Vigorous physical activity benefits the aging brain, three studies show.
Regular exercise may be the best medicine for seniors facing the onset of dementia, according to three new clinical trials.
Physical activity improved mood, memory and ability to think for participants in all three studies.
One study found that intense aerobic exercise improves blood flow to key areas of the brain, and appears to reduce the tau protein tangles that are a hallmark of Alzheimer’s disease. Alzheimer’s is the most common form of dementia.
“Blood flow decreases in those areas for all of us with age, and yet exercise increased it,” said lead author Laura Baker, a cognitive neuroscientist at Wake Forest School of Medicine in Winston-Salem, N.C. “It seems to me we’re changing aging-related effects, and we may be changing Alzheimer’s-related effects, both with exercise.”
The new research was scheduled for presentation Thursday at the Alzheimer’s Association International Conference in Washington, D.C. Findings presented at meetings are usually considered preliminary until published in a peer-reviewed medical journal.
The three studies “give us information about living better with the disease,” said Heather Snyder, director of medical and scientific operations for the Alzheimer’s Association.
“Physical exercise is potentially beneficial to people who are living with Alzheimer’s today,” Snyder said. “Even once you have cognitive impairment, there’s still a benefit to physical activity.”
Prior research has shown that exercise can improve the ability to think in healthy adults, so Baker and her colleagues turned to people with mild impairment to see if physical activity would help them, too. The 65 people in Baker’s study were 55 to 89 years old and had not been exercising beforehand. They also had prediabetes, which can increase risk of developing Alzheimer’s disease.
Participants were randomly assigned to one of two groups for six months. The first group performed stretching exercises that did not raise their heart rate much, while the second group had to perform at least 45 minutes of high-intensity aerobics four times a week.
The aerobics group had to stay within 75 percent to 85 percent of their maximum heart rate for at least 30 minutes of their workout, which most often took place on a treadmill. “For our typical 70-year-old, that means a heart rate of at least 130 beats per minute,” Baker said.
Ninety-two percent of people stuck to the exercise program, and wound up with improved fitness and better blood sugar levels, researchers found.
More important, MRI brain scans revealed that blood flow had significantly increased to the memory and processing centers of participants’ brains, with a corresponding improvement in their ability to plan, organize and pay attention.
Tests using cerebrospinal fluid samples drawn from the patients also showed a significant reduction in tau protein tangles, with the effect most pronounced in those older than 70.
“These findings are important because they strongly suggest a potent lifestyle intervention such as aerobic exercise can impact Alzheimer’s-related changes in the brain,” Baker said. “No currently approved medication can rival these effects.”
In another clinical trial, 200 people between ages 50 and 90 with Alzheimer’s were randomly assigned to either an aerobic exercise program or a control group that performed no extra exercise. The folks who exercised were asked to reach a target intensity of 70 percent to 80 percent of their maximum heart rate.
The Danish researchers found that those who exercised suffered from fewer mood problems such as anxiety, irritability and depression. The people who exercised most often and most vigorously also achieved significant improvements in mental speed and attention.
The third clinical trial took place in Canada and involved 71 people between ages 56 and 96 who had suffered ministrokes, diminishing their ability to think and remember. Half were assigned to a group that took part in regular aerobics classes.
The researchers found that participants who took aerobics significantly improved their memory and selective attention, compared with those not asked to exercise regularly.
Snyder and Baker said most seniors should be able to find some physical activity they can perform, even if they have some age-related infirmities.
“You don’t have to use any one exercise,” Baker said. “It’s anything you can get your heart rate up to where you are panting and sweating.”
However, she noted that seniors should consult their doctor before embarking on an exercise program, and ease into it. The Danish study gave participants four weeks to adapt before asking them to exercise more intensely.
If someone already has dementia, they still can benefit from exercise, but will probably need someone to guide their workout schedule, Baker added.
“But that supervision can be in the form of group exercise,” she said. “It doesn’t have to be one-on-one.”
12 oz boneless skinless chicken breast
8 oz fresh button mushroom
2 (about 1½ lb) bunch spinach
1 Tbsp garlic (minced)
1 Tbsp ginger (minced)
2 tsp light soy sauce
dash white ground pepper
2 tsp water
1 tsp cornstarch
2 tsp oil
1 Tbsp light soy sauce
1/4 tsp salt
3/4 tsp sugar
1/8 tsp white ground pepper
1 tsp sesame oil
1/2 tsp chicken broth mix
1 Tbsp cornstarch
6 oz water
Nutrition value for 1/6 portion of recipe:
Calorie 226, Fat 14.6 g, Carbohydrate 9 g, Fibre 3 g, Sugar 1 g, Cholesterol 36 mg, Sodium 502 mg, Protein 17 g.
