Nutrition Myths, with Suzanne Dixon, MPH, MS, RDN and Annette Goldberg, MS, MBA, RDN, LDN

June 16, 2016
Download MP3 (30.35 MB/33:09)

n today’s podcast, Suzanne Dixon and Annette Goldberg discuss and dispel several common myths about nutrition and cancer.  Suzanne Dixon is a Registered Dietitian and Epidemiologist, with a nutrition and research consulting business in Portland, Oregon. Annette Goldberg is an Outpatient Dietitian at the Boston Medical Center Cancer Care Center.

Transcript: 

 [music]

ASCO: You're listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, knows as ASCO, the world's leading professional organization for doctors that care for people with cancer.

In today's podcast Suzanne Dixon and Annette Goldberg discuss, and dispel, several common myths about nutrition and cancer. Suzanne Dixon is a registered dietitian and epidemiologist with a nutrition and research consulting business in Portland, Oregon. Annette Goldberg is an out-patient dietitian at the Boston Medical Center Cancer Care Center. ASCO would like to thank Ms. Dixon and Ms. Goldberg for discussing this topic.

Annette Goldberg: Hi, my name is Annette Goldberg. I am registered dietitian, working at Boston Medical Center Cancer Care Center. BMC is a 500 bed medical center located in Boston South End and is the largest safety net hospital in the area. Therefore, the patient population is quite diverse, and for me very inspiring. And please let me introduce my colleague, Suzanne Dixon.

Suzanne Dixon: Thank you, Annette. My name is Suzanne. And I am a registered dietitian and an epidemiologist with a nutrition and research consulting business in Portland, Oregon. Like you, Annette, I have a long history of working in cancer care, including time as the Director of the Outpatient Oncology Nutrition Program at the University of Michigan Cancer Center. I'm passionate about providing accurate information about nutrition and cancer that is based on facts, not fear.

Annette Goldberg: Suzanne, with the abundance of information and misinformation available through the media and internet, myths develop around nutrition and cancer. I'm sure you hear them every day as you work with patients. What are some of the myths you hear frequently?

Suzanne Dixon: You're absolutely right Annette, there are dozens of cancer and nutrition myths, and unfortunately many of these myths focus on food the person either must eat, or must avoid after a cancer diagnosis. And all this can lead to confusion and fear for people who are affected by cancer. So I've had a lot of questions lately about juicing, and it's interesting because this question can fall at opposite ends of the spectrum. Some myths around juicing and cancer fall along the lines of how juicing needs to be avoided, because juice can have too many carbohydrates, or sugar in it. And, on the opposite side are people who promote juicing as a cure-all for cancer. The truth is, as with many nutrition myths, somewhere in the middle. Juicing is obviously not going to cause or cure cancer. I know we're going to touch on a number of myths on sugar and cancer in a few minutes, so we can save that for later. But regarding the potential benefits of juicing, there are some ways people can enjoy the benefits of fresh, or homemade juice, but also make sure that juice doesn't displace healthy whole foods like fruits and vegetables, or add excess calories that can contribute to unhealthy weight gain.

So if a person wants to juice, or try juicing, there's a few tips you can follow. It can be a great way to add more servings of vegetables and fruit to an already healthy diet, but it really shouldn't be used to meet basic nutrition needs. Juicing significantly reduces the amount of fiber you get from vegetables and fruits, so you want to start by eating fruits and vegetables whole first. So if you currently do eat five or more fruits or vegetables every day, then juicing could boost your intake of these foods further, can be healthy and remember that a serving ranges from one half cup to one cup of chopped vegetables of fruits. So your first five servings of vegetables and fruit, at a minimum, should come from whole foods, not from juice. If you're not meeting that five a day goal, do that first. Once you establish, and stick to that habit, of having five servings of fruits and vegetables per day, you can add in some juicing. If you want to juice, focus on vegetables more than fruit. It's easy to overdo it on the calories if you just use fruit. So you might try cucumbers, celery, beets, and then just add a chunk of apple, or orange for sweetness, and think about drinking what you might eat.

