Conversations on Cancer is a new EWG series bringing you the latest news on cancer prevention through discussions with experts in the field. Today's guest: Jocelyn Weiss, Ph.D.
After a big Thanksgiving meal, with more holiday parties around the corner, food is on everyone’s mind. We know that a balanced diet and exercise are essential to a healthy life. But what exactly is a healthy diet?
U.S. Food and Drug Administration guidelines include eating more fruits and vegetables, limiting sugar and watching calories. These basic recommendations are a good start, but a healthy diet must also consider individual needs and goals.
Jocelyn Weiss, Ph.D., assistant director of clinical research at Mount Sinai Adolescent Health Center in New York, answered our questions about the role nutrition plays in cancer prevention. Her website, An Unprocessed Life, is packed with information on healthy foods, advice and motivation for exercising and getting active. Its mission is "to empower others to take ownership of their health to prevent and reverse disease." She shared her thoughts on nutrition, cancer and the state of the science.
EWG: An Unprocessed Life encapsulates your philosophy on food and lifestyle. Where did that philosophy come from and why is living an unprocessed life so important?
Jocelyn Weiss: My philosophy on food and lifestyle comes from my personal experience healing from hormonal and immune disorders that began as a child.
I spent much of my life treated for migraines, polycystic ovary syndrome, hypothyroidism and autoimmune disease. I hated being on medications because I felt powerless to control my health – not to mention that a couple of them had pretty potent side effects. The birth control pill made my migraines worse and Plaquenil [a medication used to treat auto-immune disease] led me to check my eyes every six months for retina damage. While I believe there is a place for medication, I also knew there had to be a better way to improve my quality of life.
A common thread emerged as I researched nutrition to improve my various conditions: eat an anti-inflammatory diet full of whole, unprocessed foods. Our way of eating has veered far from that of our ancestors due to industrialization, food subsidies, commodity crops and the inclusion of additives, preservatives and other chemicals to packaged foods.
I stopped eating meat in high school, but still consumed fat-free foods and sugar-laden cereals and yogurts. Through my genetic research, I realized that small variations in our DNA that influenced risk of disease could also affect how our bodies respond to different foods.
This concept of bio-individuality led to the discovery that certain foods I had been eating did not support my health. I found that I was sensitive to a diet rich in gluten, dairy and caffeine, as well as soy, corn and peanuts. I noted what happened after I eliminated and reintroduced them to my diet: inflammation, digestive issues, skin rashes, sinusitis and migraines.
While “unprocessed” refers to types of foods to emphasize in one’s diet, it also reflects a way of life. Our own personal journeys and definitions of wellness and happiness should be discovered individually. In addition to nutrition, our health is impacted by physical activity, stress reduction, sleep, relationships, career, personal growth, spirituality and mindfulness. After I gained a handle on my nutrition, I focused on these areas as well. Within a year of starting my journey, I was able to come off of my medications.
EWG: A healthy diet and physical activity can have tremendous health benefits, particularly for cardiovascular health. Are there also benefits when it comes to reducing cancer risks? How might those benefits compare to big players like genetics and smoking?
JW: I have observed relationships between obesity, obesity-related hormones and physical activity with endometrial and prostate cancers. Decades of large, long-term follow-up studies also link diet and physical activity to cancer risk. “Sitting is the new smoking” is a popular new tagline. All forms of physical activity protect against some cancers, as well as against weight gain and obesity. A sedentary lifestyle, on the other hand, is associated with increased weight, overweight and obesity, which are themselves risk factors for some cancers.
Researchers have found that higher consumption of plant foods protects against certain cancers. Fruits and vegetables high in nutrients such as phytochemicals help to protect the body against the effects of oxidative damage to DNA, which can lead to mutations and increased risk of cancer. They also are high in dietary fiber and low in energy density, providing additional protection against weight gain.
Overconsumption of processed and red meats is associated with increased risk of some cancers. When meat is cooked at high temperatures, heterocyclic amines, or HCAs, and polycyclic aromatic hydrocarbons, or PAHs, are formed. These chemicals are mutagenic, or damaging to DNA, in laboratory studies. Overconsumption of sugar is also linked to cancer through its role in overweight, obesity and hormone dysregulation.
Both anecdotal and research-based evidence strongly indicates that a healthy diet and physical activity can impact the risk of cancer. While it is undeniable that our genetics play a significant role in our susceptibility to disease, our DNA is not the only player. A person at higher risk of a particular disease is not guaranteed to get it if she or he minimizes exposure to other modifiable dietary and lifestyle factors.
EWG: Are there specific foods or food properties that you would suggest anyone concerned about cancer seek out or avoid when they’re at the grocery store?
