Two commonly taken dietary supplements that are part of a massive national clinical trial will also be studied at Augusta University to see if they can slow the effects of aging and improve cardiovascular health.
Researchers Yanbin Dong and Haidong Zhu of the Georgia Prevention Institute at AU have a $2.5 million study to tack on to the national Vitamin D and Omega 3 Trial (known as VITAL) being run out of Brigham and Women’s Hospital and Harvard Medical School. That trial is looking at nearly 26,000 people nationwide who are either taking those supplements or placebos for five years. The AU part will look at a subgroup of 1,000 people in that study who are in Boston, where researchers are seeing them in clinic and collecting blood samples. Part of the AU study will look at those samples for a biomarker called telomeres, Dong said.
“Telomeres are the tips of your chromosomes, which protect your chromosomes, to keep your chromosomes stable and functional,” he said. “When you are born, you have the longest telomeres. As you age, your telomeres get shorter.”
Dong and Zhu had previously looked at vitamin D supplementation in teenagers in Augusta and found that after giving a short 16-week course of vitamin D “we found cellular aging improved,” he said. But “we really need to replicate our results in a large, nationally representative clinical trial.”
Vitamin D has long been acknowledged as essential to bone health but claims for other health benefits, such as improving cardiovascular health, have found both proponents and detractors. The prestigious Institute of Medicine further inflamed the debate when its analysis concluded there was little credible evidence for many of those claims and then recommended supplement levels that many thought were too low. The VITAL study is looking to see if there is evidence the supplements can prevent cardiovascular disease, cancer and stroke in people without a prior history of those diseases.
“VITAL is a very valuable study,” Zhu said. “It is a large randomized clinical trial. The outcome from that study will provide strong evidence whether there is a beneficial effect of vitamin D and fish oil on cardiovascular health” and the other diseases.
That study will wrap up its pill-taking phase at the end of 2017 and then have a two-year follow-up. The AU study will help extend that for its cohort, Zhu said.
“We extend their follow-up for two more years,” she said. “Now it is a four-year follow-up study.”
But despite their earlier findings, Dong said they should be careful about making recommendations at this point.
“Do we have enough evidence to tell the public you need to take vitamin D supplementation, you need to take omega-3 supplementation to protect your heart or slow down your aging process?” he said. “Right now there is not enough evidence in humans to inform nutritional recommendations, for example.”
As skin ages, it makes it harder to process vitamin D from sunlight and at the same time aging seems to raise inflammatory levels in the body. In addition to their genetic analysis, the AU team will be looking at common inflammatory markers like C-reactive protein that have also been linked with cardiovascular disease, to see if the supplements have an effect.
“In this grant, we also want to investigate the effect of vitamin D and the fish oil (omega-3) on the effect of reducing inflammation, on the effect of improving cardiovascular health in addition to the effect on anti-aging,” Dong said. “Those three things are mingled together.”
While it is hard to make a recommendation for the general public, many people probably are vitamin D-deficient, the researchers said. They found in their previous study that a majority of the black teenagers and a good percentage of the whites were vitamin D-deficient “even in a sunny, Southern state,” Zhu said.
“No wonder vitamin D deficiency is more common in places like Boston, New York,” Dong added.
People who are obese are also more likely to have vitamin D deficiency, Zhu said. If people do decide they want to take a vitamin D supplement, Dong said 2,000 IUs would be the best daily dose and vitamin D3, also called cholecalciferol, is better than D2, Dong said. But they are still waiting on clinical-based evidence to make that general recommendation, he said.
“We hope the result from our study can really be informative or conclusive to nutritional guidelines that are going to be formed or updated later on,” Dong said. “But it could take a while.”