Showing posts with label may. Show all posts
Showing posts with label may. Show all posts

Fat May Be Linked to Memory Loss

Thursday, May 8, 2014


Although problems with memory become increasingly common as people age, in some persons, memories last long time, even a life time. On the other hand, some people experience milder to substantial memory problems even at an earlier age.

Although there are several risk factors of dementia, abnormal fat metabolism has been known to pose a risk for memory and learning. People with high amounts of abdominal fat in their middle age are 3.6 times as likely to develop memory loss and dementia later in their life.

Neurological scientists at the Rush University Medical Center in collaboration with the National Institutes of Health have discovered that same protein that controls fat metabolism in the liver resides in the memory center of the brain (hippocampus) and controls memory and learning.

Results from the study funded by the Alzheimer’s Association and the National Institutes of Health were recently published in Cell Reports.

“We need to better understand how fat is connected to memory and learning so that we can develop effective approach to protect memory and learning,” said Kalipada Pahan, PhD, the Floyd A. Davis professor of neurology at Rush University Medical Center.

The liver is the body’s major fat metabolizing organ. Peroxisome proliferator-activated receptor alpha (PPARalpha) is known to control fat metabolism in the liver. Accordingly, PPARalpha is highly expressed in the liver.

“We are surprised to find high level of PPARalpha in the hippocampus of animal models,” said Pahan.

“While PPARalpha deficient mice are poor in learning and memory, injection of PPARα to the hippocampus of PPARalpha deficient mice improves learning and memory," said Pahan.

Since PPARalpha directly controls fat metabolism, people with abdominal fat levels have depleted PPARalpha in the liver and abnormal lipid metabolism. At first, these individuals lose PPARalpha from the liver and then eventually from the whole body including the brain. Theore, abdominal fat is an early indication of some kind of dementia later in life, according to Pahan.

By bone marrow chimera technique, researchers were able to create some mice having normal PPARalpha in the liver and depleted PPARalpha in the brain. These mice were poor in memory and learning. On the other hand, mice that have normal PPARalpha in the brain and depleted PPARalpha in the liver showed normal memory.

“Our study indicates that people may suffer from memory-related problems only when they lose PPARalpha in the hippocampus”, said Pahan.

CREB (cyclic AMP response element-binding protein) is called the master regulator of memory as it controls different memory-related proteins. “Our study shows that PPARalpha directly stimulates CREB and thereby increases memory-related proteins”, said Pahan.

“Further research must be conducted to see how we could potentially maintain normal PPARalpha in the brain in order to be resistant to memory loss”, said Pahan.

Other Rush researchers involved in this study include Avik Roy, PhD, research assistant professor; Malabendu Jana, PhD assistant professor; Grant Corbett, neuroscience graduate student; Shilpa Ramaswamy, instructor; and Jeffrey H. Kordower, PhD, the Jean Schweppe Armour professor of neurological sciences.

Alzheimer’s disease is the most common human disorder associated with memory loss. This disease slowly destroys memory and thinking skills, and eventually even the ability to carry out the simplest tasks. Nationwide, the total payments for services for people with Alzheimer’s and other forms of dementia will total $203 billion in 2013. By 2050, the total costs are expected to increase 500 percent to a staggering $1.2 trillion.

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Musculoskeletal conditions injuries may be associated with statin use

Thursday, May 1, 2014



Using cholesterol-lowering statins may be associated with musculoskeletal conditions, arthropathies (joint diseases) and injuries, according to a report published Online First by JAMA Internal Medicine, a JAMA Network publication.

While statins effectively lower cardiovascular illnesses and death, the full spectrum of statin musculoskeletal adverse events (AEs) is unknown. Statin-associated musculoskeletal AEs include a wide variety of clinical presentations, including muscle weakness, muscle cramps and tendinous (tendon) diseases, the authors write in the study background.

Ishak Mansi, M.D., of the VA North Texas Health Care System, Dallas, and colleagues utilized data from a military health care system to determine whether statins were associated with musculoskeletal conditions based on statin use during the 2005 fiscal year. Patients were divided into two groups: statin users for at least 90 days and nonusers. A total of 46,249 patients met the study criteria and of those, researchers propensity score-matched (a statistical approach that mathematically matches the characteristics of patients in two or more groups) 6,967 statin users with 6,967 nonusers.