Most people would never sit down and eat ten raw carrots in one sitting, those big, long, huge carrots, so you shouldn't really drink that amount either. You don't need a lot of juice because juice packs a nutritional punch. So don't feel like you have to have a full eight or twelve ounce serving. If you juice just a cucumber, a carrot, and a beet, it's just somewhere around probably four or six ounces, and that's plenty. Also, embrace variety. For the most nutritional benefit, you don't want the same vegetables over and over, and that's true for eating and for juicing. Maybe one day you enjoy carrot, apple, ginger juice, and the next day you try beet and celery. Then you go for kale and cucumber, and the important point is to mix it up. Don't overdo it on juicing cruciferous vegetables. So that's things like broccoli, kale, chard, mustard greens, cauliflower, bok choy, and a few other vegetables.

Believe it or not, you really can get too much of a good thing. So cruciferous vegetables in particular can get contain nutrients that can block the absorption, and the body's use of some important minerals. So when you eat just a serving or two a day, that's really not a problem and you get all the health benefits with no downside. But for example, if you juice the equivalent of two pounds of broccoli, or a pound of kale every day, you really can create nutritional imbalances in the body. So again, variety and moderation when it comes to healthful juicing. And finally, keep in mind that if you are immune-compromised, due to your cancer treatment, this is something that your healthcare team might refer to as being neutropenic, or having a low white blood cell count. Be sure to ask your doctor, or dietician, before you consume raw foods and vegetables, and that includes unpasteurized juices. Most of these foods are safe, even for people going through cancer treatment, but some foods can't be cleaned or peeled very easily, and may need to be avoided for a short time if you're not functioning very well due to cancer treatment.

So Annette, I have been getting a lot of information and questions lately about soy, and soy being a popular cancer nutrition myth. How do you clarify the concerns for people who are concerned whether soy is good for you, or not good for you, and how much you might want to eat?

Annette Goldberg: Suzanne, I'm constantly surprised at how frequently the soy question pops up. It's a myth that's been around for awhile, and continues to come around, and around again. I'd like to take a few moments to reinforce to the group that a media blip on one research study, performed on mice, doesn't necessarily translate into evidence-based practice. I think most of the hospitals try to follow an evidence-based practice guideline. I think media snippets create confusion among our consumers and patients. It usually requires many, many studies that have been scrutinized and approved by the appropriate medical boards before recommendations become accepted practice. This is the basis for the phrase, "evidence-based practice." There are no evidence-based guidelines stating that you should eat soy, and soy prevents cancer, or that you should not eat soy, that it causes cancer.

So why have soy and soy products caused so much confusion? I think it's because soy foods can change phytoestrogens. And these are phytonutrients, or compounds, within food that have an estrogen-like chemical structure. And this is where the term phytoestrogen originated. However, phytoestrogens are not the same thing as female, or human estrogens, and soy foods do not contain human estrogen. The concern about phytoestrogen stems from research that was done in test tubes and on animals. Earlier study suggests the conflicting information, but we do know that in Japan and China, where soy foods are consumed regularly, over their life-span people tend to have a lower, not higher, risk of hormone-related cancer such as breast, ovarian, and prostate cancer. These mixed results obviously cause a lot of confusion.

Soy foods can be classified into three categories.  There's your whole soy food, such as soy beans and edamame. And there's derivatives of soy beans such as soy milk, soy cheese, tofu. And then there's concentrated soy products, such as any soy supplement you would buy at the drug store, or soy isolate. And soy beans are an excellent source of high quality soy protein, isoflavones, dietary fiber, potassium and folic acid. They contain no cholesterol, little to no saturated fat, and are a good source of essential fatty acids. So the bottom-line is. I like to express to the patients, when reviewing human studies, which reflect our everyday life, the American Cancer Society and the American Institute for Cancer Research, two well respected cancer organizations, have determined it is safe to consume one to two servings of soy foods per day. Whole soy food such as tofu and edamame are preferred, while soy supplements, and soy isolates are not advised. So it's perfectly safe to enjoy soy if you like soy, go ahead and eat it. And if you don't like soy you don't have to eat it. Suzanne, when a new diet book hits the stands I usually have to brace myself. I'm confident it won't be long before I'm asked for my thoughts on how that diet may affect cancer prevention, or how I should use this diet during my cancer treatment? How do you address the myths around specific diets and cancer prevention or survivorship?

