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Dogs Detect Breast Cancer From Bandage: Researchers

Dogs can sniff out cancer from a piece of cloth which had touched the breast of a woman with a tumour, researchers said Friday, announcing the results of an unusual, but promising, diagnostic trial.

With just six months of training, a pair of German Shepherds became 100-percent accurate in their new role as breast cancer spotters, the team said.

The technique is simple, non-invasive and cheap, and may revolutionise cancer detection in countries where mammograms are hard to come by.

“In these countries, there are oncologists, there are surgeons, but in rural areas often there is limited access to diagnostics,” Isabelle Fromantin, who leads project Kdog, told journalists in Paris.
This means that “people arrive too late,” to receive life-saving treatment, she added. “If this works, we can roll it out rapidly.”

Working on the assumption that breast cancer cells have a distinguishing smell which sensitive dog noses will pick up, the team collected samples from 31 cancer patients.

These were pieces of bandage that patients had held against their affected breast.
With the help of canine specialist Jacky Experton, the team trained German Shepherds Thor and Nykios to recognise cancerous rags from non-cancerous ones.

“It is all based on game-playing” and reward, he explained.

After six months, the dogs were put to the test over several days in January and February this year.
This time, the researchers used 31 bandages from different cancer patients than those the dogs had been trained on.

One bandage was used per experiment, along with three samples from women with no cancer.

– Saving lives –

Each bandage was placed in a box with a large cone which the dogs could stick their noses into, sniffing at each in turn – four boxes per test.

The exercise was repeated once with each sample, meaning there were 62 individual responses from the dogs in all.

In the first round, the dogs detected 28 out of the 31 cancerous bandages – a 90-per cent pass rate, the researchers announced.

On the second try, they scored 100 per cent – sitting down in front of the box containing the cancerous sample with their muzzle pressed deep into the cone.

“There is technology that works very well, but sometimes simpler things, more obvious things, can also help,” said Amaury Martin of the Curie Institute, citing the many untested stories of dogs having detected cancer in their owners.
“Our aim was see if we can move from conventional wisdom to… real science, with all the clinical and research validation that this entails.”

This was the proof-of-concept phase of Kdog.

The next step will be a clinical trial with more patients and another two dogs, but the team is still in need of project funding.

The team believes that one day dogs may be replaced by “sniffing” machines, possibly armies of electronic diagnosticians dedicated to analysing samples that people far from clinics would send them by the post.

In the meantime, Experton said there is little danger of the trained dogs using their new-found skills to accost cancer sufferers outside the lab.

“These tests happen within a very specific work environment,” he explained. “In a different context, these dogs are unlikely to simply pounce on random people in the street.

The team says it is the only one to work with breast cancer detection from skin-touch samples.
Other research projects are testing canines’ ability to smell different types of cancer in samples of the skin itself, blood or urine, even the air people exhale.

In France, the chances of surviving ten years after a breast cancer diagnosis is about 85 percent, compared to around 50 per cent in poorer countries.

 

AFP                  March 25, 2017


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The Fruit that Protects Against Colon Cancer

While there has been a lot of controversy surrounding resveratrol supplements in recent times, new research from Pennsylvania State University closes the book on fruit containing the compound and its ability to protect against colon cancer. That’s promising news for the 95,500 Americans the American Cancer Society predicts will be diagnosed with colon cancer this year alone.

The new study, published in BMC Complementary and Alternative Medicine, found that resveratrol—a plant nutrient known as a phytonutrient—may actually suppress colon cancer stem cells, giving researchers and sufferers of the disease alike hope for a new prevention and treatment strategy. Cancer stem cells are cells that are believed to drive the creation of new cancer cells and cancer tumors. The researchers found that in addition to suppressing colon cancer stem cells, resveratrol found in grapes also significantly reduced the number of cancer tumors—a whopping 50 percent reduction in the number of cancer tumors.

The same researchers also found that resveratrol in food combined with grape seed extract was an even more potent anti-cancer mixture than just resveratrol alone. They found that grape seed extract seemed to increase the potency of resveratrol.

Resveratrol has also shown great promise in the prevention and treatment of brain diseases, due to its ability to protect the brain from damage. In this capacity, resveratrol mops up harmful free radicals and protects against plaque that is linked to Alzheimer’s disease.