"Musculoskeletal conditions, arthropathies, injuries and pain are more common among statin users than among similar nonusers. The full spectrum of statins musculoskeletal adverse events may not be fully explored, and further studies are warranted, especially in physically active individuals," the authors notes.

Statin users had a higher odds ratio (OR) for musculoskeletal disease diagnosis group 1 (all musculoskeletal diseases: OR, 1.19), for musculoskeletal disease diagnosis group 1b (dislocation/strain/sprain: OR, 1.13) and for musculoskeletal diagnosis group 2 (musculoskeletal pain: OR, 1.09), but not for musculoskeletal disease diagnosis group 1a (osteoarthritis/arthropathy: OR,1.07), according to study results for the propensity score-matched pairs.

To our knowledge, this is the first study, using propensity score matching, to show that statin use is associated with an increased likelihood of diagnoses of musculoskeletal conditions, arthropathies and injuries. In our primary analysis, we did not find a statistically significant association between statin use and arthropathy; however, this association was statistically significant in all other analyses," the authors conclude. "These findings are concerning because starting statin therapy at a young age for primary prevention of cardiovascular diseases has been widely advocated."
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Green tea may help lower starchy food blood sugar spikes

Monday, April 28, 2014




Mice fed an antioxidant found in green tea -- epigallocatechin-3-gallate, or EGCG -- and corn starch had a significant reduction in increase in their blood sugar -- blood glucose -- levels compared to mice that were not fed the compound, according to Joshua Lambert, assistant professor of food science in agricultural sciences.

"The spike in blood glucose level is about 50 percent lower than the increase in the blood glucose level of mice that were not fed EGCG," Lambert said.

The dose of EGCG fed to the mice was equivalent to about one and a half cups of green tea for a human.

Lambert, who worked with Sarah C. Forester, postdoctoral fellow, and Yeyi Gu, graduate student, both in food science, said EGCG was most effective when the compound was fed to the mice simultaneously with corn starch. For humans, this may mean that green tea could help them control the typical blood sugar increases that are brought on when they eat starchy foods, like breads and bagels that are often a part of typical breakfasts.

"If what you are eating with your tea has starch in it then you might see that beneficial effect," Lambert said. "So, for example, if you have green tea with your bagel for breakfast, it may reduce the spike in blood glucose levels that you would normally get from that food."

The EGCG had no significant effect on blood sugar spikes in mice that were fed glucose or maltose, according to the researchers who released their findings in the online version of Molecular Nutrition and Food Research. Lambert said that the reason blood sugar spikes are reduced when the mice ate starch, but not these sugars, may be related to the way the body converts starch into sugar.

An enzyme called alpha-amylase that is produced in both the mouth and by the pancreas helps break down starch into maltose and glucose. EGCG may inhibit the enzymes ability to break down the starch, the researchers indicated, since they also found that EGCG reduced the activity of alpha amylase in the pancreas by 34 percent.

If the mechanism holds in humans, this may mean that people who want to limit the blood sugar spike should skip adding sugar to their cup of green tea.

"That may mean that if you add sugar into your green tea, that might negate the effect that the green tea will have on limiting the rise in blood glucose level," Lambert said.

Lambert added that the green tea and the starch would need to be consumed simultaneously. For example, drinking a cup of tea well after eating a piece of toast would probably not change the blood sugar spike.

For the study, researchers separated mice into several groups based on body weight. After a fasting period, the mice were given common corn starch, maltose, or sucrose. One group of mice received EGCG along with the feed, while a control group was not fed the compound.

The researchers then tested the blood sugar levels of both groups.

Lambert said the researchers next step is to test the compound on people.

"The relatively low effective dose of EGCG makes a compelling case for studies in human subjects," the researchers said.

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Healthy lifestyle during menopause may decrease breast cancer risk later on

Monday, April 14, 2014


Obese, postmenopausal women are at greater risk for developing breast cancer and their cancers tend to be more aggressive than those in lean counterparts. A University of Colorado Cancer Center study published in the December issue of the journal Cancer Research shows how this risk might be prevented.

