Results of a study conducted at the University of Southern California (USC) has shown that adolescent rats that freely consumed large quantities of liquid solutions containing sugar or high-fructose corn syrup (HFCS) in concentrations comparable to popular sugar-sweetened beverages experienced memory problems and brain inflammation, and became pre-diabetic.
Scott Kanoski, an assistant professor at USC’s Dornsife College of Letters, Arts and Sciences, and colleagues investigated the effects of sugar and HFCS on 76 rats. Adolescent or adult male rats were given 30-day access to chow, water, and either (1) 11% sucrose solution, (2) 11% HFCS solution, or (3) an extra bottle of water (control). Approximately 35-40% of the rats’ daily calories were obtained from sugar or HFCS. The rats then underwent a series of tests.
Results showed that in adolescent rats, HFCS intake impaired hippocampal-dependent spatial learning and memory in a Barne’s maze, whilst moderate learning impairment was also observed in the rats in the sucrose group. Further investigation revealed that protein expression of the pro-inflammatory cytokines interleukin 6 and interleukin 1β was increased in the hippocampus of the adolescent rats fed HFCS, while liver interleukin 1β and plasma insulin levels were elevated in both adolescent-exposed sugar groups. On the other hand, intake of HFCS or sucrose in adults did not impact spatial learning, glucose tolerance, or neuroinflammatory markers. “The brain is especially vulnerable to dietary influences during critical periods of development, like adolescence,” said Kanoski, “Consuming a diet high in added sugars not only can lead to weight gain and metabolic disturbances, but can also negatively impact our neural functioning and cognitive ability.”
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People can become addicted to eating for its own sake but not to consuming specific foods such as those high in sugar or fat, research suggests. An international team of scientists has found no strong evidence for people being addicted to the chemical substances in certain foods.
The brain does not respond to nutrients in the same way as it does to addictive drugs such as heroin or cocaine, the researchers say. Instead, people can develop a psychological compulsion to eat, driven by the positive feelings that the brain associates with eating.
This is a behavioural disorder and could be categorised alongside conditions such as gambling addiction, say scientists at the University of Edinburgh.
They add that the focus on tackling the problem of obesity should be moved from food itself towards the individual’s relationship with eating.
“Certain individuals do have an addictive-like relationship with particular foods and they can over-eat despite knowing the risks to their health. More avenues for treatment may open up if we think about this condition as a behavioural addiction rather than a substance-based addiction.”
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Source: Medical News Today
Evidence that sugar has a direct effect on risk factors for heart disease, and is likely to impact on blood pressure, independent of weight gain has been discovered in a study. The researchers conducted a review and meta-analysis of all international studies that compared the effects of higher versus lower added sugar consumption on blood pressure and lipids (blood fats or cholesterol) – both of which are important cardiovascular risk-factors.
“Our analysis confirmed that sugars contribute to cardiovascular risk, independent of the effect of sugars on body weight,” says Dr Te Morenga.
“Although the effects of sugars on blood pressure and lipids are relatively modest, our findings support public health recommendations to reduce added sugar in our diets as one of the measures which might be expected to reduce the global burden of cardiovascular diseases.”
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Source: University of Otago. “Sugar implicated in cardiovascular disease risk independent of weight gain.” ScienceDaily. ScienceDaily, 15 May 2014.