Foods harmful to memory

HEALTH

FOUR weeks on a diet of highly processed food led to a strong inflammatory response in the brains of aging rats that was accompanied by behavioral signs of memory loss, a new study has found.
Researchers also found that supplementing the processed diet with the omega-3 fatty acid DHA prevented memory problems and reduced the inflammatory effects almost entirely in older rats.
Neuroinflammation and cognitive problems were not detected in young adult rats that ate the processed diet.
The study diet mimicked ready-to-eat human foods that are often packaged for long shelf lives, such as potato chips and other snacks, frozen entrees like pasta dishes and pizzas, and deli meats containing preservatives.
Highly processed diets are also associated with obesity and type 2 diabetes, suggesting older consumers might want to scale back on convenience foods and add foods rich in DHA, such as salmon, to their diets, researchers say — especially considering harm to the aged brain in this study was evident in only four weeks.
“The fact we’re seeing these effects so quickly is a little bit alarming,” said senior study author Ruth Barrientos, an investigator in The Ohio State University Institute for Behavioral Medicine Research and associate professor of psychiatry and behavioral health.
“These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits — and in the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative diseases such as Alzheimer’s disease. By being aware of this, maybe we can limit processed foods in our diets and increase consumption of foods that are rich in the omega-3 fatty acid DHA to either prevent or slow that progression.”
The research is published in the journal Brain, Behavior, and Immunity.
Barrientos’ lab studies how everyday life events — such as surgery, an infection or, in this case, an unhealthy diet — might trigger inflammation in the aging brain, with a specific focus on the hippocampus and amygdala regions. This work builds on her previous research suggesting a short-term, high-fat diet can lead to memory loss and brain inflammation in older animals, and that DHA levels are lower in the hippocampus and amygdala of the aged rat brain.
DHA, or docosahexaenoic acid, is an omega-3 fatty acid that is present along with eicosapentaenoic acid (EPA) in fish and other seafood. Among DHA’s multiple functions in the brain is a role in fending off an inflammatory response — this is the first study of its ability to act against brain inflammation brought on by a processed diet.
The research team randomly assigned three-month-old and 24-month-old male rats to their normal chow (32 per cent calories from protein, 54 per cent from wheat-based complex carbs and 14 per cent from fat), a highly processed diet (19.6 per cent of calories from protein, 63.3% from refined carbs — cornstarch, maltodextrin and sucrose — and 17.1 per cent from fat), or the same processed diet supplemented with DHA.
Activation of genes linked to a powerful pro-inflammatory protein and other markers of inflammation was significantly elevated in the hippocampus and amygdala of the older rats that ate the processed diet alone compared to young rats on any diet and aged rats that ate the DHA-supplemented processed food.
The older rats on the processed diet also showed signs of memory loss in behavioral experiments that weren’t evident in the young rats. They forgot having spent time in an unfamiliar space within a few days, a sign of problems with contextual memory in the hippocampus, and did not display anticipatory fear behavior to a danger cue, which suggested there were abnormalities in the amygdala.
“The amygdala in humans has been implicated in memories associated with emotional — fear and anxiety-producing — events. If this region of the brain is dysfunctional, cues that predict danger may be missed and could lead to bad decisions,” Barrientos said.
The results also showed that DHA supplementation of the processed-food diets consumed by the older rats effectively prevented the elevated inflammatory response in the brain as well as behavioral signs of memory loss.
Researchers don’t know the exact dosage of DHA or precise calories and nutrients — taken in by the animals, which all had unlimited access to food. Both age groups gained a significant amount of weight on the processed diet, with old animals gaining significantly more than the young animals.
DHA supplementation had no preventive effect on weight gain associated with eating highly processed foods.
That was a key finding: Barrientos cautioned against interpreting the results as a license for consumers to feast on processed foods as long as they take a DHA supplement. A better bet to prevent multiple negative effects of highly refined foods would be focusing on overall diet improvement, she said. – Science Daily

Possible last chance to find origins of virus

THE World Health Organisation (WHO) says a new taskforce may be the last chance to find the origins of Covid-19.
It has nominated 26 experts to join the body, the Scientific Advisory Group on the Origins of Novel Pathogens (Sago).
More than a year-and-a-half since the virus was detected in the Chinese city of Wuhan, the question of how it first emerged remains unclear.
The team will consider if the virus jumped from animals to humans in Wuhan markets or leaked in a lab accident.
China has strongly refuted the second theory.

In February, a WHO team tasked with investigating Covid’s origins flew to China and concluded that the virus had probably come from bats but that more work was needed.
But the WHO’s director general, Dr Tedros Adhanom Ghebreyesus, later said the investigation had been hampered by a lack of data and transparency from China.
The proposed members of the Sago group include six experts who visited China as part of the previous team.

Questions around the origins of Covid-19 centre on Wuhan,
where the virus first emerged.

Aside from coronavirus, Sago will also look into the origins of other high-risk pathogens.
“Understanding where new pathogens come from is essential for preventing future outbreaks,” said Dr Tedros said.In a joint editorial in the journal Science, Dr Tedros and other WHO officials said “a lab accident cannot be ruled out”.
Michael Ryan, the WHO’s emergencies director, said Sago’s work may be the “last chance to understand the origins of this virus”.
The announcement of the new group comes as CNN reported that China was preparing to test tens of thousands of blood bank samples taken in the early months of the pandemic.
But Chen Xu, China’s ambassador to the UN in Geneva, said Sago’s work should not be “politicised”.
“It is time to send teams to other places,” he said. – BBC