“By using nutrient tracers for fat and sugar, we tracked where the body stored excess calories. In lean models, excess fat and glucose were taken up by the liver, mammary and skeletal tissues. In obese models, excess fat and glucose were taken up by tumors, fueling their growth,” says Erin Giles, PhD, postdoctoral researcher at the CU Cancer Center and the paper’s lead author.

In short, if you are lean, excess calories go to healthy tissue. If you are obese, excess calories feed the tumor.

“This implies that the menopausal window may be an opportunity for women to control their breast cancer risk through weight management,” Giles says.

In this study, Giles worked with a team of scientists including postdoctoral fellows Elizabeth Wellberg and Sonali Jindal, as well as faculty members Steve Anderson, Pepper Schedin, Ann Thor and Paul Maclean. Their study also showed that tumors from obese animals had increased levels of the progesterone receptor, and this receptor appears to give tumors a metabolic advantage for growth. To extend their findings to humans, they recruited gene analysis experts David Astling and Aik-Choon Tan who analyzed 585 human breast cancers and found that human tumors expressing the progesterone receptor had the same metabolic advantage.

“Basically, we saw an abnormal metabolic response to fat and sugar in the obese that, in many ways, mirrors the response to fat and sugar in Type II diabetes,” Giles says. Noticing this similarity, the group tested the use of the common Type II diabetes drug, Metformin, in their model of postmenopausal breast cancer.

“With treatment, tumor size was dramatically decreased in the obese, and tumors showed reduced expression of the progesterone receptor,” Giles says.

Using a pre-clinical model, the investigators found that weight gain during menopause is particularly bad for those who are obese when entering menopause. Together, the results of this study suggest that the combination of obesity and weight gain during menopause can impact breast cancer in two ways. First, tumors that arise in obese women appear to have a metabolic advantage, and second, the inability to store excess calories in healthy tissues may further fuel tumor growth.

“While drugs may be useful in controlling breast cancer risk in obese, postmenopausal women, our results imply that a combination of diet and exercise may be equally if not more beneficial,” Giles says.

The group’s ongoing studies are testing whether interventions such as diet and exercise, during the period of menopausal weight gain, can improve tumor outcomes.

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Egg white protein may help high blood pressure

Thursday, March 20, 2014


Scientists reported new evidence today that a component of egg whites — already popular as a substitute for whole eggs among health-conscious consumers concerned about cholesterol in the yolk — may have another beneficial effect in reducing blood pressure. Their study was part of the 245th National Meeting & Exposition of the American Chemical Society (ACS), the worlds largest scientific society, which continues here through Thursday.

"Our research suggests that there may be another reason to call it the incredible, edible egg," said study leader Zhipeng Yu, Ph.D., of Jilin University. "We have evidence from the laboratory that a substance in egg white — its a peptide, one of the building blocks of proteins — reduces blood pressure about as much as a low dose of Captopril, a high-blood-pressure drug."

Yu and colleagues, who are with Clemson University, used a peptide called RVPSL. Scientists previously discovered that the substance, like the family of medications that includes Captopril, Vasotec and Monopril, was an angiotensin-converting-enzyme (ACE) inhibitor. It has a powerful ability to inhibit or block the action of ACE, a substance produced in the body that raises blood pressure.

They set out to further document RVPSLs effects, using laboratory rats that develop high blood pressure and are stand-ins for humans in such early research on hypertension. The results of feeding the substance were positive, showing that RVPSL did not have apparent toxic effects and lowered blood pressure by amounts comparable to low doses of Captopril.

"Our results support and enhance previous findings on this topic," Yu said. "They were promising enough to move ahead with further research on the effects of the egg white peptide on human health."

Yu noted that the research was done with a version of the peptide that was heated to almost 200 degrees Fahrenheit during preparation — less than the temperatures typically used to cook eggs. He cited evidence from other research, however, that egg whites may retain their beneficial effects on blood pressure after cooking.

One, for instance, published in the ACS Journal of Agricultural and Food Chemistry, showed that fried egg protein, cooked at high temperatures, actually showed greater ability to reduce blood pressure than eggs boiled at 212 degrees F.