While it remains to be seen whether resveratrol supplements offer the many health benefits of the compound that is naturally found in foods, it is clear that the food sources of this plant nutrient may offer protection against diabetes, heart disease, liver disease and cancer. Some research even links the nutrient to the protection against damage from the heavy metal cadmium. Cadmium is found in cigarettes, black rubber, burned motor oil, some ceramics, fungicides (like those sprayed on apples, potatoes and tobacco), some refined wheat flour, tires, silver polish, some water and some soft drinks (from vending machines with cadmium in the pipes). It may also protect the kidneys against damage from the antibiotic gentamicin.

The food mixture used in the BMC Complementary and Alternative Medicine study involved a blend of grape skins and grape seeds. This combination offers both resveratrol and grape seed extract. I use a high-powered blender to blend whole purple grapes that contain seeds into a drink so it is easier to obtain the health benefits of grape seeds, without the unpleasant texture so many people dislike. Stir periodically as you’re drinking the grape juice blend to ensure the seed and grape skin pulp are mixed.

Experts have been recommending high amounts of colorful produce in our diet for years. Research like this new study offer greater insight into the rationale for doing so: colorful fruits and vegetables tend to have the highest amounts of phytonutrients. Purple and blue foods tend to have the highest amounts of resveratrol, but the plant nutrient is high in many foods, including: purple grapes, purple grape juice, red wine, raspberries, mulberries, blueberries, peanuts, grape seed extract, eucalyptus and spruce.

While many people tout red wine as the best source of the nutrient, the alcohol (and frequently sulfite) content offset some of its health benefits. Fresh purple grapes and grape juice tend to be the best sources of resveratrol.

By: Michelle Schoffro Cook    July 1, 2017
About Michelle    Follow Michelle at @mschoffrocook


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Certain Nuts Linked to Reduced Risk of Colon Cancer Return: Study

Nut-eaters saw a 42 percent lower chance of cancer recurrence – and a 57 percent lower chance of death than patients who did not eat nuts after completion of their cancer treatment, said the report.

Eating certain kinds of tree nuts, such as almonds, pecans, walnuts, hazelnuts and cashews, has been linked to a dramatically lower risk of colon cancer recurrence, researchers said Wednesday.

The observational study involved 826 patients who had undergone treatment for Stage III colon cancer, typically including surgery and chemotherapy. Such patients – whose cancer has not spread elsewhere in the body – have a 70 per cent chance of surviving three years after treatment.

Some 19 per cent of patients consumed two or more ounces of all types of nuts per week.

These nut-eaters saw a 42 per cent lower chance of cancer recurrence – and a 57 per cent lower chance of death than patients who did not eat nuts after completion of their cancer treatment, said the report, released ahead of the American Society for Clinical Oncology (ASCO) annual meeting, held in Chicago next month.

When researchers looked only at tree nut consumption, the chance of recurrence was 46 per cent lower and the chance of death was 53 per cent lower for those who ate at least two ounces per week, compared to people who did not eat nuts.

Peanuts and peanut butter – the most commonly consumed nuts in the United States – did not appear to have any significant effect.

“Numerous studies in the fields of heart disease and diabetes have shown the benefits of nut consumption, and we felt that it was important to determine if these benefits could also apply to colorectal cancer patients,” said lead study author Temidayo Fadelu, a clinical fellow in medicine at Dana Farber Cancer Institute.

“Patients with advanced disease who benefit from chemotherapy frequently ask what else they can do to reduce their chances of recurrence or death, and our study is an important contribution to the idea that modifying diet and physical activity can be beneficial.”

Eating nuts should not be considered a substitute for standard chemotherapy and other treatments for colon cancer, experts said.

“Rather, patients with colon cancer should be optimistic, and they should eat a healthy diet, including tree nuts, which may not only keep them healthier, but may also further decrease the chances of the cancer coming back,” said ASCO president Daniel Hayes.

Researchers cautioned that the study was observational nature and did not prove cause and effect.

A separate study discussed Wednesday ahead of the Chicago cancer conference involved 992 people whose colon cancer had not spread. It showed that following a Mediterranean diet and exercising reduced their risk of dying prematurely by 42 per cent and also cut their chances of seeing their colon cancer return.

