Doctors are now petitioning the FDA to put a breast cancer warning label on cheese.
As a result of the paleo and keto diets, patients come to me thinking that dairy is an inherently inflammatory food that should be totally removed from their diet.
The fear-mongering that we’re constantly exposed to around our nutrition and health needs to stop.
How are we supposed to tell what’s true and what’s not?
I’ll debunk some of the myths the petition brings up about dairy, and address the reporting of scientific studies in our current internet information age.
I’m going to give you an extremely valuable tool to start looking at health research in a totally different way.
Less fear more understanding.
Here are the questions and thoughts I have when articles like this petition are published:
#1 Correlation is not causation
All studies done on dairy and cancer risk are correlative, NOT causative.
Correlation means there is a relationship between two variables: in this case relative breast cancer risk and dairy. The variables influence each other; we see one increase while the other decreases, or both increase, or both decrease.
A correlation describes the size and direction of a relationship between two or more variables.
Here’s the crux: it DOES NOT mean that the change in one variable is the cause of the change in the other variable. That, my friends, is called causation and is not relevant here.
Studies on diet and cancer risk have to be correlative. There are way too many variables in a person’s diet and lifestyle to rule them all out.
Many studies try to control for a few factors like age, race, body mass index, family history, and more, which means they account for those differences in their statistical analysis.
I’m guessing you see some gaps between those factors they’ve chosen to control for. That there are probably a few more things you might do or be exposed to in your lifetime that influences cancer risk.
Some variables that I always think about that are not typically controlled for:
- Sleep quality
- Organic vs conventional diet choices
- Environmental exposure to endocrine-disrupting chemicals like phthlates
- Stress levels
- Exercise frequency and enjoyment
- Meaningful/satisfying work
- Water intake
All of these massively influence your overall health and wellness. Studies just can’t (or don’t yet) control for all of these factors.
It’s important to know when evaluating studies making large correlations like this one that there’s a lot of wiggle room in the variables that aren’t accounted for.
Ok, so studies aren’t perfect (more on that in my next few points).
The real trouble is when we get into health articles reporting on these studies, breaking down the information into a more consumable format.
It’s easy to get swept into thinking that that dairy is THE cause or even a significant cause of increased breast cancer risk when you read articles like this petition I’m currently having a cow over (pun intended).
Headlines for health articles often try to snag our minds with sensational reporting because it gets them more clicks and more eyeballs consuming their content. And most folks don’t know how to sift through the article or even the original research study to see what’s actually true.
#2 The cause of cancer is multifactorial
We can’t just point our finger at one thing, remove it or change it, then expect to be home free. Many variables are at play. But the sensationalization of health that we see daily makes us believe that we can. If we take one pill or supplement or find the one magic bullet we’ll absolve ourselves of risk.
It’s wonderful to be informed and proactive about your health. To do your research, make smart choices, and reduce your risk wherever you can.
It’s just not realistic to believe that making one change will be the answer.
And that’s actually pretty awesome.
You get to investigate lots of areas of your health, become more educated, and learn how to care for yourself more deeply!
#3 The quality of the dairy isn’t addressed
This is another variable that is widely unaccounted for in food vs cancer studies.
There is a growing body of research that supports the idea that organic fruits and vegetables are more nutritious and health-supportive for us than conventional products.
It’s always important to ask if the study in question took into account organic vs conventional growing conditions.
When animal products like dairy are concerned, it’s also important to ask if the animals were grass fed or conventionally fed, as we know grass fed dairy and meat is higher in healthy omega-3 fats, among other beneficial things.
Conventionally raised cows have a lower quality of life and are constantly shot with antibiotics that show up in their milk. Effects on human health are still to be determined, but my money is on the fact that getting dosed with antibiotics in milk isn’t good for us.
#4 What about hormones in dairy?
Some people get worked up about the estrogens that naturally occur in cow’s milk. These estrogens are not the issue. The estrogen-like effects of phthalates are a much bigger concern, but studies haven’t gotten sophisticated enough to address this variable.
Phthalates are a type of xenoestrogens, meaning they are about 100x more potent than your own! Yikes.
If the cow is mechanically milked, flexible plastic tubing is used. We know this tubing contains phthalates that are hazardous to human health. Warm milk + plastic tubing and/or a plastic container for the milk = chemicals leaching into your milk.
Yes, unfortunately this means that organic, grass-fed cow milk will be exposed to phthalates if they are mechanically milked. And most are.
The best known example of a phthalate is BPA, or bisphenol A. BPA is an endocrine disruptor that can bind to hormone receptors for your thyroid hormone, androgens (like testosterone) and estrogens. Now that sounds like more of a cancer risk to me than naturally occurring estrogens.
Check out this detailed, well-researched article for more info about hormones in milk, including how milk affects IGF-1, or insulin-like growth factor (a hot topic in cancer risk and prevention these days). He doesn’t take into account the xenoestrogens/phthalates I mentioned above, but that’s also because there’s little to no research on them in dairy.
#5 How is the dairy processed?