Older adults who ate better maintained problem-solving and planning skills, study finds.
Eating a healthier diet might reduce the risk of problems with certain brain functions as you age, findings from a recent study suggest.
Older adults with healthier diets reduced their odds of impaired “executive function” by 35 percent. Executive function refers to a collection of things done by the brain, including memory, reasoning, multi-tasking, problem-solving and planning skills.
“Healthy diet might affect cognition [thinking skills] through several mechanisms,” said study co-author Carol Derby, associate professor of neurology and of epidemiology and population health at the Albert Einstein College of Medicine in New York City.
“Healthy diet is associated with reduced rates of cardiovascular disease, with more healthy weight and with reduced risk of diabetes, all of which are risk factors for cognitive decline and dementia,” she explained.
However, this study wasn’t designed to show that eating more healthfully actually caused the better brain function, or that a good diet could prevent Alzheimer’s or dementia. The study was only designed to find an association between a healthy diet and better brain function.
Researchers presented the findings this week at the Alzheimer’s Association International Conference in Washington, D.C. Findings presented at meetings are generally considered preliminary until they’ve been published in a peer-reviewed journal.
For the study, researchers asked nearly 550 seniors about their diets. Their average age was 80 years old. None of them showed signs of dementia.
The study volunteers were asked to recall how many servings they eat weekly of grains, fried foods, snacks, sweets, soft drinks, fats, alcohol, fruits and vegetables, and specific dairy and meat products.
Each participant also took several tests to determine memory and thinking skills, along with executive function. Participants were considered to have impaired function if they scored substantially lower than average on a particular collection of skills.
After taking into consideration participants’ age, education, sex, race and heart conditions, the researchers determined that those with a healthier diet had 35 percent lower odds of impaired executive function. No links between diet and overall memory or thinking were found, the researchers said.
When the investigators looked at differences between black and white participants, they found no link between diet and any brain health test in blacks. The lack of a difference may be because black individuals tend to have a greater risk of vascular conditions, the researchers said.
Among whites, healthier scores on total fat intake were linked to 52 percent lower odds of poor executive function. Healthier scores for saturated fat intake were linked to 66 percent lower odds of poor executive function, the study found.
“We know that a diet that is too caloric or too loaded with sugars can lead to insulin resistance and vascular disease that, in turn, are not good for the brain,” said Dr. Marie Csete, president and chief scientist of Huntington Medical Research Institutes in Pasadena, Calif.
“We know that mood is affected by the content of food, and that mood affects sleep patterns, and sleep is an important factor in maintaining brain health,” added Csete, who was not involved with the study.
Still, there are other explanations for the findings than a healthier diet causing better brain health, Csete suggested, such as overall healthier lifestyles among those who also eat healthier diets.
“You might think that people who are interested in preparing healthy foods for themselves would also be interested in having more physical activity, in not smoking and in controlling their cholesterol levels,” Csete said. “Exercise is a very positive modifiable factor to help stave off loss of cognitive function.”
It’s also not clear what specifically makes up a healthy diet, though there are some general guidelines that make sense, said Dr. Luca Giliberto, an investigator physician at the Litwin-Zucker Research Center for the Study of Alzheimer’s Disease at the Feinstein Institute for Medical Research in Manhasset, N.Y.
“One would assume that a diet rich in natural vitamins, low in saturated fats and rich in omega-3 fats, low in refined sugars and rich in high-quality proteins would do the trick,” Giliberto said. “In reality, it is probably the balance of all these aspects and the attached quality of life, physical and mental activity, and personal satisfaction that complete the recipe for good cognition.”
Meanwhile, an excess of refined sugars, saturated fats and too few natural vitamins and good proteins increases the risk of atherosclerosis and oxidative stress in the body, which can contribute to mental decline, Giliberto explained.
“It is never too late to start prevention, especially when it comes to food and physical activity,” Giliberto said. “The two often go hand in hand.”
1 duck carcass (raw or cooked), plus 2 legs or any giblets, trimmed of as much fat as possible
1 large onion, unpeeled, with root end trimmed
2 carrots, cut into 5 cm pieces
1 parsnip, cut into 5 cm pieces
1 leek, cut into 5 cm pieces
2 to 4 garlic cloves, crushed
2.5 cm piece fresh root ginger, peeled and sliced
1 tbsp black peppercorns
4 to 6 thyme sprigs, or 1 tsp dried thyme
1 small bunch coriander (6-8 sprigs), leaves and stems separated
1 small carrot
1 small leek, halved lengthwise
4 to 6 shiitake mushrooms, thinly sliced
2 green onions, thinly sliced
freshly ground black pepper
Makes 4 servings
Source: French Classic Cuisine Made Easy
Mike Orcutt wrote . . . . .