Thursday, May 18, 2017 


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Eat Your Way Through the Holidays with Healthy Cancer-Fighting Options

With the many winter holidays upon us, one of the great challenges is maintaining a healthy diet. Choosing healthier options helps many of us ward off extra pounds, but for those with cancer it is crucial to overall health.

If you are undergoing cancer treatment, such as chemotherapy or radiation, you need extra nutrients to help maintain your energy and keep you feeling strong. Even if your appetite has waned, you still need to make good food choices that fuel your body and help you heal.

Many traditional holiday foods can be high in unhealthy fats, refined carbohydrates, and added sugars which, when eaten in excess, can make you feel fatigued and miss out on nutrients vital for healing

Knowing what to eat and what to avoid can make the holiday season a healthy one for you. Follow the guidelines below to increase your intake of cancer-fighting nutrients, and keep you feeling your best this holiday season.

Fill one-fourth of your plate with complex carbohydrates. Carbohydrates are essential nutrients because they provide energy for body and brain. Good sources include whole grains (like oats, barley, farro, millet, and buckwheat), fruits, vegetables and beans. They also provide phytonutrients that offer cancer-fighting benefits and fiber to keep you fuller longer. Start by adding extra veggies to side dishes. Switch to whole-grain flour for baking your favorite holiday treats, try a bean dip or hummus with veggies as an appetizer, and include fresh fruits for dessert.

Choose healthy fats. Fat has been given a bad rap, but all fats are not equal. You want to avoid or limit saturated fats (the ones found in animal products like butter, cheese, and red meat) and trans-fatty acids (those that have been hydrogenated — often found in packaged foods and baked goods). Unsaturated fats are the good ones — olive oil, nuts, seeds, avocado, and fatty fish.

santa

Include protein at every meal. Protein is important for healing during and after treatment. It also is essential for maintaining strength and energy.  Choose a variety of plant sources, such as nuts and nut butters, seeds, beans, legumes, and soy.  Good sources of animal proteins include grass-fed beef, free-range poultry, wild-caught fish, eggs, and low-fat dairy.

Emphasize “Seasonal” Superfoods. Superfoods are the superheroes of nutrition —many are rich in antioxidants, vitamins and minerals to help you heal and reduce inflammation, thus reducing your risk of chronic diseases and promoting cancer survivorship. Many superfoods are popular during the holidays — such as cruciferous vegetables (kale, spinach, broccoli, cabbage, cauliflower), beans and legumes, citrus, sweet potatoes, nuts and mushrooms. Fresh cranberry sauce with orange and sweetened with agave or honey is an ideal choice to include in your holiday meals. Try adding antioxidant-rich pomegranate seeds to a kale salad for a festive starter, or warm up with pumpkin or butternut squash bisque. Sweet potatoes, baked or mashed, with a drizzle of pure maple syrup and a sprinkle of cinnamon, make a healthy and delicious side dish. Green beans sautéed with mushrooms and red bell peppers, steamed broccoli with lemon zest and garlic, and roasted Brussels sprouts caramelized with balsamic vinegar are all foods to fill up on. And if you’ve saved room for dessert, top a scoop of vanilla ice cream or yogurt with blueberries or raspberries and a sprinkle of cacao nibs.  Looking for something decadent? Bake an apple with cinnamon and nutmeg, and top it with chopped almonds or walnuts and maple syrup.

Remember: it is OK to have small portions of your favorite holiday foods, but fill most of your plate with a variety of plant-based foods such as colorful fruits and vegetables, whole grains, beans, and nuts.

Make a conscious effort to focus on healthy options this holiday season that will keep you strong and help you fight cancer.

Presented by Massachusetts General Hospital Cancer Center
 
 
This post is a sponsored collaboration between Massachusetts General Hospital Cancer Center and Boston magazine’s advertising department.


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What is Acrylamide?

Acrylamide is a chemical used mainly in certain industrial processes, such as in making paper, dyes, and plastics, and in treating drinking water and wastewater. There are small amounts in some consumer products, such as caulk, food packaging, and some adhesives. Acrylamide is also found in cigarette smoke.

Acrylamide can also form in some starchy foods during high-temperature cooking, such as frying, roasting, and baking. Acrylamide forms from sugars and an amino acid that are naturally in food; it does not come from food packaging or the environment.

How are people exposed to acrylamide?

