Is saturated fat or sugar the main culprit in the obesity epidemic that is now sweeping the world? Was the focus on saturated fats the result of some scientists using their power and influence against others, leading to 50 years of wrong dietary advice? Was Arcel Keys the Lysenko of the dietary wars? Has recent research changed the way we look at sugar versus fat in our diet? Newsclick discusses these questions with Dr. Satyajit Rath from Indian Institute of Immunology. He identifies the changes not so much to fads or fancies of researchers but the new insights we now have into metabolic diseases -- hypertension, heart diseases, diabetes.These diseases have an inflammatory component in them, which we did not know earlier. Dietary advice was always about balanced diet and exercise; that has not changed. He also explained that a lot of the distortions in what finally comes out as dietary advice has less to do with scientific or medical advice but the power of the food industry and agri-livestock business and market power.
Prabir Purkayastha (Prabir): Hello and welcome to Newsclick. Today we have with us Dr. Satyajit Rath and we’ll be discussing some of the issues that have hit the new recently, thanks to some journalistic reporting, some technical papers. This concerns what is good for us to eat. Whether eggs are good for us, whether fats, meat products are really as bad as they’d been painted, are sugars the key problem. So what is it really that we should do as far as diet is concerned and some of this relates to the controversies that have now come up. Satyajit, there have been some papers professor Lustig talking about what is Ancel Keys major findings, supposedly driving this whole field of diet in one direction. Professor Yudkin was virtually ex communicated the 70s for whatever reasons, who apparently had the thesis that sugars, were the main culprit in what is now regarded as an epidemic of obesity, type 2 diabetes, of course it’s also there now in quiet large numbers in India. Do you think there is something which is true in this, that we had some skewing of the field in one direction and now coming back on you think its manufactured controversy?
Dr. Satyajit Rath (Satyajit): I'm going to sit very uncomfortably on the fence in a variety of directions on this one. So, the answer to the first question; is there a re-ordering of priorities that’s been going on for a while? And the answer is yes. There has been. We have been inclined to thinking of facts as a primary culprit. We are now swinging away from facts and trying to identify sugars, particularly fructose but sugars in general, simple sugars in general as a primary culprit.
Prabir: When you say fructose, what does it mean in terms of mainly sugar, how much is it used, how do we actually consume fructose?
Satyajit: Well, fructose is called fructose because it's found in fruits but it’s a simple sugar, it's not as simple as glucose but it is still a simple sugar exactly the same way that sucrose is a simple sugar found in, sugar. You can get energy from all of these, the pathways, the biochemical pathways by which we derive energy from all of these are a little bit different and those differences have been to some extent implicated in how our bodies respond differently to large amounts of fructose versus large amount of sucrose verses perhaps large amounts of glucose. Of course we also make glucose from complex carbohydrates, much larger molecules of polysaccharides as they say and the biochemical pathways from which we derive sugars from those are yet another area of investigation.
Prabir: So, Fructose has been implicated more seriously as it were than other sugars and this has made the field sort of comeback, that there is a possibility sugars are also implicated in a large way in some of these issues, it’s not just fats in our diets or what used to be called saturated fats in our diet.
Satyajit: Let me complicate this a little bit. When we talk about what we eat and what the consequences are in terms of obesity, in terms of type 2 or insulin resistant or adult onset diabetes, or cardio vascular diseases that lead to either strokes or heart attacks. In all of these, when we talk about the problems of nutrition, we tend to think about nutrients as having a nutritional effect on the body, a metabolic effect on the body. The major difference that the past couple of decades have certainly made to this entire debate, is the fact that we have realised that it’s not simple as that, that what we have so far called, when I was student certainly, were called metabolic diseases and where either implicitly or explicitly identified as not being related to inflammation, have now been recognized as having a very strong input from the inflammatory processes in the body. It’s just that we’ve taken time to work that out, to acknowledge it. We still don’t understand it well, but to acknowledge it.
Prabir: A quick question here. Explain to us, what is it when you say metabolic diseases, what are the kinds of diseases we are talking about?
Satyajit: So, as I said we’re talking about, we eat more than we spend, this despite all recent controversies I suspect still remains true. We put on weight, whether all of us put on weight at exactly the same rate or not? Not. And those pathways are there for clearly modified by other circumstances, that’s obesity eventually. we have steady accumulation of what are called fatty deposits under the lining of our blood vessels, that’s called atherosclerosis that leads to narrowing, to roughening, to clotting and therefore it gives us heart attacks, it gives us brain strokes, that’s called, that used to be called a metabolic disease. It’s no longer, clearly no longer called that. We, our bodies become less and less able to remove sugar and use it from circulation and therefore our blood sugar levels go up, because our tissues become insulin resistant. Insulin allows our tissues to take up sugar and if our tissues are insulin resistant then there is not uptake of sugar, sugar accumulates in circulation, that has its own consequences, we call type 2 or insulin resistant diabetes. All of these form the great morass of what used to be called age related metabolic diseases.
