THURSDAY, May 3 (HealthDay News) -- Jogging regularly could add about six years to your life, a new Danish study suggests.

"The results of our research allow us to definitively answer the question of whether jogging is good for your health," Peter Schnohr, chief cardiologist of the long-term Copenhagen City Heart Study, said in a news release from the European Society of Cardiology. "We can say with certainty that regular jogging increases longevity. The good news is that you don't actually need to do that much to reap the benefits."

In conducting the study, the researchers compared the mortality of joggers and non-joggers who took part in the population study of 20,000 people aged 20 to 93 that began in 1976. In making their comparison, they asked 1,116 male joggers and 762 women joggers about their jogging routine, including how fast and how long they jogged weekly.

"With participants having such a wide age span we felt that a subjective scale of intensity was the most appropriate approach," explained Schnohr, who is based at Bispebjerg University Hospital, in Copenhagen.

In the follow-up period of up to 35 years, the study found that 10,158 non-joggers and 122 joggers died. The researchers noted this was a 44 percent drop in the risk of death for male and female joggers.

The researchers found that male joggers can extend their life by 6.2 years, and women by 5.6 years.

Jogging at a slow pace for one to two and a half hours weekly provided the most significant benefits.

"You should aim to feel a little breathless, but not very breathless," said Schnohr. "The relationship appears much like alcohol intakes. Mortality is lower in people reporting moderate jogging, than in non-joggers or those undertaking extreme levels of exercise."

The study's authors noted there are several health benefits of jogging that contribute to increased life expectancy, including improvements in:

• Oxygen uptake
• Insulin sensitivity
• Lipid profiles (raising "good" HDL cholesterol and lowering triglycerides)
• Heart function
• Bone density
• Immune function
• Psychological function

The improved psychological well-being may be due to the fact that people have more social interactions when they're out jogging, explained Schnohr.

The researchers added that jogging also helps lower blood pressure, reduce platelet aggregation and prevent obesity.

The study was slated for presentation Thursday at a meeting of the European Association for Cardiovascular Prevention and Rehabilitation, called EuroPRevent2012, in Dublin.

Data and conclusions presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.

More information

The U.S. National Institutes of Health provides more information on the health benefits of exercise.  

MIght be with a 'Soft' J

By Alex Crees  

Eating foods such as chicken, fish and nuts may help lower blood levels of a protein strongly associated with Alzheimer's disease and memory problems, according to new research.

In the Columbia University study, people who consumed diets rich in omega-3 fatty acids had significantly lower levels of a protein called beta-amyloid in their blood than those who did not consume as much of the nutrient.  

According to the research, eating one more gram of omega-3s than average per week was associated with 20 to 30 percent lower levels of beta-amyloid.  One gram is approximately equal to half a fillet of salmon.

However, study author Dr. Nikolaos Scarmeas, a neurologist at Columbia University Medical Center in New York and a member of the American Academy of Neurology, recommended not focusing on eating particular quantities of omega-3s, but rather, simply incorporating as much of the nutrient into one's diet as possible.

"It was a continuous association.  More and more intake of omega-3s was associated with lower and lower levels of beta-amyloid in the blood.  There was no threshold effect," Scarmeas said.

The association between omega-3 consumption and beta-amyloid was unaffected by whether or not a person took supplements - meaning if two people consumed the same amount of omega-3s, one through food and the other through supplements, the person who consumed more omega-3 rich foods typically had lower blood levels of beta-amyloid.

It is believed that the build-up of beta-amyloid in the brain,  not the blood, is a precursor for Alzheimer's.  However, past studies have indicated there may be a relationship between blood levels and brain levels of the protein.

"There is complex, conflicting literature; we do not understand very well biologically how levels of beta-amyloid in the blood, brain and spinal fluid are related exactly," Scarmeas said. "In some studies, higher levels of beta-amyloid in the blood relate to higher levels of beta-amyloid in the brain.  Other studies have suggested the opposite."

Scarmeas added that his own lab had observed that people with higher blood levels of beta-amyloid were more likely to develop dementia, while people with lower levels tended not to. 

The beneficial impact of omega-3 on brain health would fall in line with past studies of the nutrient, according to Scarmeas.  Omega-3s have long been associated with positive benefits for memory and cognition.

Scarmeas speculated that omega-3s may be able to reduce oxidative stress on the brain and the resulting vascular damage, or even have some kind of impact on beta-amyloid in the brain.  Though, there is not enough support yet to suggest the nutrient and protein are directly related, he added.

"Previous studies have suggested that omega-3s and other aspects of diet may be related to brain function," he said. "Here we demonstrate one possible mechanism could be through amyloid, the main biological mechanism that relates to Alzheimer's disease. There have been animal studies suggesting omega-3s could relate to amyloid brain biology.  We've demonstrated this association may also be present in humans."

The study was published Wednesday in the journal Neurology.