Month: July 2023

Colon cancer is the second-deadliest form of cancer after lung cancer. If recent messages about colon cancer screening have left you a little confused, that's understandable. In August, the American College of Physicians (ACP) released updated guidance for colon cancer screening that differs from other major organizations, including recommendations from the American Cancer Society (ACS) and the US Preventive Services Task force (USPSTF).

So, what do you need to know?

How does the advice differ?

First, please note that this advice applies only to people at average risk without a family history of colon cancer. If you have family history, or if other health issues put you at higher-than-average risk for colorectal cancer, talk to your doctor about the best course of action for you.

The main point of disagreement relates to the age at which people should start getting screened. The new ACP guidance says 50, while the other two organizations recommend 45. That earlier age is endorsed by the U.S. Multisociety Task Force on Colorectal Cancer. It's also endorsed by many physicians, including Harvard Medical School professor Dr. Andrew T. Chan, a gastroenterologist and director of epidemiology at Massachusetts General Hospital Cancer Center, who helps explain key facts below.

Why do experts suggest starting screening earlier?

"We're facing an unexplained and alarming increase in the incidence of colon cancer in people younger than 50," says Dr. Chan.

Overall, deaths from colon cancer dropped by 2% per year from 2011 to 2020. But that's not the case among people younger than 50. In that age group, deaths from colon cancer rose between 0.5% and 3% during the same time period, according to statistics published in 2023.

The rising rates of colon cancer in younger people are occurring in all racial and ethnic groups, with the steepest rises seen among Alaskan Natives and Native Americans. Overall, Blacks and African Americans are more likely to get and die from colon cancer than whites, and early-onset cases are higher in Black individuals than whites.

Efforts to encourage colon cancer screening began in the mid-1990s. Today, about 60% of adults over 50 follow the advice to receive a colonoscopy (described below) on a regular basis. This track record, while not perfect, likely explains the decline in deaths from colon cancer in older adults.

"I think that promoting earlier screening will help stem the rise in early-onset cases, at least for those in their 40s. We've also seen that earlier colonoscopies may be associated with lowering incidence of colon cancer even later in life, "says Dr. Chan.

What are the different screening tests for colon cancer?

The two most widely used screening tests are a standard colonoscopy and various stool-based tests.

Colonoscopy. For this test, a gastroenterologist or surgeon snakes a long, flexible tube with a camera on the end through your rectum and beyond to inspect the entire length of your colon. Considered the gold-standard test, this procedure can detect precancerous polyps called adenomas, and allow for their removal.

The test requires taking laxatives and drinking lots of fluids beforehand to clean all the fecal material (stool) out of your colon. Serious complications, which include perforation or bleeding, are rare, occurring in about three in 1,000 procedures. If no polyps are found, a repeat colonoscopy isn't recommended for another 10 years. If you have polyps, or your risk or symptoms change, this interval will be shorter.

Stool tests. The more worrisome colon polyps (adenomas) often shed tiny amounts of blood and abnormal DNA into the stool. This can be detected from samples you collect yourself at home.

• Two tests, the fecal occult blood test (FOBT) and fecal immunochemical test (FIT), check for blood. They require small stool samples that you put on a card or in a tube that's then mailed to a lab. These tests should be done every year.
• A third option, the FIT-DNA test, checks for both blood and abnormal DNA; it's usually repeated every three years.

Additionally, the guidelines from the American College of Physicians suggest another option: flexible sigmoidoscopy, which inspects only the lower part of the colon, once every 10 years, combined with a fecal FIT testing every two years. However, doctors in the United States rarely order sigmoidoscopy today.

If flexible sigmoidoscopy or any of these stool tests show evidence of a problem, a colonoscopy is needed to check for adenomas or cancer.

Why might stool-based screening make sense for younger adults?

Colonoscopy isn't necessarily the best initial screening test for everyone, says Dr. Chan. That's especially true for younger people, mainly because it's time-consuming and inconvenient.

"Maybe you just can't find time in your schedule or are worried about having a colonoscopy," he says. If that's the case, a stool-based test — which is noninvasive and takes very little time — is an appropriate option.

"The worst option is not doing anything, because early detection and treatment can prevent deaths," he says.

