Ketogenic Diet and Potential Applications for Cancer Therapy

Lorenzo Cohen, PhD

Jennifer McQuade, MD, LAc

Stephanie Maxson, MS, RD

September 12, 2014

Ketogenic Diet - History

• Hippocrates recommended fasting for seizure therapy• First scientific publication – France, 1911• First efficacy studies of ketogenic diet for epilepsy – US 1925• Interest waned in 1938 with phenytoin, then renewed ~1990

Ketogenic Diet

• Composition:– High fat– Very low CHO (<50 gm/day)– Adequate protein

• Increases reliance on fatty acids instead of glucose → mimics fasting

• Low serum glucose during fasting triggers hormone changes → lipolysis

• Free fatty acids then converted to ketone bodies in liver– acetoacetate and β-hydroxybutyrate

Indications

• Indications:– Intractable epilepsy, all ages. Mechanism unknown.– Inborn metabolic disorders ie. pyruvate dehydrogenase complex deficiency

• Experimental Uses:– DM type 2– PCOS– Autism– Bipolar disorder– Cancers, especially brain and skin

• Contraindications:– Fatty acid oxidation defects– Primary carnitine deficiency

Adverse Effects

• Short-term:– Hypoglycemia– Acidosis– Dehydration, poor appetite– Constipation, diarrhea

• Long-term:– Growth retardation– Micronutrient deficiencies– Hypertriglyceridemia– Renal stones– Irritability, lethargy

• Serious but rare:– Acute pancreatitis– Cardiomyopathy– Acute hemolytic anemia

Diet Details

• KD typically 4:1 or 3:1– gm fat : gm protein + gm CHO– Lower ratios to better meet protein requirements or improve tolerance– Compared to standard diet (25% fat, 20% protein, 55% CHO) → 1:6.7

• Menus are calculated to the nearest gram• Foods weighed to the nearest 10th gm• Typically includes high fat foods: heavy cream, sour cream, butter,

margarine, oil, mayonnaise• Protein sources added second• Very limited portions of CHO foods, including fruits and vegetables,

added last.

KD Mechanisms- Epilepsy• Epilepsy-

– Metabolic changes likely related to the KD’s anticonvulsant properties include – but are not limited to – ketosis, reduced glucose, elevated fatty acid levels, and enhanced bioenergetic reserves. Direct neuronal effects induced by the KD may involve ATP-sensitive potassium (KATP) channel modulation, enhanced purinergic (i.e., adenosine) and GABAergic neurotransmission, increased brain-derived neurotrophic factor (BDNF) expression consequent to glycolytic restriction, attenuation of neuroinflammation, as well as an expansion in bioenergetic reserves and stabilization of the neuronal membrane potential through improved mitochondrial function.

– Direct role of ketones in decreasing neuronal excitation- “available evidence thus far fails to strongly support a primary mechanistic role for ketone bodies”

SHORT ANSWER= WE DON’T KNOW

Fig. 4 Decreased metabolism of glucose by tumors, visualized by PET with the glucose analog FDG, predicts response to anticancer therapy.

M G Vander Heiden et al. Science 2009;324:1029-1033

Published by AAAS

Fig. 2 Schematic representation of the differences between oxidative phosphorylation, anaerobic glycolysis, and aerobic glycolysis (Warburg effect).

M G Vander Heiden et al. Science 2009;324:1029-1033

Published by AAAS

Fig. 3 Metabolic pathways active in proliferating cells are directly controlled by signaling pathways involving known oncogenes and tumor suppressor genes.

M G Vander Heiden et al. Science 2009;324:1029-1033

Published by AAAS

Klement 2014

Metabolic heterogeneity vs. inflexibility

• Differential stress response– Particularly in brain

- Debarardinis- UTSW- NSCLC- C13 infusion during surgery- both glycolysis and

tca inc relative to normal tissues- regional heterogeneity- glycolysis correlates with compromised perfusion

-High OxPhos as mechanism of resistance

Calorie restriction vs. ketogenic diet

• Very little evidence for direct anti-tumor effect of ketones

• Tolerability

Gastric cancer cell line 2312/87 relies on glycolysis

In vivo study design

• 24 nude mice-> 12 KD + 12 SD• Cages of 6 animals• Hind flank innoculation of gastric cancer cell line

2312/87• Dietary intervention began same day as inoculation• Ad libitum access to their diet• Endpoint: Tumour volume 600 -700 mm3 • Survival time: Interval between subcutaneous

tumour cell inoculation and the endpoint

In vivo study design• 40.7% curd cheese• 19.9% mackerel• 8.1% blue veined cheese,• 8.1% white veined cheese• 8.1% bacon• 4.0% Tavarlin bread • 8.1% flaxseed• 2.7% sesame seed• 300 ml of Tavarlin oil (28.7% saturated fatty acids, 35.7% unsaturated fatty

acids, and 35.6% polyunsaturated fatty acids with a ratio of omega-6/omega-3 of 1.77:1)

• 100 ml Tavarlin lactate drink

MCT 21.45%

Ketogenic diet significantly decreases rate of tumor growth

Ketogenic diet influences tumor “take”

Ketogenic diet significantly prolongs“survival”

P=0.001

Impact on body weight, ketosis, glucose, insulin

β-OHB levels :1.3 ± 0.5 mmol/l KD vs. 0.6 ± 0.1 mmol/l SD (P < 0.001)

Glucose levels:5.5 ± 2.7 mmol/l KD vs. 6.3 ± 1.3 mmol/l SD (P = 0.59)

Insulin levels:63.3 ± 32.5 pmol/l KD vs. 72.0 ± 41.0 pmol/l SD (P=0.84)

MCT KD anti-cancer, but why?

