Food and Cancer: Is There a Link?
There has been a lot of research done to see if there is a link between certain foods and cancer. Flo.Health spoke with Dr.Lauren Talbert, a clinical dietitian certified in oncology nutrition, to learn more about the topic and determine whether there is a link between certain foods and cancer.
What foods influence the risk of cancer?
Certain foods and diets, according to Dr. Talbert, can indeed influence cancer, and there is also a link between obesity and cancer.
According to the American Institute for Cancer Research, approximately 40% of cancer cases in the United States, which could be as high as 700,000 per year, could be avoided if their recommendations for diet, weight, and exercise are followed.
"Obesity has been linked to a number of cancers, including breast cancer." These are esophageal cancer, pancreatic cancer, colorectal cancer, endometrial cancer, kidney, gallbladder cancer, ovarian cancer, liver cancer, advanced prostate cancer, stomach cancer, mouth cancer, and postpartum breast cancer. "Basically, the cancers that I just mentioned — there is research that supports the fact that obesity increases the risk of developing them," Dr. Talbert explains.
What are foods that can prevent cancer?
Plant phytochemicals, which give plants their colour, odour, and flavour, have been studied for their effect on cancer cells, according to Dr. Talbert. Dr. Talbert gives the following example:
"A carotenoid like lycopene has been studied, and lycopene can be found in red, orange, and green fruits and vegetables like broccoli, carrots, tomatoes, and leafy greens." There is also evidence that these phytonutrients can inhibit cancer cell growth, act as antioxidants, and boost the body's immune response.
"Other plant-based foods — the way I explain it to people is that if something has a stronger flavour or a bright colour, it usually means it has more antioxidants." Green, leafy vegetables, cruciferous vegetables such as cauliflower, Brussels sprouts, or broccoli, and brightly coloured orange vegetables such as pumpkin or winter squash all contain phytochemicals that have been shown to fight cancer."
Moreover, the more plant-based foods you consume, the more phytochemicals you consume.
"And, in terms of other foods, cancer is a disease that feeds when the body is inflamed." So eating more anti-inflammatory foods, such as the ones mentioned above, but also things like fatty fish, can help fight inflammation and possibly lower cancer risk," Dr. Talbert explains.
Can a ketogenic diet help treat cancer?
The ketogenic diet, according to Dr. Talbert, is not well-defined. "It ranges from 20 to 50 grammes of carbohydrates per day." And, just to give you an idea, the average amount that someone consumes in a day is around 130 to 150 grammes."
The ketogenic diet is high in fat and protein and low in carbohydrates. The theory is that if you deprive your body of carbohydrates, it will turn to its fat reserves for energy.
The only solid research on the ketogenic diet and cancer suggests that it may be beneficial for people suffering from certain types of brain tumours. Because the brain runs on glucose, it is thought that limiting your intake of glucose may aid in the treatment of certain types of brain cancer.
"However, from what I've read, it's low in fibre and can interfere with digestion and constipation." It's obviously extreme and difficult to follow. However, the benefits for these critically ill patients may not outweigh the drawbacks. It may extend someone's life, but you're pretty strict with this diet. "In general, unless someone has a specific type of brain cancer, I would not recommend it," Dr. Talbert says.
What impact does soy have on cancer?
Dr. Talbert, as a certified oncology nutritionist, has worked primarily with cancer patients who are women, so she has spoken extensively about soy.
Soy contains phytoestrogens, also known as plant estrogens. Under a microscope, they resemble oestrogen. Researchers predisposed rodents to breast cancer years ago, and those given more soy isoflavones developed the disease at a higher rate. Many people have concluded that eating soy causes cancer based on that research.
However, studies have shown that people who consume more soy have a lower risk of developing cancer, and that cancer survivors, particularly breast cancer survivors, who consume more soy have a lower risk of cancer recurrence.
