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ADA 81st Symposium: Effect of Dietary Carbohydrate Restriction on Health-Related Quality of Life and Cognition

Jul 27, 2021
 
Editor: Steve Freed, R.PH., CDE

Author: Torré Anderson, II, Fourth Year Doctor of Pharmacy Candidate, Florida A&M University College of Pharmacy and Pharmaceutical Sciences, Institute of Public Health 

We know the positive effects of carbohydrate restriction on glycemia, but what is the impact on quality of life and cognition?

Nutritional therapy is an essential aspect of diabetes management. In contrast to the benefits of weight loss and exercise shown over time, a change in macronutrient intake may cause more immediate results. Studies have shown that macronutrients influence satiety, gut hormone secretion, glucose metabolism, and insulin secretion in healthy adults and those living with type 2 diabetes mellitus (T2DM). Large caloric intake of carbohydrates in those with a high glycemic index is associated with developing type 2 diabetes and coronary artery disease in healthy adults. Carbohydrate restrictions may be a practical approach to improve glycemia, but the effects of restriction on other aspects of quality of life and cognition are unknown.

 

This study aimed to investigate the effect of dietary carbohydrate restriction during a 6-week hypo-caloric induced weight loss in patients with type 2. Researchers conducted a parallel randomized clinical trial. Researchers analyzed the study outcomes health-related quality of life (HRQoL) and cognition performance. Potential study participants were individuals age 18 or older with type 2 diabetes, HbA1c 6.5-11%, BMI > 25 kg/m2, and not on any drug therapy or being treated with metformin or dipeptidyl peptidase-4  (DPP-4) inhibitor. Participants would be randomized in a 1:1 ratio to two groups to receive either a carbohydrate-reduced high protein diet or a conventional diabetes diet. Carbohydrate-reduced high protein dietary intervention consisted of 40% calories of fat, 30% calories of protein, and 30% carbohydrates per meal. The conventional diabetes dietary intervention consisted of 33% calories of fat, 17% calories of protein, and 50% carbohydrates per meal. All meals were provided free of charge to the patient for better adherence outcomes.

At week 0, participants were asked to complete the SF-36 health survey to collect baseline characteristics of health-related quality of life in eight domains. Health-related quality of life domains included physical functioning, role physical, bodily pain, and general health. Mental component domains had social functioning, role emotional, vitality, and mental health. After five weeks of dietary restrictions, participants were asked to complete a follow-up SF-36 health survey to measure change from baseline characteristics. Researchers also performed global cognition testing at weeks 0 and 6 to assess three cognitive domains of the patients using the neuropsychological test battery.

Of the 72 adults with type 2 diabetes who were screened for eligibility for the study, 67 filled out the SF-36 questionnaire, and 55 completed the cognition test at baseline and the end of treatment. Researchers observed well-controlled participants on both dietary interventions with an average HbA1c of 7.3%. Bodyweight was shown to be reduced equally by 6% in both treatment groups at week five follow-up (median (IQR), CD: 2.7 (1.1;4.2)% and CRHP: 2.1 (0.7;3.7)%; both p<0.001). Physical component summary items improved in six of the eight domains related to health-related quality of life in the carbohydrate-reduced high protein dietary group (1.8 (-0.7;5.7)%, p<0.01) compared to the conventional diabetes dietary group. Researchers observed improved mental component summary in items related to cognitive domains related to health-related quality of life in the carbohydrate-reduced high protein dietary group. There were no statistically significant differences observed between the conventional diabetes dietary group and the carbohydrate-reduced high protein dietary group on any health-related quality of life domains. Neither of the nutritional groups was affected by global cognition, memory, or psychomotor speed. The conventional diabetes dietary group did see improvement in the executive function domain, but it wasn’t significant compared to the carbohydrate-reduced high protein dietary group. The traditional diabetes group showed statistically significant change in symbol-digit modalities test performance with a higher score than the carbohydrate-reduced high protein dietary group.

No negative impact on quality of life or cognitive function was observed in patients with type 2 diabetes when reducing carbohydrate intake during a six-week weight loss intervention. Dietary restrictions improved physical components of health-related quality of life over 6-week hypo-caloric weight-loss interventions; however, they were not statistically significant. Both diets adequately maintained HbA1c levels. While carbohydrate restriction may be beneficial to cognitive domains of health-related quality of life, both diets had no impact on cognitive function. Individuals may benefit from the conventional diabetes diet in cognitive function, but more research on the effects is necessary. Weight loss improves physical domains associated with health-related quality of life independent of diet composition. Carbohydrate restriction may benefit mental health but without negatively affecting overall cognition. This study offered real-world data to an unknown aspect of dietary control that could improve the overall quality of life for those living with type 2 diabetes.

Practice Pearls:

  • Individuals may benefit from the conventional diabetes diet in cognitive function, but more research on the effects is necessary.
  • Physical component summary items improved in six of the eight domains related to health-related quality of life in the carbohydrate-reduced high protein dietary group (1.8 (-0.7;5.7)%, p<0.01).
  • No negative impact on quality of life or cognitive function was observed in patients with type 2 diabetes when reducing carbohydrate intake during a six-week weight loss intervention.

 

Jensen, N.J et al. (2021, June). Effect of Dietary Carbohydrate Restriction on Health-Related Quality of Life and Cognition. American Diabetes Association. Copenhagen; Denmark. (Requires ADA Symposium login.)

 

Torré Anderson, II, Fourth Year Doctor of Pharmacy Candidate, Florida A&M University College of Pharmacy and Pharmaceutical Sciences, Institute of Public Health