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11 February 2010

Study fails to link saturated fat, heart disease

Research has shown that saturated fat can raise blood levels of "bad" LDL cholesterol, and elevated LDL is a risk factor for heart disease and stroke. Because of this, experts generally advise people to limit their intake of fatty meat, butter and full-fat dairy.

The American Heart Association (AHA) suggests that adults get no more than 7 percent of their daily calories from the fat; for someone who eats 2,000 calories a day, that translates into fewer than 16 grams of saturated fat per day.

But in the new analysis, which combined the results of 21 previous studies, researchers found no clear evidence that higher saturated fat intakes led to higher risks of heart disease or stroke.

The findings, published in the American Journal of Clinical Nutrition, may sound like good news for steak lovers, but a past AHA president cautioned against "over interpreting" the results.

"No one is saying that some saturated fat is going to harm you...people should enjoy their food," said Dr. Robert H. Eckel, a professor of medicine at the University of Colorado School of Medicine in Denver.

But, he pointed out, many studies have shown that dietary saturated fat can raise people's cholesterol, and the new analysis is not going to change recommendations to keep saturated fat intake in check.

Perhaps more importantly, though, Eckel said that the thinking on diet and heart health is moving away from a focus on single nutrients and toward "dietary patterns."

A number of studies have linked the so-called Western diet to greater heart disease risks; that diet pattern is defined as one high in red and processed meats and saturated fats -- but also high in sweets and other refined carbohydrates like white bread.

On the other hand, diets described as Mediterranean or "prudent" -- generally high in fruits and vegetables, whole grains, fish, unsaturated fats from vegetable oil -- may help lower the risk of heart disease and stroke.

It's that type of eating pattern that people should strive for, Eckel said.

For the current study, researchers led by Dr. Ronald M. Krauss, of the Children's Hospital Oakland Research Center in California, pooled data from 21 studies that included a total of nearly 348,000 adults.

Participants, who were generally healthy to start, were surveyed about their diet habits and then followed for anywhere from five to 23 years. Over that time, 11,000 developed heart disease or suffered a stroke.

Overall, Krauss and his colleagues found, there was no difference in the risks of heart disease and stroke between people with the lowest and highest intakes of saturated fat.

The analysis included what are known as epidemiological studies -- where the researchers looked for associations between people's reported diet habits and their risk of heart disease and stroke. These types of studies have inherent limitations, like depending on people's recollection of their eating habits.

In addition, the study could not address whether saturated fat intake has different effects on heart disease and stroke risk for different age groups. Nor could it look at the effects of replacing saturated fat in the diet with polyunsaturated fats -- like those found in vegetable oils and fish -- or with carbohydrates.

Study links sugary soft drinks to pancreas cancer

WASHINGTON (Reuters) - People who drink two or more sweetened soft drinks a week have a much higher risk of pancreatic cancer, an unusual but deadly cancer, researchers reported on Monday.


People who drank mostly fruit juice instead of sodas did not have the same risk, the study of 60,000 people in Singapore found.

Sugar may be to blame but people who drink sweetened sodas regularly often have other poor health habits, said Mark Pereira of the University of Minnesota, who led the study.

"The high levels of sugar in soft drinks may be increasing the level of insulin in the body, which we think contributes to pancreatic cancer cell growth," Pereira said in a statement.

Insulin, which helps the body metabolize sugar, is made in the pancreas.

Writing in the journal Cancer Epidemiology, Biomarkers & Prevention, Pereira and colleagues said they followed 60,524 men and women in the Singapore Chinese Health Study for 14 years.

Over that time, 140 of the volunteers developed pancreatic cancer. Those who drank two or more soft drinks a week had an 87 percent higher risk of being among those who got pancreatic cancer.

Pereira said he believed the findings would apply elsewhere.

"Singapore is a wealthy country with excellent healthcare. Favorite pastimes are eating and shopping, so the findings should apply to other western countries," he said.

But Susan Mayne of the Yale Cancer Center at Yale University in Connecticut was cautious.