Prabir: Now you’re saying inflammation is found to be another part of the problem and we have not still identified for our audience, what is inflammation in this sense?
Satyajit: Exactly. So, a reason why we, one reason why we didn't perhaps quiet see inflammation as playing a role is, we’re used to inflammation as a local manifestation. Like if you have an injury there is redness, there is swelling, there is pain. There are classic markers of what inflammation is. You take some anti-inflammatory drugs and for most people you can see the symptoms of subside and in these diseases typically, there is no localised inflammation and that may have been one reason why perhaps we didn’t quiet see it coming. So what do I mean by inflammation? Well the same chemical compounds that bring about the localised changes, many of them are present throughout the body and because they are present throughout the body, you refer to them as systemic, meaning present in the entire system and it is the systemic inflammation that seems to be playing a clear and yet not terribly well understood role, in what we used to call metabolic disorders and metabolic diseases.
Prabir: So essentially the field has developed in a direction now, that we see far more complexities in the simple sugar causing problem, or fat causing problem, just simple plus-minus of the energy we take in the body causing a problem. So we’re really looking at really more complex interplay of different factors, would that be the reason that we are sort of understanding less then what we did appear to understand earlier, therefore not giving simplistic solution?
Satyajit: Yes, we are indeed in that somewhat unsatisfactory situation. We have understood much more complexity that’s made us much less certain and as you said, on the one hand we’ve stop thinking about nutrients as having their effects on body and diseases purely through nutritional metabolic pathways but also through altering inflammatory pathways on the one hand. And that complicates matters to the point that simple predictions are not easy, that’s not to say that they are not made easy in public discourse but that’s a different argument. Similarly, we’ve also begun to see that all bodies are not the same in responding to nutritional stimulation, to inflammatory stimulation, to fat in general and there are a large number of environmental and related stimuli that we’ve begun to understand re-shape our responses.
Prabir: So essentially though simple solutions but we can go away from the absolutes don't do this or do that, to some simple maxims we still need to follow. Don't need too much, don’t have too much of sugar or too much of fat, have a balanced diet which is all of course were being said. But do you see that the policy prescriptions that came out of the earlier nutritional debates of the 70s which really was professor Yudkin in Britain, who argued that it was really sugar which was deadly, against Ancel keys who argued that the saturated fat which was the main cause and Yudkin was virtually excommunicated from the university system, he was denied access to his lab, virtually stopped being called in different places and Ancel keys really in some sense, he and his followers were…But more importantly, it changed the way the industry as well as the regulatory systems behaved and as a consequence, this became the received wisdom all over the world. I have my dietician telling me exactly what you say shouldn't have been said.
Satyajit: So, the answer yes. And again let me complicate this further. The complication is not simply a matter of “scientists”, “epidemiologists”, “nutritionists”, doing some ‘pure’ work that is then taken by society, by industry, by the state in direction x, y, or z. It’s also that, the scientists who are doing this work already have, are already socio-cultural beings. They have their preferences, their prejudices, their positions and their connections which shape how and what they will think. Now, this is not to say that reasonably and soundly and rigorously collected data are without value, of course not. That’s the only way we have of dealing with the world. Yet, it is not as though we as society have somehow corrupted some pure knowledge that science gave us. We need to keep that in mind. That said, really at the individual level, we’ve always said what you said; exercise, don't just lie around, eat in moderation, eat as diverse a diet as possible, take care of your micro-nutrients because those are the ones easiest to miss because they are, micro. Don't stress yourself, these are all common sense things or what have come to be common sense things that at the individual level physicians have advised people for a very long time. So, what’s the problem? And in a sense if you think about it, the problem comes one step at a time. When you say these things, people say yes but exactly how much. And in a perfectly well meaning sense, groups of physicians will put out an ‘authorised’ set of guidelines that say, for each dietary component somewhere around this much, these are guesstimates, of course they are. But once they are out there, the term ‘authorised’ valorises them perhaps beyond what they should be valorised at. And this becomes relevant in two critical directions. One, the regulatory systems of the state begin to treat them as scriptures. It’s in the nature of regulation to treat numbers as binary decision makers. If you are up to here, you are okay. If you are beyond that, you’re in criminal territory. There’s, there are no grey zones and once that happens, you have an entire sector of our society beginning to game these binary decision makers because their profit depends on precisely where they’re placed.
Prabir: When you talk about the players, you’re really talking about large industry associations, companies and so on. Sugar based industries, Pepsi-cola, coco-cola, and so on.
Satyajit: The meat industry associations, the industrial farming associations, you name it.
Prabir: You know Satyajit, you would like to put us to the test, of deciding for ourselves. I don't think that makes us very comfortable, but if that's the way we have to go as a society, that’s a way we have to go. Thank you very much to be with us and throw us into further confusion than we already were, regarding what is already a very controversial and a complex field. Thank you very much.