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Health Matters

Nutrition and cancer risk

Conway McLean, DPM, Journal columnist

Although recent events have diverted our collective gaze, a tremendous amount of interest has been directed toward cancer and its treatment over the last half century. As seen in most medical tv shows, cancer is one of those concerns in the forefront with any undiagnosed malady. It’s referred to as “The Big C”, and many types of cancer have their own non-profit organization with various events devoted to fund-raising.

Collectively, our therapies for cancer have improved tremendously from not that long ago. The prognosis, although obviously dependent on the type, is no longer the death sentence it once was. Regardless, the word itself carries such a weight, people tremble at its mention. It’s a diagnosis no one wants to get.

Half of all the Americans currently alive will hear the words “you have cancer” at some point in their lives. This means our chances of developing the disease are 1 in 2 during our lives. But prior estimates, from studies recently performed placed this ratio at 1 to 3; a third of those alive at that time were going to get a cancer diagnosis. Although this increase has taken place over time, one has to wonder about the cause of this change.

An especially relevant component of this is our increasing longevity. The longer we live, the more time we have for errors to build up in an individual’s DNA, our genetic code. This is what cancer is: an accumulation of cells with damaged genetic material. And so, as time passes, our risk of developing cancer goes up as we accumulate more of these faults in our genes. More of us are living longer so there is more opportunity for cancer to develop.

Certainly, nutrition plays some role in cancer prevention. But it is inappropriate to make a connection within a short time frame, meaning what you ate a year before being diagnosed with breast cancer is not very relevant, at least as compared to a decade or two before. But people want specifics, some recommendations. What does the research show when it comes to nutrition and cancer?

Turns out, having a healthy diet is the most important thing you can do to prevent cancer. Let’s start with your primary meal of the day: it should be composed of at least three-fourths vegetables and less than a quarter of it protein from animals, which is more like the diet consumed in ancient times when a meal with meat was a rarity. It is only recently that meat has become the focus of the meal, with most Americans consuming far more protein than is needed.

Fish is generally a healthier option as protein sources go. As to environmental damage, it is a significantly better choice than beef, but still, not really a good one. Nutritionally, it is an excellent choice, except for concerns revolving around mercury levels in ocean fish, with the greatest uncertainty for the larger species like tuna. If you are a devout carnivore, try eating fish two or three times a week, with sardines, mackerel, and anchovies being a safer option since they have less mercury and other toxins (PCBs!).

Many fruits and vegetables have cancer-fighting potential. For example, lycopene, a phytochemical found in cooked tomatoes and tomato products, has been shown to slow the growth of breast, lung, and endometrial tumors and to reduce prostate, stomach, and pancreatic cancer risks.

Raw vegetables seem to be protective against both breast and prostate cancer. Cruciferous vegetables, like broccoli, cauliflower and cabbage, appear to reduce the risk of breast cancer. These are an excellent supplier of isothiocyanates, a natural substance which helps to detoxify cancer-promoting chemicals. Broccoli is an especially effective anticancer food, yet it works even better when combined with tomato sauce, onions or garlic.

As a general rule, adding onions, garlic or leeks to all your dishes when you cook is an extremely healthy practice. Varying your vegetables from one meal to the next is also an excellent idea, or even mixing them together. The only cooking oils to be used routinely is olive and canola oil. Soybean, corn and sunflower oils have too much omega 6 fatty acids and should be removed entirely from the kitchen.

Speaking of omega fatty acids, eggs also should be of the omega 3 type. Most modern chicken producers feed their hens primarily corn and soybeans. The result is an egg containing 20 times more omega-6 fatty acids than they should, which increases levels of inflammation in the body. Omega-3’s have a beneficial effect on the human body in that they help to regulate cell-growth. When it comes to organic foods, they are worth some added expense because it means you are getting less pesticides (although “organic” does not mean no pesticides).

Spices tend to have numerous benefits. Certain herbs have been shown to help boost immune function and lower systemic levels of inflammation. By doing these things, they help to decrease your cancer risk. For example, turmeric is a natural anti-inflammatory. This powerful yellow spice has many uses in a variety of cuisines. Research shows Mediterranean herbs help to reduce the growth of cancer cells. Some common examples include thyme, oregano, basil, and rosemary. Not only do they have health benefits but they make your food taste better!

The next topic is a painful one, but I must inform you of one heinous recommendation: reduce your potato intake. I personally consume and enjoy potatoes in all their many incarnations, but they raise one’s blood sugar. To many, this is a bad thing: hyperglycemia feeds inflammation and cancer growth.

We are confident that certain food stuffs are carcinogenic, meaning they have been implicated in an increased risk for developing cancer. Fried or burnt foods have high levels of acrylamide, a probable human carcinogen. This substance is mainly found in highly-cooked plant foods like potato and grain products (think of french fries or potato chips).

Wouldn’t it be wonderful if there were a diet that could assure you a life free from cancer? Unfortunately (as of now), there is no such thing. The best we can do is to find a way to eat that reduces the odds of a cancer diagnosis. But our society is getting older, with centenarians a common occurrence these days. Although we are doing it better, it would seem cancer treatments are going to consume an ever-greater portion of our health care dollars. We need a greater emphasis on primary prevention. Early detection is likely the best way to counter the effects of an aging population and the burden of cancer care.

Clearly, this is a subject we need to know more about. Future studies need to look at the differences between specific types of fat and types of carbohydrates. Studies have suggested that higher-fiber, high-phytochemical plant foods, which are rich in carbohydrates, may have protective effects, while refined carbohydrates and sugars may have negative ones. Others have suggested that olive oil and monounsaturated fat, as well as omega-3 fatty acids may help reduce breast cancer risks.

The dietary habits that tend to increase our cancer risk come down to one of excess and one of insufficiencies. The excessive consumption of too much red meat, refined carbohydrates and sugars, and fried foods. The insufficiency: too many Americans consume inadequate quantities of phytochemical-rich plant foods and get too little exercise.

We know changing your diet and lifestyle after getting a cancer diagnosis is probably not going to change the course of the disease. But making these kinds of changes at any time in your life is always a good thing. We are not certain what effect it will have on your risk of developing cancer, but it will go a long way toward heart health, a strong immune system, and less risk of all the other chronic diseases. And isn’t that enough?

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with a move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments at drcmclean@outlook.com.

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