Introduction
Prostate cancer (PC) is one of the major health concerns among men
globally (1). It is presently the second most frequent diagnosed cancer
and the sixth leading cause of cancer death for males worldwide (2-5).
Among the Iranian males, PC is recognized as the third most prevalent
malignancies and the six common cancer in Iranian population (6, 7).
Based on the latest systematic review and meta-analysis on the available
evidence, the incidence rate of prostate cancer is 7.1 per 100 000 in
Iranian population. However, it has also been showed that the rate of
disease incidence increased from 1996 to 2012 that should be noticed
regarding the epidemiological and clinical practices (8). Well-known
risk factors for prostate cancer are age, ethnicity, and family history
of the disease (9). However, some other risk factors such as diet,
alcohol consumption, exposure to ultraviolet radiation, chronic
inflammation, and occupational exposure might be involved in the
pathogenesis of the disease(10).
The association between dietary patterns and the risk of PC has been
investigated in several studies, which has led to inconsistent results.
Some studies showed that adherence to a Western dietary pattern could
increase the risk of prostate cancer (11-15), but others did not find
any associations (16-18). In addition, some studies showed inconsistent
findings about the association between healthy eating index and
Mediterranean dietary pattern and the risk of PC (11, 13, 14, 16-23).
Recently, the importance of dietary acid load is highlighted as the
evidence shows that dietary intake is a key factor in the regulation of
body’s acid-base status (24, 25) and the kidneys are the main route of
excretion of the acid load to maintain acid-base balance (26).
Basically, it seems that western diets (with higher meat consumption),
and healthy diets (with higher fruits and vegetables consumption and
lower meat and processed grain intake) are associated with the acidic
and alkali status of the diets, respectively (25, 27). In order to
estimate dietary acid load, the potential renal acid load (PRAL) and the
net endogenous acid production (NEAP), calculate from dietary intake
(24, 28). The association between dietary acid load and several
cardiovascular risk factors has been investigated previously
(29-33). However, few studies investigated the association
between diet-dependent acid load with cancer (34, 35). Therefore, we
aimed to investigate the association between diet-dependent acid load
and risk of PC in Iranian population.