Do you take your coffee with milk, or eat cereal with milk every morning? Many women do, but according to new research, including cow’s milk in your diet daily may not be as good for you as you’d expect, dramatically increasing women’s risk of breast cancer. Here we will review previous and recent research on the link of breast cancer and cow’s milk to help you make up your mind whether or not adding milk to your diet is right for you.
The Health Effects of Milk
The debate over milk is a long one, and with the newest research in mind, we think it will only become more complex with time. Milk is an easily accessible nutritious food, full of proteins and essential nutrients, such as calcium, potassium, and vitamins A and B12. This is why, to this day, The Dietary Guidelines for Americans continue recommending 3 cups of low-fat or fat-free milk and dairy foods daily for everyone past the age of 9 years.
However, research seems to reveal a more nuanced picture: similarly to many foods, cow’s milk is beneficial to some people (e.g. kids, depression sufferers) while triggering sensitivities and worsening certain conditions in others (e.g. acne sufferers, adult, and older women), especially when consumed in excess. We have previously discussed this topic in detail in the article The Health Benefits and Dangers of Drinking Cow's Milk.
Meanwhile, in this article, we’ll focus on a topic we haven’t covered before, a specific condition that was recently correlated with daily milk consumption - breast cancer. According to a 2020 study from Loma Linda University School of Public Health, cow’s milk increases the risk of breast cancer by as much as 80%, but soy milk, cheese, and yogurt don’t.
Daily Milk Consumption and Breast Cancer
Interestingly, the previously-mentioned study initially set out to explore how soy milk may influence the development of breast cancer since previous studies suggested there might be a correlation between soy milk and breast cancer. Mid-way through the study, the researchers realized they had to adjust their analysis, as the positive correlation was not linked to soy milk, but rather to dairy milk.
This new study was observational, looking at 52,795 women of the average age of 57 over the course of 8 years. At the beginning of the study, none of the women exhibited any signs of breast cancer, but throughout the follow-up period, 1,057 of them developed breast cancer. Half of all the participants were vegetarian and drank soy milk, whereas the other half drank dairy milk.
The results of the study were just as surprising to the researchers themselves as they were to the public. Drinking only 1 cup of dairy milk daily (irrespective of the fat content of the milk) was associated with a 50% increase in breast cancer risk, and drinking 2-3 cups yielded a 70-80% increased risk.
These findings are not particularly consistent with previous findings, as another research article from 2017 investigating the link between milk and breast cancer actually found no correlation, though other smaller studies did find an increased, but also decreased risk. Do keep in mind, though, that none of these previous studies actually contrasted dairy milk consumption with plant alternatives, which is a meaningful distinction that certainly adds credibility to the 2020 Loma Linda study.
What About Soy Milk and Other Dairy Products?
The takeaway message is clear - adult women should certainly be aware of the amount of dairy milk they consume and maybe try not to stick to the recommended 3 cups a day, especially if anyone in your family had suffered from breast cancer.
What about other types of dairy and soy milk?
The 2020 Loma Linda study concluded that soy milk, yogurt, and cheese didn't increase the risk of breast cancer in their participants. In addition, the other study we linked from 2017 found that plain white yogurt actually lowered the risk of breast cancer in their participants, while American cheddar and cream cheeses actually increased the risk of the disease.
To sum up, the most recent research suggests that maybe it's worth drinking as little dairy milk as possible for women. So, maybe add yogurt to the morning cereal and opt for plant-based milk instead of dairy milk in your coffee, after all.