Nov 28, 2014

Yogurt Every Day May Help Keep Diabetes Away

Eating a serving a day of yogurt may lower your risk of developing type 2 diabetes, new research suggests.

"The data we have gathered show that yogurt consumption can have significant benefit in reducing the risk of diabetes," said senior study author Dr. Frank Hu, a professor of nutrition and epidemiology at Harvard School of Public Health, in Boston. "It's not a huge effect, about an 18 percent reduction [in risk]." "Yogurt is not magic for curing or preventing diabetes," Hu said. "That's the bottom line and the message we want to convey to our consumers, that we have to pay attention to our diet pattern. There is no replacement for an overall healthy diet and maintaining [a healthy] body weight."

In type 2 diabetes, the body does not produce enough insulin or the body's cells develop a resistance to insulin, and blood sugar levels then get too high.

For the study, Hu and his team pooled the result of three large studies that tracked the medical histories and lifestyle habits of health professionals: the Health Professionals' Follow-up Study of more than 51,000 male health professionals; the Nurses' Health Study, which included more than 121,000 women nurses; and the Nurses' Health Study II, which followed nearly 117,000 women nurses.

During the study follow-up, there were about 15,000 cases of type 2 diabetes. When they looked at total dairy intake, they saw no effect on the risk of diabetes. However, when they zeroed in on yogurt, they found one serving a day was linked with about a 17 percent reduced risk.

The researchers next pooled their result with other published studies that looked at links between dairy foods and type 2 diabetes. They found a serving of yogurt a day reduced risk by 18 percent. The meta-analysis, in which all the results were pooled, includes 14 different groups with nearly 460,000 people. About 36,000 developed type 2 diabetes. The researchers took into account age, body-mass index and other lifestyle factors. Hu said they did not differentiate between types of yogurt, whether it was Greek-style yogurt or not, and the fat content.

While previous studies have found that yogurt is good for maintain a healthy body weight and lowering risk for type 2 diabetes, ''most of the studies were small," Hu said. So his team decided to look at much larger groups. Exactly how the yogurt may help is not certain. The thinking by many experts is that the probiotics in yogurt ("good" bacteria) alter the intestinal environment in a beneficial way, helping to reduce inflammation and improve the production of hormones important for appetite control, he said. The take-home message, Hu said, is that more study is needed, but that yogurt seems to have a place in a healthy diet.

Martin Binks, an associate professor of nutritional sciences at Texas Tech University in Lubbock, said that studies that look at diet are inherently limited in their ability to measure true dietary intake. Even so, he said, the link may warrant future study. It's too soon, however, to change advice about diet based on this research, Binks said.

Dr. Osama Hamdy, medical director of the Obesity Program at Joslin Diabetes Center in Boston, points out: "Yogurt in general is beneficial." But he said, "this is an association, not cause and effect."

Nov 21, 2014

Study shows blood pressure medication is not linked to breast cancer

Women who take a common type of medication to control their blood pressure are not at increased risk of developing breast cancer due to the drug, according to new study by researchers at the Intermountain Medical Center Heart Institute in Murray, Utah.

Researchers analyzed the records of more than 3,700 women who had no history of breast cancer, and who had long-term use of calcium channel blocker medications to control their blood pressure. Researchers found only a minimal increase in risk in one study and a 50 percent reduced risk in a second, leading them to recommend the continued use of these important medications to help prevent heart attack and stroke.

Calcium channel blockers are commonly used to help prevent calcium from entering cells of the heart and blood vessel walls, resulting in lower blood pressure.

"We found no robust data that calcium channel blocker medications increase a person's risk of breast cancer," said Jeffery L. Anderson, MD, a cardiologist and researcher at the Intermountain Medical Center Heart Institute. "Given the important role calcium channel blocker medications play in treating heart conditions, we think it's premature to discontinue their use. At this point we recommend that patients continue taking these medications to treat their hypertension."

The Intermountain Heart Institute study was in response to a similar study released last year by the Fred Hutchinson Cancer Research Center in Seattle. That study suggested that the odds of getting breast cancer was 2.5 times higher for women who take calcium channel blocker medications. Results of the Intermountain study indicated small to no increased risk.

The Intermountain Medical Center Heart Institute study carefully examined data collected from more than 3,700 women ages 50 to 70 with no history of breast cancer in two Intermountain Healthcare databases. For each group, researchers compared women who were prescribed calcium channel blocker medications to similar women who weren't prescribed the medications.

In their review of a general population medical records database, researchers found the odds of breast cancer to be 1.6 times higher by using calcium channel blockers, which was significant, but much smaller than reported by the Seattle group.

But, in contrast, in the data collected from patients treated in the Intermountain Cardiac Catheterization Laboratory, a reverse relationship was found -- a 50 percent reduction in risk of developing breast cancer for women who took the calcium channel blockers. The contrasting results found in these two independent analyses led researchers at the Intermountain Medical Center Heart Institute to conclude that it is likely not the medication that caused the changes in breast cancer risk but other factors (e.g., selection biases).

Nov 13, 2014

Mediterranean diet can reverse metabolic disorder, lower risk of diabetes, obesity, heart disease

The Mediterranean diet doesn't just protect against heart disease: It may actually reverse metabolic syndrome, a cluster of symptoms linked to heart disease and diabetes.

The findings came from a study conducted by researchers from the Universitat Rovira i Virgili and the Hospital Universitari de Sant Joan de Reus in Reus, Spain.

