Thursday, November 29, 2007

Exercise improves thinking, reduces diabetes risk in overweight children

Exercise improves thinking, reduces diabetes risk in overweight children

Exercise improves thinking, reduces diabetes risk in overweight children

Just three months of daily, vigorous physical activity in overweight children improves their thinking and reduces their diabetes risk, researchers say.

Studies of about 200 overweight, inactive children ages 7-11 also showed that a regular exercise program reduces body fat and improves bone density.

Is exercise a magic wand that turns them into lean, healthy kids? No. They are still overweight but less so, with less fat, a healthier metabolism and an improved ability to handle life, says Dr. Catherine Davis, clinical health psychologist at the Medical College of Georgia and lead investigator.

All study participants learned about healthy nutrition and the benefits of physical activity; one-third also exercised 20 minutes after school and another third exercised for 40 minutes. Children played hard, with running games, hula hoops and jump ropes, raising their heart rates to 79 percent of maximum, which is considered vigorous.

Aerobic exercise training showed dose-response benefits on executive function (decision-making) and possibly math achievement, in overweight children, researchers write in an abstract being presented during The Obesity Societys Annual Scientific Meeting Oct. 20-24 in New Orleans. Regular exercise may be a simple, important method of enhancing childrens cognitive and academic development. These results may persuade educators to implement vigorous physical activity curricula during a childhood obesity epidemic.

Functional magnetic resonance imaging studies, which show the brain at work, were performed on a percentage of children in each group and found those who exercised had different patterns of brain activity during an executive function task.

Look what good it does when they exercise, says Dr. Davis. This is an important public health issue we need to look at as a nation to help our children learn and keep them well.

Tuesday, November 27, 2007

Blue-blocking Glasses To Improve Sleep And ADHD Symptoms Developed

Blue-blocking Glasses To Improve Sleep And ADHD Symptoms Developed

Scientists at John Carroll University, working in its Lighting Innovations Institute, have developed an affordable accessory that appears to reduce the symptoms of ADHD. Their discovery also has also been shown to improve sleep patterns among people who have difficulty falling asleep. The John Carroll researchers have created glasses designed to block blue light, therefore altering a person's circadian rhythm, which leads to improvement in ADHD symptoms and sleep disorders.

How the Glasses Work

The individual puts on the glasses a couple of hours ahead of bedtime, advancing the circadian rhythm. The special glasses block the blue rays that cause a delay in the start of the flow of melatonin, the sleep hormone. Normally, melatonin flow doesn't begin until after the individual goes into darkness.

[...]

Studies indicate that promoting the earlier release of melatonin results in a marked decline of ADHD symptoms.

Better Sleep/Disease Prevention/Depression Relief

Major uses of the blue-blocking glasses include: providing better sleep, avoiding postpartum depression, preventing Seasonal Affective Disorder and reducing the risk of cancer.

An alternative to the glasses has also been developed in the form of night lights and light bulbs with coatings that block the blue light. Instead of wearing the glasses, an individual may simply turn off ordinary lights and, instead, turn on the ones with filters that remove the blue rays. The night light is a convenient "plug-in" device. The cost of the items ranges from approximately $5 for light bulbs and night lights to $40-$60 for glasses.

Background

Advancing the circadian rhythm has been shown to improve both objective and subjective measures of ADHD symptoms in studies at the University of Toronto. Twenty-nine adults diagnosed with ADHD participated in a three-week trial.

Dr. Richard Hansler is the lead John Carroll University researcher in the development and uses for the blue-blocking glasses. He is one of the principle owners of a company that makes these new products.

Saturday, November 24, 2007

This explains your doughnut addiction - Los Angeles Times

This explains your doughnut addiction - Los Angeles Times

Researchers have learned that rats overwhelmingly prefer water sweetened with saccharin to cocaine, a finding that demonstrates the addictive potential of sweets.

Offering larger doses of cocaine did not alter the rats' preference for saccharin, according to the report.

Scientists said the study, presented this week in San Diego at the annual meeting of the Society for Neuroscience, might help explain the rise in human obesity, which has been driven in part by an overconsumption of sugary foods.

In the experiment, 43 rats were placed in cages with two levers, one of which delivered an intravenous dose of cocaine and the other a sip of highly sweetened water. At the end of the 15-day trial, 40 of the rats consistently chose saccharin instead of cocaine.

