for a brief article, click here) but you don’t have to be a Buddhist to practice meditation. In fact, one of the most important persons who has promoted mindfulness is Jon Kabat-Zinn, a researcher at the University of Massachusetts. You can see a video presentation by him on YouTube by clicking here.