Suzanne Dixon: I know what you mean I hear about crazy diets every single day, just from everything. In the media, from patients, from neighbors and friends, and there are a couple of important things to keep in mind when you're trying to evaluate specific diet in cancer. And the first thing is that when it comes to cancer prevention, the type of diet that seems best for reducing risk, is a plant-based diet. So what do I mean by a plant based diet? Many people think it has to be a vegetarian, or a vegan diet, but that's not necessarily true. A plant-based diet just means a majority of what you eat comes from minimally processed whole plant foods. So that would include things such as vegetables, legumes, which is peas, beans and lentils, nuts and seeds, fruit and whole grains. A smaller portion of your diet can come from animal foods. And so for a healthy cancer risk reducing plant based diet, consider your plate. This is a great place to start because everybody can picture what a plate looks like. And when you sit down to eat, about two thirds, to three quarters of your plate, should be covered by plant foods. And make those-- in particular some green leafy vegetables, legumes, and other colorful vegetables and fruits.

And then the other one quarter, to one third, will contain lean protein and starchy vegetables, or grains. And that might be fish, chicken, lean red meat, and potatoes, or rice. Or if a person does favor a vegetarian diet, you could use legumes, or dairy and eggs for your protein. So examples of plaint based diets include the Mediterranean diet, and there's also the Okinawa diet, which is an island off in Japan, where people tend to have a lot of longevity. They live a long time and don't get a lot of cancer, or heart disease. So those types of diets are very helpful. So for cancer survivors, one of the most important things to keep in mind is that there's no one-size-fits-all for optimal cancer survivorship. So we know plant-based diets are great for cancer prevention, as far as survivorship, we also know that they can be good for people over the long-term. But we do know that some people that are in active cancer treatments, and with certain type of cancer, they're at a high risk of malnutrition, and something we call unintentional weight loss. Both of these things can make treatment really hard to tolerate and can worsen your symptoms and side effects. So in some cases, malnutrition can become serious enough to interfere with the ability of a person to receive their planned treatment. And of course that's never a good thing, because getting all of your planned treatments on time is critical to having the best possible outcome, which would be a cure, or good control of your cancer.

So in these cases, when people are having a lot of unintentional weight loss, we would recommend a high protein, high calorie diet to help that person regain strength, and rebuild their nutritional storage to better tolerate that treatment. So for other people, the opposite problem can occur, and that is they can struggle not to gain excess weight and body fat. Treatments can include things like steroids, which can lead to increased appetite and weight gain. Other treatments can lead to loss of lean tissue such as muscle and this can slow your metabolism. For these people we focus more on the type of diet that we'd recommend for cancer prevention, lots of healthy whole plant foods, and other ways of eating they can help a person feel full on fewer calories. And of course we'd want some good quality lean protein in there such as fish, chicken, lean meat and legumes. And if a person is able, and if their doctor has given them the okay to do so, we really do encourage moderate, regular physical activity such as walking, biking or swimming.

And if possible, resistance training to build and maintain strength. Again, we'd involve the entire medical team because we want to make sure it's safe for a person to add in that physical activity. Some people might have balance issues, or other problems that make being physically active a challenge, due to their cancer treatments, or other medical concerns. So we really might make a referral to a physical therapist, or even an exercise physiologist to help this person come up with a program that's safe and manageable. The thing that's interesting about that is, it might seem counter intuitive but getting some physical activity, and again we're not talking about running a marathon, or anything that extreme, but just simple regular walking can decrease fatigue. And, because fatigue is one of the top complaints of people going through cancer treatment, it's good to know that being more active can lessen that fatigue.

And finally, when it comes to diets during cancer, and after cancer treatment, we have patients that might be interested in trying newer experimental ways of eating, in order to bolster the effectiveness of treatment. And so for cancers that don't have a very good prognosis, maybe something like an aggressive brain tumor, or cancers that have spread to other parts of the body, some researchers are beginning to investigate using specific dietary approaches, in an attempt to make it harder for the cancer cells to continue growing. And try to make the treatments more effective, make the cancer cells more sensitive. One experimental approach you've probably heard about Annette, because I know I'm getting lots of questions about are the ketogenic diet. And a lot of people mistakenly believe it's just a low carb diet, or a low carbohydrate diet. But it's much beyond just simply cutting back on carbohydrates.