"Although this study found a risk, the finding was based on a relatively small number of cases and it remains unclear whether it is a causal association or not," said Mayne, who serves on the board of the journal, which is published by the American Association for Cancer Research.

"Soft drink consumption in Singapore was associated with several other adverse health behaviors such as smoking and red meat intake, which we can't accurately control for."

Other studies have linked pancreatic cancer to red meat, especially burned or charred meat.

Pancreatic cancer is one of the deadliest forms of cancer, with 230,000 cases globally. In the United States, 37,680 people are diagnosed with pancreatic cancer in a year and 34,290 die of it.

The American Cancer Society says the five-year survival rate for pancreatic cancer patients is about 5 percent.

Some researchers believe high sugar intake may fuel some forms of cancer, although the evidence has been contradictory. Tumor cells use more glucose than other cells.

One 12-ounce (355 ml) can of non-diet soda contains about 130 calories, almost all of them from sugar.

Omega-3 may combat mouth bacteria, boost oral health

The dental health benefits of omega-3 fatty acids may include anti-bacterial effects, extending the benefits beyond inflammation, says a new study from the University of Kentucky.

Omega-3 fatty acids of marine and plant origin were found to have strong anti-bacterial activity against a range of oral pathogens, according to findings published in Molecular Oral Microbiology.

EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) and ALA (alpha-linolenic acid), as well as their fatty acid ethyl esters could inhibit the growth of oral pathogens, including Streptococcus mutans, Candida albicans, and Porphyromonas ginigivalis at relatively low doses.

“To date, this is the first study to demonstrate the significant antibacterial activity of omega-3 fatty acids and their esters against oral pathogens,” wrote Dr Brad Huang and Dr Jeff Ebersole from the Center for Oral Health Research at U of K’s College of Dentistry.

Talking to NutraIngredients, lead author Dr Huang said: “Most Omega-3 studies on oral health have been focused on the inflammation part; for some reason, the anti-bacterial activity has not mentioned or ignored, including a recent Japanese study. (To read NutraIngredients’ coverage of the Japanese please click here .)

“On the contrary, the anti-bacterial part of the omega-3 fatty acids could be very important.

“Certainly, it could be a potential new use of omega-3 fatty acids as the nutraceuticals in the future,” added Dr Huang.

The new study looked at the effects of EPA, DHA, ALA and their fatty acid ethyl esters, ALAEE, EPAEE, DHAEE on a range of oral pathogens. All the omega-3 compounds studies were found to exhibit strong antibacterial activity.

The study, sponsored by the US National Institutes of Health, found that all six compounds showed cent 50 per cent inhibitory activity for concentrations ranging from 1 to 10 micrograms per millilitre.
“Although our data support the in vitro effect, the in vivo effects would still need to be empirically determined,” wrote the researchers. “However, EPA and ALA had a much stronger antibacterial activity than DHA in vitro so it is expected that EPA and ALA will have stronger in vivo effects than DHA.”

Dr Huang confirmed that work in this area was ongoing and expanding. “We currently plan to explore this new activity and will try to translate this into products, such as chewing gum.

“Of course, we plan to study and answer those questions about the optimal dosages, pharmacokinetics, the delivery into the oral cavity, and what kind of in vivo dosage/effect to expect, and so on,” he added.

Bitesize look at omega-3 for oral health

Talking to NutraIngredients, Harry Rice, PhD, director, regulatory & scientific affairs for the omega-3 trade association GOED (Global Organization for EPA and DHA Omega-3s) said that the study of resolvins and protectins, which are metabolites of EPA and DHA, is much more advanced than the study of EPA and DHA.

“I think it's worth separating the two groups (resolvins and protectins) versus (EPA and DHA) because of their classification as (pharmaceuticals) versus (foods and supplements) respectively. The majority of research on oral health (i.e. gingivitis and periodontitis) and the long-chain omega-3 fatty acids, EPA and DHA, has been conducted in animals or in vitro.

“The science is promising and in time, I believe it will become more developed,” added Dr Rice.