Long-term exposure to air pollution can lead to physical changes in the brain, learning and memory problems and even depression, according to scientists.

Studies with mice have revealed that pollution exposure can lead to changes in the hippocampus of the brain, which is responsible for learning and memory.  Mice that were exposed to pollution over a 10 month period took longer to learn information from their surroundings and were less likely to remember what they had learned.

The mice also showed higher levels of anxiety and more depressive-like behaviors than mice who had been kept in clean air.

Researchers speculate that this may be due to the fact that air pollution exposure can decrease the number of signal receptors in the brain and lead to reduced cell complexity.

The researchers expressed concern over what these findings could mean for humans.

“The results suggest prolonged exposure to polluted air can have visible, negative effects on the brain, which can lead to a variety of health problems,” said Laura Fonken, lead author of the study and a doctoral student in neuroscience at Ohio State University.

“This could have important and troubling implications for people who live and work in polluted urban areas around the world.”

Previous research has indicated that air pollution exposure similar in concentration to that found in urban areas causes widespread inflammation in the body and can be linked to high blood pressure, diabetes and obesity.

The inflammation can even be observed in certain areas of the brain, such as the hippocampus, which is particularly susceptible to damage.

The study was published in the journal Molecular Psychiatry.

An analysis of heart disease and stroke statistics collected from 192 countries by the World Health Organization shows that the relative burden of the two diseases is closely linked to national income.

University of California researchers found that developing countries tend to suffer more death and disability by stroke than heart disease.  Meanwhile, the United States and other countries with higher national incomes tend to experience the opposite.

This finding may help health officials design tailored interventions to best fit the needs of developing countries, the researchers say.

“In general, heart disease is still the number one cause of death worldwide, but there is quite a lot of variation across the globe,” said Anthony  Kim, MD, MAS, assistant professor of neurology at UCSF .

For instance, there was a wide variation in the mortality rate for stroke highlighted by the new research.  Rates ranged from a worldwide low of 25 deaths per 100,000 in the island nation of Seychelles to a high of 249 deaths per 100,000 in Kyrgyzstan – a rate nearly 10 times greater.

In the United States, there are approximately 45 deaths per 100,000 people due to stroke.

Heart disease and stroke are similar in that they are both are caused by reduced or restricted blood flow to vital organs and share many of the same common risk factors, such as hypertension, diabetes, high cholesterol, obesity, physical inactivity and smoking.

However, because they affect very different tissues – the heart and the brain – they diverge in terms of symptoms, approaches to critical care, follow-up treatment and the duration and cost of recovery.

“There was a striking association with national income,” Kim said.

In the United States, for instance, heart disease is the number one killer and stroke the number four, according to the Centers for Disease Control and Prevention. This also holds true for the Middle East, most of North America, Australia and much of Western Europe.

The opposite is true in many developing countries. Stroke  is more prevalent in China, many parts of Africa, Asia and South America.

Overall, nearly 40 percent of all nations have a greater burden of stroke compared to heart disease.

“This is significant,” said Kim, “because knowing that the burden of stroke is higher in some countries focuses attention on developing a better understanding of the reasons for this pattern of disease and may help public health officials to prioritize resources appropriately.”

The study was published in the journal Circulation.

Aerobic exercise is the best way to target unwanted belly fat, according to a new study.

Duke University researchers compared the effects of aerobic exercise versus resistance training and found that aerobic exercise was the most efficient and effective way to lose belly fat.

Belly, or abdominal fat, is located deep in the abdominal cavity and fills spaces between internal organs. Prior research has associated it with increased risk for heart disease, diabetes, and certain cancers.

“When it comes to increased health risks, where fat is deposited in the body is more important than how much fat you have,” said Cris Slentz, Ph.D, lead researcher. “Our study sought to identify the most effective form of exercise to get rid of that unhealthy fat.”

For the study, participants were assigned to one of three exercise groups: aerobic exercise, resistance training, and a combination of the two. People assigned to aerobic exercises burned 67 percent more calories than those who did resistance training.

Furthermore, the results showed that aerobic exercise was better than resistance training at improving fasting insulin resistance and reducing liver enzymes and triglyceride levels, which are known risk factors for heart disease.

Resistance training showed no significant reductions in visceral fat, liver fat, liver enzyme levels or improvements in insulin resistance. The combination group showed similar results to those who did aerobic training alone.