The classical ketogenic diet involves eating a diet in which there are about three to four grams of fat, for every one gram of carbohydrate, plus protein. In essence it's a very, very high fat diet with very low carbohydrate and protein. And so you're going to end up with a diet that's about 80% of calories coming from fat, which is quite extreme, and it really shouldn't be attempted without medical supervision and the help of a dietician. And what that diet is intended to do is to encourage the body to use fat, and ketones, for energy instead of carbohydrates. Ketones are something the body produces when it's burning mostly fat for energy, and the body can then use those products of fat metabolism as an additional energy source. And there's a lot of interest in using the ketogenic diet for people receiving, for example, for brain tumors, and this is because brain cells don't do real well operating just on fat and ketones for energy. Most of the cells in our body can do quite fine with carbohydrates, protein, fat, or ketones for energy, but the brain just tends to like carbohydrates.

So the theory is that if brain cells don't do that great without carbohydrates, brain cancer cells might also be sensitive to not having that source of energy. So drastically reducing that supply of glucose, or carbohydrate, to the brain, it's hoped that that could maybe slow, or help the growth of the tumor. But, again, it's really important to remember that this is a very experimental type of an approach. And also, because our brains don't do well with fat and ketones for energy, this type of diet, the ketogenic diet, can leave people feeling really foggy, fatigued or light-headed. And it also has very little carbohydrate, and pretty much no fiber, which can lead to constipation and other GI problems.

So for someone with, say, an incurable brain cancer, that could be a side effect that might be worth the price for giving it a chance to maybe control your tumor better. But we don't yet know if the diet works, and it's really just based on theory right now. But there's some good news in that there are lots of clinical trials ongoing. So we should know, probably within the next few years, if that type of a very extreme dietary approach, will improve outcomes in hard to treat cancers. And then, at the opposite end of the spectrum, we have lots of studies looking at low fat and vegan type diets to improve health, and hopefully reduce some of the recurrent-- in one example, the WINS study, or Women's Intervention Nutrition Study, which looked at comparing breast cancer survivors. A couple thousand women were followed, and randomized to follow either a really low fat diet, or just a standard healthy diet where approximately 30 to 35% of the calories would come from fat. So in this study, the women in the low fat group did manage to get their fat calories down to about 22 to 24% of their total calories. Which is a lot less than the 35% from the group that was just on the regular, standard diet. And what the researchers saw was that there was a 24%, non-significant reduction in recurrence of risk in women in the intervention group. And what I mean by non-significant is that statistically that could've been due to chance.

So we can't absolutely be certain the diet provided a survival benefit. But at least the change was in the right direction. In other words it looked like a reduction in that risk. But the exciting thing is, when the researchers looked at the results by tumor type, say ER positive versus ER negative breast cancers, they found a 42 % reduction in risk of occurrence in women with a history of ER negative breast cancers, who were on the low fat diet, when they compared those women with the ER negative breast cancers, who were following the usual, or control diet. And that was really statistically significant. And because ER negative breast cancers tend to be more aggressive, and harder to treat, that was an important finding, because it tells us that a low fat diet might be another way to give women an advantage for remaining cancer free, if they have one of these ER negative tumors. Dr. Dean Ornish, who is best known for his heart disease research, has been looking at low fat, vegan diets for men with prostate cancer. And he's looked at men who have prostate cancer in their body, but they're doing what's called a watchful waiting, or active surveillance.

So they're being followed by their doctors, but not receiving active treatment at that time. And he looked at a vegan diet, along with stress management, yoga, meditation, and things along those lines. And what he did find is that it improved their markers in the blood, what we call bio markers, in a direction that seemed to be favorable for preventing the cancer from growing and spreading. So compared with the men following a typical American diet, the men in the vegan group experienced slower increases in their blood PSA, or prostate specific antigen levels. So that was a very positive sign. So as you can see, there are a lot of ways that diet could be used to potentially improve those outcomes in people who have cancer. But unfortunately, at this point, we really aren't sure, with absolutely certainty, which diets are best for which tumor types. As I mentioned, the ketogenic diet could be good for certain tumors, like a brain tumor. While a low fat or vegan type diet seems to be better for some of what we call the lifestyle cancers, such as breast or prostate cancer.

