How Can You Shrink an Enlarged Prostate in 7 Steps?
Ken D. Berry, MD, family physician
Published 11/13/26
Enlarged prostate, also called BPH or benign prostatic hyperplasia, afflicts millions of men. The urinary symptoms are obvious to the man living with them. Hormones are involved. In my view the hormone driving most of the problem is not testosterone, DHT or estrogen. It is insulin.
Why does insulin enlarge the prostate?
The prostate is a gland that responds to growth signals. Insulin is one of the body's main growth hormones. An improper diet can leave you hyperinsulinemic after meals or all day. High insulin can bind receptors tied to IGF-1 signaling in prostate cells. Over years that means more cells and bigger cells, which squeezes the urethra running through the prostate and causes the urinary problems.
The goal is a low normal insulin level for as many hours of the day as possible.
What are the 7 easy steps?
- Avoid all sugar. That includes added sugar in soft drinks and desserts, and high-sugar fruits such as grapes, bananas, cherries, papaya and pineapple. Sugar spikes blood glucose, which spikes insulin, which feeds prostate growth.
- Avoid all grains, including whole grain bread. Amylase in your mouth starts turning that starch into sugar as you chew. Wheat, rice, oats and corn all drive the same insulin path.
- Avoid unfermented soy. Soy is estrogenic and can worsen the estrogen to testosterone balance in a way that, in my view, favors prostate enlargement. Traditionally fermented options such as natto are a different case.
- Avoid low fat dairy. Use only full fat dairy. Some men do fine with full fat cheese, yogurt or kefir. Other men need to stick to heavy cream, butter and ghee only, or their prostate symptoms get worse.
- Avoid vegetable seed oils. Their omega-6 to omega-3 ratio favors inflammation, including in the prostate, which makes BPH symptoms worse.
- Eat a low carbohydrate diet. Ketogenic or carnivore both keep insulin low normal for most of the day.
- Use intermittent fasting. Work toward 14 to 18 hours without eating. You do not have to start at 18 hours. Fasting helps reset insulin to low normal, and it is free.
How fast should you expect results?
In my view these seven steps can address the large majority of the prostate problem. You did not enlarge the prostate overnight. Do not expect a fix in days or weeks. It can take several months or up to a year. Lowering insulin stops the inappropriate growth signal. As cells turn over, newer cells are more normal in size and number. That is gradual.
What about prescription prostate medicines?
Prescription medicines can help symptoms. In my view they do not fix the root cause of chronic hyperinsulinemia. It is fine to use one for a few months while diet does its work. Be ready for a long list of side effects, some serious. Decide that with your own doctor.
Do testosterone, estrogen and DHT cause BPH?
A low testosterone to estrogen ratio raises BPH risk. Testosterone itself does not. DHT itself is not the main driver I am talking about here. Young men with very high testosterone do not walk around with huge prostates. Enlarged prostate shows up later, when testosterone falls, carbohydrate intake has been high for decades, and insulin has been high for years.
Do saw palmetto, nettle root or pumpkin seed extract help?
Some men report big symptom relief. Others notice little. In my view those supplements might be a small piece. Focus on the insulin root cause first.
This is not medical advice. Work with your own doctor or urologist on prostate symptoms, medicines and labs before you change diet or supplements.
Frequently asked questions
Is testosterone the main cause of an enlarged prostate?
In my view, no. Insulin is the growth hormone I focus on for most of the problem.
Will keto or carnivore shrink my prostate in a week?
No. Plan on months, maybe a year, while insulin stays low normal and cells turn over.
Can I keep taking my prostate prescription while I change my diet?
Often yes for a while, with your doctor's guidance. Medicines help symptoms. They do not remove the insulin driver.
Is whole grain bread okay for BPH?
No. Starch still becomes sugar in your mouth and raises insulin.
Should every man stop all dairy?
Not necessarily. Drop low fat dairy. Some men tolerate full fat cheese and yogurt. Others do better with only butter, ghee and heavy cream.
Are prostate supplements required?
No. Optional. Diet and fasting come first in my approach.
This information is not medical advice. Work with your own doctor on your health and medications.
Research referenced in the video
I point to research in the show notes linking insulin and insulin resistance with benign prostatic hyperplasia. These are the description links I opened and verified. I left out a prostate-cancer diet review that does not address BPH.
Kopp W (2018), "Diet-Induced Hyperinsulinemia as a Key Factor in the Etiology of Both Benign Prostatic Hyperplasia and Essential Hypertension?": https://pubmed.ncbi.nlm.nih.gov/30455570/ (PMC6238249: https://pmc.ncbi.nlm.nih.gov/articles/PMC6238249/)
Vikram A, Jena G, Ramarao P (2010), "Insulin-resistance and benign prostatic hyperplasia: the connection": https://pubmed.ncbi.nlm.nih.gov/20553919/
Dahle SE, Chokkalingam AP, Gao YT, et al. (2002), "Body size and serum levels of insulin and leptin in relation to the risk of benign prostatic hyperplasia": https://pubmed.ncbi.nlm.nih.gov/12131317/
Hammarsten J, Hogstedt B (2001), "Hyperinsulinaemia as a risk factor for developing benign prostatic hyperplasia": https://pubmed.ncbi.nlm.nih.gov/11223674/
Nandeesha H, Koner BC, Dorairajan LN, et al. (2006), "Hyperinsulinemia and dyslipidemia in non-diabetic benign prostatic hyperplasia": https://pubmed.ncbi.nlm.nih.gov/16516184/
About Dr. Berry
Dr. Ken Berry is a board-certified family physician who has cared for over 25,000 patients in more than two decades of practice in rural Tennessee. He grew up in Hohenwald, Tennessee, and earned his MD at the University of Tennessee Health Science Center.
He is the author of the #1 bestselling Lies My Doctor Told Me and the creator of the Proper Human Diet.
He lives on a farm in Holladay, Tennessee, with his wife Neisha and their two children.
