Richard Horton, editor-in-chief of The Lancet magazine, stated this year that “A large part of the scientific literature, perhaps half, can quite simply be false.”

When I discussed Horton’s astounding statement with representatives from SBU(The Swedish Agency for Health Technology Assessment), they agreed with his assessment. Often, methods are insufficient as a result of too limited selections, or that small effects are over exaggerated and that the researchers draw incorrect conclusions.

But, there are also a lot of partial studies and conflicts of interest where the authors may have various connections to the industry which can be open or hidden as well as conscious or unconscious.

Someone who has submerged themselves into this matter and is rather experienced, at now 83 years old, is food professor Marion Nestle at New York University whom I’ve had the pleasure of interviewing several times. Forbes magazine has ranked her as the world’s second most influential foodie, just behind by Michelle Obama. In recent years she has kept herself amused on her blog by picking apart studies that have been extensively cited in both established media and social media. Her findings, after a closer look, reveal the “studies” as nothing more than pure marketing for manufacturers.

When she, for a period of time, went through 168 industry-funded studies on diet and nutrition, it turned out that 156 of these produced a result that benefited the sponsor’s product. Even though she asked her followers for help, she only managed to find twelve studies where the result went against the study’s financiers.

It became the prelude to the book Unsavory truth – How Food Companies Skew the Science of What We Eat, which was released last fall. There, Marion Nestle shows how money goes directly from large food giants to researchers’ labs, which in turn delivers “scientific” results that can meet all the high standardized requirements except one, you guessed it, to be independent. Marketing and research merge into to one another.

One of several obvious problems with sponsored studies is the concern that unwanted results are never published and instead remain forever locked away in a chest somewhere. But more often than not, according to Marion Nestle, it is actually about more subtle influences such as, what is to be studied or not, by whom, how and not least, how the questions in the studies are formulated.

Are eggs good or bad to eat? Personally, I am not worried about eating an egg per day, none the less it is a fact that many of the studies which downplay the risks of eggs are sponsored by the egg industry. Same goes for health benefits pertaining to chocolate, avocados or nuts, or studies that want to restore confidence in potatoes, even a push to eat breakfast.

Research on wine’s excellence come from and benefits wine-producing countries and the benefits of soy are never described as well as by soy-sponsored university researchers in the US or Canadian agricultural districts. Around the Mediterranean, many results sing the song of olive oil, while a study of the life-giving forces of canola oil, or the lingonberry , is more likely to come from Sweden.

Full-scale market wars, which are reflected in the research, are underway in a variety of industries. Milk is challenged by soy and oat beverages. The manufacturers of sugar and sweeteners have long been pestering eachother with studies showing the excellent properties of their own product and the other’s harmful effects.

I myself like nuts and avocados. Of course, sponsorship does not mean that the results must be wrong, but that the credibility is reduced. It would simply be better if independent and impartial researchers looked at the matter. Perhaps there are many other commodities that are just as useful, but never explored. The consequence is that the focus is on a few selected superfoods when the biggest health benefit is actually eating variety.

Marion Nestle has been in the midst of the American diet debate for five decades, including as a member of committees that evaluate research and establish national guidelines.

Based on her own experience as a target for lobbying, and as a pioneer in independent research on food, she describes how the academic nutrition research emerged from the outset as the industry’s extended arm, where all the focus was on increasing and streamlining production. Not only researchers but entire departments at large universities were and still are sponsored by, or have side assignments for, the food industry. Marion Nestle sometimes lectures in the Pepsi auditorium at Cornell.

Yet she finds only eleven (11!) studies that attempted to clarify the consequences of industry-funded food research. Why do so few researchers want to investigate this? This can be compared to thousands of studies on the pharmaceutical industry’s sponsorship.

It strikes me that many science bloggers are willingly and methodically shredding studies done by independent researchers at universities funded by public funds, but rarely digging themselves into issues of power and impartiality. Ultimately, it may be about who formulates the framework and the rules of the game for research.

Of course, eating healthy is not particularly difficult, Marion Nestle points out. Eat your vegetables and fruits, don’t eat too much, and don’t eat a lot of junk food. Her best advice is to eat a large variety of unprocessed food and to be active.

And there you have it, a health book that simultaneously reviews researchers.

This is a guest post. The opinions expressed are the writer’s own.