Increasing blood sugar levels are associated with cognitive decline, a long-term study found. Researchers assessed cognitive function in 5,189 people, average age 66, and tested their blood sugar using HbA1c, which measures blood glucose levels over weeks or months. They followed the group for as long as 10 years.

There was no association between blood sugar levels and cognition at the start. But consistently over time, scores on the tests of memory and executive function declined as HbA1c levels increased, even in people without diabetes.

The study, in the journal Diabetologia, was observational and the underlying mechanism is not known, said lead author Wuxiang Xie, a researcher at the Peking University Health Science Center. He called for more research, saying: “Diabetes-related microvascular complications might be, at least in part, the reason for the subsequent cognitive decline.”

Precision nutrition method doesn’t work

A precision nutrition approach to weight loss didn’t hold up in a study testing low fat versus low carb depending on dieters’ genetic or metabolic makeup. Stanford researchers studied 600 overweight adults and found that weight loss averaged about 13 pounds over a year regardless of the diet type or genes. However, participants who ate the fewest processed and sugary foods lost the most weight.

Obesity may affect melanoma survival

Obese men treated for metastatic melanoma may survive longer than their normal-weight peers. Researchers did a retrospective analysis of 1,918 people in a study in Lancet Oncology. Compared with men of normal weight, obese men in treatment had nearly double the progression-free survival time and nearly double the overall survival time. There was no such association in women.

Dr. Jennifer L. McQuade said obesity might change the response to therapy. She added, “We need to emphasize that obesity is still a risk factor for many diseases, including 13 different types of cancer.”

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