Een dieet met veel vitamine A of carotenoïden verlaagt waarschijnlijk blaaskanker

Research Question:
Epidemiological studies have reported on the preventive effect of vitamin A intake on bladder cancer. However, the results are inconsistent. It was therefore carried out this review article.

Lowers a high intake of vitamin A or carotenoids the chances of getting bladder cancer?

Study Design:
This overview article contained 25 studies (11 cohort and 14 patient-controls studies) between 1988 and 2013 with a total of 11580 people with bladder cancer.

Results and conclusions:
The researchers found in the 11 studies that a high total vitamin A intake compared to a low intake, the chances of getting bladder cancer significantly with 18% [95% CI = 0.65-0.95, I2 = 46.3%] reduced

The researchers found that a high total vitamin A intake compared to a low intake, the chances of getting bladder cancer in cohort studies non-significant 14% [95% CI = 0.67-1.03, I2 = 33.3%] reduced.

The researchers found that a high total vitamin A intake compared to a low intake, the chances of getting bladder cancer in case-control studies significantly with 32% [95% CI = 0.59-0.97, I2 = 60.4%] reduced.

The researchers found that a high retinol intake compared to a low intake, the chances of getting bladder cancer non-significant 12% [95% CI = 0.73-1.02, I2 = 53.9%] reduced.

The researchers found that a high retinol blood value compared with low blood value, the chances of getting bladder cancer significantly with 36% [95% CI = 0.38-0.90, I2 = 7.6%] reduced.

The researchers found that a high carotenoid intake compared to a low intake, the chances of getting bladder cancer significantly with 33% [95% CI = 0.55-0.79] reduced.

The researchers found that a high alpha-carotene intake compared to a low intake, the chances of getting bladder cancer significantly with 13% [95% CI = 0.76-0.99] reduced.

The researchers found that a high beta-carotene intake compared to a low intake, the chances of getting bladder cancer significantly with 11% [95% CI = 0.82-0.97] reduced.

The researchers found that a high beta-cryptoxanthin intake compared to a low intake, the chances of getting bladder cancer significantly with 14% [95% CI = 0.73-1.00] reduced.

The researchers found that a high carotenoid blood value compared with low blood value, the chances of getting bladder cancer significantly with 57% [95% CI = 0.55-0.79] reduced.

The researchers found that a high alpha-carotene blood value compared with low blood value, the chances of getting bladder cancer significantly with 44% [95% CI = 0.37-0.75] reduced.

The researchers found that a high beta carotene blood value compared with low blood value, the chances of getting bladder cancer significantly with 59% [95% CI = 0.05-0.78] reduced.

The researchers found that a high lutein and zeaxanthin blood value compared with low blood value, the chances of getting bladder cancer significantly with 50% [95% CI = 0.12-0.87] reduced.

The researchers concluded that a diet high in vitamin A or carotenoids the chances of getting bladder cancer probably reduced. Probably because the reduced risk in cohort studies was non-significant.

Original title:
Vitamin A and risk of bladder cancer: a meta-analysis of epidemiological studies by Tong, Wang RJ, [...], Chen Y.

Link:
http://www.wjso.com/content/pdf/1477-7819-12-130.pdf

Additional information about El Mondo:
The reduced risk found in cohort studies now weighs once heavier than found in patient-control studies because cohort studies less are more sensitive to errors that may affect the results. Find here more studies on carotenoids.