And the most important takeaway, though, when you think about all of these fad diets and different diets that people might be interested in, is that there really is no one size fit's all for people diagnosed with cancer. And if you want to try a special diet you have to do your homework. Learn as much as you can about the pros and cons of each diet, and work with your doctor and a knowledgeable dietician to make sure you're meeting your nutrition needs during and after cancer treatment. So Annette, the vitamin and mineral supplement industry is a big business. It's probably at least as big, if not bigger, than the fad diet industry. And in 2011-- [chuckle] yeah, very true. US sales of all dietary supplements, so this is 2011, so we're talking already five years ago. But even back then, $30 billion with that industry. So we know that these supplements are big business, and many of the supplements are advertised that they can keep people healthy and maybe have cancer-fighting effects, or bolster the immune system. So how do you address the supplement and cancer nutrition myths?

Annette Goldberg: Suzanne, I was just speaking to a patient about this today. As you mentioned, the supplement industry is really big business, and I like to remind my patients that the supplement industry is not under the same FDA guidelines for testing, and ensuring the safety of their products, as the pharmaceutical industry is. So the supplement industry is self-regulated. When there are any issues, it's really up to the consumer to report these adverse effects. Then, if appropriate, the FDA will investigate. So there are many things out on the shelves that really have not been thoroughly investigated on how they will interact with anything that you eat, or certainly any treatment that you're undergoing. According to the oncology nutrition for clinical practice, 40% of the pharmaceutical products used in cancer treatment are derived from plants. And in addition, 30 plant-derived compounds are currently being investigated for use in cancer therapy. So there are many solutions that we actually have gained from our environment. But my concern is that there are many other active, but perhaps untested, plant compounds that are widely available in dietary supplements.

So you and I understand the concern. Supplements may affect the patient's treatment by influencing how their body metabolizes their treatment plan. You can increase, or decrease, the amount of a drug within the blood, and this can influence its therapeutic effect. This could possibly cause unexpected side effects, poor response to treatment or, even worse, hospitalization. So it's very critical to approach supplements with caution. Always speak to your oncology team before taking any supplement. I'm sure every dietitian is a little bit different, but I am very conservative with my approach to consuming vitamins, minerals and supplements, especially during treatment. I recommend patients to take only a multivitamin with no more than the RDA levels provided. And specific vitamins should be used only for determined deficiencies by your doctor. So many of us have a vitamin D deficiency,  some patients might have an iron deficiency, and when the doctor prescribes those, then it's quite all right. They've already considered all the interactions and the treatment that the patient is going through. Beyond that any supplement should be discussed with your oncology team. And Suzanne, as you mentioned previously when addressing juicing and diets, the best advice is get your vitamins, minerals, antioxidants from your whole foods. That's the way your body likes it.

Suzanne Dixon: Absolutely. I think it's important for people to understand that sometimes when you get an effect, if you take a diet or a supplement, it might seem like a really great thing. For example, maybe someone find that they take a particular herb, or supplement, and it seems to lessen their side effects. Maybe that seems good on the surface, but you have to wonder if you're lessening your side effects, does that mean you're also lessening the effectiveness of the treatment itself? So we really need to be cautious about not interpreting, when we see research on dietary supplements in any one particular way, but think about all the different ways that it might be affecting the person's body, and their treatment. And again you're smart in that conservative approach because you definitely don't want to jeopardize a patient's ability to get through treatment and have the best possible outcome.

Annette Goldberg: Yes, it's definitely one of those unknowns that make me very nervous when patients talk about it. Lastly Suzanne, before we run out of time, my favorite has to be the myth around sugar. This is in the news everyday [chuckles] one way or another. I'm sure you hear it all the time. So tell me a little bit about your response and how you address the beast that we know as sugar-causing cancer, or sugar-feeding cancer.

