Diet and Cognitive Training in Hematologic Cancer Survivors

The goal of this clinical trial is to examine feasibility of a cognitive intervention program in blood cancer survivors. The main questions it aims to answer are:

* is it feasible to combine a ketogenic diet supplementation and online cognitive training in an intervention program
* will patients using the combined intervention program have improved cognitive functioning compared to those who don't use it
* how long will the intervention programs effects last

Participants randomized to the intervention arm will consume an exogenous ketogenic supplementation and use an online cognitive training program for 12 weeks, while waitlist arm functions as a control group and will receive the online cognitive training only after a wait period of 12 weeks. Researchers will compare the intervention and waitlist control groups to see if the intervention improves cognitive functioning.

The investigators propose using "off-the-shelf" products in a 12-week multicomponent cognitive intervention program to address the cognitive impairment in outpatient hematologic malignancy survivors. The program includes two components: i) A modified ketogenic diet using an exogenous ketogenic supplementation using the KetoCal product (\[https://shop.myketocal.com/product/ketocal-41-lq\]) and ii) online cognitive training using Lumosity program (http://www.lumosity.com/).

A ketogenic diet is characterized by high fat, moderate protein and very low carbohydrate intake. Participants will follow a modified ketogenic diet consuming exogenous Ketocal tetrapaks daily to substitute \~700 calories of their daily calorie needs and limit their carbohydrate intake while maintaining an eucaloric diet. The KetoCal is a nutritionally complete, ready-to-feed ketogenic meal replacement product. The study goal is to achieve safe and tolerable levels of mild nutritional ketosis (0.5-2mmol/L betahydroxybutyrate (BHB) blood concentration). Diet education will be provided to participants on how and when to consume the KetoCal formula, foods and beverages consistent with a ketogenic diet and foods and beverages to avoid, and how to measure the ketosis using a breathalyzer daily. Safety and Tolerability monitoring will occur by recording treatment-emergent and/or treatment-related adverse events, regular monitoring of weight and satiety levels, and routine laboratory testing using fasting blood samples at baseline and 12 weeks.

The Lumosity program offers over 60 tasks in game-like format that cover the main cognitive domains: processing speed, working memory, attention and executive function. Training will involve a daily session of 5 training tasks for 12 weeks. Each time the patient is logged in for a session, a customized report will be generated by the Lumosity program to capture performance information.

Participants' cognitive functioning will be assessed at baseline and 12 weeks using objectively measured cognitive function to estimate the preliminary efficacy of intervention program; and at 24 weeks to examine the sustained effects of the multi-component intervention program.

The findings from this project will inform a definitive phase III trial of a multi-component intervention to improve cognitive outcomes in patients with hematologic malignancy.

Eligibility Criteria:
Inclusion Criteria:

* Adult with hematologic malignancy diagnosed at age ≥21 years
* Outpatient at least 3 months from completion of blood or marrow transplant (BMT) or at least 6 months from diagnosis for patients not treated with BMT
* Evidence of mild-to-moderate cognitive impairment using either the Modified Telephone Interview for Mild Cognitive Impairment (TICS-M) or PROMIS 8a short form raw score = 19 -37
* Have daily access to an internet-connected home computer
* Can fluently read and write in English
* Can understand and sign the study-specific Informed Consent Form

Exclusion Criteria:

* History of pre-existing neurological disorder or documented major psychiatric disorder
* Significant auditory, visual, or motor impairments
* History of color blindness
* Participated in neuropsychological intervention within the past 6 months
* Evidence of active chronic graft vs. host disease (GvHD) for allogeneic BMT
* History of pre-existing metabolic disease
* Allergies to soy or milk
* Body Mass Index (BMI) ≤20