I’ll be back on the Dr. Oz Show today talking about ovarian cancer prevention with Dr. Oz and Dr. Diljeet Singh. As with many cancers, we talked about the risk of being overweight. My thanks to Dr. Oz and his team for inviting me to talk about this important topic!
After a two week vacation from this blog and my twitter account (only half of which was because I was actually on vacation!), I came back today with a guest post over at AICR. Hop over and join the conversation about what cancer screening strategies are available for prevention.
Today marks the start of National Women’s Health Week – a fantastic initiative that brings together all kinds of different groups around important issues for women, like physical activity and self-care! I have the huge honor of guest blogging about women’s cancers over at the American Institute for Cancer Research (AICR) blog today. AICR is the amazing group behind the reports on nutrition, physical activity and obesity and cancer. The report, which undergoes continuous updating as new science emerges, is an incredibly comprehensive expert review of the science around food, exercise, weight and cancer.
Check it out the blog and the report!
I saw a post on Twitter recently from Jody (@jodyms), who was so excited to be able to participate in a cancer research trial. And I was thrilled to see it. There is a lot of bad information out there about research. And, yes, there is still too much weak scientific research going on and we haven’t fully accounted for the unethical research practices of our past. But here’s why we shouldn’t throw the baby out with the bath water.
There is lots of research out there that can help you.
I’m going to do something that may not be really popular, or good for my career, but let me explain how I’d talk to my mom and her friends about participating in research. Let’s say one of the ladies in my mom’s yoga group, Barb, was approached about participating in a 6 month weight loss trial. Women of her age and menopausal status are a popular demographic for these kinds of studies that promise 10% body weight loss (or more) in a fairly short time with an intense tightly controlled dietary regimen. They’ll measure all kinds of physiologic changes. And this kind of science is valuable – it might provide clues to what happens in the body when weight changes – helping us better understand why weight changes lead to disease risk changes. Or, as I’ve seen in plenty of grant applications, identify the physiologic or molecular target that we can put a drug on to get the benefit of weight loss for health, without the work of losing weight. We need people who will participate in trials like these – they are important for advancing science. But is there a real benefit for Barb? Honestly, maybe not much. The study isn’t interested in helping Barb make better, healthier, choices. They aren’t including the behavioral strategies she needs to achieve long term weight loss. That’s not their goal. (Harsh? yes. True? pretty much.) So when the study is over, Barb will go back to living her life and the weight will likely come back. (You can say maybe not, but I can pull a pile of studies that show this is what happens – achieving short term weight loss is relatively easy in science, keeping it off is not. Most people gain the weight back, and then some – so they are worse off.) And it turns out, weight cycling is actually not good for your health. Maybe participating in that study does more harm than good for Barb.
But what if Barb was approached about participating in a weight maintenance study? Honestly, it would probably sound a whole lot less appealing to Barb, who’d like to lose a little weight. But the weight maintenance study is focused on helping Barb make long term changes in her life. Those that are durable. Durability is what matters for your risk of heart disease, diabetes and cancer. Is Barb going to see a benefit from participating in this study? Yup. Because even if she doesn’t lose any weight, if she doesn’t gain any weight, she’s better off. The reality is there all kinds of in between and Barb needs to know what she’s getting and what she’s not getting.
I’m not saying people shouldn’t participate in trials that provide them with no direct personal benefit. The generous men and women who have knowingly volunteered to do so have advanced science in countless, critical ways. My lab does BOTH kinds of studies. We ask people to complete surveys during their cancer care that will provide us with important information to identify intervention targets and it won’t directly benefit the men and women who complete those surveys. But there is also science out there that can benefit the participants, directly, and we do this science too. If you aren’t willing to do the former, you might be willing to do the later. If you’re asked to participate in a research study, ask the questions and find out more before you say no. It might be a study that helps us advance science or it might be one that helps you AND advances science.
I caught a story on NPR’s Morning Edition that made me do a double take. Thanks to a new book, the decades old concept of getting 10,000 steps per day, as measured by a pedometer, is getting headlines. This is great because pedometers have underpinned health research, including that in my lab, for years. The NPR story argues the 10,000 step metric is wrong and we should focus on getting 30 minutes of moderate intensity walking (enough to ramp up yor heart rate) five days a week (150 minutes/week). So which one is right? How do you know if you’re doing enough? Turns out they are both right.
There is lots of evidence that people who get, on average, 30 minutes a day of walking, have lower rates of heart disease, diabetes, stroke and some cancers. But most of that science hasn’t specifically studied 30 minutes per day. Some of the people who expended that amount of energy did so by doing more intense activity for less time, or for a longer time on fewer days. Does that make the 30 minute recommendation wrong? No! But it also isn’t the only way. And remember that doing more is even better in those studies. We call it a dose response – up the dose and you up the response ( in this case, lower the risk). And that’s why the recommendation is actually no longer 30 minutes for 5 days, but 30 minutes for most days – ideally ALL days.