"In this large, multicentre, randomized clinical trial involving people with high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil was associated with a smaller increase in the prevalence of metabolic syndrome compared with advice on following a low-fat diet," the researchers wrote.

"Because there were no between-group differences in weight loss or energy expenditure, the change is likely attributable to the difference in dietary patterns."

A heart-healthy diet

Metabolic syndrome refers to a cluster of symptoms that is associated with a higher risk of diabetes, cardiovascular disease and premature death, and affects about 25 percent of all adults globally. The condition can be diagnosed in anyone who has three or more symptoms. Symptoms include high blood sugar, high triglycerides, low HDL ("good") cholesterol, high blood pressure and central obesity (a large waist circumference).

The researchers wondered how the Mediterranean diet could affect metabolic syndrome, because the diet has previously been shown to reduce the risk of cardiovascular disease and type 2 diabetes, as well as lead to better health, longer life and less age-related cognitive decline. For example, a 2013 study published in the New England Journal of Medicine found that people who ate a Mediterranean diet were about 30 percent less likely to develop cardiovascular disease than people who ate a low-fat diet.

The Mediterranean diet has high quantities of olive oil, seeds and nuts, whole grains and beans; moderate to high quantities of dairy, primarily in the form of yogurt and cheese; moderate quantities of fish and poultry; low to moderate consumption of red wine; and low consumption of red meat.

Metabolic syndrome decreased 30 percent

In the new study, researchers randomly assigned 5,801 adults between the ages of 55 and 80 who were considered at high risk of developing heart disease to follow one of three diets: a low-fat diet (control group), a Mediterranean diet plus extra olive oil or a Mediterranean diet plus extra nuts. Participants were followed for an average of 4.8 years.

By the end of the study, there was no difference between the three groups in the numbers who had developed new cases of metabolic syndrome. This showed that, despite being higher in fat, the Mediterranean diet did not worsen metabolic outcomes.

The more surprising outcome came among patients who already had metabolic syndrome at the beginning of the study. Among the groups on one of the two Mediterranean diets, the incidence of metabolic syndrome actually fell by 28.2 percent. Participants receiving extra olive oil were more likely to see decreases in central obesity and blood sugar, whereas participants receiving extra nuts were more likely to see a decrease in central obesity alone.

"Mediterranean diets supplemented with olive oil or nuts were not associated with a reduced incidence of metabolic syndrome compared with a low-fat diet; however, both diets were associated with a significant rate of reversion of metabolic syndrome," the researchers wrote.

Increasingly, research is suggesting that the benefits of the Mediterranean diet also extend far beyond metabolic health. In a 2010 study conducted by researchers from the University of Navarra in Pamplona, Spain. The Mediterranean diet was found to lower the risk of developing depression by 30 percent -- even after researchers controlled for risk factors including anxiety, personality, lifestyle habits and family status.

Nov 7, 2014

Vitamin D improves memory and brain cell function

Spending more time in the sun to boost your vitamin D levels may help stave off the cognitive decline associated with aging, according to a study conducted by researchers from the University of Kentucky.

The study suggests that a vitamin D supplement helps accelerate the biological mechanisms responsible for recycling and renewing neurotransmitters (signaling chemicals) in an area of the brain that plays a key role in memory and learning. This leads to an improved ability of neurons to receive and process signals related to memory formation and retrieval.

"This process is like restocking shelves in grocery stores," researcher Nada Porter said.

Study confirms higher recommended doses

Scientists have long known that vitamin D plays a critical role in forming and maintaining healthy bones and teeth. In recent years, they have begun to learn that the vitamin is also essential to immune function, and that insufficient levels may increase the risk of cancer, autoimmune diseases and other health problems. Studies suggest that low vitamin D levels may also increase the risk of age-related cognitive decline.

In the new study, researchers placed rats on diets with either high, medium or low levels of vitamin D3. After six months, they tested the rats' ability to remember the location of a platform in a water maze. They then moved the platform, and tested the rats' ability to remember the new location.

"This was a more challenging task and, therefore, more sensitive to the subtle changes in memory that occur with aging," Porter said.

Rats who had been on the high-vitamin-D diet used shorter routes to reach the new platform than the other rats, and also reached it more quickly. The paths that they used tended to be relatively simple and consist of few direction changes. In contrast, the paths used by the low-dose rats resembled the loopy drawings made by kindergarteners.

The researchers also found that the rats on the high-dose diet showed changes in gene expression in the region of the brain known as the hippocampus, which is believed to play a central role in cognition and memory formation and consolidation. These rats' brains showed accelerated transport of neurotransmitters.

The vitamin D dose that produced improvements in rats was equivalent to a dose 50 percent higher than the Institute of Medicine's current daily recommendation for humans, which is based on the levels needed for bone health. The levels in the study are consistent, however, with the higher daily doses that many vitamin D experts are now recommending.

The researchers noted that the D3 form of vitamin D is associated with very few side effects.

Sunlight improves brain health

A number of prior studies have suggested a connection between vitamin D and cognitive decline. Some studies have shown that dementia patients have lower vitamin D levels than their healthy counterparts. A study in 2009 found that low vitamin D levels were associated with worse performance on tests of attention, memory and orientation in time and space.

Other studies have suggested that vitamin D can also lower the risk of Parkinson's disease, schizophrenia and even depression.

Although vitamin D can be found in certain foods (mainly those that are artificially fortified), the best source of the vitamin is ordinary sunlight. Light-skinned people can generate all the vitamin D their bodies need with about 15-30 minutes of unprotected sun exposure on their faces and hands daily; darker skin requires correspondingly longer exposure (up to twice as much).