In certain foods

Acrylamide has probably always been in some foods, but this wasn’t known until Swedish scientists first found it in certain foods in 2002.

Acrylamide doesn’t appear to be in raw foods themselves. It’s formed when certain starchy foods are cooked at high temperatures (above about 250° F). Cooking at high temperatures causes a chemical reaction between certain sugars and an amino acid (asparagine) in the food, which forms acrylamide. Cooking methods such as frying, baking, broiling, or roasting are more likely to create acrylamide, while boiling, steaming, and microwaving appear less likely to do so. Longer cooking times and cooking at higher temperatures can increase the amount of acrylamide in foods further.

Acrylamide is found mainly in plant foods, such as potato products, grain products, or coffee. Foods such as French fries and potato chips seem to have the highest levels of acrylamide, but it’s also found in breads and other grain products. Acrylamide does not form (or forms at lower levels) in dairy, meat, and fish products.

In cigarette smoke

Acrylamide is also found in cigarette smoke. This is probably one of the major ways smokers are exposed.

On the job

People who work in certain industries (particularly in the paper and pulp, construction, foundry, oil drilling, textiles, cosmetics, food processing, plastics, mining, and agricultural industries) may be exposed to acrylamide in the workplace, mainly through skin contact or by breathing it in. Regulations limit exposure in these settings.

Does acrylamide increase the risk of cancer?

Researchers use 2 main types of studies to try to figure out if a substance causes cancer.

  • Lab studies: In these studies, animals are exposed to a substance (often in very large doses) to see if it causes tumors or other health problems. Researchers might also expose normal cells in a lab dish to the substance to see if it causes the types of changes that are seen in cancer cells. It’s not always clear if the results from these types of studies will apply to humans, but lab studies are a good way to find out if a substance might possibly cause cancer.
  • Studies in people: This type of study looks at cancer rates in different groups of people. It might compare the cancer rate in a group exposed to a substance to the cancer rate in a group not exposed to it, or compare it to the cancer rate in the general population. But sometimes it can be hard to know what the results of these studies mean, because many other factors might affect the results.

In most cases neither type of study provides enough evidence on its own, so researchers usually look at both lab-based and human studies when trying to figure out if something causes cancer.

Based on the studies done so far, it’s not yet clear if acrylamide affects cancer risk in people.

Studies in the lab

Acrylamide has been found to increase the risk of several types of cancer when given to lab animals (rats and mice) in their drinking water. The doses of acrylamide given in these studies have been as much as 1,000 to 10,000 times higher than the levels people might be exposed to in foods. It’s not clear if these results would apply to people as well, but in general it makes sense to limit human exposure to substances that cause cancer in animals.

Studies in people

Since acrylamide was first found in certain foods in 2002, dozens of studies have looked at whether people who eat more of these foods might be at higher risk for certain cancers.

Most of the studies done so far have not found an increased risk of cancer in humans. For some types of cancer, such as kidney, endometrial, and ovarian cancer, the results have been mixed, but there are currently no cancer types for which there is clearly an increased risk related to acrylamide intake.

The studies that have been done so far have had some important limits. For example, many of the studies relied on food questionnaires that people filled out every couple of years. These questionnaires might not have accounted for all dietary sources of acrylamide. In addition, people might not accurately remember what they have eaten when asked in personal interviews or through questionnaires.

While the evidence from human studies so far is somewhat reassuring, more studies are needed to determine if acrylamide raises cancer risk in people. The American Cancer Society supports the call by federal and international agencies for continued evaluation of how acrylamide is formed, its health risks, and how its presence in food can be reduced or removed.

acrylamide

What expert agencies say

Several national and international agencies study substances in the environment to determine if they can cause cancer. (A substance that causes cancer or helps cancer grow is called a carcinogen.) The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies.

The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). Its major goal is to identify causes of cancer.

IARC classifies acrylamide as a “probable human carcinogen” based on data showing it can increase the risk of some types of cancer in lab animals. The evidence in humans was considered to be “inadequate” at the time of the last IARC review of the subject (1994), and at that time acrylamide was not known to be found in foods.

The National Toxicology Program (NTP) is formed from parts of several different US government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). In its most recent Report on Carcinogens (2014), the NTP has classified acrylamide as “reasonably anticipated to be a human carcinogen” based on the studies in lab animals.

