Increased dairy intake associated with increased risk of prostate cancer

Men with high intakes of dairy products, especially milk, are at significantly higher risk of prostate cancer than men with low intakes, according to a new study conducted by researchers at Loma Linda University Health. .. This study found no such association between increased risk of prostate cancer and calcium intake in non-dairy products, and found that substances other than calcium are involved in the risk of breast cancer in breast cancer. Suggests.

Our findings add significant weight to other dairy-related evidence, not non-dairy calcium, as a correctable risk factor for prostate cancer... “

Gary Fraser, MBChB, PhD, Principal Investigator and Professor, Faculty of Medicine and Public Health, Loma Linda University

The results of this study show that men who consumed about 430 grams of dairy products (1¾ cup of milk) per day compared to men who consumed only 20.2 grams of dairy products (1/2 cup of milk) per day. It reveals that the risk of prostate cancer has increased by 25% per week). Men who consumed about 430 grams of dairy products per day also faced an even greater increased risk compared to men who consumed zero dairy products.

Fraser said the variability in results was minimal when comparing the intakes of whole-fat milk with lean or non-fat milk. No significant association between cheese and yogurt has been reported.

Fraser and co-authors today published a study entitled “Dairy Products, Calcium Intake, and Risk of Developing Prostate Cancer in the Adventist Health Study-2.” American Journal of Clinical Nutrition.

The study evaluated the dietary intake of more than 28,000 North American men who were widely exposed to dairy products and calcium, all of which were initially free of cancer. Dietary intake was estimated from the Food Intake Frequency Questionnaire (FFQ) and 24-hour repetitive recalls. The baseline questionnaire included demographics, family history of prostate cancer, physical activity, alcohol consumption, prostate cancer screening, and BMI.

The researchers then used the cancer status registry to track participants’ prostate cancer status for an average of nearly eight years. By the end of the study period, the State Cancer Registry reported 1,254 new cases of prostate cancer among participants during follow-up.

As part of the analysis, Fraser and co-authors derived non-dairy calcium intake (from nuts, seeds, Brassicaceae and other green vegetables, legumes, fruits, and fortified cereals) from dairy intake. Said it was separated. They used a statistical model to focus on dairy intake, regardless of other factors such as non-dairy calcium intake, prostate cancer family history, race, and age.

The large and diverse nature of the cohort put the research authors in a strong position to assess these differences, Fraser said. “Our study cohort showed large disparities and differences in dairy intake and calcium levels, so we were able to ask questions with extraordinary strength.”

One interesting factor to note, according to Fraser, is that the results did not show a uniform increase in risk in men with gradual increases in dairy intake. In other words, increasing dairy intake by 50 grams did not provide the same increased risk as the portion grew larger.

“Most of the ongoing increase in risk occurs by the time we reach 150 grams, which is about two-thirds of a glass of milk per day,” Fraser said. “It’s as if the biological or biochemical pathway is saturated with about two-thirds of a glass of milk per day.”

Previous studies may have missed a curvilinear effect or uneven increase in risk between dairy consumption and prostate cancer if most of the participants had already drank one or more glasses of milk per day. There is sex. However, the cohort of this study allowed researchers to compare a wide range of dairy consumption, including very low levels.

The data provided little evidence of an association between calcium intake and accidental prostate cancer. “One interpretation is that dairy products, or some closely related unknown risk factors, are causally linked to the risk of prostate cancer,” the study said.

Fraser said a possible reason for these associations between prostate cancer and dairy products could be the sex hormone content of the dairy products. Up to 75% of lactating cows are pregnant and prostate cancer is a hormone-responsive cancer. In addition, previous reports have shown that intake of dairy products and other animal proteins and blood levels of insulin-like growth factor-1 (IGF-1), a hormone thought to promote certain cancers, including the prostate. High is associated.

A previous study of the Adventist Health Study-2 on the effects of dairy products on women’s breast cancer risk reported similar results in both non-uniform risk and risk magnitude associated with increased consumption levels, Fraser said. ..

“Similarities between us Breast cancer in women The one-year-old paper and this paper on men are impressive, “he said.” It seems that the same biological mechanism may be working. “

When further research investigated how it could increase the risk of breast cancer, Fraser clarified this for wise men with a family history of prostate cancer or other risk factors.

“If you think you’re at higher risk than average, consider milk alternatives other than soy, oats, cashew nuts, and other dairy products,” he said.

This study is part of the Adventist Health Study-2, a long-term health study that investigates the relationship between lifestyle, diet, and illness among members of the Seventh-day Adventist Church. The Adventist Health Study is partially funded by the generosity of the Ardmore Institute of Health.