The study in my prior post (Enlarged Prostate? There’s A Lot You Can Do Diet-Wise To Relieve Symptoms) referenced the study below:
Intakes Of Energy And Macronutrients And The Risk Of Benign Prostatic Hyperplasia, American Journal of Clinical Nutrition, April 2002
I’ve been reading it to understand a little better how food affects the prostate.
What I’ve learned … There are two components to BPH, a structural component (an enlarged prostate which compresses the urethra) that is static or always there, and a dynamic component that causes lower urinary tract symptoms (LUTS). The dynamic component is controlled by the sympathetic nervous system. Norepinephrine or epinephrine (adrenaline) react with receptors in smooth muscle of prostate and urethra causing contraction. Drugs that block this receptor, like Flomax, relax smooth muscle, easing urination.
Of the 33344 members of the Health Professionals Follow-up Study, we observed direct associations between:
– Total energy intake and total BPH and high-moderate to severe lower urinary tract symptoms.
– Total and animal protein intakes and total BPH and BPH surgery.
– EPA and DHA and total BPH, BPH surgery, and enlarged prostate.
– Total polyunsaturated fats and all definitions of BPH.
When I look down the list of nutrients linked to enlarged prostate or symptoms/LUTS, three things stand out: 1. energy intake, 2. total and animal protein, and 3. polyunsaturated fat including omega-3s.
1. How can eating more calories cause symptoms? Especially when it doesn’t seem related to BMI or body size? One thing I can think of … anything that causes you to release adrenaline will contract smooth muscle and make it difficult to pee. For some people that can include a large meal. Certain foods can also produce high epinephrine. They said this:
One possibility for the positive relation between total energy intake and total BPH is that activation of the sympathetic nervous system by a high energy intake may cause the prostate smooth muscle to contract, resulting in a worsening of lower urinary tract symptoms.
2. They said this about why eating more protein can aggravate symptoms (protein makes you pee because you have to get rid of its nitrogen. But there may be other mechanisms, especially for animal protein, like IGF-1):
Another plausible role of protein may be related to its contribution to the osmolar concentration of the diet that increases the obligatory water loss, which may increase urination (100 g protein contains 16 g N that must be excreted, mostly as urea, contributing 500 mOsmol). Because the kidneys can only concentrate urine up to a certain osmolality, the osmolar concentration of the diet, which is largely related to protein and salt, induces an obligatory water loss. It is plausible that the osmolar load from a large protein meal as it is digested influences urinary flow, which may exacerbate any existing urinary symptoms.
3. One of the most potent contributers to symptoms was polyunsaturated fat, the type you find in margarine and seed oils and, of course, fish oil. The long-chain omega-3 fatty acids EPA and DHA, being highly unsaturated, are very problematic. They have been linked not only to BPH but to prostate cancer.
EPA and DHA were associated with total BPH, BPH surgery, and enlarged prostate. These polyunsaturated fatty acids were most clearly related to enlarged prostate, suggesting a mechanism of BPH etiology different from that of the other nutrients. The high degree of unsaturation of EPA and DHA suggests a mechanism involving lipid peroxidation. Lipid peroxides may result in increases in tissue concentrations of NAD and NADPH, which increase 5α-reductase and prostatic DHT concentrations, thus possibly increasing epithelial and stromal growth (1). A hormonal etiology appears consistent with the finding that EPA and DHA were associated with the mechanical, or static, component rather than with the dynamic component of BPH. A weak positive association between vegetable fat and total BPH and high-moderate to severe lower urinary tract symptoms and enlarged prostate also might be due to peroxidation. Serum DHT is reported to be positively correlated with vegetable fat intake (35), but the relation between plasma hormones and BPH risk is controversial (36). The degree of unsaturation of fatty acids in cell membranes appears to influence 5α-reductase activity (13), which is a determinant of intracellular DHT concentrations in the prostate.
Besides a mechanism involving androgenic effects, numerous previous studies have shown that lipid peroxides are involved in the regulation of cellar proliferation and cytotoxicity. Dietary EPA and DHA are sources of lipid peroxides, and their cytotoxicity is concentration dependent (37) and may influence BPH through nonhormonal mechanisms (38).
The paragraphs above don’t just say that these omega-3s aggravate symptoms, they implicate them in the very development of enlarged prostate. How does information like this get so buried? How do people still end up recommending seafood consumption, and taking EPA and DHA supplements?
The argument against eating seafood keeps getting stronger.