What happens to that dairy AFTER the cows are milked? The article in question mentions that a 2017 study found women who consumed the most American, cheddar, and cream cheese had a 53% increased risk for breast cancer. This is terrible reporting. More on that in #6.
These cheeses are among the most processed forms of dairy out there, especially American cheese. So what else is in these products that our bodies might not be liking? Weird additives and preservatives? Ultra pasteurization that kills beneficial enzymes and nutrients?
More variables to account for!
#6 The importance of relative risk and odds ratio
I really want to address that 53% increased risk in breast cancer stated by the Physicians Committee for Responsible Medicine for consuming those specific types of cheeses.
Here’s the issue with most health research statistics: they’re often twisted to make them sound like a much bigger deal than they actually are.
I want to teach you how to know what’s really going on.
If we look at the ACTUAL STUDY, we see that the risk is very different than what the article portrayed.
Let me break it down for you.
Eating these foods DOES NOT mean that you are now 53% more likely to get breast cancer.
To find out what it actually means, we need to look into a bit of statistics. I know you’re excited.
If you want to nerd out and learn about the complex intricacies of OR (odds ratio, cited in this study) and RR (relative risk, a similar but not quite the same concept), check this out.
I’ll try to keep it short and sweet.
If we look at the actual study, we see that the odds ratio for eating these cheeses and breast cancer development is 1.53.
That means we’re increasing the odds of getting breast cancer by 53%.
Now we have to compare this to our lifetime risk* of breast cancer.
*I chose lifetime risk, rather than risk by age because this study controls for age.
For American women, the lifetime risk is about 1 in 8, or 12.5%.
Now it’s time to do some simple math.
To find out your relative risk, multiple that 12.5% by 1.53.
So we see that 0.125 x 1.53 = 19.1%.
According to this correlative study, your chances of developing breast cancer over your lifetime went up by 6.6% if you consume large amounts of American, cheddar, and cream cheeses. Not 53%.
Ok, before you swear off cheese all together, check this out.
This same study reported a 39% DECREASE in risk if you eat yogurt regularly.
So let’s do the math!
0.125 x 0.61 = 7.6%.
So by eating yogurt, you’ve decreased your chances of developing breast cancer over your lifetime by 4.9%.
And by the way, this study also says that total dairy intake was associated with 15% LOWER RISK in breast cancer overall, which equates to about a 1.1% decrease in relative risk.
For a deeper explanation of relative risk and how to interpret these numbers, check out this super helpful article.
In short, the Physicians Committee for Responsible Medicine WAS NOT responsible in their statistics reporting.
This type of fear-mongering is rampant in studies about our health.
It leaves us terrified and not knowing what to believe.
Understanding how to interpret these findings is super important and it’s often best to go to the source itself (the study) and check it out yourself.
Anything related to our diet and cancer risk has a long way to go in terms of creating a more accurate picture.
In this one study alone we say an 11.5% swing in relative cancer risk just based on the type of dairy you ate (American cheese vs yogurt).
That kind of variability makes me raise an eyebrow and question the validity of the whole study.
It’s important to educate ourselves, but it’s also important to be aware of the mass of other factors at play that the research just isn’t accounting for yet.
So what should I understand about dairy and my health?
Here are some facts to hang your hat on!
#1 Get organic, grass-fed dairy
Minimize the crap your body has to deal with processing and detoxing whenever you can.
#2 Be concerned about the phthalate levels in dairy products, even the organic ones
Organic dairies mechanically milk cows and use plastic tubing. If you can find someone who milks by hand and stores the milk in glass bottles, woohoo! This person is a unicorn. Never let them go!
To be responsible consumers, start respectful having conversations with the dairies you buy from. This is a complex and difficult topic, as modern dairy farming is built around mechanical milking with plastic tubing. But the more we educate and advocate for ourselves, the more likely things are to change.
#3 Dairy isn’t great for everyone
Some people are dairy intolerant, meaning they really can’t break dairy down in their digestive tracts.
Some people, like myself, can digest A2 casein only. Dairy in the US is almost entirely A1 casein. For more information on A1/A2 casein proteins check out this article where I give you all the details!
Both of these issues can cause gut problems like heartburn, gas and bloating, diarrhea or constipation, or can lead to so much irritation that leaky gut develops, causing symptoms to appear in other body systems.
No bueno.
This inflammation and irritation over time is much more concerning than naturally occurring hormones in milk.
If you’re not sure if you’re sensitive to dairy, the best way to check is to remove it entirely (milk, butter, ice cream, all the cheeses, etc.) for at least 3 weeks, then add it back in by eating a fair amount of it! For more guidance grab my cheatsheet on reintroducing foods into your diet.
The most important point here is that your nutritional choices need to be personalized to you.
If you don’t do well with a food, leave it out of your diet!
If you think you’re ok with it, try to find the best quality version of it you can for great health prevention and maintenance.
If you’re not sure, try an elimination diet or enlist a professional to help you through complex and confusing food choices that are out there nowadays.
No study will ever be a better barometer than your own body.