When sugar water was substituted for the saccharin solution, the results were the same, researchers said.

Further testing the rat sweet tooth, scientists subjected 24 cocaine-addicted rats to a similar trial. At the end of 10 days, the majority of them preferred saccharin.

"Intense sweetness is more rewarding to the rats than cocaine," said coauthor Magalie Lenoir of the University of Bordeaux in France.

Lenoir said mammalian taste receptors evolved in an environment that lacked sugar and so were not adapted to the high concentrations of sweets found in the modern diet. Excess sugar could increase levels of the brain chemical dopamine, she said, leading to a craving for sweets.

Cocaine also increases dopamine, she said, but through a different brain mechanism.

Carol Rossetti: Syndrome X: Are you at risk?

Noblesville Daily Times - News, Sports, & Weather for Hamilton County, Indiana - Carol Rossetti: Syndrome X: Are you at risk?

Since November is National Diabetes Month, I decided I would talk about how you could develop Type II Diabetes, how you can reverse it, and why as a society we are now seeing children as young as 9 developing an over 40 condition.

Two of the key players in this life and death drama are glucose known as blood sugar and the hormone insulin. Because of the foods we eat, we are overdosing on these essential elements. Both substances accelerate the aging process.

Syndrome X is caused primarily by a diet high in refined carbohydrates such as cereals, muffins, breads, and rolls, pastas, cookies, doughnuts, and sodas. These foods not only elevate your glucose and insulin levels out of sight but they are also non-foods as they do not supply the necessary vitamins, minerals, and amino acids necessary for good health.

Historically, Type II Diabetes or Adult-On Set Diabetes has grown to epidemic proportions over the last 30 years. Our government Watch Dogs, those who we think are looking after our collective health, announced in the 70’s that if we just ate more pasta and less meat, we would be healthier. So we did and here we are. Refined carbohydrates become pure sugar in our body.

When people ate proteins and vegetables along with some fruits and a modest amount of whole grain breads, we were a healthier society. This is the true balanced diet. Some of the diets my clients bring me that were given to them by one of these Watch Dog groups are so shocking that I wonder how those who create them can sleep at night.

What are we feeding our children? It is any wonder they are getting heavier and heavier, they are developing Type II Diabetes in record numbers, and ADHD symptoms are increasing. As an advanced society, this is truly shameful. Our fascination with junk food is killing us.

I sponsored a seminar at a university in California in 1977 called Sugar and the Mind. We’ve known for a very long time that sugar is a drug and how it affects the body and the mind. There was a recent study was conducted that clearly demonstrated that rats preferred sugar to cocaine. This was true even in those who were addicted. Rats were allowed to choose a high sugar sweetener or IV cocaine. In virtually every instance, the rats chose the sugar. Sugar is extremely addictive and it is hard to get people to give it up. It’s even harder as a parent to get your children off the massive amounts of sugar they ingest on a daily basis. But you must!
If you are pre-diabetic that means that you need to make some major changes immediately. Look at your diet very closely. Does it include lots of fruit, lots of breads, pasta, crackers, noodles, pastries? Are you a fruit juice lover? A glass of orange juice has about the same amount of sugar as a chocolate bar. It takes a lot of oranges to make a glass of juice. You are better off to eat one orange.

These high sugar foods cause a huge rise in inflammation in our body and Inflammation is the culprit in heart disease.

Friday, November 23, 2007

Democrats party of rich, study finds :: The Washington Times, America's Newspaper

Democrats party of rich, study finds :: The Washington Times, America's Newspaper

Democrats like to define themselves as the party of poor and middle-income Americans, but a new study says they now represent the majority of the nation's wealthiest congressional districts.

In a state-by-state, district-by-district comparison of wealth concentrations based on Internal Revenue Service income data, Michael Franc, vice president of government relations at the Heritage Foundation, found that the majority of the nation's wealthiest congressional jurisdictions were represented by Democrats.

He also found that more than half of the wealthiest households were concentrated in the 18 states where Democrats hold both Senate seats.

"If you take the wealthiest one-third of the 435 congressional districts, we found that the Democrats represent about 58 percent of those jurisdictions," Mr. Franc said.