Yu believes that egg white peptides, either in eggs or as a supplement, could become useful as an adjunct to high-blood-pressure medication. For now, he said people with high blood pressure should consult their health care provider before making any changes.

And he noted that findings about egg white and high blood pressure add to the emerging nutritional image of eggs. Once regarded as a food to avoid in a healthy diet, studies in recent years have concluded that many people can eat eggs without raising their blood cholesterol levels, benefiting from an inexpensive food low in calories and rich in protein, vitamins and other nutrients.
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Omega 3 Supplements May Prevent Skin Cancer

Tuesday, March 18, 2014


Consuming omega-3 fish oils can help to prevent skin cancer, according to the first clinical trial exploring the influence of fish oils on the skin immunity of humans.

The study was conducted by a team of researchers from the University of Manchester and funded by the Association for International Cancer Research, and examined the effect of taking omega-3 on 79 healthy participants.

Findings of the study, published in The American Journal of Clinical Nutrition, revealed that consuming regular doses of fish oils increases immunity to sunlight.

It directly decreases sunlight-induced immunity suppression - called immunosuppression - which affects the bodys power to combat skin cancer and infection.

Professor Lesley Rhodes, Professor of Experimental Dermatology from the Photobiology Unit Dermatology Centre at the Universitys School of Medicine and Salford Royal NHS Foundation Trust, said their study was the first of its kind conducted using humans:

"There has been research in this area carried out on mice in the past but this is the first time that there has been a clinical trial directly in people. It has taken a number of years to get to this stage and the findings are very exciting. This study adds to the evidence that omega-3 is a potential nutrient to protect against skin cancer. Although the changes we found when someone took the oil were small, they suggest that a continuous low level of chemoprevention from taking omega-3 could reduce the risk of skin cancer over an individuals lifetime."

The volunteers consumed a 4g dose of omega-3 - approximately one and a half portions of oily fish each day. Then they were exposed to either 8, 15, or 30 minutes of summer midday sun in Manchester using a specific light machine.

A number of other participants took a placebo before being exposed to the sunlight machine.

Immunosuppression was shown to be 50 percent lower in the subjects that took the omega-3 and were exposed to 8 and 15 minutes of sunshine compared with the volunteers who did not take the supplement. Little to no impact on those in the 30 minute group was shown.

The conclusions from this study are significant in the battle against skin cancer, because earlier studies have always shown that sunscreens are frequently applied incorrectly and only worn on vacation.

However, Professor Rhodes points out omega-3 is not a substitute for suntan lotion or physical protection, and that it should be seen as additional protection factor to help keep the skin from burning.

Historically, fish oil has already been associated with health benefits like protecting against cardiovascular disease, helping prevent age-related vision loss, and even slowing the growth of prostate cancer cells.
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Fish oil supplements may protect the heart in stressful situations

Monday, March 10, 2014



Fish oil supplements may protect the heart in stressful situations, according to a recent study. Jason Carter, a researcher at Michigan Technological University, conducted the study with 67 healthy volunteer test participants in their 20s. Over a 2-month period, they were either given nine grams of fish oil pills or nine grams of olive oil as a placebo.

The test subjects were screened for heart rate, blood pressure and other related metrics. At the end of the test period, both groups took a mental arithmetic test that involved adding and subtracting numbers in their head. Their stress response was measured at that time.

“Those in the fish oil group showed blunted heart rate reactivity while they were stressed compared to those who took olive oil," said Carter. "Similarly, the total [muscle sympathetic nerve activity] reactivity to mental stress was also blunted in the fish oil group.” There was not much difference between the two groups at rest, however.
Results of the study were published in the May edition of the American Journal of Physiology – Regulatory, Integrative, and Comparative Physiology, published by the American Physiological Society. It is available online at http://bit.ly/10j0CSS

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Frequent heartburn may predict cancers of the throat and vocal cord

Saturday, March 8, 2014



Frequent heartburn was positively associated with cancers of the throat and vocal cord among nonsmokers and nondrinkers, and the use of antacids, but not prescription medications, had a protective effect, according to data published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

"Previous studies examining gastric lux and cancers of the head and neck have generated mixed results," said Scott M. Langevin, Ph.D., postdoctoral research fellow at Brown University in Providence, R.I. "Most of those studies had either few numbers of cases or they were not adjusted for confounding factors. Ours is a large, population-based study with robust parameters that strongly suggests gastric lux, which causes frequent heartburn, is an independent risk factor for cancers of the pharynx (throat) and larynx (vocal cord)."

