Research Review: Low-Carb Diets for Metabolic Syndrome + Cognitive Training for Brain Fog

Could You Have Metabolic Syndrome Without Knowing It?

Metabolic syndrome is a cluster of conditions that occur together, including increased blood pressure, high blood sugar, excess belly fat, and abnormal cholesterol levels. It can increase your risk of heart disease, stroke, and diabetes—and for people with multiple sclerosis, metabolic syndrome can accelerate disability progression.

The concerning reality? Metabolic syndrome often has no obvious symptoms. Many people live with this condition without realizing it. Warning signs include a waist measurement larger than your hip measurement, low HDL (good) cholesterol, elevated triglycerides, or elevated fasting glucose levels.

This study caught my eye:

Are Low Carbohydrate Diet Interventions Beneficial for Metabolic Syndrome and Its Components? A Systematic Review and Meta-Analysis of Randomized Controlled Trials (Int J Obes (Lond). 2025;49(7):1252-63)

This comprehensive review analyzed 30 randomized controlled trials involving 3,806 adults to answer a crucial question: Are low-carbohydrate diets beneficial for metabolic syndrome?

The study found that compared to the control diet, a low-carbohydrate diet reduced body mass index, improved hemoglobin A1C (a marker of blood sugar control), and lowered diastolic blood pressure.⁽¹⁾

My Takeaway: This research reinforces why I screen all my patients for metabolic syndrome. When present, I recommend reducing dietary carbohydrates as a first-line intervention. For some people, a Paleolithic diet provides sufficient carbohydrate restriction. Others benefit more from a ketogenic approach. The key is finding the right level of carbohydrate reduction that works for your individual biochemistry and lifestyle.

Another paper that got my attention was this one:

Beyond Cognition: Cognitive Re-Education’s Impact on Quality of Life and Psychological Well-Being in People with Multiple Sclerosis—A Narrative Review.

This review study examined how cognitive re-education (a structured approach to helping people improve their thinking) can impact quality of life and psychological well-being in people with multiple sclerosis. Cognitive problems—usually referred to as "brain fog"—affect your thinking, memory, and concentration, and they're incredibly common among people with MS and other autoimmune conditions.

The researchers in this study explored structured cognitive re-education programs like memory exercises, attention training, and other neuropsychological interventions. They found that people who participated in intentional cognitive training programs experienced improvements in mental health, work performance, and social functioning.⁽²⁾

My Takeaway: In my clinical practice, my patients often experience reductions in anxiety and depression, decreased fatigue, and improved working memory when they work to improve their nutrition and self-care practices.^(3-6) This research supports what I observe in my practice, as well as what we’ve consistently observed in our clinical trials.

If brain fog is affecting your daily life, I recommend a three-pronged approach: optimizing your nutrition (particularly by reducing processed foods and adding nutrient-dense whole foods); incorporating gentle exercise that feels sustainable; and asking your healthcare team about referrals for cognitive rehabilitation training. This combination of better nutrition, movement, and targeted brain training can create meaningful improvements in cognitive function. I also recommend a few basic supplements to support achieving the best nutrition for your brain. We often have deep nutritional deficits we need to overcome. Targeted supplements can make sure your brain has what it needs to function optimally. These include vitamin D3 + vitamin K2, a multivitamin/ multimineral, fish oil and magnesium, which we have combined into the Wahls Protocol® Basic Support Kit.

Citations

1. Zheng Q, Gao X, Ruan X, Chen S, Pan X, Wang R, et al. Are low carbohydrate diet interventions beneficial for metabolic syndrome and its components? A systematic review and meta-analysis of randomized controlled trials. Int J Obes (Lond). 2025;49(7):1252-63.
2. Manocchio N, Moriano C, D'Amato A, Bossa M, Foti C, Nocentini U. Beyond Cognition: Cognitive Re-Education's Impact on Quality of Life and Psychological Well-Being in People with Multiple Sclerosis-A Narrative Review. NeuroSci. 2025;6(3).
3. Saxby SM, Shemirani F, Crippes LJ, Ehlinger MA, Brooks L, Bisht B, et al. Effects of a Remote Multimodal Intervention Involving Diet, Walking Program, and Breathing Exercise on Quality of Life Among Newly Diagnosed People with Multiple Sclerosis: A Quasi-Experimental Non-Inferiority Pilot Study. Degener Neurol Neuromuscul Dis. 2024;14:1-14.
4. Groux AR, Walker ES, Shemirani F, Lee JE, Irish AK, Rubenstein LM, et al. Diet-Induced Changes in Functional Disability among People with Multiple Sclerosis: A Secondary Pooled Analysis of Two Randomized Controlled Pilot Trials. Sclerosis. 2024;2(3):156-65.
5. Wahls TL, Titcomb TJ, Bisht B, Eyck PT, Rubenstein LM, Carr LJ, et al. Impact of the Swank and Wahls elimination dietary interventions on fatigue and quality of life in relapsing-remitting multiple sclerosis: The WAVES randomized parallel-arm clinical trial. Mult Scler J Exp Transl Clin. 2021;7(3):20552173211035399.
6. Lee JE, Bisht B, Hall MJ, Rubenstein LM, Louison R, Klein DT, et al. A Multimodal, Nonpharmacologic Intervention Improves Mood and Cognitive Function in People with Multiple Sclerosis. J Am Coll Nutr. 2017;36(3):150-68.