The US Environmental Protection Agency (EPA) maintains the Integrated Risk Information System (IRIS), an electronic database that contains information on human health effects from exposure to various substances in the environment. The EPA classifies acrylamide as “likely to be carcinogenic to humans” based on studies in lab animals.

(For more information on the classification systems used by these agencies, see Known and Probable Human Carcinogens.)

It’s important to note that the determinations above are based mainly on studies in lab animals, and not on studies of people’s exposure to acrylamide from foods. Since the discovery of acrylamide in foods, the American Cancer Society, the FDA, and many other organizations have recognized the need for further research on this topic. Ongoing studies will continue to provide new information on whether acrylamide levels in foods are linked to increased cancer risk.

Are acrylamide levels regulated?

In the United States, the FDA regulates the amount of residual acrylamide in a variety of materials that come in contact with food, but there are currently no regulations on the presence of acrylamide in food itself. In 2016, the FDA issued guidance to help the food industry reduce the amount of acrylamide in certain foods, but these are recommendations, not regulations.

The EPA regulates acrylamide in drinking water. The EPA has set an acceptable level of acrylamide exposure, which is low enough to account for any uncertainty in the data relating acrylamide to cancer and other health effects.

In the workplace, exposure to acrylamide is regulated by the EPA and the Occupational Safety and Health Administration (OSHA).

Can I lower my exposure to acrylamide?

For most people, the major potential sources of acrylamide exposure are in certain foods and in cigarette smoke. It’s not yet clear if the levels of acrylamide in foods raise cancer risk, but for people who are concerned, there are some things you can do to lower your exposure.

Certain foods are more likely to contain acrylamide than others. These include potato products (especially French fries and potato chips), coffee, and foods made from grains (such as breakfast cereals, cookies, and toast). These foods are often part of a regular diet. But if you want to lower your acrylamide intake, reducing your intake of these foods is one way to do so.

The FDA’s advice on acrylamide is to adopt a healthy eating plan, consistent with the Dietary Guidelines for Americans, that:

  • Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.
  • Includes lean meats, poultry, fish, beans, eggs, and nuts.
  • Is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.

This type of diet is likely to have health benefits beyond lowering acrylamide levels.

Acrylamide has been detected in both home-cooked and in packaged or processed foods. Acrylamide levels in foods can vary widely depending on the manufacturer, the cooking time, and the method and temperature of the cooking process. Since acrylamide is formed from natural chemicals in food during cooking, acrylamide levels in cooked organic foods are likely to be similar to levels in cooked non-organic foods.

When cooking at home, some methods may lower the acrylamide levels produced in certain foods.

For potatoes, frying causes the highest acrylamide formation. Roasting potato pieces causes less acrylamide formation, followed by baking whole potatoes. Boiling potatoes and microwaving whole potatoes with skin on does not create acrylamide.

Soaking raw potato slices in water for 15 to 30 minutes before frying or roasting helps reduce acrylamide formation during cooking. (Soaked potatoes should be drained and blotted dry before cooking to prevent splattering or fires.)

Storing potatoes in the refrigerator can result in increased acrylamide during cooking. Therefore, store potatoes outside the refrigerator, preferably in a dark, cool place, such as a closet or a pantry, to prevent sprouting.

Generally, acrylamide levels rise when cooking is done for longer periods or at higher temperatures. Cooking cut potato products, such as frozen French fries or potato slices, to a golden yellow color rather than a brown color helps reduce acrylamide formation. Brown areas tend to have more acrylamide.

Toasting bread to a light brown color, rather than a dark brown color, lowers the amount of acrylamide. Very brown areas contain the most acrylamide.

Acrylamide forms in coffee when coffee beans are roasted, not when coffee is brewed at home or in a restaurant. So far, scientists have not found good ways to reduce acrylamide formation in coffee.

Not smoking and avoiding secondhand smoke are other ways to potentially reduce your exposure to acrylamide, as well as to many other potentially harmful chemicals.


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Alcohol Causes 7 Kinds of Cancer, Study Concludes

Alcohol researcher Jennie Connor says the link is a causal one and that no alcohol is considered safe and risk does go up as you drink.

