The principle of
ketogenic diet (KD) is restriction of
carbohydrates to a maximum of 5-10% of the total daily caloric intake, aiming at shifting body metabolism toward
ketone bodies. Different studies suggested promising results of KD to help patients to lose weight, to reduce
insulin requirements in diabetes, to supplement
cancer protocols, to treat neurological conditions and to optimize control of metabolic and
cardiovascular diseases. However, literature about the anti-inflammatory properties of KD in
rheumatic diseases is still limited. The beneficial effects of
weight loss in patients with inflammatory
arthritis can be explained by biomechanical and biochemical factors.
Obesity is associated with macrophage activation and production of pro-inflammatory
cytokines including TNF-α, IL-1b, and
IL-6. The clinical effect of KD may be primarily attributed to improvement of
insulin sensitivity.
Insulin resistance is associated with an increase of TNF-α, IL-1α, IL-1β,
IL-6, and
leptin. Moreover, reduction of body's adipose tissue and
weight loss account for part of the anti-inflammatory effects and for the impact of KD on cardiovascular health. In
rheumatoid arthritis, fasting was shown to be effective in reducing disease symptoms, possibly through the production of β-hydroxybutyrate (BHB), the main
ketone body. BHB may exert inhibitory effects also on
IL-17 and intermittent fasting improved the clinical manifestations of
psoriatic arthritis. In
ankylosing spondylitis, current literature doesn't allow to draw conclusion about the effects of KD. Future prospective studies will be needed to elucidate the potential beneficial effects of KD on specific domains and clinical outcomes in patients with inflammatory
arthritis.