Fish Oil, Vitamin D and Exercise: How Helpful Are They If You're Over 70?
Vitamin D, fish oil supplements and weight training have long been touted for their health benefits, but for healthy seniors, none of them -- either in combination or alone -- boosts physical or mental performance or prevents broken bones, Swiss researchers report.
For three years, they tracked more than 2,100 men and women (average age: 74) who were randomly assigned to a program involving one or more of the three health interventions.
The upshot: "The results suggest that additional vitamin D and omega-3 [fish oil] intake in active 70-plus adults without previous illnesses, carries no benefit for the risk of non-vertebral fractures, or for muscle and memory function," said study leader Dr. Heike Bischoff-Ferrari, head of geriatrics and aging research at University Hospital Zurich.
But the takeaway was not entirely discouraging.
Ongoing analysis suggests taking a gram a day of fish oil reduced seniors' overall infection risk by 11%. And some specific infection risks dropped even more -- including a dramatic 62% reduction in urinary tract infections, a common ailment in older folks.
Even if their risk of broken bones was unimproved, participants who took 2000 IUs of vitamin D every day saw a "significant" drop in their systolic (upper) blood pressure readings, Bischoff-Ferrari said. Vitamin D supplementation was also linked to a 16% drop in overall infection risk among 70- to 74-year-olds.
"In view of the safety and affordability of the supplements, as well as the high mortality rate from infections in older adults, these results are relevant for public health," she said.
Researchers also tested the impact of two exercise regimens: a strength-training program and an "attention control exercise program" for joint flexibility. Each involved three 30-minute sessions per week. Some participants either exercised or took supplements; others did a mix of both.
For participants without major preexisting health problems, researchers found no statistically significant health benefit from the regimens. They said most participants started the study in excellent shape, which may have limited the chance to show bigger benefits.
"Over 80% were moderately to highly physically active, and about half were healthy agers without comorbidities," Bischoff-Ferrari said. "In fact, all participants over the three years improved their blood pressure, their cognitive function and their lower extremity function."
Another complicating factor might be the amount of daily supplementation that was tested, said Lona Sandon, director of clinical nutrition at University of Texas Southwestern Medical Center in Dallas, who reviewed the findings.
"One of my first thoughts on this study is: Was the dose of intervention enough to cause a difference?" Sandon said. "The vitamin D dose was only 2000 IUs … [which is] considered the current upper limit for vitamin D. However, there is much scientific controversy about just how much vitamin D really is the upper limit and needed to alter blood levels. We make much more vitamin D from sunlight than this."
The fish oil dose was also relatively low, Sandon noted. Studies showing benefit for things like lowering inflammation use much higher doses, and strength training was also below current recommendations of two hours a week, she added.
"Only about two-thirds of the participants self-reported meeting the 30-minutes, three days/week [requirement]," Sandon pointed out. "So do the results surprise me? Not at all with those doses."
Her bottom line: "Getting adequate vitamin D in food and from sunshine is good for us and essential," Sandon said. "Omega-3s are essential nutrients for the body and proper functioning, too. Exercise does help keep us physically and mentally functioning better. People should not give up on eating healthy and keeping moving. I do not see a downside to any of these things."
The findings were published Nov. 10 in Journal of the American Medical Association.
There's more information on the seniors and health recommendations at the U.S. National Institute on Aging.
SOURCES: Heike Bischoff-Ferrari, M.D., Dr.P.H., chair, Department of Geriatrics and Aging Research, University Hospital Zurich, Switzerland, and director, Center on Aging and Mobility, University Hospital and City Hospital Waid, Zurich; Lona Sandon, Ph.D., R.D.N., L.D., associate professor, Department of Clinical Nutrition, and director, master of clinical nutrition coordinated program, University of Texas Southwestern Medical Center, Dallas; Journal of the American Medical Association, Nov. 10, 2020