The Fats Of Life Revealed
The heart health benefits of omega-3-rich fish oil may be linked to its ability to favorably influence the variability in heart rates, says a meta-analysis of 15 studies. Read more at Nutraingredients.
Study Abstract: American Journal of Clinical Nutrition
Millions of people worldwide are exposed to arsenic from contaminated water, and we are all exposed to arsenic via the food we eat. New research published in BioMed Central’s open access journal Nutrition Journal has demonstrated that people who ate more dietary vitamin B12 and animal protein had lower levels of arsenic (measured by deposition in toenails). Total dietary fat, animal fat, vegetable fat and saturated fat were also all associated with lower levels of arsenic, while omega 3 fatty acids, such as those found in fish oil, were associated with increased arsenic.
Long term exposure to high levels of arsenic is known to cause skin lesions, cancer and cardiovascular disease, and also affects foetal development. Even low concentrations of arsenic are potentially dangerous. Arsenic is found in some water supplies, but more people are exposed via their diet. Staples such as rice contain arsenic, especially the toxic inorganic forms, while fish, although high in total arsenic, contains organic forms which are thought to be less toxic.
Inside the body arsenic is methylated to aid excretion in urine but arsenic also has an affinity for keratin and can be deposited in hair and nails as they grow. Consequently levels of arsenic preserved in nails or hair can be used as a biomarker for arsenic exposure over periods of months to years.
Researchers from Dartmouth College and the Geisel School of Medicine at Dartmouth looked at the levels of arsenic in toenails of residents of New Hampshire who all use private groundwater wells as their household water source.
Results of the study showed that arsenic in nails was positively associated with both alcohol and omega 3 fatty acids, however, lower levels of arsenic were found for people who ate greater amounts of vegetable and animal fat. Prof Kathy Cottingham, who directed the study, explained, “While there may be a direct interaction between fats and arsenic preventing absorption or binding to keratin in nails, the results may simply reflect dietary preference, with people who eat a diet rich in fats not eating foods high in arsenic, such as rice.”
Joann Gruber, who led the study, noted that, “Humans can be very efficient at removing arsenic from the body. Improved methylation reduces the amount of inorganic arsenic circulating in the body. Surprisingly, we didn’t see a reduction in toenail arsenic with other dietary factors known to be necessary for arsenic methylation such as folic acid. This may be because the population we sampled had adequate amounts of these factors in their diet.”
The authors are currently working on similar studies in children, through the Children’s Environmental Health and Disease Prevention Center at Dartmouth.
22 October 2010 Elsevier
New Study in Journal of the American Dietetic Association
Periodontitis and tooth loss. Although traditional treatments concentrate on the, a common inflammatory disease in which gum tissue separates from teeth, leads to accumulation of bacteria and potential bone bacterial infection, more recent strategies target the inflammatory response. In an article in the November issue of the Journal of the American Dietetic Association , researchers from Harvard Medical School and Harvard School of Public Health found that dietary intake of polyunsaturated fatty acids (PUFAs) like fish oil, known to have anti-inflammatory properties, shows promise for the effective treatment and prevention of periodontitis.
“We found that n-3 fatty acid intake, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are inversely associated with periodontitis in the US population,” commented Asghar Z. Naqvi, MPH, MNS, Department of Medicine, Beth Israel Deaconess Medical Center. â€œTo date, the treatment of periodontitis has primarily involved mechanical cleaning and local antibiotic application. Thus, a dietary therapy, if effective, might be a less expensive and safer method for the prevention and treatment of periodontitis. Given the evidence indicating a role for n-3 fatty acids in other chronic inflammatory conditions, it is possible that treating periodontitis with n-3 fatty acids could have the added benefit of preventing other chronic diseases associated with inflammation, including stoke as well.â€
Using data from the National Health and Nutrition Examination Survey (NHANES), a nationally representative survey with a complex multistage, stratified probability sample, investigators found that dietary intake of the PUFAs DHA and (EPA) were associated with a decreased prevalence of periodontitis, although linolenic acid (LNA) did not show this association.
The study involved over 9,000 adults who participated in NHANES between 1999 and 2004 who had received dental examinations. Dietary DHA, EPA and LNA intake were estimated from 24-hour food recall interviews and data regarding supplementary use of PUFAs were captured as well. The NHANES study also collected extensive demographic, ethnic, educational and socioeconomic data, allowing the researchers to take other factors into consideration that might obscure the results.
The prevalence of periodontitis in the study sample was 8.2%. There was an approximately 20% reduction in periodontitis prevalence in those subjects who consumed the highest amount of dietary DHA. The reduction correlated with EPA was smaller, while the correlation to LNA was not statistically significant.
In an accompanying commentary, Elizabeth Krall Kaye, PhD, Professor, Boston University Henry M. Goldman
School of Dental Medicine, notes that three interesting results emerged from this study. One was that significantly reduced odds of periodontal disease were observed at relatively modest intakes of DHA and EPA. Another result of note was the suggestion of a threshold dose; that is, there seemed to be no further reduction in odds or periodontal disease conferred by intakes at the highest levels. Third, the results were no different when dietary plus supplemental intakes were examined. These findings are encouraging in that they suggest it may be possible to attain clinically meaningful benefits for periodontal disease at modest levels of n-3 fatty acid intakes from foods.
Foods that contain significant amounts of polyunsaturated fats include fatty fish like salmon, peanut butter, and nuts.
- Full bibliographic informationArticle: â€œn-3 Fatty Acids and Periodontitis in US Adultsâ€ by Asghar Z.
Naqvi, MPH, MNS; Catherine Buettner, MD, MPH; Russell S. Phillips, MD; Roger B. Davis, ScD; and Kenneth J. Mukamal, MD, MPH, MA.
Commentary: â€œn-3 Fatty Acid Intake and Periodontal Diseaseâ€ by Elizabeth Krall Kaye, PhD
Both appear in the Journal of the American Dietetic Association, Volume 110, Issue 11 (November 2010) published by Elsevier.