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Food and Cancer: Is There a Link? An Eye-Opening Interview with Lauren Talbert

There’s been a lot of research conducted to find a correlation between certain foods and cancer. We interviewed Lauren Talbert, a clinical dietitian certified in oncology nutrition to get some clarity on the subject and find out if there’s a link between certain foods and cancer.

Yes. The American Institute for Cancer Research is basically the best resource in America when it comes to lifestyle and cancer, particularly cancer risk. And they have said that about 40 percent of cancer cases, which could be as high as 700,000 each year, could be prevented if their recommendations are followed with regards to diet, weight, and exercise.

There are particularly certain cancers that have actually been linked to obesity. These would be esophageal, pancreatic, colorectal, endometrial, kidney, post-partum breast cancer, gallbladder, ovarian, liver, advanced prostate, stomach, and mouth cancer. So basically, the cancers that I just listed — there is research that supports that obesity has an increased effect on the risk of developing them.

Plants have what we call phytochemicals, and they provide plants with their color, their odor, and their flavor. And these phytochemicals have actually been studied, particularly in labs, to see their effect on cancer cells.

And basically, the more plant-based foods you eat, the more phytochemicals you consume. I'll give you an example.

A carotenoid, such as lycopene, has been studied, and lycopene can be found in red, orange, and green fruits and vegetables, in things like broccoli, carrots, tomatoes, and leafy greens. And there's research to show that these phytonutrients can inhibit cancer cell growth, work as antioxidants, and also improve the body's immune response.

Other plant-based foods — the way that I sort of explain it to people is if things have a stronger flavor or a bright color, generally, they have more antioxidants. So green leafy vegetables, cruciferous vegetables like cauliflower, Brussels sprouts, or broccoli, bright-colored orange vegetables like pumpkin or winter squash: These all have particular phytochemicals that have been shown to fight cancer.

And with respect to other foods, cancer is a disease that feeds in an inflamed state. So eating more anti-inflammatory foods, which includes the above-mentioned foods, but also things like fatty fish, can also help fight inflammation and possibly help with lowering cancer risk.

The ketogenic diet is not well-defined. It varies from as low as 20 to 50 grams of carbohydrates a day. And just to give you an idea, the typical amount would be about 130 to maybe 150 grams that somebody consumes in a day.

The ketogenic diet is basically very low in carbohydrates and higher in fat and protein. And the thought is that if you starve your body from carbohydrates externally, your body is going to break down your stores and use those for energy.

The only research in terms of cancer that's pretty solid with the ketogenic diet would be for people that have specific brain tumors. Because our brain only functions on glucose, there's the thought that if we deprive the glucose from our diet it could help with specific brain cancers.

But from what I've read, it's very hard to follow, it's low in fiber, and it can affect our digestion and constipation. It's obviously very extreme and hard to follow. But the benefit of it for these patients that are so ill may not really outweigh the problems following it. It may prolong somebody's life, but you're pretty strict with this specific diet. In general, unless somebody has a particular type of brain cancer, it's not something that I would recommend.

I am certified in oncology nutrition. I've worked particularly with women with cancer so I've spoken a lot about soy.

Soy contains these nutrients called phytoestrogens, and they are plant estrogens. They look like estrogen under a microscope. Years ago, there were some rodent studies, and they predisposed these rodents to an increased risk of getting breast cancer, and those that were given more of these soy isoflavones had a higher development of the cancer. So people took that research and basically put it onto humans and said, "Don't eat any soy foods because it's going to cause cancer."

But since then, there's been a lot of observational studies, first of all, showing that those who eat more soy have a lower risk of developing cancer, and then cancer survivors, particularly breast cancer survivors, who eat more soy have lower risk of cancer recurrence.

The message that I deliver is that the phytoestrogens in these soy foods do not act like human estrogen. They're completely different. And since these rodent studies, we've learned that rodents metabolize soy very differently than humans metabolize soy. So I think that people are confused about soy, possibly scared. I meet a lot of people who don't eat it.

