Feasibility and metabolic outcomes of a well-formulated ketogenic diet as an adjuvant therapeutic intervention for women with stage IV metastatic breast cancer: The Keto-CARE trial

<p><em>Purpose:</em></p> <p>Ketogenic diets may positively influence cancer through pleiotropic mechanisms, but only a few small and short-term studies have addressed feasibility and efficacy in cancer patients. The primary goals of this study were to evaluate the feasibility and the sustained metabolic effects of a personalized well-formulated ketogenic diet (WFKD) designed to achieve consistent blood beta-hydroxybutyrate (<span>β</span>HB) &gt;0.5 mM in women diagnosed with stage IV metastatic breast cancer (MBC) undergoing chemotherapy.</p> <p><em>Methods: </em></p> <p>Women (n = 20) were enrolled in a six-month two-phase, single-arm WFKD intervention (NCT03535701). Phase I was a highly-supervised, ad libitum, personalized WFKD, where women were provided with ketogenic-appropriate food daily for three-months. Phase II transitioned women to a self-administered WFKD with ongoing coaching for an additional three-months. Fasting capillary <span>β</span>HB and glucose were collected daily; weight, body composition, plasma insulin, and insulin resistance were collected at baseline, three- and six-months. </p> <p><em>Results:</em></p> <p>Capillary <span>β</span>HB indicated women achieved nutritional ketosis (Phase I mean: 0.8 mM (n = 15); Phase II mean: 0.7 mM (n = 9)). Body weight decreased 10% after three-months, primarily from body fat. Fasting plasma glucose, plasma insulin, and insulin resistance also decreased significantly after three-months (p &lt; 0.01), an effect that persisted at six-months.</p> <p><em>Conclusions</em>:</p> <p>Women diagnosed with MBC undergoing chemotherapy can safely achieve and maintain nutritional ketosis, while improving body composition and insulin resistance, out to six-months.</p>