• Most studies of ketogenic diet are in fact studies of calorie restricted ketogenic diet and evidence for CRKD antitumor effects strong whereas mixed for ad libitum KD

• Decrease in Insulin/IGF/Glucose more consistent in calorie restriction studies

• Is it anti-tumor effects of the Omega-3’s and MCT?• Anti-angiogenic

– good fats or reduced pyruvate-> dec HIF-1 activation of VEGF– “Metabolic catastrophe”

The “Products”

ERGO: A pilot study of ketogenic diet in recurrent glioblastoma

J. Rieger, O. Bahr, GD Maurer, et al.

International Journal of Oncology (2014)44:1843-52.

• Primary Objective: feasibility of ketogenic diet in glioblastoma patients

• Secondary Objectives:– Diet safety– Percentage of patients achieving ketosis– Quality of life– Progression-free survival– Overall survival

Human Study

• Prospective, open-label, single-arm pilot

• Inclusion criteria:– Age ≥ 18yo– Relapse ≥ 6 months after initial surgery AND ≥ 3 months

after completion of radiation– Relapse during OR after temozolomide– No other reasonable chemo options OR chemo refused– Karnofsky performance score (KPS) ≥ 60%

• Exclusion criteria:– DM requiring insulin OR cardiac insufficiency

- 12.5 months – median time from dx to start of study treatment (6-42 mos.)

Ketogenic Diet

• 60 grams CHO/day → estimated 1.4:1• No calorie restriction

– Instructed to eat to satiety

• Fermented yogurt drink: 500ml/day• 2 plant oils:

– “basic” oil and “addition” oil (99% fat)

• No standardized meal plan– Instructed on keto diet– Provided recipes and written instructions– Subjects prepared own meals

Data Collection

• Assessed at baseline, follow-ups (6-8 week intervals), and clinical progression :– seizures, medications, vitals– Glu, HbA1c, triglycerides, cholesterol, LDL, HDL– KPS, mini-mental status, QOL questionnaire– Neurological examination

Data Collection (cont)

• Subjects collected:– Urine ketones 2-3 times per week– “Nutritional plan”

• Weekly questionnaire (scale of 0-3):– Diarrhea/constipation– Hunger– Glucose demand

• MRI: q6-8 weeks or with clinical progression– Response or stable → continue diet– Progression → “allowed” to continue diet with salvage therapy– Progression with combination → diet discontinued

- 20 subjects enrolled (12/07-3/10)

Safety/Tolerability• Followed diet avg 6.8 days/wk• No serious adverse events• Majority w/ no const./diarrhea• Hunger first week but improved

following weeks

Efficacy

For all subjects:• Median time to progression:

5 weeks (3-13)• Median overall survival after

start of diet: 32 weeks (6-86+)

• Trend for longer PFS in subjects with stable ketosis (>50%)

Efficacy (cont)

• Progression in all 17 subjects

• 7 continued diet with bevacizumab salvage therapy– 1 complete response and 5 partial responses

→ Overall response of 85% – compared these subjects to a cohort of 28 patients treated with

bev at same institution without ketogenic diet- ORR 65% (p=0.4). These response rates are both significantly higher than those reported in the Phase II trials of bev salvage (28-40%)

• Median PFS from bev:– with keto diet: 20.1

weeks (12-124)– without keto diet: 16.1

weeks (4-90+) (p=0.38, 95% CI 15-17wk)

Efficacy (cont)

Mouse Study

• Does keto diet modulate the efficacy of bevacizumab?

• Pilot study combining keto diet with bev in mice– 44 female, athymic mice – Glioma cells implanted into right striatum– ad lib food and water

– randomized to standard CHO-rich diet OR keto diet (3.14:1)– twice weekly intraperitoneal injections of bev OR saline

(starting day 12)

Methods

• Day 24, 5-7 animals per group: β-hydroxybutyrate• Day 28, 3 animals per group:

– tumor measured by MRI– bioluminescence imaging to map concentrations:

• ATP• lactate• glucose

• Remainder sacrificed at onset of symptoms OR loss of >20% weight

• KD alone had no effect on survival.• Combined bev and KD prolonged survival significantly compared to

bev alone

• Tumor volume tended to be smaller with combination bev and KD (p<0.05)

• Bev sig. reduced ATP in tumor tissue; trend for stronger effect in mice fed KD

Conclusion

• Keto diet is feasible and safe, but probably has no significant clinical activity when used as single agent in recurrent glioma.

Discussion:• Diets poorly monitored and documented• Diet ratio moderately ketogenic• CHO limits not individualized• No sig change in glucose; related to steroids?

Discussion

• Ketogenic versus calorie restriction?• Feasibility of maintaining a ketogenic diet?• Role of specific fats – any fat or ideal to have MCT?• Is it the high fat that matters or just low carbs/GL?• More relevant for some cancers (e.g., brain)?