Alcohol is a direct cause of seven forms of cancer. Tough words to swallow, but those are the conclusions of researchers from New Zealand, who say they found that no matter how much you drink, alcohol will increase your risk of cancer.

“There is strong evidence that alcohol causes cancer at seven sites in the body and probably others,” the authors write in the latest issue of the journal Addiction.

Those seven cancer sites are:

  • liver
  • colon
  • rectum
  • female breast
  • larynx, (the throat organ commonly called the voice box)
  • orolarynx (the middle part of the pharynx) behind the mouth
  • esophagus (commonly the “food pipe”)

The researchers from the University of Otago reviewed previous studies and meta-analyses, analyzing all the major studies done over the last decade on alcohol and cancer. They include studies from such prestigious names as the American Institute for Cancer Research and the International Agency for Research on Cancer.

alcohol

Several of these studies drew links between alcohol and cancer. But lead researcher Jennie Connor, the chair in preventive and social medicine at the university, says her team wanted to know if there was evidence of a causal relationship — meaning that alcohol was the direct cause of some of these cancers.

“And the first conclusion of the paper is that there is very strong evidence that the link we see between drinking and cancer in all these studies is a causal one,” Connor told CTV News Channel from Dunedin, New Zealand.

In fact, the team estimates that of all cancer deaths worldwide, 5.8 per cent of them can be attributed to alcohol.

The link between alcohol and cancer was strongest with cancer of the larynx and orolarynx than with the other cancers

Perhaps not surprisingly, the team found a “dose-response relationship” between alcohol and cancer, meaning that the more that a person drinks, the higher their risk to develop cancer.
So what constitutes a “safe” level of drinking?

“There doesn’t seem to be any threshold below which drinking is actually safe with respect to cancer,” Connor said.

“So the straightforward obvious answer to your question is that no alcohol is safe, and any alcohol increases your risk of some types of cancer.”

One bit of good news is that the cancer risk will drop for those who quit drinking, falling back to risk levels similar to “never drinkers” after 20 years.
As for what it is about alcohol that causes cancer, the researchers aren’t sure, as their paper was not designed to answer such questions.

“Confirmation of specific biological mechanisms by which alcohol increases the incidence of each type of cancer is not required to infer that alcohol is a cause,” they wrote.

This is not the first paper to conclude that alcohol is carcinogenic, and yet there persists a perception that a small amount of alcohol is not only safe but beneficial.

Many point to studies that found that drinking wine is good for the heart increases longevity. Connor says that there are a still a lot of myths about alcohol out there.

“(These myths) arise from research that has been updated now, or discredited, or there’s more doubt about it than they used to be,” she said.

“This paper also examines the connection between alcohol and being good for your heart – coronary disease – and it finds that evidence base is actually quite weak. So information evolves over time.”

Friday, July 22, 2016     CTVNews.ca Staff
 


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Helpless to Prevent Cancer? Actually, Quite a Bit Is in Your Control

North Americans seem very afraid of cancer, with good reason. Unlike other things that kill us, it often seems to come out of nowhere.

But evidence has increasingly accumulated that cancer may be preventable, too. Unfortunately, this has inflamed as much as it has assuaged people’s fears.

As a physician, I have encountered many people who believe that heart disease, which is the single biggest cause of death among North Americans, is largely controllable. After all, if people ate better, were physically active and stopped smoking, then lots of them would get better. This ignores the fact that people can’t change many risk factors of heart disease like age, race and family genetics.

People don’t often seem to feel the same way about cancer. They think it’s out of their control. A study published in Science in January 2015 seemed to support that view. It tried to explain why some tissues lead to cancer more often than others. It found a strong correlation between the number of times a cell divides in the course of a lifetime and the risk of developing cancer.

In other words, this study argued that the more times DNA replicates, the more often something can go wrong. Some took this to mean that cancer is much more because of “bad luck” than because of other factors that people could control.

Unfortunately, this simple explanation is not really what the study showed. Lung cells, for instance, divide quite rarely, and still account for a significant amount of cancer. Cells in the gastrointestinal tract divide all the time and account for many fewer cancers. Some cancers, like melanoma, were found to be in the group of cancers influenced more by intrinsic factors (or those we can’t control), when we clearly know that extrinsic factors, like sun exposure, are a major cause.

