High-sugar diet may worsen cognition, cardiometabolic health

Key takeaways:

• A cohort of healthy midlife adults were randomized to eat both low- and high-sugar diets for 10 days.
• The high-sugar diet adversely affected both cognitive ability and cardiometabolic health.

PHILADELPHIA — Consuming a high-sugar diet over 10 days was associated with memory issues as well as negative cardiometabolic health compared with a low-sugar diet, according to a poster presentation.

“We’re interested in some of the lifestyle/behavioral factors, but modifiable risk factors, like diet, are aspects that are a little bit more controllable,” Kevin P. Decker, PhD, postdoctoral researcher in the department of kinesiology and applied physiology at the University of Delaware, told Healio at the Alzheimer’s Association International Conference.

Working with the hypothesis that higher sugar intake will have a deleterious effect on blood pressure, Decker and colleagues sought to determine if a spike in added sugars over the course of 10 days given to midlife adults could diminish memory recall and decrease cardiometabolic health.

Specifically, their study compared diets consisting of 2,000 calories per day in which sugar accounted for 20% to 25% of total calories vs. 5% of total calories in 38 healthy adults (63.2% female, mean age 57±4 years) with no prior history of cardiovascular disease.

The study was divided into four phases. In the initial phase, participants were required to keep a 3-day diet record so the researchers could determine eligibility. Once it was established, enrollees were given baseline tests, including BP and blood-based biomarkers, then randomly assigned to receive either diet. The tertiary phase was randomization, during which participants picked up the 10-day supply of food and drink to be consumed at their own leisure with a “meal plan” guideline. At the end of the 10 days, all submitted to further BP and biomarker testing, along with cognitive evaluations (Brief Visuospatial Memory Test [BVMT]; Hopkins Verbal Learning Test [HVLT]).

Following a minimum 2-week washout period to prevent carryover effects from initial randomization, the diets were flipped; those given a high-sugar diet were switched to low-sugar and vice versa.

According to the results, the 10-day, high-sugar diet led to lower total memory recall in the BVMT compared with the low-sugar alternative, while also leading to delayed memory recall in both the BVMT and HVLT.

The researchers further discovered the high-sugar diet negatively impacted cardiometabolic health, with elevated triglycerides and BP compared with the low-sugar diet.

“We saw that there was lower memory recall on the high-sugar diet compared [with] the low-sugar diet,” Decker told Healio. “Diet affects cardiometabolic health, which also affects brain health.”