American Society for Nutrition

A Conversation with Purdue University's Dr. Connie Weaver

The American Society for Nutrition (ASN) publishes some of the world's most respected and widely read nutrition journals. The Society also hosts a yearly clinical conference, Advances and Controversies in Clinical Nutrition, which focuses on critically appraising current nutrition controversies and identifying opportunities for integrating evidence-based research findings into clinical practice. At the 2012 meeting, Dr. Connie Weaver, Head of the Department of Nutrition Science at Purdue University, spoke about calcium and cardiovascular disease risk. Dr. Weaver recently provided a follow-up to this current health topic and discussed her experiences as an ASN member.

Interviewer: Would you tell us a bit about the recently published article: “A Review of Calcium Supplements and Cardiovascular Disease Risk”?

Dr. Weaver: There has been a lot of concern, of late, regarding a potential association between calcium and Vitamin D supplements and an increased risk of cardiovascular problems. This concern stemmed from retrospective analysis of randomized, controlled trials that were originally designed to test calcium and Vitamin D supplementation against a placebo for bone health. A group of New Zealand scientists reanalyzed these results, however, and found that the supplements were also associated with an increased risk of myocardial infarction. Obviously, these concerns raised quite a few alarms, leading to additional analyses, some of which have found no association and others that have found other kinds of cardiovascular risks. There is not currently any mechanistic explanation for these findings, but I argue that we need more of this type of data before we jump to any kind of conclusion.

Our research attempts to address that need via an animal model- a pig on an atherogenic diet with metabolic syndrome and atherosclerosis. We are currently completing a study in which the pigs are given as needed calcium or high calcium either as calcium carbonate supplements or as dairy. We are trying to determine if more calcium accumulates in the soft tissue, particularly the coronary artery, to determine if there is a risk. To do so, we used a calcium tracer that measures very small amounts of calcium in the arteries.

Interviewer: What is the future of calcium research? What breakthroughs do you think are most promising for further investigation, and what specific obstacles does it face?

Dr. Weaver: Calcium supplement sales have fallen off of late due to the media attention about the potential association with cardiovascular risk. Now, of course, that makes us worry about bone health, since we have pretty firm evidence about the benefits of calcium for bone. While patients are understandably worried about the risks, we don't want to see those benefits compromised. Our article was an attempt to summarize what we know at this time and to point a way forward, using this animal model.

In regard to this one problem, it is difficult to convince the scientific community whether this animal model can translate to humans. Unfortunately, it is also difficult in humans to get causal data because you can't randomize people to take calcium supplements or placebo long enough, nor, obviously, can you sample their artery to test calcium accumulation. So you are either stuck with trusting what you see in an animal model or relying on circumstantial evidence in humans.

Interviewer: Would you give us an overview of your talk at the Advances & Controversies in Clinical Nutrition Meeting?

Dr. Weaver: Well, that panel was related to this problem. It was set up as a dialogue rather than a debate. I worked with a cardiologist to answer questions directed by the moderator or from the audience about how calcium supplements could conceivably aggravate soft tissue calcification, whether that is plausible, and whether the form of calcium matters. This session was subsequently made available via ASN's website, so the discussion expanded significantly even after it was over.

Interviewer: What was your experience like as a presenter at the meeting? What would you say to encourage investigators or clinicians who may want to participate in the 2013 meeting?

Dr. Weaver: The wonderful thing about ACCN is that it has a smaller, more intimate feel, especially in contrast to some of the larger meetings like Experimental Biology. The size difference allows for much more direct interaction between panelists and audience members. You have a good chance for dialogue on the spot. The webinar portion also gave us an opportunity to expand the conversation and to address questions that we may not have had time to get to during the session.

Interviewer: How did you first get involved in nutrition? What motivated you to pursue a career in the field?

Dr. Weaver: I actually first got interested in nutrition as a member of 4-H, when I was a kid. It really got me interested in science and health.

Interviewer: How did you get involved with ASN? What motivated you to join, and what aspects of membership have been most helpful to your professional advancement?

Dr. Weaver: I joined ASN after attending Experimental Biology in my first year as a professor at Purdue. The networking has always been the number one benefit for me via both society meetings and committees. ASN also does an excellent job of staying abreast with public policy discussions and keeping members informed about the aspects of those discussions with the potential to impact our work. The organization has helped build essential links between researchers, clinicians, and policymakers. The publications, of course, are essential as well.

December 2012

Interview with Dr. Connie Weaver

Interview with Dr. Connie Weaver