Rats do it, people do it... consume too much sugar, that is. Also, run through mazes.
Rats consuming a high fructose diet had impaired memory, based on their performance in a maze test. Adding omega 3 fatty acids back to their diet helped mitigate the fructose problem. However the rats with the best memory function were those who had no (minimal*) fructose and an adequate amount of omega 3s.
This summary leaves the impression that only two groups of rats were tested (high fructose with or without omega 3).
The paper makes it clear that two other groups with no fructose were also tested. The no fructose/deficient omega 3 group did worse on the memory tests than the no fructose/adequate omega 3 group, but not as badly as the high fructose/adequate omega 3 group. The high fructose/deficient omega 3 group brought up the rear, but no, that was not because they had become too obese to waddle thrugh the maze.
The takeaway (assuming this holds up in people, which it will) - Americans eat too much sugar, which contributes to obesity, diabetes, Alzheimers, and other mental deterioration. Fish oil supplementation can help; cutting way, way back on sugar can help more.
And I had a post last February about the inevitable taxation and regulation of sugar. The increase in Western consumption over the last two centuries is astonishing, and apparently beyond our metabolism:
Author Robert Lustig is a YouTube hero for his long lecture on the evils of sugar. Gary Taubes described Dr. Lustig's thinking in a NY Times magazine article, "Is Sugar Toxic?". The gist of the gist - fructose, half of the common sucrose molecule, is metabolized differently from glucose, the normal constituent of other starchy foods. Our bodies just weren't designed to process the amounts of fructose people routinely consume these days, and the results are visible everywhere.
A bit of British history:
Britain's annual per capita consumption of sugar was 4lbs in 1704, 18lbs in 1800, 90lbs in 1901 - a 22-fold increase to the point where Britons had the highest sugar intake in Europe.
Here in the US we are up to about 150 lbs per person per year, up about 50% from 1950. Set against that is the Australian Paradox - since 1980 obesity Down Under has tripled while sugar consumption has fallen. Hmm... is anyone going to let a bit of science come between them and a new batch of regulations and taxes?
Treats used to be, well, a treat. Now its a breakfast bar. Also, a lunch bar and dessert after dinner. And a snack or two.
As to what is happening Down Under with sugar and obesity, I would love an explanation. A short summary of the original study is here; a rebuttal is here, and the vigorous dissent by Rory Robertson is continued here (Mr. Robertson is another "I dropped sugar and twenty pounds" guy; we are everwhere!). His gist - bad data led to a bad conclusion. Bonus gist - the 'Paradox' authors favor a low glycemic index approach. Since the glycemic index measures glucose in the bloodstream, fructose always scores well.
From the news account:
Professor Swinburn, who is the director of the World Health Organisation collaborating centre for obesity prevention at Deakin University, says the study's summary of the data as showing ''a consistent and substantial decline in total refined or added sugar by Australians over the past 30 years'' belies the facts ''and is a serious over-call in my opinion''.
His conclusion is that ''the ecological trends of sugar and obesity are pretty well matched and I do not believe there is any paradox to explain''.
MINIMAL FRUCTOSE: From the paper:
The two custom diets used were based on the composition of the American Institute of Nutrition diet and prepared commercially (Dyet s, Bethlehem, PA, USA) as previously described (Greiner et al. 2003). Both diets had the same basal macronutrients, vitamins, minerals and basal fats (hydrogenated coconut and safflower oils). For the casein source, vitamin-free casein Alacid 710 (NZMP North America Inc., CA, USA) was used. Dextrose, maltose-dextrin, cornstarch and sucrose were used as carbohydrate sources.
There will be fructose and glucose in the sucrose, so the "no fructose" diet is my misnomer.