Suzanne Dixon: That's a fantastically popular myth that is out there [laughter], and just never seems to go away. And to be fair, it's really true that our general diets have far too much simple sugar in them. We eat too many processed foods and we eat a lot of excess sugar, much of which we may not even be aware of. There's sugar in things like cereal, and bread, and ketchup, and salad dressing, all these things you might be thinking, "Oh, this is fine. I'll eat this," but it might have quite a bit of sugar in it. So I really like to encourage people to think about just the global issue of eating too much sugar, mainly because it's not good for us. It adds excess calories and it displaces other foods and calories that come from more nutrient-dense foods. That is, I think, true, that we generally all get too much sugar, and it never hurts any of us to cut our sugar down a little bit if we can, in terms of simple sugars. But in terms of the myth of sugar-feeding cancers? I think that's kind of a funny phrase because sugar really feeds all of our cells. So when people say "sugar feeds cancer" I kind of chuckle and say, "Well of course it feeds cancer, because it feeds every cell in our body." All of our cells like simple sugar in the form of blood glucose, in order to fuel their energy needs.

So sugar-feeding cancer is really not saying anything that's revolutionary or new, and I always comment that of course it does, because that's what our cells like, including cancer cells, they work on sugar. But when people think about, "Well, I'm going to cut every little smidgen of sugar, or carbohydrate out of my diet--" the other think to be aware of is that cancer cells are really crafty, I always say. They're very tricky and they can shift around in terms of how they're metabolizing different things in our diets. And so perhaps you think, "Okay, I'll just cut sugar," but those cancer cells sometimes can shift and then maybe they can use fat for energy. Or they could shift again and use more protein. So the idea of completely eliminating sugar to treat cancer, as I mentioned when I was talking about fad diets and different diets, there are some studies looking at things like the ketogenic diet. But that type of an extreme approach is not proven and for many cancer types we seem to find that the opposite is true. That when people eat plenty of healthy carbohydrates like plants, the fruits and vegetables, and whole grains, and legumes they actually have less cancer, not more, and they have better survival. So sugar feeding cancer is kind of a myth that it sounds scary, but in reality it's really not scary, in the sense that sugar is just a general energy and fuel for all of our cells.

Annette Goldberg: I think some of the issues, as you just said, were around use of the different terminology. And of course you and I know sugar, carbs, complex carbs, all of the different terms, and how they're used, but the general population doesn't and so there's confusion, I think, when there's talks about sugar, carbohydrates, carbs. It's used as a catch-all term and these terms definitely have very different definitions. So when patients say, "I don't want to eat sugar," or, "I don't want to eat carbs," I think it becomes very confusing, and there are so many good carbohydrates for us. Of course, we want our patients to eat vegetable, and fruits, and complex carbohydrates, and their oatmeal, and whole wheat. And so it becomes very frustrating. I think the use of the term "sugar feeds cancer" as a catch phrase, is very detrimental to the patient population. As you had mentioned with your ketogenic diet, the brain prefers glucose. Why, unless we're in the situation, which you had spoken of, that this is very concentrated with brain cancer, why would we not want to make sure that we're feeding our brain properly as well?

Suzanne Dixon: Absolutely, and interestingly, going back to-- I mentioned earlier the WINS, or Women's Interventions Nutrition Study and also the Dean Ornish studies about prostate cancer, and I always point out to people when they think, "Okay, carbohydrates are bad," maybe they're using this phrase carbohydrates and sugar interchangeably, but those diets were very, very low fat. I'm pretty sure, I can guarantee you, that those extra calories that they cut out, in the form of fat, they didn't make up with protein, they made it up with carbohydrates. Here you have, on the one hand, people pushing things like really extreme kind of carbohydrate restricted ketogenic diet, but we know that in a few clinical trials that have been investigating these questions about diet patterns, and cancer outcomes, that even when you take someone, for example, women with breast cancer, or men with prostate cancer, and put them on a very high carbohydrate diet, you see some pretty great outcomes. But the difference is that those carbohydrates are coming from healthy whole plant foods, not from things like soda, or sugary cereals, things along those lines.

Annette Goldberg: Now I have read a little bit that a lot of research now is surrounding insulin, and insulin's effect on a cancer cell. So it's not necessarily the sugar, but the fact that they're eating too much refined sugar, simple carbs, and your spikes in insulin might influence cancer cell growth. And, as we know, increase the risk of other chronic diseases.

Suzanne Dixon: Yes, absolutely. And that actually brings home the idea about balance, and making sure that our diets are well-balanced. It turns out that when you eat a lot of simple sugar, especially if you eat it on, say, an empty stomach, you can get these spikes in your insulin levels. And there are other hormones that are related to insulin, such as insulin like growth factor, and other growth factors. And those can go up and down quite variably, based on how much simple sugar you're eating. And it's true that if you eat a lot of simple sugar all day long, that's the main thing you're eating, you might get these spikes in your insulin. And it's not necessarily the sugar itself that's the problem, but it turns out that having high insulin levels can spur cells that are cancerous, or maybe even pre-cancerous, to grow more aggressively.

