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New Study Finds 'Mediterranean' Diet Significantly Reduces Brain Shrinkage (bbc.com)
schwit1 writes that 562 elderly research subjects cut their brain shrinkage in half just by changing their diet. (Paywalled article here). The BBC reports:
A study of pensioners in Scotland found that those with a diet rich in fresh fruit, vegetables and olive oil had healthier brains than those with different eating habits. They suffered less brain shrinkage than those who regularly ate meat and dairy products. The study was carried out by University of Edinburgh researchers.... Scientists found that those who adhered most closely to the diet retained significantly greater brain volume after three years than those who did not... Lead researcher Dr Michelle Luciano said: "As we age, the brain shrinks and we lose brain cells, which can affect learning and memory. This study adds to the body of evidence that suggests the Mediterranean diet has a positive impact on brain health."
These were pensioners in Scotland.
How far from the Mediterranean would you like to go?
You're right that we keep getting contradictory information, but the problem often isn't that the studies are bad in themselves, it's that the reporting on the study is bad.
I agree with this, but I don't quite agree with the restricting the blame as you do...
But reporters don't necessarily understand all of that, and in any case, that kind of nuanced and intelligent reporting won't sell ad time on CNN. [...] However, the far bigger problem is that most of our news outlets suck.
Etc.
That may all be true, but it's a far deeper problem than that. It's fundamentally tied up with science funding. Here's what actually happens:
(1) Researchers do research and write detailed findings. ("A correlates with B.")
(2) Researchers know that studies which get citations will help their careers, and studies that get more attention will help get them future funding. So, they include a lot of stuff in the "Discussion" section of their study that's incredibly speculative, but it makes it look like their findings will lead to a cure for cancer or something. (E.g., "We've shown correlation between A and B, but some preliminary studies show a connection among B, C, and D, and if C and D are true, then we might even have future research leading to E," where E is "curing cancer.")
(3) A university press office wants to draw attention to its faculty and its prominence as a university, so when it writes up the findings, it plays up the "MAY lead to cancer cure!" angle. The press office interviews the faculty member in charge, who gives an interview agreeing about what the study "MAY" ultimately lead to, but this gets bumped to the first paragraph of the press release, while the hedging "this is just a preliminary finding..." quote gets buried in paragraph 4 of the press release (whereas the hedging was integrated in the discussion section of the original paper). Now we effectively have the correlation between A and B buried deep in the press release, while C and D (which most people will have heard of) get the main story, and the speculation on E is foregrounded.
(4) Now science reporters finally get a crack at this. They see the university press release and its "may cure cancer!" in the first paragraph, which the mainstream news reporters now upgrade to the headline. They bury any hedging even further into the story, where few people will ever read it. They also find three other "experts" who are eager to get their names in the press, and who also present somewhat hedging statements, but the quotations are selected and broken up in ways that exaggerate the importance. In this case, A and B are now completely left out of the story (even though that's what the study measured) because average people don't know about them and wouldn't understand that. E becomes the headline, and C and D are used to support it.
So, while I agree with you that the news media is sensationalizing things, it's actually endemic to the whole process. Everyone from the actual researchers to the university press offices to the mainstream news media wants to get the study noticed.
Moreover, if you look at what actually happens AMONG SCIENTISTS is the same thing. Unless they are specialists in the particular area, they often just read the abstract of the old study, and if the original researchers includes some speculative sentence about the "broad ramifications" of the study in the abstract, the study frequently gets cited as if it PROVED this. I've seen instances of this in some fields where some "well-known" fact gets cited all the time, but when you track it back to the original study, what you actually find is a hedging very preliminary claim made in a discussion section that was never very well supported by the data (and the original researchers often explicitly hedge and SAY "more research is needed" or whatever).
I'll definitely agree with you that there are problematic elements here. And the news media is a part of it. But it's certainly not the only (and maybe not even the main) part of how bad science becomes accepted dogma.
Since when have nutritionists pushed starch?
First off, the parent post didn't say "nutritionists push starch" -- the post referred to SPECIAL INTERESTS. And the post you're responding to specifically cited the food pyramid, which was endorsed by the U.S. government and nutritionists. The base of that pyramid (i.e., the largest portion of daily food intake) was "Bread, Cereal, Rice and Pasta."
This is what one of the leading nutritionists at the USDA said later about what happened in the 1980s:
When our version of the Food Guide came back to us revised, we were shocked to find that it was vastly different from the one we had developed. As I later discovered, the wholesale changes made to the guide by the Office of the Secretary of Agriculture were calculated to win the acceptance of the food industry. For instance, the Ag Secretary's office altered wording to emphasize processed foods over fresh and whole foods, to downplay lean meats and low-fat dairy choices because the meat and milk lobbies believed it'd hurt sales of full-fat products; it also hugely increased the servings of wheat and other grains to make the wheat growers happy. [...]
Where we, the USDA nutritionists, called for a base of 5-9 servings of fresh fruits and vegetables a day, it was replaced with a paltry 2-3 servings (changed to 5-7 servings a couple of years later because an anti-cancer campaign by another government agency, the National Cancer Institute, forced the USDA to adopt the higher standard). Our recommendation of 3-4 daily servings of whole-grain breads and cereals was changed to a whopping 6-11 servings forming the base of the Food Pyramid as a concession to the processed wheat and corn industries. Moreover, my nutritionist group had placed baked goods made with white flour -- including crackers, sweets and other low-nutrient foods laden with sugars and fats -- at the peak of the pyramid, recommending that they be eaten sparingly. To our alarm, in the "revised" Food Guide, they were now made part of the Pyramid's base.
Normally I'm not a believer in "conspiracy theories," but here we have the story told by a former director of nutrition at the USDA. To my knowledge, no one has come out to contradict her account in the years since she made those claims.