Langevin and his colleagues identified 631 patients from a large group of individuals enrolled in a population-based, case-control study in the greater Boston area. Of the 631 participants, 468 had throat cancer and 163 had cancers of the vocal cord. An additional 1,234 individuals matched for age and gender with no prior history of cancer were recruited using town records to serve as controls for the study.

All participants completed a questionnaire on their history of heartburn, smoking and drinking habits, family history of cancer and sociodemographic information. Because some head and neck cancers are caused by infection with human papillomavirus 16 (HPV 16), the researchers tested for the presence of antigens to HPV 16 viral proteins in the blood of all participants.

Langevin and his colleagues found that among participants who were neither heavy smokers nor heavy drinkers, a history of frequent heartburn was linked to a 78 percent increased risk for cancers of the throat and vocal cord. They also found that among those who had frequent heartburn, taking antacids, but not prescription medications or home remedies, had a protective effect, with a 41 percent reduced risk for cancers of the throat and vocal cord. The protective effect of antacids was consistent, irrespective of the participants smoking or drinking status, HPV 16 status or tumor site.

"Additional studies are needed to validate the chemopreventive effects of antacids among patients with frequent heartburn," said Langevin. "The identification of gastric lux as a risk factor for throat and vocal cord cancers, however, may have implications in terms of risk stratification and identification of high-risk patients."
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Eating more fiber may lower risk of first time stroke

Sunday, January 26, 2014



Study Highlights:

- Eating foods with more fiber was linked to a lower risk of first-time stroke.
- Every seven-gram increase in total dietary fiber was associated with a 7 percent lower risk of first-time stroke.
- The results reinforce the importance of a diet that includes at least 25 grams of fiber daily.

Eating more fiber may decrease your risk of first-time stroke, according to new research in the American Heart Association journal Stroke.

Dietary fiber is the part of the plant that the body doesn’t absorb during digestion. Fiber can be soluble, which means it dissolves in water, or insoluble.

Previous research has shown that dietary fiber may help reduce risk factors for stroke, including high blood pressure and high blood levels of low-density lipoprotein (LDL) “bad” cholesterol.

In the new study, researchers found that each seven-gram increase in total daily fiber intake was associated with a 7 percent decrease in first-time stroke risk. One serving of whole wheat pasta, plus two servings of fruits or vegetables, provides about 7 grams of fiber, researchers said.

“Greater intake of fiber-rich foods – such as whole-grains, fruits, vegetables and nuts – are important for everyone, and especially for those with stroke risk factors like being overweight, smoking and having high blood pressure,” Diane Threapleton, M.Sc., and Ph.D. candidate at the University of Leeds’ School of Food Science & Nutrition in Leeds, United Kingdom.

Researchers analyzed eight studies published between 1990-2012. Studies reported on all types of stroke with four specifically examining the risk of ischemic stroke, which occurs when a clot blocks a blood vessel to the brain. Three assessed hemorrhagic stroke, which occurs when a blood vessel bleeds into the brain or on its surface.

Findings from the observational studies were combined and accounted for other stroke risk factors like age and smoking.

The results were based on total dietary fiber. Researchers did not find an association with soluble fiber and stroke risk, and lacked enough data on insoluble fiber to make any conclusions.

The average daily fiber intake among U.S. adults is lower than the American Heart Association’s recommendation of at least 25 grams per day. Six to eight servings of grains and eight to 10 servings of fruits and vegetables can provide the recommended amount.

Most people do not get the recommended level of fiber, and increasing fiber may contribute to lower risk for strokes,” Threapleton said. “We must educate consumers on the continued importance of increasing fiber intake and help them learn how to increase fiber in their diet.”
In the United States, stroke is the fourth leading cause of death, killing more than 137,000 people annually. Among survivors, the disease is a leading cause of disability.

In addition to following a nutritious diet, the American Heart Association recommends being physically active and avoiding tobacco to help prevent stroke and other heart and blood vessel diseases.

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