Researchers in the U.K. aim for a new commercial potato that resists many of the worst vulnerabilities of potato crops around the world.
Super spuds are coming.
A genetically modified potato that could resist destructive blight, defend itself against parasitic worms, avoid bruising, and cut down on the accumulation of a suspected carcinogen during cooking would be worth many billions of dollars per year to potato producers across the world. It could also serve as a model technology for addressing issues that affect many different crops and are increasingly likely to cause concerns about global food security as the population grows and the world’s climate becomes more unpredictable.
This mega-resilient potato is the goal of a new project officially launched by researchers in the United Kingdom in June. If they are successful, this would be the first potato to have all these traits, each of which has already been demonstrated in previous genetically modified versions of popular potato varieties. The five-year endeavor will be led by Jonathan Jones, a scientist at Sainsbury Lab in the U.K. and one of the world’s leading experts on the genetics of plant diseases.
The potato Jones is aiming for will contain three genes his group has shown to confer resistance to late blight and two genes researchers at the University of Leeds have found to block infestation by a tiny worm called the potato cyst nematode. It will also have DNA the U.S. company J.R. Simplot used to engineer a potato variety, recently commercialized, that has fewer dark spots and contains less asparagine, a chemical that can cause the accumulation of a suspected carcinogen during high-temperature cooking.
Jones’s group has already engineered a blight-resistant potato, using a single gene it cloned from one found in a wild potato plant. For a commercial product, though, a single resistance gene will not be enough, he says, because it would likely lead to the emergence of pathogen strains resistant to that gene. Jones says an important objective of this project is to test the hypothesis that “stacking” multiple resistance genes can safeguard against this danger. His group found all three genes in wild potatoes.
Potatoes are a key staple crop all over the world. In terms of direct human consumption, they are among the top foods globally, along with wheat and rice. They are also quite susceptible to disease, particularly late blight, which led to the Irish potato famine in the mid-1800s. Caused by a fungus-like organism, it remains a “disastrous scourge” on potato crops, Jones says, and farmers in the U.K. must spray pesticide 15 times a year to combat it. The disease costs the U.K.’s potato industry more than $90 million per year. Globally, it costs some $5 billion.
Parasitic nematodes are a similarly massive economic drain on the potato industry in the U.K. and worldwide owing to the costs of pesticides and lost crops. Researchers from the University of Leeds are contributing DNA sequences to Jones’s new potato that will give it powerful weapons to fight the worms. The Leeds group has shown that introducing genes expressed only in the roots of the new potato should provide the crop with two distinct deterrents against them.
Bruising is another expensive problem. Since consumers prefer potatoes without dark spots, companies waste a huge amount of perfectly edible food. Simplot, which is helping to fund Jones’s project and contributing expertise and technology, recently gained U.S. regulatory approval to sell a potato containing DNA that cuts down on the amount of certain sugars responsible for bruising, as well as the amount of asparagine. Asparagine is responsible for the accumulation of acrylamide, which may increase the risk of certain cancers, during cooking.
To deliver the new DNA, Jones and his colleagues will use a well-established method called transformation, which takes advantage of a natural process by which bacteria transfer DNA to plants. Then they will use extensive screening and DNA analysis to identify a few potatoes that appear to have all the desired traits, and those will be tested in the field. “We want to get things in the field as soon as possible,” says Jones, who says the researchers should know within three years whether they have any lines worth commercializing.
If successful, says Jones, the project will illustrate the value of this technology as a way to make production more sustainable and address food security needs. The same general approach is applicable to other crops and can address other destructive diseases, such as wheat rust, he says.
Since it would have benefits to consumers, farmers, and the environment, “it sounds like they are developing the perfect potato,” says Ewen Mullins, a senior researcher at Teagasc, Ireland’s agriculture research agency. Mullins, who tests the environmental impact of novel plant breeding technologies, says the biggest challenges Jones’s group will face will probably not be technical. The science has progressed so much in recent years that it’s now “relatively straightforward” to develop an organism with this many new traits, he says, though there will be an extensive safety and regulatory process afterward. “The hard part is actually getting consumer acceptance for it,” Mullins says. That process, he adds, should ideally go on in parallel with the technology development.
Source: MIT Technology Review