For Michael Price Nelson, fighting cancer meant changing how he browsed the aisles at the grocery store. The prostate cancer survivor, 70, enrolled in a clinical trial that called for a radical shift in his daily diet. Adapting was hard—but the benefits keep on coming. He shared with us seven reasons why he joined a clinical trial.

Name: Michael Price Nelson
Age: 70
Hometown: Long Beach
Occupation: Retired marketing professional, novelist (his first book, The Lincoln Moon, was recently published)
Pandemic Projects: Reading the entire Shakespeare canon; raising Linus, his rescue "pandemic puppy"
Diagnosis: Prostate Cancer
Clinical Trial: Carbohydrate and Prostate Study 3 (CAPS3): Carbohydrate Restricted Diet Intervention for Men on Prostate Cancer Active Surveillance
Status: Completed

I was diagnosed with prostate cancer two and a half years ago, when I went in for my annual physical. My prostate-specific antigen (PSA) was up to about five or six, a big change from the year before. I was pretty apprehensive about it, but it turned out I had the slow-growing kind of prostate cancer. Instead of surgery, they recommended active surveillance. I wanted to do something, though, and I was curious about whether changing my diet might help. My doctor told me to talk to Dr. Stephen Freedland at Cedars-Sinai, so I did. Dr. Freedland had a study related to prostate cancer and diet, and he thought I'd be a perfect fit.

I was in the second wave of patients of Dr. Freedland's extremely low-carb diet trial. The guidelines called for restricting my carbs to fewer than 20 grams per day, which is almost nothing. It seemed impossible to me, but the team was incredibly supportive. I was assigned a dietitian who worked with me weekly, and it was so helpful to have that assistance. I don't know if I ever achieved under 20 grams of carbs a day, but I was definitely below 100.

Finding a good partner for the trial really helps. The people at Cedars-Sinai were great—I had phone numbers I could call to get all my questions answered. It was so wonderful to get such personal support.

The diet was a real change. I was used to looking at nutrition labels on food, particularly the fat and sugar content, but I'd never paid attention to carbs. When I started, I was shocked: There are huge numbers of carbs in cereals, crackers, a lot of fruit—basically, anything you'd even remotely enjoy. I discovered white wine is low in carbs, which helped. I'm also a chocolate lover, and I learned the higher the cacao content, the lower the carbs. Things like that helped me cope.

I participated in the study for about six months. It was tough, especially getting through Thanksgiving and Christmas—I had to stay far away from the dressing and potatoes! But I managed to pull it off. I even went on a cruise to New Zealand and Australia, and those are notorious for decadent, all-you-can-eat buffets. I was probably one of the only people who left the ship having lost weight!

I've kept a lot of the diet habits I developed during the study. It's really helped me manage my weight, and I feel good.

During the study, I adopted a mindset of, "Everything in moderation, but even moderation." If I'm at a dinner somewhere and there are a lot of carbs, I eat what I want to eat. But there's always tomorrow, and I go back to low-carb the next day. Being flexible allows me to enjoy myself instead of feeling like I'm living with one hand tied behind my back.

To anyone out there considering a trial like this, you can do it! It seems daunting, but you just have to get through the first few weeks. And remember: The goal of this type of diet study is aspirational—don't beat yourself up if you can't do it immediately. You'll find your rhythm, and it won't feel like such a burden.

More than two years after my diagnosis, I'm still shocked when someone calls me a cancer survivor. I just don't think about myself in that way. But I'm certainly being proactive—the folks at Cedars-Sinai have asked me to participate in a new study focused on prostate cancer and exercise. My experience was so positive with the first one that I'm going to do another!