Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the practical application of health information. Nutrition. Exercise. Diet. Supplementation. I look at the science behind them, and let you know whether it’s something to consider or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
I don’t know everything. That frustrates me to no end. I want to understand how the body works in every facet as it deals with challenges like weight loss, exercise, and increasing healthspan. That’s an impossible task. There are some scientists that I believe are experts in their field so I listen to what they say. I still read the research they cite but they are not inclined to exaggerate as people who are pitching a miracle nutrient do. They are worth listening to. I recently listened to an interview with Dr. William Li, a physician and researcher in preventing and treating cancer with food and nutrition. He knows the science because he’s done some of himself with his research team. He is a researcher and gifted speaker so I thought it would be informative for you if I summarize some of the information Dr. Li shared in the interview, especially what to eat and what not to eat related to cancer prevention and treatment. You can find information for the the entire interview in the Notes.
I thought he gave the best explanation of how cancer develops for the lay person I’ve ever heard. I’ve stated it myself for over 25 years but didn’t come close to nailing it the way he did. We develop cancer cells at a rate of over 10,000 times per day. Cancer cells are cells that had mistakes in their DNA and did not develop properly after replication. With trillions of cells dividing every day, mistakes are going to happen. Every day, your immune system cleans up the mess to eliminate the threat of those cells taking root. When the immune system gets compromised, the clean-up process may not be as complete and some cells may start to replicate. That’s when the potential for cancer begins. That’s why a healthy diet can help as the right nutrients can boost the immune system to work properly and prevent those cells from taking root.
How do we prevent cancer? There is the obvious. Don’t smoke cigarettes, pipes, cigars, or vape. In fact, vaping may prove to be more hazardous than the other forms of getting nicotine because of all the artificial chemicals used in the production of the vape juice. Don’t drink alcohol to excess. Alcohol is a nutrient that is hard on the liver. It may contain great phytonutrients from grapes and barley and hops. But drinking alcohol to excess means the effects of the alcohol can exceed the benefits from the nutrients.
One that is more difficult to control is exposure to environmental toxins. Specifically microplastics and forever chemicals. I’ve stopped drinking bottled water until the science on microplastics becomes clearer. I’m not suggesting that you or I never put a liquid in plastic containers to our lips again; just not as the primary source of water or other liquids. The forever chemicals is going to be more of a problem as the federal government just postponed restrictions on releasing PFAS and other toxins into the environment for an additional two years. Big business wins at the expense of our health. Invest in a good water filtration system for your home, if you can. That’s a practical defense against forever chemicals until we know more.
Now, let’s get to the actual foods to avoid. Preserved meats like pepperoni and salami are at the top of the list. Bacon lovers? That’s preserved as well. There are nitrites and other harmful chemicals in those types of meat. Another class of foods to avoid are grilled meats. It’s not the meat; it’s the chemicals that envelope the meat as it’s grilled over a fire. The fats from the meat drip into the fire where they are burned up. The smoke can contain toxins. Cleaning the grill regularly to prevent the build-up of fat helps as well.
Soda is also something to use with caution but it’s not the sugar! The chemicals that are added to soda like the artificial flavors, colors, and preservatives can contain chemicals that can be hazardous to cells. Oh, and that thing about sugars feeding cancer you’ve probably hear about? That doesn’t happen and is more urban legend than truth.
The final class of foods to avoid are the UPF. There are several reasons similar to the soda. The artificial preservatives, colors, flavor enhancers, emulsifiers, and more used to hook us on the umami and salty flavors or the sweet flavors are the problem. That, as well as completely deconstructing some food like wheat or a potato, putting it back together with the aforementioned chemicals, and extruding it through a die to get a uniform crisp or other shape is as un-natural as it gets.
One question that I get about UPF is how do you know what is UP or not? The shortest answer is look at the list of ingredients. If you can’t find it in your pantry, it’s probably an UPF. Potato chips are processed but the label says potato, oil for cooking, and salt. UPF would add 3-10 more ingredients for color, flavor, and to keep them shelf stable. Check the notes to get a website so you can read more about the food rating system called NOVA.
Before I get into the top 5 foods Dr. Li mentioned in the interview, he also said this, which I agree with wholeheartedly. You don’t have to stop eating pepperoni on your pizza or stop grilling your burgers. What you should not do is make them mainstays of your diet. Once a week, not a problem. Every day? That’s too much. Be reasonable and you can still enjoy that pizza with a beer if you want. Just not an entire pizza and a 6-pack every night..
Now to the foods that you should eat. The first one has gotten more bad press than any other food I can think of: soy and all its products, from protein powders to soy milk to tofu and tempeh. The isoflavones genistein and daidzein appear to be anti-cancer phytonutrients. This is only controversial due to the large body of overly cited studies on rodents that suggest that isoflavones from soy will feminize males and promote breast and other cancers. The facts don’t support that position, especially about breast cancer as more than a dozen studies show that soy reduces the risk of breast cancer and reduces recurrence in women who have had breast cancer. But the anti-soy negativity is real and tough to overcome. Fortunately, there are more anti-cancer nutrients out there.
The second is cooked tomatoes. We know that the phytonutrient lycopene is important for men to reduce the risk of CVD. But tomatoes releases more lycopene when cooked, especially if cooked in olive oil, as lycopene is fat soluble. However you like them tomatoes are beneficial.
The next is apples, especially the ones with red skin. Again, it is most likely the phytonutrients in the apples skin as well as the fiber in the apple but an apple a day just might really keep the doctor away—and cancer as well.
The fourth class of foods to eat every day are berries. Blueberries. Raspberries. Black berries. They contain a phytonutrient explosion of flavonols, all with the some form of anti-cancer property. Whether in smoothies, cooked in a pie, or just covered with cream, berries are one of the best classes of foods to eat every day.
The fifth surprised me: drink coffee or tea every day. The phytonutrient chlorogenic acid is found in both coffee and tea, black or green. These polyphenols have anti-cancer properties so I can only add, bottoms up.
One of the most important points Dr. Li makes, and one I have also supported for a couple of decades, would go something like this. Don’t live your life in a vacuum. Do the positive things. Eat the healthspan extending foods more than you eat the not as good foods. That’s what he said he does. Is it 51% to 49%? We don’t know that for sure so I’d go with 80-20 as that seems to apply to a variety of things. Life is to be lived without a checklist on a clipboard to keep score. Do the best you can day to day. I would add don’t forget to get some exercise as well. Day by day is a way to increase your healthspan.
That’s all the time I have for this episode. If you like this podcast, please hit the share button and tell your friends and colleagues about it. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
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References:
Zoe podcast with Dr. William Li. Recorded in April 2026.
https://www.eatrightpro.org/news-center/practice-trends/examining-the-nova-food-classification-system-and-healthfulness-of-ultra-processed-foods