Wednesday, November 21, 2007

Physical Inactivity Rapidly Induces Insulin Resistance and Microvascular Dysfunction in Healthy Volunteers -- Hamburg et al. 27 (12): 2650 -- Arterios

Physical Inactivity Rapidly Induces Insulin Resistance and Microvascular Dysfunction in Healthy Volunteers -- Hamburg et al. 27 (12): 2650 -- Arteriosclerosis, Thrombosis, and Vascular Biology

Conclusions— Physical inactivity was associated with the development of insulin resistance, dyslipidemia, increased blood pressure, and impaired microvascular function in healthy volunteers. Our findings may provide insight into the pathogenesis of vascular disease in sedentary individuals and emphasize that even short-term physical inactivity may have adverse metabolic and vascular consequences.

Physical inactivity is associated with cardiovascular disease. We examined the effect of 5 days of bed rest on insulin resistance and vascular function in healthy subjects. Bed rest induced vascular dysfunction, insulin resistance, dyslipidemia, and increased blood pressure. Our findings provide insight into the pathogenesis of vascular disease in sedentary individuals.

Could This Be It...............? - NeuroTalk Communities

Could This Be It...............? - NeuroTalk Communities

Breakthrough in Parkinson's gene therapy
By Roger Highfield, Science Editor
Last Updated: 10:01pm GMT 19/11/2007

Evidence that a breakthrough has been achieved in gene therapy for serious brain diseases has come with the release of the hard evidence that it works in Parkinson's disease.

Patients were given injections of billions of copies of genetically altered viruses into parts of the brain

The world's first gene therapy for a brain disease brought about significant improvements in the mobility of Parkinson's sufferers. American doctors said it could also herald a landmark in the treatment of other neurological disorders, such as Alzheimer's or epilepsy but there was a lingering doubt that the reports by a dozen patients of improvements of up to 65 per cent in mobility could be anecdotal or due to the placebo effect.

Today, Prof David Eidelberg of the of The Feinstein Institute for Medical Research in Manhasset, New York, and colleagues report in the Proceedings of the National Academy of Sciences evidence that the brain chemistry of the patients has been altered by gene therapy, ending concerns that the evidence that it worked depended too much on what the patients said and not enough on objective measures. "It is the first solid evidence of benefit from gene therapy. It is objective," Prof Eidelberg told The Daily Telegraph.

Parkinson's affects about 120,000 people in Britain, with 10,000 new cases diagnosed every year. It robs sufferers of the ability to walk and even eat, causes long motionless periods known as "freezing" as well as head and limb tremors. As the disease progresses, higher doses of drugs are required, leading to side-effects that include involuntary movements.

Sufferers include the former world boxing champion Muhammad Ali and the actor Michael J Fox.

advertisementThe research team, from the New York-Presbyterian Hospital/Weill Cornell Medical Centre and the New Jersey-based company Neurologix, used the gene therapy to fix some of the damage caused by the disease.

Parkinson's occurs when the brain cells - neurons - that release the messenger chemical known as dopamine die. Protein deposits also form in the brain, and levels of another messenger chemical called GABA - which calms overexcited brain cells - drop.

Tuesday, November 20, 2007

Carbs decrease testosterone in men, estrogen in women, causing health problems

New research supports advice to eat complex carbs and avoid sugar

(Vancouver – November 8, 2007) – Eating too much fructose and glucose can turn off the gene that regulates the levels of active testosterone and estrogen in the body, shows a new study in mice and human cell cultures that’s published this month in the Journal of Clinical Investigation. This discovery reinforces public health advice to eat complex carbohydrates and avoid sugar. Table sugar is made of glucose and fructose, while fructose is also commonly used in sweetened beverages, syrups, and low-fat food products. Estimates suggest North Americans consume 33 kg of refined sugar and an additional 20 kg of high fructose corn syrup per person per year.

Glucose and fructose are metabolized in the liver. When there’s too much sugar in the diet, the liver converts it to lipid. Using a mouse model and human liver cell cultures, the scientists discovered that the increased production of lipid shut down a gene called SHBG (sex hormone binding globulin), reducing the amount of SHBG protein in the blood. SHBG protein plays a key role in controlling the amount of testosterone and estrogen that’s available throughout the body. If there’s less SHBG protein, then more testosterone and estrogen will be released throughout the body, which is associated with an increased risk of acne, infertility, polycystic ovaries, and uterine cancer in overweight women. Abnormal amounts of SHBG also disturb the delicate balance between estrogen and testosterone, which is associated with the development of cardiovascular disease, especially in women.