Now what about those 10,000 steps I’ve been recording on my pedometer? In the NPR story, they said you have to walk 5 miles to get there and it takes 2 hours to get it – four times that 30 minute walk. Do the steps mean nothing? Or do you need to do so much more if you are using the step metric instead of the time one? Goodness no. On BOTH.
The recommendations comes from much of the same science. Here’s the science (& math). The average healthy adult gets between 6000 and 8500 steps per day just going about her daily life (those who are sedentary or suffering from a chronic disease get 3500 to 5000 steps per day and younger adults more like 7-13,000 steps). A brisk 30 minute walk accumulates about 3-4000 steps. So an average adult going about her day who adds a 30 minute walk would get about 10,000 steps per day. Making the recommendations about the same.
The benefit of the 10,000 steps per day recommendation is that it merges two distinct, but important concepts in science – being active and not being sedentary. It turns out, regardless of how much exercise you get, people who sit more are at higher risk for disease. So a person who is sedentary (getting 3500 steps per day) who adds a 30 minute walk will be at about 7000 steps per day. Is this person better off, healthwise, than the one who didn’t take the walk? ABSOLUTELY. But is he doing as well as the person who doesn’t sit all day AND gets a 30 minute walk? Nope.
Think about it like this. If you drive to work and sit around the office all day, drive home, heat up dinner in the microwave and sit around for the rest of the evening (whether you are reading or watching TV provided you aren’t snacking, it doesn’t matter for the purposes of this example), you might get only 2500 steps the whole day. I know this because I’ve had days like that. Even if I add a 30 minute walk in there, I’m still largely sedentary. But if I walk to the train and make an effort to go down the hall to discuss a project with my colleague instead of emailing her, if I get up and pace the hallway for a minute instead of checking the ESPN headlines, I’m over 5000 steps, maybe even 6000 steps before I even take a purposeful walk.
The pedometer also keeps people honest. We don’t intentionally lie to ourselves about these things, but that 6 minute walk to and from the train becomes 10 each way and the 10 minute walk with the dog becomes a walk, not 2 minutes of walking and 8 minutes of standing around during sniffing and stuff. Suddenly, 15 minutes is 30. But the steps are steps.
The ideal is both an active day and purposeful walking. Not either or. And saying the former is better ignores the science about the dangers of sitting. Which shows not moving all day is bad, regardless of our exercise. And if you read between the lines, the NPR story says as much, since their expert advocates for walking meetings, which might not be vigorous enough to “count” toward that 30 minutes of moderate intensity exercise the science says we need to reduce chronic disease risk. Remember, it isn’t a 30 minute leisure stroll!
So if you’re taking a 30 minute walk and your pedometer is only at 6000 steps at bedtime – is that a failure? No. In our research, we know to tailor the goal to the audience. And thanks to our understanding g of dose response, we know there’s a benefit to something over nothing.
In our cancer prevention segment on activity we introduced Virginia. She’s closer to a 6-8000 steps per day person some days after our intervention (But working hard to keep doing more!). But her blood pressure is down and her glucose regulation is better. Do I think our intervention didn’t work because she didn’t hit 10,000 steps? Not even close. Because the other thing about that step counting helps is the durability. More than a year after the intervention ended, she’s still walking and counting steps. The pedometer gives her credit for what she does – she knows more is better but we also know something is better than nothing! And for chronic diseases we know it is long term behavior change that matters most.
Limiting red meat intake is one of the key messages I talk about for cancer prevention. Red meat significantly increases risk of colon cancer and may also increase risk of lung, esophageal, stomach and pancreatic cancers. We aren’t exactly sure why (and it probably varies for different diseases). One possible reason are the risks associated with eating charred meat in particular (which I talked about in this video that significantly decreased the number of invitations I get to holiday BBQs!).
But, as with many of the things you can do to lower your cancer risk, eating less red meat isn’t just about cancer. Eating red meat also increases your risk of heart disease and diabetes. The good news is that making a simple switch can change that risk. Faculty Harvard recently reported that replacing just one serving a day of red meat with nuts, low fat dairy or whole grains can lower diabetes risk.
What does this add to our knowledge? We’ve known that red and processed meats increase disease risk and the Harvard data adds to that, but few studies have been able to examine the effect of changing the risky behavior. The Harvard study modeled the change to see what happened to diabetes risk. And risk went down.
So what’s the take home message? Regardless of what you’ve been doing to now, you can change what you’re doing and change your risk. So go nuts for nuts (or whole grains).