“Resistance training is great for improving strength and increasing lean body mass,” says Slentz. “But if you are overweight, which two thirds of the population is, and you want to lose belly fat, aerobic exercise is the better choice because it burns more calories.”

People with metabolic syndrome are at a significantly increased risk of developing kidney disease, according to a new study.

In a review of 11 studies involving 30,416 people, Cleveland researchers found that people with metabolic syndrome have a 55 percent increased risk of developing kidney problems indicative of kidney disease.

“Primary care physicians may need to consider using metabolic syndrome as a marker to identify patients at higher risk of developing kidney disease,” said Sankar Navaneethan, MD, study researcher.

Metabolic syndrome is made up of a group of medical disorders, including high blood pressure, high blood sugar, excess body fat in the waist or abdomen, low good cholesterol and higher levels of fatty acids.

A person is diagnosed with metabolic syndrome when they exhibit three or more of the above characteristics.

The risk of a person developing kidney disease increases with each symptom of metabolic syndrome that a person has. Metabolic syndrome also increases the risk of other health problems such as diabetes, heart disease, stroke and premature death.

Metabolic syndrome can be prevented or managed through eating a healthy diet, exercising and losing weight.

The study was published in the Clinical Journal of the American Society of Nephrology.

Recently, I read a study that claims that fat people can be just as healthy as slim people, as long as they have no chronic health problems.

The study, which followed 6,000 obese people over a 16 year period, concluded that fat can indeed by healthy based on results that indicated that the overweight people lived just as long and had less heart problems than their slim counterparts.

Personally, I wouldn’t put much weight (no pun intended) behind this study. I think it’s sending a terrible message to the public.

Ask any doctor, and they’ll tell you: health-wise, it’s not okay to be obese. Excluding cardiovascular problems, there are still many other chronic diseases associated with being overweight.

People who are overweight are at greater risk for type 2 diabetes, which can take many years to develop, or arthritis, among other problems. All of these issues can have a severely negative impact on quality of life and longevity.

The fact is, medically, it is necessary for all humans to strive to be at an ideal body weight. Sure, there are plenty of skinny, sick people out there, but their health issues would probably be compounded if they had excess body weight to deal with as well.

One good thing that the study did recommend was that obese people keep up an active lifestyle. I agree that maintaining a fitness regimen can help in many ways, including aiding with weight loss.

It’s not okay to settle for being above a healthy weight. People should all fight to reach their ideal weight. Trust me, I’m certainly familiar with that fight myself, and I hope my efforts will pay off in the end.

A new study finds a strong association between red meat consumption, especially when the meat is processed, and an increased risk of type 2 diabetes.

The study also indicates that replacing red meat with other proteins, such as low-fat dairy, nuts or whole grains, can significantly lower that risk.

Harvard researchers analyzed data from over 100,000 people followed for an average of 20 years, as well as looking at data from existing studies. They found, after adjusting for age, body mass index and other lifestyle factors, that a daily 100-gram serving of unprocessed red meat could increase the risk of type-2 diabetes by 19 percent. A hundred grams is about the size of a deck of cards.

A serving half that size of processed meat, such as a hot dog or two slices of bacon, was associated with a 51 percent increased risk.

“Clearly, the results from this study have huge public health implications given the rising type 2 diabetes epidemic and increasing consumption of red meats worldwide,” said senior author Frank Hu. “The good news is that such troubling risk factors can be offset by swapping red meat for a healthier protein.”

For example, a person who substitutes their daily serving of meat with nuts can lower his or her risk of type 2 diabetes by 21 percent. Low-fat dairy is associated with a 17 percent lowered risk, and whole grains decreases the risk by 23 percent.

Based on the findings, the researchers advise to minimize consumption of processed red meat like hot dogs, bacon, sausage and deli meats, which generally have high levels of sodium and nitrates, and reduce consumption of unprocessed red meat.

If possible, red meat should be replaced with healthier choices, such as nuts, whole grains, low-fat dairy products, fish or beans, the researchers said.

Diabetes has reached epidemic levels worldwide, affecting nearly 350 million adults. It affects 25.6 million adults in the United States alone.

The researchers say their findings may have some impact on U.S. dietary guidelines.

The study will be published in the American Journal of Clinical Nutrition.