[...]

The discovery dispels the earlier assumption that too much insulin reduces SHBG, a view which arose from the observation that overweight, pre-diabetic individuals have high levels of insulin and low levels of SHBG. This new study proves that insulin is not to blame and that it’s actually the liver’s metabolism of sugar that counts.

But the body turns complex carbohydrates INTO glucose, or sugar!

Do Low-Carb Diets Help Diabetes?

Do Low-Carb Diets Help Diabetes?
Small Study Shows Restricting Carbohydrates Reduces Need for Medications
By Salynn Boyles
WebMD Medical News
Reviewed by Louise Chang, MD

March 15, 2006 -- Should people with type 2 diabetesdiabetes follow very low carbohydrate diets? The American Diabetes Association (ADA) says "no", but a small study from Sweden suggests such a diet may be one of the best ways to manage the disease and reduce the need for medication.

In the study, 16 obese patients with type 2 diabetes followed a calorie- and carbohydrate-restricted diet for 22 months. Most showed continuing improvements in blood sugar that were independent of weight lossweight loss; the average daily dosage of insulin among the 11 insulin-dependent patients was cut in half.

"Many people are essentially cured of their [type 2] diabetes by low-carbohydrate diets, but that message is not getting out," says low-carb proponent and biochemistry professor Richard Feinman, PhD, of the SUNY Downstate Medical Center in Brooklyn, N.Y.

While agreeing that carbohydrate restriction helps people with type 2 diabetes control their blood sugar, ADA spokesman Nathaniel G. Clark, MD, tells WebMD that the ADA does not recommend very low-carb diets because patients find them too restrictive.

"We want to promote a diet that people can live with long-term," says Clark, who is vice president of clinical affairs and youth strategies for the ADA. "People who go on very low carbohydrate diets generally aren't able to stick with them for long periods of time."

Sunday, November 18, 2007

Stone Age feminism? - The Boston Globe

Stone Age feminism? - The Boston Globe

Almost as provocatively, a husband-wife anthropological team has raised the possibility that female derring-do may have contributed to Neanderthals' demise.

The University of Arizona's Steven L. Kuhn and Mary C. Stiner, use archeological evidence to argue that Neanderthal females - unlike Homo sapien women of the Upper Paleolithic period - joined men in hunts at a time when stabbing giant beasts with a sharpish stone affixed to a stick represented the cutting edge of technology.

That's courageous, but probably bad practice for a population that never numbered much more than 10,000 individuals. The loss of a few males to a flailing hoof or slashing antler is no big deal, in the long run. But losing females of child-bearing age could bring doom to a hard-pressed species.

"All elements of [Neanderthal] society appear to have been involved in the main subsistence pursuit" of hunting large animals, Kuhn said. "There's not much evidence of classic female roles.

"Putting the reproductive core of the population - pregnant women, mothers of infants, children themselves - at such danger could have put Neanderthals as a whole at serious demographic disadvantage," he said.

Not only would women suffer casualties, Kuhn said, their full participation in the hunt would mean they were not harvesting wild grains and other foods that could sustain their roving bands when game was scarce.

What finished off the Neanderthals is still bitterly disputed by paleoanthropologists and others in the field.

On one side are those who think Neanderthals were "culturally" overwhelmed by modern humans who just happened to possess better tools and weapons - throwing spears, for example, not jabbing spears - or adopted customs more appropriate for the Ice Age. From early days, human women appear to have sewed hide clothing, tended fires, and gathered vegetables rather than risking their lives on the hunt.

On the other side are those who believe modern humans were inherently superior, possessing "cognitive advantages" - read: more smarts - that made their ascent and Neanderthal decline inevitable. Cavefolk simply couldn't compete effectively with the more clever new kids on the block.

"Neanderthals were smart, sophisticated. They mastered fire. They made tools. But modern humans had selectively advantageous [genetic] traits that gave them an edge," said Richard G. Klein, a Stanford University paleoanthropologist. "Even tiny advantages in cognition, communication skills, and memory would have had huge downstream effects over time."

There are other plausible explanations for the Neanderthal extinction. Warming at the end of the Ice Age surely wasn't easy for robust people built for the cold. Or an epidemic could have so depopulated Neanderthal bands that the survivors couldn't replenish the species. A more sinister idea is that early humans wiped them out in a prehistoric genocide.

