A low carbohydrate, high protein diet suppresses intratumoral androgen synthesis and slows castration-resistant prostate tumor growth in mice.
Study Goal
The researchers aimed to determine the impact of a low carbohydrate diet compared to a Western diet on prostate cancer tumor growth and steroid regulation in mice.
Results Summary
The study found that a low carbohydrate diet significantly reduced tumor growth rate in castrated mice but not in intact mice. It also altered steroid profiles and cholesterol levels, with lower DHT concentrations in the low carb group.
Population
Mice bearing LNCaP xenograft tumors (intact and castrated).
Effective Dosage
Not specified
Duration
Not specified
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low carbohydrate diet | decrease | tumor growth rate | castrated mice | - | saw a statistically significant reduction | #1 |
low carbohydrate diet | no change | LNCaP tumor progression (total tumor volume) | intact mice | - | No differences | #2 |
low carbohydrate diet | no change | serum PSA | - | - | No correlation | #3 |
low carbohydrate diet | neutral | Steroid profiles, alongside serum cholesterol and cholesteryl ester levels | - | - | significantly altered | #4 |
low carbohydrate diet | decrease | DHT concentration | CRPC-bearing mice | 58% | was 58% that of | #5 |
low carbohydrate diet | increase | AKR1C3 protein levels | tumors isolated from intact mice | - | had higher | #6 |
low carbohydrate diet | decrease | HSD17B2 protein levels | intact mice | - | had lower | #7 |
low carbohydrate diet | increase | HSD17B2 | CRPC tumors from mice | - | had higher concentrations | #8 |
low carbohydrate diet | increase | SRD5A1 enzymes | CRPC tumors from mice | - | had higher concentrations | #9 |
low carbohydrate diet | no change | serum insulin | castrated mice | - | no correlation | #10 |
low carbohydrate diet | no change | GH serum levels | castrated mice | - | no correlation | #11 |
low carbohydrate diet | no change | insulin receptor (IR) in tumor tissue | castrated mice | - | no correlation | #12 |
low carbohydrate diet | no change | IGF-1R in tumor tissue | castrated mice | - | no correlation | #13 |
Western diet | increase | serum insulin | Intact mice | - | had higher | #14 |
Western diet | increase | blood glucose | Intact mice | - | associated with significantly higher | #15 |
Western diet | increase | tumor tissue IR | Intact mice | - | associated with significantly higher | #16 |
Dietary factors continue to preside as dominant influences in prostate cancer prevalence and progression-free survival following primary treatment. We investigated the influence of a low carbohydrate diet, compared to a typical Western diet, on prostate cancer (PCa) tumor growth in vivo. LNCaP xenograft tumor growth was studied in both intact and castrated mice, representing a more advanced castration resistant PCa (CRPC). No differences in LNCaP tumor progression (total tumor volume) with diet was observed for intact mice (P = 0.471) however, castrated mice on the Low Carb diet saw a statistically significant reduction in tumor growth rate compared with Western diet fed mice (P = 0.017). No correlation with serum PSA was observed. Steroid profiles, alongside serum cholesterol and cholesteryl ester levels, were significantly altered by both diet and castration. Specifically, DHT concentration with the Low Carb diet was 58% that of the CRPC-bearing mice on the Western diet. Enzymes in the steroidogenesis pathway were directly impacted and tumors isolated from intact mice on the Low Carb diet had higher AKR1C3 protein levels and lower HSD17B2 protein levels than intact mice on the Western diet (ARK1C3: P = 0.074; HSD17B2: P = 0.091, with α = 0.1). In contrast, CRPC tumors from mice on Low Carb diets had higher concentrations of both HSD17B2 (P = 0.016) and SRD5A1 (P = 0.058 with α = 0.1) enzymes. There was no correlation between tumor growth in castrated mice for Low Carb diet versus Western diet and (a) serum insulin (b) GH serum levels (c) insulin receptor (IR) or (d) IGF-1R in tumor tissue. Intact mice fed Western diet had higher serum insulin which was associated with significantly higher blood glucose and tumor tissue IR. We conclude that both diet and castration have a significant impact on the endocrinology of mice bearing LNCaP xenograft tumors. The observed effects of diet on cholesterol and steroid regulation impact tumor tissue DHT specifically and are likely to be mechanistic drivers behind the observed tumor growth suppression.