Field Notes

Upping Intake of Omega-3s May Help Protect Hearing

Researchers report that blood levels of the omega-3 fatty acid DHA were inversely correlated with hearing difficulty in a new population-based cross-sectional study. Middle-aged and older adults with higher DHA levels were 8% to 20% less likely to report age-related hearing issues than those with lower DHA levels.

“Higher DHA levels have previously been found to be associated with a lower risk of heart disease, cognitive impairment, and death. Our study extends these findings to suggest a role for DHA in maintaining auditory function and helping reduce the risk of age-related hearing loss,” says Michael I. McBurney, PhD, a senior scientist with the Fatty Acid Research Institute and an adjunct professor in the Department of Human Health & Nutritional Sciences at the University of Guelph and the Friedman School of Nutrition Science and Policy at Tufts University.

Using data from the UK Biobank, the researchers analyzed self-reported hearing status and blood DHA levels of over 100,000 people aged 40 to 69 in the United Kingdom. After accounting for potential confounding variables, the results showed that people in the highest quintile (one-fifth of participants) of blood DHA levels were 16% less likely to answer yes to the question, “Do you have difficulty hearing?” compared with those in the lowest quintile of DHA levels. Similarly, those in the highest quintile for DHA levels were 11% less likely to answer yes to the question, “Do you have difficulty following conversations when there is background noise?” compared with people in the lowest quintile for DHA levels.

While the results show a significant association between DHA levels and hearing, McBurney cautions that a cross-sectional population study doesn’t provide enough evidence to definitively conclude that DHA maintains auditory function or that inadequate DHA levels contribute to hearing loss. However, the findings add to a mounting body of evidence of the importance of omega-3 fatty acids, including DHA in particular, to maintain health and help protect against aging-related declines in a variety of body functions.

Omega-3s may help protect the health of cells in the inner ear or mitigate inflammatory responses to loud noises, chemicals, or infections. Previous studies conducted in older adults and in animals have similarly suggested that higher omega-3 levels are inversely related to and may protect against age-related hearing loss.

Our bodies have a limited ability to produce DHA, so the amount of DHA found in our blood and tissues largely depends on our omega-3 intake. DHA levels can be increased by regularly consuming seafood or by taking dietary supplements.

“There’s strong evidence that higher blood levels of omega-3 fatty acids are beneficial,” McBurney says. “Fatty fish and omega-3 supplements are both good dietary sources. If choosing to use a dietary supplement, compare products by reading the Supplement Facts panel for EPA+DHA content.”

It’s estimated that around 20% of people—over 1.5 billion people worldwide—live with hearing loss, and this number is expected to rise as the population ages in the coming decades. Hearing loss can range from mild to profound; it affects communication and social interactions, educational and job opportunities, and many other aspects of daily life.

Environmental factors as well as genetic proclivities and medicines contribute to hearing loss. Proven ways to reduce the risk of hearing loss include protecting the ears from loud noises by using protective equipment and getting appropriate medical care for infections.

— Source: American Society for Nutrition

 

School Meals Could Be Healthier If Compliant With US Nutrition Standards

Today’s school meals are more healthful than they were for the parents of American kids, but still one in four school meals are of poor nutritional quality. The latest Dietary Guidelines for Americans, in place for 2020–2025, call for meals with less sugar and salt and more whole grains.

Fully synchronizing school meals with these new standards could positively impact hundreds of thousands of children into their adulthood, with the added benefit of saving billions in lifetime medical costs, report investigators from the Friedman School of Nutrition Science and Policy at Tufts University in The American Journal of Clinical Nutrition. By modeling the national implementation of updated school lunch guidelines, the research team found even incomplete compliance by schools would lead to overall reductions in short- and long-term health issues for participating K–12 students.

“On average, school meals are healthier than the food American children consume from any other source, including at home, but we’re at a critical time to further strengthen their nutrition,” says senior author Dariush Mozaffarian, DrPH, a cardiologist and Jean Mayer Professor of Nutrition at the Friedman School. “Our findings suggest a real positive impact on long-term health and health care costs with even modest updates to the current school meal nutrition standards.”

The researchers used a simulation model to derive a data-driven estimate of three changes to the school meal program, including limiting percent of energy from added sugars to lower than 10% of total energy per meal, requiring all grain foods to be whole grain, and lowering sodium content to the Chronic Disease Risk Reduction amount for sodium intake in the 2020–2025 Dietary Guidelines for Americans. A portion (35%) of these dietary changes were estimated to continue into adulthood. If all schools fully complied with the new standards, these were estimated to prevent more than 10,600 deaths per year due to fewer diet-related diseases, saving more than $19 billion annually in health care–related costs during later adulthood. The worst-case estimate, in which schools remained with their current food offerings, saved a little over half as many lives and health care dollars.

School meals aligning to new dietary guidelines for added sugars, sodium, and whole grains would have modest, but important, short-term health benefits for children. For example, these changes were estimated to reduce elementary and middle school students’ BMI by 0.14 and systolic blood pressure by 0.13 mm Hg. Benefits were about half as large for high school students because fewer older students eat school-provided meals.

“Using a comparative risk assessment model, our estimations are based on the best available, nationally representative data on children and adults and the best available evidence on how dietary changes in childhood relate to BMI and blood pressure, how dietary changes persist into adulthood, and how diet influences disease in adulthood,” says first author Lu Wang, a postdoctoral fellow at the Friedman School. “Our new results indicate that even small changes to strengthen school nutrition policies can help students live longer, healthier lives.”

The study’s findings, which can’t prove the outcomes they describe but are derived from a mathematical model based on the best available demographic and health data, are timely given the USDA’s recent commitment to updating the school meal nutrition standards to align with the 2020–2025 dietary guidelines. The price to fully implement new school meal standards is yet to be determined, but previous alignments suggest it would add at least another $1 billion nationally to the cost of these programs, or only about 5% of the total predicted annual long-term health care savings this change would yield.

Research reported in this article was supported by an award from the National Institutes of Health's National Heart, Lung, and Blood Institute (R01HL115189) and the Center for Science in the Public Interest. Complete information on authors, funders, methodology, and conflicts of interest is available in the published paper. The content is solely the responsibility of the authors and doesn’t necessarily represent the official views of the funders.

— Source: Tufts University