"On the other hand, humans and Neanderthals coexisted for thousands of years, so I think talk about genocide says more about how modern humans think," said Paabo. "What finally happened could be really boring. Maybe Neanderthals ran out of reindeer to hunt. So they dwindled and died. Species can disappear without us killing them."

1 Awesome Gmail tip You Don’t Know about. Seriously. | MakeUseOf.com

1 Awesome Gmail tip You Don’t Know about. Seriously. | MakeUseOf.com

Just about when I thought I got everything out of Gmail, I discovered my top favorite feature. We have published over 30 tools in Gmail RoundUp 1 and almost 80 tools and tips in Gmail RoundUp 2 but never mentioned anything similar to this one. Tribute for this one goes to my ‘I am not into computers‘ type girlfriend.

Let’s say that your email address is ‘GeorgeBush@gmail.com’, basically everything sent to any of the following email addresses will be forwarded to your primary email.

* GeorgeBush@gmail.com
* G.eorgeBush@gmail.com
* Ge.orgeBush@gmail.com



* GeorgeBus.h@gmail.com



* GeorgeBush@googlemail.com
* G.eorgeBush@googlemail.com
* Ge.orgeBush@googlemail.com



* GeorgeBus.h@googlemail.com

And that’s not all, you can place as many dots as you want, it can be even something like ‘G.e.o.r.g.e.B.u.s.h@gmail.com’ and you’ll still get it on ‘GeorgeBush@gmail.com’

Additionally, I just also found out that you can embed random text to your email ID using ‘+’ sign. That is to say ‘GeorgeBush+anythingyouwant@gmail.com’ can be used as your email address, as well.

Ok I got it. Now what ?

1. One email for every purpose

Instead of using different email addresses for various purposes (work, school, friends, etc.) you can use different variations of your Gmail and filter incoming mails by ’sent to’ address. For instance, all incoming mail sent to ‘Name.Surname@gmail.com’ can be put to folder ‘work’, messages sent to ‘NameSurname@gmail.com’ can be put to ‘friends’, ‘N.ameSurname@gmail.com’ can be used for newsletters, and so on.

2. Track/Block spammers

When signing up for some website, say thatwebsite.com, you can add thatwebsite to your Gmail user ID (eg. GeorgeBush+thatwebsite@gmail.com). This way you can block your subscription whenever you want and even identify those websites that distribute your email address to spammers.

Thursday, November 15, 2007

Low carb diet best for Crohn's, IBD

New study by Dr. Richard Gearry shows new benefit for low-carb living

Although all you ever hear in most media accounts of low-carb diets, especially the Atkins diet, are negative and demeaning comments, the fact is this healthy dietary approach has been showing some truly remarkable health benefits in the research laboratory this year. We've seen that low-carb helps burn more body fat, is effective for treating teenage obesity, has been shown to be a reasonable alternative to a low-fat diet , beats out all other diets for weight loss and health success, and so much more!

Now we have another health benefit from livin' la vida low-carb:
improves inflammatory bowel disease (IBD), aka Crohn's disease and ulcerative colitis. Although we saw widespread reporting about this study that alleges the Atkins diet increases the risk of bowel cancer earlier this year, the latest research from New Zealand shows low-carb living IMPROVES bowel health.

-
Lead researcher Dr. Richard Gearry, MBChB, PhD, a consultant gastroenterologist from the New Zealand-based Christchurch Hospital and a senior lecturer at Otago University's Christchurch School of Medicine, and his researchers observed 100 patients with IBD over a six- to eight-week period and noticed that a low-carb diet helped ease the pain associated with this condition in over half of them.

The study participants were treated at Box Hill Hospital in Victoria, Australia and Dr. Gearry decided to feed them foods that would not cause inflammation in the abdomen and bowel. Interestingly, the foods that DO cause problems with IBD sufferers have a certain macronutrient composition that is well-known to most medical professional.

"Doctors have known for a long time that patients know what affects their condition and causes symptoms," Dr. Gearry noted. "Dietitians and doctors and scientists looked at this more closely and identified a number of foods that can cause abdominal pain and diarrhea."

Wanna see a few of these culprit foods that make IBD worse? Check out this list: wheat, onions, milk, ice cream, apples, honey, legumes, and other fruits. Hmmm, do you see what all of these foods have in common? They're high-carb!

