A study conducted by Kaiser Permanente researchers found that women diagnosed with early-stage breast cancer who eat full-fat dairy products after diagnosis are more likely to die from breast cancer than women who eat low-fat dairy products after being diagnosed.
The study, entitled “High- and Low-Fat Dairy Intake, Recurrence, and Mortality After Breast Cancer Diagnosis” was published by the Journal of the National Cancer Institute.
Researchers conducted the study to find out if eating full-fat dairy products increased the risk of cancer recurrence — cancer that returns after being diagnosed cancer-free. The full-fat dairy products used in the study included:
- Whole Milk
- Condensed or Evaporated Milk
- Ice Cream
The researchers followed nearly 1,900 women who had been diagnosed with early-stage breast cancer between 1997 and 2000. At the beginning of the study, the women completed a 120-question survey, including questions pertaining to the following:
- How often they ate dairy products during the previous year
- How large the serving size was when they ate dairy products
- What type of dairy products they ate
- Whether the dairy products were full-fat, 2%, 1% or non-fat/skim
Six years later, the researchers sent the exact same survey to all of the women who had completed it previously. About 1,500 of the women returned the second survey. These women were studied for another 12 years.
Low-fat milk and butter were the top dairy foods that the women reported eating most often. Overall, the women reported that they ate about 0.8 servings each day of low-fat dairy products, and about 0.5 servings each day of full-fat dairy products. During the follow-up, 349 of the women had a breast cancer recurrence, and 189 of the women died from breast cancer. A total of 372 of the women died from other causes.The study showed that the women who reported eating one or more servings per day of full-fat dairy products had a 64% higher risk of dying from any cause and a 49% higher risk of dying from breast cancer, compared to the women who ate fewer servings per day of full-fat dairy products or women who ate low-fat dairy products.
There was no association between the amount of low-fat dairy products eaten and breast cancer survival rates, and there was also no association between the risk of recurrence and the amount of full-fat dairy products eaten — the main reason for conducting the study.
What Does This Mean?
If you’ve followed along up until now, you might be thinking, “So what does the study actually tell us?” While the study doesn’t prove that full-fat fairy products cause breast cancer, it does show an association between full-fat dairy products and worse breast cancer outcomes (fatalities), suggesting that women who are diagnosed with breast cancer should take full-fat dairy products out of their diet.
If you or someone you know has been diagnosed with early-stage breast cancer, minimizing the risk of recurrence is vital to health and survival. Eating a healthy diet that’s low in processed foods and sugar, avoiding alcohol and smoking, maintaining a healthy weight and exercising regularly can help to reduce the risk of recurrence.