Almond-based low-carb diet, depression and blood sugar in type 2 diabetes
What it found
In people with type 2 diabetes, a diet that replaced some staple food with almonds improved depression scores and long-term blood sugar more than a low-fat diet over 3 months.
The almond diet also changed gut bacteria and kept a gut hormone higher.
What they found
Studies in people
Depression
The almond diet group had a significant drop in depression score after 3 months, while the low-fat diet group did not. The almond group's score was significantly lower than the low-fat group's at the end.
Blood sugar control
Both groups improved their HbA1c, but the almond diet group had a bigger drop than the low-fat group after 3 months.
Gut bacteria
The almond diet increased certain short-chain fatty acid-producing bacteria (Roseburia, Ruminococcus, Eubacterium) compared to the low-fat diet or to baseline. It also decreased Bacteroidetes and Bacteroides.
GLP-1 hormone
After 3 months, the almond diet group had higher fasting GLP-1 levels than the low-fat diet group, though neither group changed significantly from their own baseline.
Weight and BMI
Weight and BMI improved significantly within the almond diet group over 3 months, but there was no significant difference between the two groups at the end.
What the authors conclude
“A-LCD could exert a beneficial effect on depression and glycometabolism in patients with T2DM.”
Also in their conclusions
- They conclude that an almond-based low-carb diet may be an effective intervention for improving both depression and blood sugar control in patients with type 2 diabetes.
- They speculate that the improvement in depression may be linked to the diet stimulating growth of short-chain fatty acid-producing bacteria, increasing short-chain fatty acids and GPR43 activation, and maintaining GLP-1 secretion.
- They advise that future studies should further examine short-chain fatty acids and GPR43 activation.
How it was done
The authors wanted to find a diet that helps both depression and blood sugar in people with type 2 diabetes, since most diets focus only on blood sugar. Almonds had shown promise for both.
They randomly assigned 45 people with type 2 diabetes to either an almond-based low-carb diet (56 g almonds per day replacing 150 g staple food) or a low-fat diet for 3 months. Depression scores, HbA1c, gut bacteria and GLP-1 were measured at the start and after 3 months.
What it can’t tell you
- The study included people with type 2 diabetes both with and without depression, so the findings may not apply to those with clinical depression.
- Depression was not monitored continuously, so the earliest time point for improvement is unknown.
- The study did not measure short-chain fatty acids or GPR43 activation, so the proposed mechanism is speculative.
Who paid
- Funding
- Funded by Suzhou Science and Technology Project, China (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Soochow University, China; University of California, USA; University of Greenwich, UK
The paper
- Title
- An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Ren M, Zhang H, Qi J, et al (2020). An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial. Nutrients. doi:10.3390/nu12103036Free full textPubMed 33022991DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error