About the Author

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio View all posts by Julie Corliss

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

Ever see ads for products that promise to supercharge immunity? Activate your body’s natural defenses? Support a healthy immune system while delivering a potent boost derived from nature’s hottest immune-enhancing ingredients?

While the words may change to reflect the latest trends, the claims certainly sound amazing. But do the multitude of products promoted as immune boosters actually work? What steps can we take to support the immune system? Both are important questions, especially in the wake of a deadly pandemic and as flu and cold season arrives.

IV drips, supplements, cleanses, and superfoods

The lineup of immune-boosting products and advice includes:

• Home intravenous (IV) drips. Want a health professional to come to your home with IV fluids containing various vitamins and supplements? That’s available in many US cities, and some companies claim their formula is designed to supercharge immunity. These on-demand IV treatments aren’t risk-free and can be quite expensive.
• Vitamins and supplements. Popular options include turmeric, milk thistle, and echinacea, often in combination with various vitamins. Hundreds of formulations are available.
• Superfoods and foods to avoid. If you search online for “foods to boost the immune system” you’ll see thousands of articles touting blueberries, broccoli, spinach, dark chocolate, and other foods to keep infections away. There’s also a list of foods to avoid, such as sugary drinks or highly processed meats, because they’re supposed to be bad for your immune system.
• Cleanses and detox treatments. No doubt you’ve seen pitches for cleanses and detox products intended to remove toxins from the body. Their marketing warns that the environment is full of harmful substances that get into the body through the air, water, and food, which we need to remove. Advocates suggest that, among other harmful effects, these often unnamed toxins make your immune system sluggish.

Are the heavily marketed IV drips, supplements, or detox products endorsed by the FDA?

No. In fact, the standard disclaimer on supplements’ claims of immune-boosting properties says: “This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.”

Yet sellers are allowed to use phrases like “boosts immune function” and “supports immune health.” These terms have always seemed vague to me. More importantly, they’re confusing:

• Boosting immunity is what vaccinations do. They prime your immune system to help fight off a specific infectious organism (like the flu shot before each flu season).

• Immune support typically describes vitamins such as vitamin C, or other nutrients necessary for a healthy immune system. It’s true that a deficiency of vital nutrients can cause poor immune function. But that doesn’t mean a person with normal levels of nutrients can expect supplements to improve their immune system.

Can products marketed as immune boosters actually boost immunity?

Unless you have a deficiency in a key nutrient, such as vitamin C or zinc, the short answer is no.

That is, there’s no convincing evidence that any particular product meaningfully improves immune function in healthy people. For example, results of studies looking at various supplements for colds and other similar infections have been mixed at best. Even when taking a particular supplement was linked to reduced severity or duration of an infection like a cold, there’s no proof that the supplement boosted overall immune function.

This goes for individual foods as well. None has ever been shown to improve immune function on its own. It’s the overall quality of your diet, not individual foods, that matters most. A similar approach applies to advice on foods you should avoid, such as sugary drinks or highly processed meats: the best foods to avoid in support of your immune system are the same ones you should be limiting anyway.

How to get the most out of your immune system

It’s not a secret and it’s not a product. What’s good for your overall health is good for immune function. The best ways to keep your immune system at peak performance are:

• Eat well and follow a heart-healthy diet, such as the Mediterranean diet.
• Exercise regularly and maintain a healthy weight.
• Don’t smoke or vape.
• If you drink alcoholic beverages, drink only in moderation.
• Get plenty of sleep.
• Minimize stress.
• Get regular medical care, including routine vaccinations.
• Take measures to prevent infection such as frequent hand washing, avoiding people who might have a contagious illness, and wearing a mask when it’s recommended.

This list probably looks familiar. These measures have long been recommended for overall health, and can do a lot to help many of us.

Certain illnesses — HIV, some cancers, and autoimmune disorders — or their treatments can affect how well the immune system works. So some people may need additional help from medications and therapies, which could truly count as immune boosting.

The bottom line

Perhaps there will come a time when we’ll know how to boost immune function beyond following routine health measures. That’s simply not the case now. Until we know more, I wouldn’t rely on individual foods, detox programs, oral supplements, or on-demand IV drips to keep your immune system healthy, especially when there are far more reliable options.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD