The highest average intakes of lycopene, beta-carotene, or vitamin A were associated with a 40 to 50 percent reduction in the odds of LUTS, compared with the lowest average intakes, according to results of a study with 1466 men published in the Journal of Nutrition.
Furthermore, the associations were observed in men with moderate-to-high iron levels, said the researchers, which suggested the mechanism behind the potential benefits is related to the antioxidant potential of the micronutrients.
On the other hand, high-dose supplements containing vitamin C were reported to increase the risk of LUTS, which suggests that increased acidity of the urine may be a contributor to the development of LUTS, said the researchers. However, additional research is required to confirm such observations, they added.
“Clinically, our results provide support to recommendations for increased fruit and vegetable consumption, particularly those rich in carotenoids and vitamin C, as these may have benefits that extend to moderate-to-severe LUTS in men,” report the researchers from Harvard and Northwestern Universities.
“If confirmed by other studies, the potential public health importance of dietary and supplement associations is underscored by the recognized need for non-invasive, modifiable lifestyle options for the prevention and treatment of LUTS,” they added.
LUTS are reported in upwards of 40 percent of older men, and symptoms include frequent and urgent urination as well as a weak urinary stream. The causes of LUTS have not been full elucidated, but some studies suggest inflammation, oxidative damage, and involvement of the nervous system.
Led by Nancy Maserejian, affiliated with Boston-based New England Research Institutes, the researchers analyzed data from 1,466 men aged between 30 and 79 enrolled in the Boston Area Community Health survey (2002–2005). Data was collected using food frequency questionnaires (FFQs) and in-person interviews. The American Urological Symptom Index was used to define moderate-to-severe LUTS.
Results showed a significant reduction in the risk of LUTS for men consuming the greatest amounts dietary carotenoids. Specifically, men with the highest average intakes beta-carotene (4,780 micrograms per day) were 44 percent less likely to be report storage symptoms than men consuming the lowest average levels (775 micrograms per day).
In addition, the highest average intakes of lycopene from dietary sources (2,248 micrograms per day) were associated with a 39 percent reduction in total LUTS, compared with the lowest average intakes of 285 micrograms per day.
Similar associations were found for dietary vitamin A, said the researchers, with men with the highest average intakes vitamin A (10,926 International Units per day) were 47 percent less likely to be report storage symptoms than men consuming the lowest average levels (4,717 IU per day).
On the other hand, supplements of high-dose vitamin C were associated with an increased risk for LUTS.
“Positive associations between supplemental vitamin C and LUTS could hypothetically be due to effects of high-dose vitamin C on acidity of urine composition,” said the researchers. “For the average adult, body stores of vitamin C are adequately maintained with 75 mg/d ascorbic acid, and doses above 200 mg are mostly excreted.”
This would increase the acidity of the urine, and there is evidence in the literature that indicates that urine acidity may increase the desire and urgency to urinate. “Overall, our findings suggest that for some men, LUTS could be ameliorated by changing urine composition through modification of high-dose supplement use,” added Dr Maserejian and her co-workers.
Source: Journal of Nutrition
Volume 141, Pages 267-273
"Dietary, but not supplemental, intakes of carotenoids and vitamin C are associated with decreased odds of lower urinary tract symptoms in men”
Authors: N.N. Maserejian, E.L. Giovannucci, K.T. McVary, J.B. McKinlay