"Often they are sugars and carbohydrates that are not absorbed when they pass through the bowel and when they get into the colon they can ferment and produce gas and pain," Dr. Gearry explained.

So, it's no surprise why livin' la vida low-carb worked so well for these patients with IBD. It's healthy for them and keeps their symptoms at bay. Best of all, the low-carb lifestyle was so simple and pleasurable enough to the study participants that they WANTED to be on it.

"Most patients found that the diet was easy to implement and that the taste was acceptable, which is very important if people are to follow this diet," Dr. Gearry added.

The findings of this study were presented at the recent Australian Gastroenterology Week conference in Perth and will also be presented next week at the Annual Scientific meeting of the New Zealand Society of Gastroenterology.

Dr. Gearry is hopeful his findings on the low-carb diet for Crohn's disease is embraced worldwide as a viable treatment option for this and other bowel conditions.

Have you seen anything else in the media about THIS study like you did that ridiculous blood vessel study last week , hmmmm? Not likely!

Wednesday, November 14, 2007

Meditation helps executive dysfunction :: Sarah Wang: GET SMART(ER)

Sarah Wang: GET SMART(ER)

Concentrate, and Relax

If you thought you'd have to spend all day with your nose in a book to get smart, think again. There's evidence that meditation does wonders for the thinker.



While studying the brain structure of people who practice Buddhist insight meditation regularly, Massachusetts General Hospital researchers found meditators have thicker brain matter in the area that deals with executive function, which refers to our ability to plan, think abstractly, understand rules and initiate appropriate responses. The study didn't look at whether those with thicker brain matter have higher-functioning brains, says lead study author Sara Lazar, but the team aims to find out.



In the meantime, Richard Davidson, professor of psychology and psychiatry at the University of Wisconsin at Madison and director of the Waisman Laboratory for Brain Imaging and Behavior, offers plenty of support for meditation. Davidson has long studied the impact of meditation on attention and concentration, and has found that "even relatively short-term meditation practice can substantially change certain aspects of attention and change the brain systems that underlie it."



Meditation can also help train people to regulate their emotions. Monks, it turns out, are masters of this, as Davidson found in a study. That inner calm "is extremely important for well-being and also very important for learning," he says. "If you are hyper-responsive to stress and to negative stimuli in your environment, it would interfere with your capacity to learn." Which in non-scientific terms means that getting all riled up every time your boss does that annoying thing with her teeth could be keeping you from your intellectual peak.

Meditation is good for executive dysfunction and ADD

Dopamine and Obesity :: Obese rats have lowered dopamine :: Life Extension Daily News

Life Extension Daily News

A brain-imaging study of genetically obese rats conducted at the U.S. Department of Energy's Brookhaven National Laboratory provides more evidence that dopamine - a brain chemical associated with reward, pleasure, movement, and motivation - plays a role in obesity. The scientists found that genetically obese rats had lower levels of dopamine D2 receptors than lean rats. They also demonstrated that restricting food intake can increase the number of D2 receptors, partially attenuating a normal decline associated with aging.

"This research corroborates brain-imaging studies conducted at Brookhaven that found decreased levels of dopamine D2 receptors in obese people compared with normal-weight people," said Brookhaven neuroscientist Panayotis (Peter) Thanos, lead author of the current study, which will be published in the journal Synapse and is now available online.

It's not clear whether reduced receptor levels are a cause or consequence of obesity: Overeating may chronically reduce receptor levels, which, over the long term, could eventually contribute to obesity. But having genetically low receptor levels may also lead to obesity by predisposing the individual to overeating in an attempt to stimulate a "blunted" reward system. Either way, revving up receptor levels by restricting food intake could enhance the impact of this common strategy for combating obesity.

"Consuming fewer calories is obviously important for people trying to lose weight, plus improving the brain's ability to respond to rewards other than food may help prevent overeating," Thanos said. Because food intake can have such a dramatic effect on dopamine receptor levels, "this study also provides further evidence for the interplay of genetic factors with the environment in the development of obesity in our society," he said.

The finding that food restriction can attenuate the effects of aging on the brain's ability to respond to dopamine may also help explain why food restriction slows down other changes associated with aging, such as declines in locomotor activity and sensitivity to reward.