So there is a solution, and that's that when you eat carbohydrates, there's a few things that you can do that will help balance out those carbohydrates, so that you don't get those big insulin spikes. I always describe to people that there are three things that will blunt the glucose and insulin response. In other words, they will slow how quickly that glucose moves from your GI tract, into your bloodstream, which in turn will slow how quickly your pancreas releases insulin to deal with that blood sugar. And it's protein, fat, and fiber. Those are the three things, protein, fat, and fiber. So if you eat just a big bunch of plain sugar, white table sugar for example, you drink a soda on an empty stomach, you'll get that big insulin swing that we talked about. But if you actually combine that food with protein, fat, or fiber, you greatly blunt, or slow down, how quickly that sugar gets in your system, which in turn slows down and blunts that insulin response. So I always point out to people that even if, for example, you're going to have a snack, and you say, "Well, I'll have a piece of fruit. Or maybe I'll have two pieces of fruit," you can get that more balanced approach by, say, having a piece of fruit with a handful of nuts. So I often like to snack on something like an apple, or an orange, and a handful of walnuts.

So that little bit of sugar is in that fruit is actually going to be balanced out by the protein, fat, and fiber from those nuts. You can balance out what you're eating that way. So I encourage people, if they want to have a treat, like a cookie, or a piece of cake, or something along those lines, if you eat it as part of your normal, healthy diet-- for example, you have a special night out and you want to have dessert, then you've already eaten that dinner, and you've already had plenty of protein, fat, and fiber in your system. So you're not going to get a big glucose response from eating that dessert. On the other hand, if you were to sit down and say, have a cookie and a can of Coke for a snack on an empty stomach, that doesn't do your body any favors. So you want to try to keep it balanced, keep the total amount of sugar intake low, but when you do eat it, I would say enjoy it and just keep it in the context of a total healthy diet.

Annette Goldberg: I'm guessing that's why mom told us that we had to eat our dinner before we could have our dessert [laughter]. One of the many things that mom got right [chuckles]?

Suzanne Dixon: Yes. Most definitely. She knew even intuitively that we should keep that balanced.

Annette Goldberg: Right. Well Suzanne, I think it's quite important to constantly address the many nutritional myths that surround cancer. Our cancer patients have many challenges and stresses already managing their diagnosis, and I don't want to see them unnecessarily worrying over a media snippet regarding their nutrition. I hope our podcast help clarify some of the more popular myths. What are your closing thoughts?

Suzanne Dixon: I completely agree that cancer patients have a lot of things to deal with. And if you add stress around what you're putting into your mouth, that's just one extra thing that you don't need. And I always point out to people, there are so many things you can't control about a cancer diagnosis. You can't control your genetics, you can't control your age, you can't control your gender, you can't control your family history, you can't necessarily control what types of treatment you're going to get, because you want to go with whatever the best  available treatment that's recommended by your doctor. So you're probably not going to change that up. One thing you can control is how you eat, and how you move your body. And so I always think it's a shame if people get so nervous, and so caught up in nutritious-ness, that they lose the benefit of having that sense of control over something in their life that can help nourish their body, and keep them healthy, and get them healthy after a cancer diagnosis. So I think it's important for people not to get swayed too much by these myths and instead say, "Wow, I can make all of these healthy choices. Do some things for myself with my diet, and it's the one thing that I can do for me that will help me heal after a cancer diagnosis."

Annette Goldberg: Right, and it's nice to be able to enjoy your food.

Suzanne Dixon: Absolutely.

Annette Goldberg: All right, Suzanne, it was a pleasure speaking with you.

Suzanne Dixon: Yeah.

ASCO: Thank you Ms. Dixon and Ms. Goldberg. For more information visit www.cancer.net/healthyliving. And for more expert interviews and stories from people living with cancer, visit the Cancer.Net blog at www.cancer.net/blog.

Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high quality cancer care. Thank you for listening to this to this Cancer.Net podcast.