Further, this study was focused more on the relative risks of cancer in one type of tissue versus another. What we really care about is how much we can reduce our own risk of cancer by changing our behavior.

A more recent study published in Nature argues that there is a lot we can do. Many studies have shown that environmental risk factors and exposures contribute greatly to many cancers. Diet is related to colorectal cancer. Alcohol and tobacco are related to esophageal cancer. HPV is related to cervical cancer, and hepatitis C is related to liver cancer.

And you’d have to be living under a rock not to know that smoking causes lung cancer and that too much sun can lead to skin cancer.

Using sophisticated modeling techniques, the researchers argued that less than 30 percent of the lifetime risk of getting many common cancers was because of intrinsic risk factors, or the “bad luck.” The rest were things you can change.

Most recently, in JAMA Oncology, researchers sought to quantify how a healthful lifestyle might actually alter the risk of cancer. They identified four domains that are often noted to be related to disease prevention: smoking, drinking, obesity and exercise.

health lifestyle concept on blackboard

health lifestyle concept on blackboard

They defined people who engaged in healthy levels of all of these activities as a “low risk” group. Then they compared their risk of getting cancer with people who weren’t in this group. They included two groups of people who have been followed and studied a long time, the Nurses’ Health Study and the Health Professionals Follow-up Study, as well as national cancer statistics.

Of the nearly 90,000 women and more than 46,000 men, 16,531 women and 11,731 men fell into the low-risk group. For each type of cancer, researchers calculated a population-attributable risk, which is the percentage of people who develop cancer who might have avoided it had they adopted low-risk behaviors.

About 82 percent of women and 78 percent of men who got lung cancer might have prevented it through healthy behaviors. About 29 percent of women and 20 percent of men might have prevented colon and rectal cancer. About 30 percent of both might have prevented pancreatic cancer. Breast cancer was much less preventable: 4 percent.

Over all, though, about 25 percent of cancer in women and 33 percent in men was potentially preventable. Close to half of all cancer deaths might be prevented as well.

No study is perfect, and this is no exception. These cohorts are overwhelmingly white and consist of health professionals, who are not necessarily like the population at large. But the checks against the national data showed that if anything, these results might be underestimating how much cancer is preventable by healthy behaviors.

This also isn’t a randomized controlled trial, and we can certainly argue that it doesn’t prove causation.

A bigger concern to me is that people might interpret these findings as assigning fault to people who get cancer. You don’t want to get into situations where you feel as if people don’t deserve help because they didn’t try hard enough to stay healthy. Much of cancer is still out of people’s control.

I was especially worried because, in this study, “low risk” status required all four healthy lifestyles. Failing in any one domain put you in the high-risk category, and that seemed like a lot to ask of people.

On further reading, though, I discovered that the requirements weren’t overly burdensome. Not smoking was defined as never having smoked or having quit at least five years ago. That’s clearly good for health. Moderate alcohol consumption was defined as no more than one drink a day on average for women, and no more than two for men. That’s pretty much what I have argued for in writing about this issue in the past; it in no way requires abstinence.

Adequate weight was defined as a B.M.I. of at least 18.5 and no more than 27.5. The cutoff for “overweight” is 25, meaning that you don’t have to be thin; you just have to be less than obese (B.M.I. 30). Finally, exercise was defined as 150 minutes a week of moderate-intensity activity or 75 minutes of vigorous-intensity activity. That’s a reasonable and quite achievable goal.

I was surprised to realize that I’m already “low risk.” I bet many people reading this are “low risk,” too.

As we talk about cancer “moonshots” that will most likely cost billions of dollars and might not achieve results, it’s worth considering that — as in many cases — prevention is not only the cheapest course, but also the most effective.

Simple changes to people’s behaviors have the potential to make sure many cancers never occur. They have a side benefit of preventing health problems in many other areas, too. Investment in these efforts may not be as exciting, but it may yield greater results.

Aaron E. Carroll is a professor of pediatrics at Indiana University School of Medicine.

The Upshot provides news, analysis and graphics about politics, policy and everyday life. Follow us on Facebook and Twitter.
A version of this article appears in print on July 7, 2016, on page A3 of the New York edition
 with the headline: Small Lifestyle Changes Can Sharply Cut Cancer Risk.
Aaron E. Carroll      THE NEW HEALTH CARE      JULY 5, 2016