Unhealthy lifestyle linked to nearly half of US cancer deaths

A study by Islami et al was published in CA: A Cancer Journal for Clinicians suggests nearly half of cancer deaths in the US are caused by smoking, poor diet and other unhealthy habits.

The investigators analyzed data from the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute.  They calculated how many of cancer cases and deaths can be attributed to factors that people can change.  They found that among more than 1.5 million cancers in 2014, 42% of the cancers (659,640 of 1,570,975) and 45% of deaths (265,150 of 587,521) in 2014 were traced to modifiable habits mentioned above.

Specifically smoking was associated with more cancer cases and deaths than any other single risk factor, accounting for nearly 20 percent of all cancer cases and 30 percent of all cancer deaths, followed by excess body weight which caused 7.8% of cases and 6.5%, of deaths. The data also indicated that excessive alcohol drinking causes 5.6 of cancer cases and 4 percent of deaths.  Lung cancer had the highest number of cancers (184,970 cases and 132,960 deaths), followed by colorectal cancer (76,910 cases and 28,290 deaths).

The authors suggest a vast potential for reducing cancer morbidity and mortality through lifestyle changes such as decreases in smoking; secondhand smoke; excess body weight; alcohol intake; consumption of red and processed meat an increased consumption of fruits/vegetables, dietary fiber; physical activity and decrease exposure to ultraviolet radiation; and cancer-associated infections.

Decreased sodium intake may decrease mortality

According to a study by Cook et al published in the Journal of the American College of Cardiology keeping sodium intake low may prolong life.

The researchers conducted two trials, phase I between1987 to 1990, over 18 months, and phase II between1990 to 1995, over 36 months, both were undertaken in TOHP (Trials of Hypertension Prevention), which implemented sodium reduction interventions. The studies included multiple 24-h urine samples collected from pre-hypertensive adults 30 to 54 years of age. Post-trial deaths were ascertained over a period of 24 years.

After following 3,126 people with hypertension for 24 years, the investigators found an increased mortality risk for those on high-sodium intake and a direct relationship with total mortality, even at the lowest levels of sodium intake. The 12% increase in total mortality per 1,000 mg of Na increased intake per 24 hours was impressive. 

Most Americans consume more salt than they need, according to the Dietary Guidelines published by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture.  The guidelines recommend that sodium intake should not exceed 2,300 milligrams of sodium a day, about a teaspoon of table salt.  The guidelines also recommend that individuals with hypertension, blacks, and and older adults should limit sodium intake to 1,500 mg per day.

The investigators concluded that their findings are suggestive that reduced sodium intake may prolong life. 

a

New Blood Pressure Guidelines

Until recently high blood pressure was defined as blood pressure (BP) persistently above 140 mm Hg systolic or 90 mm Hg diastolic, but according to the 2017 hypertension guideline from a joint task force by the American College of Cardiology (ACC) and the American Heart Association (AHA), based on a review of almost 1,000 studies redefined high BP as readings persistently above 130 over 80 mm Hg which is now defined as hypertension. The new guideline is meant to prevent strokes, heart attacks, heart and kidney failure through lifestyle changes such as eating a healthy diet, exercising, reducing salt intake, loosing weight if overweight and taking antihypertensive medications if needed.

The ACC/AHA guideline provides four categories of BP, ranging from normal to stage II hypertension, as shown in the image above.  The guidelines, which were published in the Journal of the American College of Cardiology, prescribe exactly how blood pressure should checked.  Physicians and nurses are urged to let patients rest five minutes first and then to average at least two readings over two separate visits.  Meanwhile, patients are urged to take regular readings at home, with a device checked out by their health care providers.  The four categories are based on average BP measurements and for individuals with an abnormal systolic BP and diastolic BP, the designation should go to the higher category. To confirm a new diagnosis of hypertension, an out-of-office in the patient’s house confirmation of elevated BP is strongly suggested as the “white coat” high BP can wrongly categorize someone as having hypertension.

Based on the new guideline 46 percent of US adults, many of them under the age of 45, will now be considered hypertensive while under the previous guideline, 32 percent of US adults had hypertension.