fresh baked bread

Just the smell of freshly baked bread increases IQ by 10 points.
A quick survey of the latest headlines will show what appears to be an all-out war in the dietary advice world. On the one hand, the woefully misguided talk of a 'meat tax' is all over the headlines after a 'study' came out saying it will, surprise surprise, save lives. Yet the LA Times just published an article that's getting a lot of traction titled 'The case against carbohydrates gets stronger', similar to the title of Dr. David Ludwig's widely circulated article 'The case for a low-carb diet is stronger than ever'. The battle lines are being drawn, vegans versus carnivores, high carb versus low carb, Dr. Shawn Baker versus Dr. Neal Barnard. Or so it would seem.

While there's little doubt this is confusing the public to no end (as evidenced by the growing number of Youtube videos on the 'vegan ketogenic diet', a vain attempt to meet opposing dietary advocates in the middle), the argument really should be framed for what it is - the attempt of truth and science to overcome the push from monolithic government bodies and industry. No matter who wins the headline war, which is really a fixed game, the number of people out there cutting the carbs and getting healthier as a result, is making waves.

So it was little surprise to see another shot fired from the pro-carb camp: The Daily Mail published an article this week singing the praises of carbohydrates titled, 'How CARBS could be the secret to living longer: Diet low in protein and rich in bread, pasta and rice may protect against dementia'. This after publishing 'Veganism backlash begins! Forget gobbling up your greens these women swear an ALL-MEAT diet has made them Slim, sexy and more full of energy than ever' less than a week before. Apparently the Daily Mail, with their ridiculously long headlines and gratuitous use of all-caps, is just as confused as the rest of us.

So give another point to team carb! Paleo can suck it. Ketogenic is nothing but a slow decline via carb-deficiency in the making. All these low-carbers are going to die early after losing their minds to dementia. THAT'S WHAT YOU GET FOR GOING AGAINST GOVERNMENT REGULATED EATING GUIDELINES. You get death. Death and crazy.

Not so fast. Despite the headline, and the pictures of bread and pasta in the body, the study they're reporting on isn't actually about carbohydrates being good for dementia (or longevity). Taking the evidence that calorie restriction leads to longevity and better brain health, combined with the evidence that eating as much as you want of carbohydrates while limiting protein leads to longevity, but that no evidence exists that this same diet would also lead to better brain health as calorie restriction does, the study authors decided to see if eating high carb, low protein confers the same benefits to the brain as calorie restriction (hope you followed that). They found evidence that it kind of does.
In conclusion, both CR [calorie restriction] and LPHC [low protein, high carbohydrate] diets impacted on brain aging in the hippocampus. Although the behavioral and cognitive changes were subtle, there were more dramatic effects on gene expression, protein activity, and dendritic spine morphology. Overall, the lowest protein, highest carbohydrate diets (5% and 10% protein) generated changes, which approached those seen with CR. A very low-protein, high-carbohydrate diet may be a feasible nutritional intervention to delay brain aging.
So they didn't see much in terms of behaviour changes, but many of the markers they measured seemed to be close to what is seen in CR. But, and this is interesting, the same thing has been found in diets that restrict protein but have enough fat to reach satiety (a ketogenic diet, in other words). This has been speculated as the mechanism by which ketogenic diets work - by mimicking caloric restriction without actually restricting any calories. After all, calorie restriction is more or less impossible for humans to maintain. It's easy enough to force mouse prisoners to eat less than they would normally, but humans not under forced confinement only have so much willpower.

So what do these three dietary patterns - calorie restriction; high carb-restricted protein; and high fat-restricted protein - have in common? They all restrict protein. In the first case, when someone is cutting total caloric intake on a calorie restricted diet, they are in all likelihood cutting protein consumption. If both LPHC and LPHF (the F stands for fat) diets can mimic CR, it seems that much of the benefits to brain health and longevity alike can be ascribed to limiting the amount of protein. The fat or carbs seem rather irrelevant in this case - it's all about the protein. The fat or carbs are there to make it so you don't feel like you're starving. There's not enough evidence to know for sure, but this is certainly what's suggested.

But regardless, the Daily Mail is full of shit (what's new?). This study isn't a signal to go out and eat as many carbs as possible because it's going to somehow protect you from dementia. The carbohydrate probably had very little to do with the results the scientists saw. This study was trying to mimic a CR diet without CR and finding a possible way of doing that (other than the ketogenic diet, apparently; fat is bad, after all). And the mice in the study were not fed a diet "rich in bread, pasta and rice", as implied in the headline, they were fed industrially processed 'mouse chow' composed of an unidentified starch, casein protein (from milk) and soy oil. It was also done on mice, not humans, so the idea that loading up on bread, pasta and rice is going to give you the same effects seen in the study is highly, highly unlikely. This article is, unsurprisingly, complete bunk.

As for whether a LPHC diet is as beneficial as a LPHF diet, the jury is still out. This study is really not enough to say one way or another. I'm sure this study will provide vegans with some more ammunition to 'prove' their naturally high carb, low protein diet is superior, but there's really very little here to go on. However, given the already established detrimental effects of carbohydrate, (the brain's silent killers), and the benefits of ketogenic diets, as well as the copious anecdotal stories of the health benefits of dropping carbs, my money is on keto.