But again, going back to the plant-based diet: it's a great source of nutrients that comes from that. Soy is high in fiber and protein, potassium, magnesium, copper, manganese, and calcium, so it's a very beneficial food to consume.

A common question that I get is if sugar feeds cancer. "Now that I have this cancer diagnosis I should probably stop eating fruit". And it's not that sugar feeds cancer, sugar actually feeds all cells, benign cells or malignant cells.

If you eat excessive amounts of processed sugar, that can lead to obesity, and like I said before, that has been shown to link to cancer.

However, if you do eat excessive amounts of processed sugar, that can lead to obesity, and like I said before, that has been shown to link to cancer. When patients are asking me about sugar and cancer, I focus on consuming natural sugars that occur in fruits or even dairy products versus added sugars that may be added to cereals, desserts, or sugary drinks. It's not that sugar feeds cancer, but it's not a good idea to be eating a lot of added or processed sugars.

There's been a lot of research that shows that those who eat more red meat have an increased risk of colorectal cancer. And the recommendation from the American Institute of Cancer Research is to have your intake at 18 ounces or less a week of red meat.

And there are three reasons why they think that red meat could increase cancer risk:

  • It contains heme iron. And they say that that compound may be damaging to the lining of the colon.
  • Red meat stimulates the production of n-nitroso compounds which may be causing cancer too.
  • Generally, red meat is cooked at very high temperatures. And this could produce two different types of carcinogens. One is called heterocyclic amines (HCAs). And the other is called polycyclic aromatic hydrocarbons (PAHs). 

So basically, for these three reasons, there's been research to show that those who eat more red meat have an increased risk of cancer, particularly colon cancer, but also other cancers.

Then there's processed red meat and that actually has been found to be even more harmful to your health. Processed meats are things that have been preserved by smoking, curing, salting or adding chemicals, so things like sausages, hotdogs, or deli meat.

The research for processed meat is even more significant when it comes to cancer risk. I generally tell patients to try to avoid processed meat as much as they can. And whenever they are eating red meat, shift as much as they can towards a plant-based diet. Instead of having a beef burger for dinner, maybe once in a while use portobello mushrooms instead of beef.

HCAs are generally consumed when you cook at a high temperature. If you marinate something before cooking it, you can actually lower the amount of HCAs that are formed during the cooking process.

And then the PAHs, they're deposited on the meat when the meat is smoked. If you put a steak on a grill and it's hot, so it gets that char, and the longer that it's on the grill the longer that it's exposed to these PAHs. And that's basically the smoke from the grill coming up and creating this kind of charred smoky look. So basically, if you can pre-cook your meat, say, you put it in the oven for a few minutes then you put it on the grill, you can lower the risk of getting so many PAHs.

When it comes to vitamins, you only want to take a vitamin to correct its deficiency. Here in the US, we have a lot of vitamin D deficiency and vitamin B12 deficiencies as people age.

When it comes to cancer, there's really no research that shows that taking extra supplements in the form of a vitamin can actually lower your risk of cancer. And years ago there was a study called the SELECT trial. They were looking at vitamin E and selenium with its role to reduce risk of prostate cancer in men. And what they found was pretty interesting. It was actually that those substances didn't decrease risk; they actually increase risk. Then there was also research looking at beta-carotene supplements with the same finding — that they actually increase risk of cancer.

So when it comes to vitamins, it's best to try to get your vitamins from your diet. But if you can't get your vitamins from your diet, say, you're a vegan, and you're not getting enough B12, taking your supplements or correcting its deficiency would be recommended. But there's a lot of companies out there that are promoting their specific vitamins to fight cancer or prevent cancer. And to date, we don't know enough about that. You know, a big one would be vitamin D. You're basically taking vitamin D to correct its deficiency. There is no research that shows that taking extra vitamin D is going to help prevent any cancer. But there is research showing that adequate levels of vitamin D can support your health with regards to cancer.

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