[intro music] Host – Dan Keller Hello, and welcome to Episode Eighty-seven of Multiple Sclerosis Discovery, the podcast of the MS Discovery Forum. I’m Dan Keller. Animal data, laboratory studies, and even some human evidence suggest that restricting caloric intake may have a salutary effect on diseases that involve inflammation, possibly including MS. I spoke with Dr. Ellen Mowry of Johns Hopkins University at last fall's ECTRIMS meeting in Barcelona about the rationale for testing caloric restriction in patients with MS and a study that she's carrying out in this regard. Interviewee – Ellen Mowry Laura Piccio and Anne Cross at Wash U, among others, looked at calorie restriction in a mouse model of MS, EAE. And they were able to show that reducing calories prior to the disease reduces the disease and/or its severity. And there are a lot of other in vitro data, other mouse models, and even some human data from other patient populations suggesting that intermittent fasting or intermittent calorie restriction not only reduces inflammation, but may improve oxidative stress handling in mitochondrial function. So we were really interested in whether the ecological observation that the incidence of MS increasing sort of is tied to the same time period in obesity epidemic and that Langer-Gould has showed, among others, that childhood obesity, especially in girls, seems to be a risk factor for MS. So could we be just eating too much, and is that sort of contributing to a burden of MS risk or to a worse prognosis? So we're doing a trial—it's funded by the National MS Society—of a controlled feeding trial where we're randomizing people to either continuing a sort of traditional western diet at the same level of calories they would need to maintain their current weight; to eating that diet most days, but two days a week having only 25% of their caloric needs for that day; or to a group where that same number of calories or percentage of calories is restricted, but spread out over a week. So we should be able to look at the relative impact of just weight reduction, for example, versus the timing of calorie intake to some extent. And we're also really curious to see like when we're done with the early phase of that study, which is eight weeks and we'll be providing foods to people, whether or not patients can sustain that diet afterwards for a longer period of time. Because I think there's really great building rationale for evaluating diet as a potential modifier of the disease. But the other side of studying diet and dietary modifications in people with MS is that we don't know how to encourage people and help them participate in meaningful lifestyle changes that are sustainable. So I think we need to look at that carefully as well. Interviewer – Dan Keller Is there any gradient of incidence of MS by BMI? Dr. Mowry So Annette's study really showed a pretty strong impact of adolescent obesity in girls on MS risk with I would think about a fourfold increase in the odds of developing MS if you were an extremely obese adolescent girl compared to a normal or underweight. And other studies have looked at this as well and shown a very similar set of results. So I would call it sort of a fourth environmental risk factor for MS. I think enough studies have shown a similar association that we can consider that a likely risk factor at this point. MSDF In your study on caloric restriction, are you giving any thought to the composition of the diet? Or are you going to be heavy on carbohydrates, minimize fats, the reverse? Dr. Mowry So we're actually aiming for the 50th percentile of the typical American diet for all the macronutrients, fat, carbo, and protein. The reason is we really want to study the concept of caloric restriction in isolation, and in particular, in a pilot study where you don't have a huge number of people, you can't al