If you have multiple sclerosis, you've probably spent a lot of energy thinking about which disease-modifying therapy is right for you. That's important. But a growing body of research suggests something else deserves a seat at the table: your metabolic health, and specifically, insulin resistance. There are no symptoms of insulin resistance, and 80% of people with insulin resistance do not know that they have it.

Are you one of them?

The Cardiometabolic-MS Connection

Cardiometabolic disease — hypertension, type 2 diabetes, and dyslipidemia — is common in people with MS, and it isn't just a bystander condition.¹ A 2026 study from UT Southwestern's MS clinic found that among untreated MS patients, those with cardiometabolic disease had roughly five times higher odds of a relapse or new MRI activity in the two years before testing compared to those without.1 The same study found that inflammatory proteins linked to active MS — including markers like CCL20, CXCL9, and TRAIL-R1 — were measurably elevated in people with cardiometabolic conditions, and rose further as the number of conditions increased.¹ Notably, this elevated inflammatory signature persisted even in people who were on disease-modifying therapy. In other words, treatment alone didn't fully erase the metabolic contribution to disease activity.¹

People with MS also appear to carry a higher overall burden of physical and mental health comorbidities than the general population, which is part of why metabolic screening deserves more attention in routine MS care.²

Why Insulin Resistance Deserves Special Attention

Insulin resistance deserves particular attention because it may not just travel alongside MS — it may be more common in MS to begin with. A 2024 systematic review and meta-analysis pooling 18 studies found a significant association between both insulin resistance and insulin levels and MS, lending support to the idea that metabolic disturbances like insulin resistance can influence brain function and contribute to neurological disease.³ Other studies using oral glucose tolerance testing and HOMA-IR calculations have found similar patterns: insulin resistance affecting nearly half of MS patients in one case-control study, compared to none of the healthy controls, even though most of these patients weren't overweight or diabetic.⁴ A separate cross-sectional study of drug-naive MS patients found significantly higher HOMA-IR and reduced insulin sensitivity compared to matched controls, despite normal glucose tolerance — suggesting an early, silent phase of insulin resistance in the natural course of the disease.⁵ Related work has also linked fasting insulin and reduced insulin sensitivity to cognitive performance in MS patients, hinting that the metabolic and neurological threads may be more tangled than previously thought.⁶

This matters biologically. Chronic insulin resistance drives low-grade systemic inflammation and can compromise the integrity of the blood-brain barrier — the same barrier that, when it breaks down, lets immune cells and inflammatory proteins into the central nervous system and contributes to new lesions and relapses.⁷

Why Screening Makes Sense

Insulin resistance is frequently silent. Fasting glucose can look normal for years while insulin resistance quietly builds — it typically only shows up on tests that measure insulin directly, like a fasting insulin level. Given how often it's found in MS, and given that identifying it opens the door to intervention long before someone crosses into prediabetes or diabetes, there's a reasonable argument for MS clinics to check fasting insulin and glucose as part of routine metabolic screening, not just wait for a diagnosis of diabetes.

Where Low-Carbohydrate Diets Fit In

If insulin resistance is identified, carbohydrate restriction is one of the more direct dietary levers available, because it's the most efficient way to lower the insulin demand a body has to keep up with. Small but growing clinical trial evidence has started testing this directly in MS populations. A pilot study of a modified Atkins (ketogenic) diet in relapsing-remitting MS found the diet was safe and tolerable over six months, with improvements in fatigue, depression, and disability metrics.8 A larger, 18-month randomized controlled trial comparing a standard healthy diet, an intermittent fasting diet, and a ketogenic diet (20–40 g of carbohydrate per day) in relapsing-remitting MS found that cardiometabolic risk markers — including BMI, abdominal fat, blood lipids, and blood pressure — improved across all three groups, with additional signals of benefit for neurofilament light chain and cognition in the fasting and ketogenic arms specifically.⁹

It's worth noting that low-carbohydrate approaches aren't the only dietary strategy under active study. A randomized controlled trial of a low-fat diet also found meaningful improvements in MS-related fatigue.10 Low-fat and low-carb approaches aren't necessarily in competition — they may simply be targeting different mechanisms (caloric/fat load versus insulin demand). But for the specific problem of insulin resistance, carbohydrate restriction has the most direct mechanistic link.

The Takeaway: Questions to Ask Your Care Team

None of this replaces disease-modifying therapy, and none of it is a cure. But the evidence is converging on a simple point: metabolic health isn't separate from MS management, it's part of it. If you have MS, it's worth asking your care team:

• Have I been screened for insulin resistance (fasting insulin, HOMA-IR), not just diabetes?
• Do I have hypertension, dyslipidemia, or prediabetes that isn't being actively managed?
• If insulin resistance is present, would a structured, dietitian-guided low-carbohydrate approach make sense for me?

Addressing cardiometabolic health won't replace your MS treatment plan — but it may make that treatment work harder for you.

This post is for general information and isn't a substitute for individualized medical advice. Talk to your neurologist or a registered dietitian before making significant dietary changes, especially if you take medications affected by carbohydrate intake (like insulin or sulfonylureas).

References

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