A 57-year-old white Australian male was diagnosed with advanced prostate cancer (Gleason Score: 9) in early September 2020. He had played sport at an elite level for many years and was keeping highly active at the time of diagnosis but was seeking dietary advice to help optimize the effects of his medical treatment, which included one dose of radiation (177Lutetium-Prostate-Specific Membrane Antigen), and surgery six weeks later involving a radical prostatectomy with pelvic lymph node dissection.

At his initial dietary consultation his self-reported weight was 88 kg, height 183 cm (estimated BMI of 26 kg/m²) and waist circumference was 84 cm. Medical history prior to diagnosis included an egg allergy as a child, intermittent sinusitis, hemorrhoids, and surgeries for sports-related injuries. Family history included obesity, diabetes, breast cancer (mother) and dyslipidemia (father).

He reported having changed his diet from the typical Western dietary pattern to a vegan diet immediately post-diagnosis. Protein intake was approximately 12% of his total energy intake and was solely from plant sources. Thus, the quantity and quality of protein intake needed to be increased to promote enhanced recovery from his upcoming radiation and surgery. Total dietary fat intake was estimated at approximately 37% of total energy intake (goal < 30%), and he was deficient in several micronutrients: vitamins B2, B12, A, zinc, and selenium.

His previous blood results were reviewed and showed a history of dyslipidemia. Nutrigenomic tests were also undertaken via the SmartDNA Genomic Wellness Test (https://www.smartdna.com.au/). He was provided with an OC-100 (DNA Genotek) Saliva Test Kit and mass array analysis was conducted on more than 167 genetic variants or SNPs, although based on his bloods, the focus was on his genetic predisposition to lipid metabolism [5].

He was provided with an initial meal plan of a high plant-based diet (approximately 75% of intake) averaging 12,000 kJ per day. Protein intake was increased to around 20% of total energy intake from both suitable animal and plant sources to ensure that he met his iron, vitamin B12 and micronutrient requirements. Other dietary recommendations focused on reducing consumption of total and saturated fat, and refined sugars.

He kept regular food diaries and dietary consultations across all phases of his active treatment and successfully underwent radiation therapy and surgery without any clinically significant issues other than some temporary general fatigue and loss of fitness. Dietary adjustment based on his food diaries helped to alleviate these symptoms e.g., slight increase in low GI carbohydrate intake.

Table 1 presents the lowered lipid levels corresponding with his dietary modifications. Results from his targeted nutrigenomic tests in Table 2 indicate a genetic predisposition to dyslipidemia, which could be managed via his personalized diet (Table 1). Total cholesterol reduced from 6.2 mmol/L to 5.1 mmol, triglycerides from 2.4 mmol to 1.0 mmol/l and LDL cholesterol from 3.8 mmol to 3.4 mmol following his dietary intervention. PSA levels are also shown to drop to 0.1ug/L following radiation and surgery. At two years post treatment there was no detectable disease recurrence or plans for ADT.