JW: My number one recommendation is to focus on the perimeter of the grocery store, as this is where the produce and less processed foods are located.
I’m almost always asked whether people should buy all their foods organic. In an ideal world, I would say yes. Unfortunately, the U.S. agricultural system doesn’t let everyone afford buying all their foods organic. Instead focus on the crops with the highest concentrations of pesticides.
Organophosphates, for example, are a class of pesticides widely used in agriculture to kill pests, but their residue can also be toxic to humans. I refer clients and friends to EWG’s Dirty Dozen list and suggest that they at least try to buy those items organic.
Many canned food containers are lined with bisphenol A, particularly acidic foods such as tomatoes. Choose frozen vegetables over canned, which are usually higher in nutrients since they are frozen soon after harvesting. Either cook tomato sauce from scratch or buy it in jars. It’s possible to find brands that are explicitly labeled as BPA-free, but research shows that alternative chemicals used to replace BPA may not be less toxic.
When buying fish, balance the impact of wild-caught versus farmed for sustainability and health. Farmed fish are generally dosed with hormones and antibiotics, along with swimming in and ingesting water of low quality. The sustainability of industrial-scale wild fishing, however, raises overfishing concerns. Also take care not to over-consume larger fish varieties, such as tuna and swordfish, with accumulated high levels of mercury. Seafood Watch from the Monterey Bay Aquarium is a website and a mobile app that provides recommendations for the best sources of sustainable seafood.
Lastly, read nutrition labels when purchasing packaged products. Avoid products with added sugars, preservatives, food additives and color dyes. While the FDA maintains that artificial food dyes are safe, some research has shown dyes and the preservative sodium benzoate contribute to hyperactive behavior in children. Many yogurt brands also contain as much sugar as a can of soda.
Carrageenan, a food texturizer derived from red algae and included in many dairy and milk-alternative products, has been shown to be inflammatory in lab studies. Monosodium glutamate, MSG, present in packaged foods under many names, can trigger headaches and other allergic symptoms.
If you do not recognize or cannot pronounce ingredients on a label, there’s a good chance you should not eat that product.
EWG: I hear a lot of advice for people to eat whole foods. Are there things you think people may mistakenly believe are whole foods? And are there any whole foods you would not include as part of a healthy diet?
JW: Even more than “whole foods,” I hear people should eat “clean.” There are so many ways to interpret this advice. People should eat as close to nature as possible. When buying packaged goods, you should recognize the ingredients on the label as foods you could and would eat individually.
People should aim to crowd out the foods that aren’t so good for them with the ones that are. As the writer Michael Pollan says, “Eat food. Not too much. Mostly plants.” This really sums up my philosophy on eating. Eat real, unprocessed or minimally processed foods. Eat in moderation. Eat meals rich in vegetables, fruits, legumes, nuts and seeds. Consider animal products as a condiment rather than the main [dish].
Strict rules and limitation alone do not create wellness and a healthy life. There is always room for fun – and chocolate, especially dark chocolate, which is full of healthy antioxidants.
EWG: Scientific research is so important for uncovering how disease works. In some cases we may know that something, such as obesity, is associated with cancer, but don’t fully understand why. What studies are still needed to help us understand how food, diet and exercise are associated with the development of cancer or other chronic diseases?
JW: As an epidemiologist, I believe in the power of well-designed studies to uncover important associations. Science has a tendency to be reductionist, leading to the idolatry or demonization of single ingredients, mechanisms or risk factors. Findings get pulled from peer-reviewed studies, plastered in the public media and then written about in diet books.
No single nutrient, food item or body characteristic exists in a vacuum. In addition, even the strongest findings come with some degree of uncertainty as to whether they apply to the entire population. If we hope to make sense of the complex milieu in which disease happens, and influence behavior, we need to understand the mechanisms by which different factors impact health.
The microbiome is an emerging area that is showing promise . Microbial cells (bacteria and viruses) outnumber other cells in our body 10 to 1. They play important roles in metabolism, immunity, digestion and other pathways. The key is to look at mechanisms in the context of a holistic, larger picture.
EWG: What’s going to be on your holiday plate? Any recipes from your blog you would suggest for the holidays?
JW: Over the past couple of years, most of my family has gotten on board with healthier eating, but the holidays are always tricky. My mom has rumbled about a brisket with all the trimmings, so I’ll likely poach a piece of wild-caught Alaskan salmon along with all the veggie sides.
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Our next conversation, coming in January, will be with Nicole Deziel, assistant professor at the Yale School of Public Health, who'll discuss what household exposures can tell us about health.