"The message that I deliver is that the phytoestrogens in these soy foods do not act like human oestrogen," says Dr. Talbert. They are diametrically opposed. And, as a result of these rodent studies, we now know that rodents metabolise soy very differently than humans. As a result, I believe that people are confused, if not scared, about soy. I meet a lot of people who refuse to eat it."
Soy is high in fibre, protein, potassium, magnesium, copper, manganese, and calcium, making it a nutritious food to consume as part of a plant-based diet.
Can sugar and refined carbs impact the risk of cancer?
Dr. Talbert is frequently asked if sugar feeds cancer. Sugar does, in fact, feed cancer — it feeds all cells, cancerous or not.
Excessive consumption of processed sugar can lead to obesity, which has been linked to cancer.
"However, if you eat an excessive amount of processed sugar, it can lead to obesity, and as I previously stated, obesity has been linked to cancer." When patients ask me about sugar and cancer, I advise them to consume natural sugars found in fruits and dairy products rather than added sugars found in cereals, desserts, and sugary drinks. "It's not that sugar causes cancer, but eating a lot of added or processed sugars isn't a good idea," Dr. Talbert says.
What is the impact of red meat or processed meats on the risk of cancer?
According to Dr. Talbert, there has been a lot of research that shows people who eat a lot of red meat have a higher risk of colorectal cancer. The American Institute of Cancer Research recommends eating no more than 18 ounces of red meat per week.
They believe that red meat may increase the risk of cancer for three reasons:
Then there's processed red meat, which has been shown to be even worse for your health. Meats that have been preserved by smoking, curing, salting, or adding chemicals, such as sausages, hot dogs, or deli meat, fall into this category.
"When it comes to cancer risk, the research for processed meat is even more significant." I generally advise patients to avoid processed meat as much as possible. And, whenever they eat red meat, they should try to eat as much as possible from a plant-based diet. "Instead of having a beef burger for dinner, try portobello mushrooms once in a while," Dr. Talbert suggests.
How does overcooked and grilled food impact the risk of cancer?
According to Dr. Talbert, chemicals such as HCAs (heterocyclic amines) are commonly consumed when cooking at high temperatures. You can reduce the amount of HCAs formed during the cooking process by marinating something before cooking it.
"When meat is smoked, PAHs (polycyclic aromatic hydrocarbons) are deposited on it." If you put a steak on a hot grill to get that char, the longer it's on the grill, the longer it's exposed to these PAHs. And that's the smoke from the grill coming up and creating this charred, smoky look. So, basically, if you can pre-cook your meat, say, by putting it in the oven for a few minutes before grilling it, you can reduce your risk of getting so many PAHs," she explains.
What’s the impact of vitamin supplements on the risk of cancer?
Dr. Talbert claims that you only need to take a vitamin to correct a deficiency. "As people age in the United States, there is a lot of vitamin D deficiency and vitamin B12 deficiency," she says.
According to Dr. Talbert, there is no evidence that taking extra supplements in the form of vitamins can reduce your risk of cancer.
"Several years ago, there was a study known as the SELECT trial. They were investigating the role of vitamin E and selenium in lowering the risk of prostate cancer in men. And what they discovered was quite intriguing. It was actually the case that those substances did not reduce risk; rather, they increased risk. "There was also research looking at beta-carotene supplements that found the same thing — that they actually increase cancer risk," Dr. Talbert says.
There is no evidence that supplementing with vitamin D will help prevent cancer. However, studies have shown that adequate levels of vitamin D can benefit your health in terms of cancer prevention.
As a result, it's best to try to get your vitamins through your diet. However, if you are unable to do so — for example, if you are a vegan and are deficient in B12 — taking a supplement to correct the deficiency is advised.
"However, there are a lot of companies out there promoting their specific vitamins to fight or prevent cancer." And, as of now, we don't know enough about it. One of the most important is vitamin D. You're basically supplementing vitamin D to make up for a deficiency. There is no evidence that supplementing with vitamin D will help prevent cancer. "However, there is research that indicates that adequate levels of vitamin D can support your health in terms of cancer," Dr.Talbert says.