Researchers from the University of South Florida and the University of Miami say the case control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset.  Their findings appear in the online version of an article  published June 5 in the Journal of Alzheimer’s Disease. The collaborative study involved 124 people, ages 65 to 88, in Tampa and Miami.

“These intriguing results suggest that older adults with mild memory impairment who drink moderate levels of coffee — about 3 cups a day — will not convert to Alzheimer’s disease — or at least will experience a substantial delay before converting to Alzheimer’s,” said study lead author Dr. Chuanhai Cao, a neuroscientist at the USF College of Pharmacy and the USF Health Byrd Alzheimer’s Institute. “The results from this study, along with our earlier studies in Alzheimer’s mice, are very consistent in indicating that moderate daily caffeine/coffee intake throughout adulthood should appreciably protect against Alzheimer’s disease later in life.”

The study shows this protection probably occurs even in older people with early signs of the disease, called mild cognitive impairment, or MCI.  Patients with MCI already experience some short-term memory loss and initial Alzheimer’s pathology in their brains.  Each year, about 15 percent of MCI patients progress to full-blown Alzheimer’s disease.  The researchers focused on study participants with MCI, because many were destined to develop Alzheimer’s within a few years.

Blood caffeine levels at the study’s onset were substantially lower (51 percent less) in participants diagnosed with MCI who progressed to dementia during the two-to-four year follow-up than in those whose mild cognitive impairment remained stable over the same period.

No one with MCI who later developed Alzheimer’s had initial blood caffeine levels above a critical level of 1200 ng/ml – equivalent to drinking several cups of coffee a few hours before the blood sample was drawn.  In contrast, many with stable MCI had blood caffeine levels higher than this critical level.

“We found that 100 percent of the MCI patients with plasma caffeine levels above the critical level experienced no conversion to Alzheimer’s disease during the two-to-four year follow-up period,” said study co-author Dr. Gary Arendash.

The researchers believe higher blood caffeine levels indicate habitually higher caffeine intake, most probably through coffee.  Caffeinated coffee appeared to be the main, if not exclusive, source of caffeine in the memory-protected MCI patients, because they had the same profile of blood immune markers as Alzheimer’s mice given caffeinated coffee. Alzheimer’s mice given caffeine alone or decaffeinated coffee had a very different immune marker profile.

Since 2006, USF’s Dr. Cao and Dr. Arendash have published several studies investigating the effects of caffeine/coffee administered to Alzheimer’s mice.   Most recently, they reported that caffeine interacts with a yet unidentified component of coffee to boost blood levels of a critical growth factor that seems to fight off the Alzheimer’s disease process.

USF Health's Dr. Chuanhai Cao, study lead author

“We are not saying that moderate coffee consumption will completely protect people from Alzheimer’s disease,” Dr. Cao cautioned.  “However, we firmly believe that moderate coffee consumption can appreciably reduce your risk of Alzheimer’s or delay its onset.”

Alzheimer’s pathology is a process in which plaques and tangles accumulate in the brain, killing nerve cells, destroying neural connections, and ultimately leading to progressive and irreversible memory loss.  Since the neurodegenerative disease starts one or two decades before cognitive decline becomes apparent, the study authors point out, any intervention to cut the risk of Alzheimer’s should ideally begin that far in advance of symptoms.

“Moderate daily consumption of caffeinated coffee appears to be the best dietary option for long-term protection against Alzheimer’s memory loss,” Dr. Arendash said.  “Coffee is inexpensive, readily available, easily gets into the brain, and has few side-effects for most of us. Moreover, our studies show that caffeine and coffee appear to directly attack the Alzheimer’s disease process.”

In addition to Alzheimer’s disease, moderate caffeine/coffee intake appears to reduce the risk of several other diseases of aging, including Parkinson’s disease, stroke, Type II diabetes, and breast cancer.  However, supporting studies for these benefits have all been observational (uncontrolled), and controlled clinical trials are needed to definitively demonstrate therapeutic value.

A study tracking the health and coffee consumption of more than 400,000 older adults for 13 years, and published earlier this year in the New England Journal of Medicine, found that coffee drinkers reduced their risk of dying from heart disease, lung disease, pneumonia, stroke, diabetes, infections, and even injuries and accidents.

With new Alzheimer’s diagnostic guidelines encompassing the full continuum of the disease, approximately 10 million Americans now fall within one of three developmental stages of Alzheimer’s disease — Alzheimer’s disease brain pathology only, MCI, or diagnosed Alzheimer’s disease.  That number is expected to climb even higher as the baby-boomer generation continues to enter older age, unless an effective and proven preventive measure is identified.

“If we could conduct a large cohort study to look into the mechanisms of how and why coffee and caffeine can delay or prevent Alzheimer’s disease, it might result in billions of dollars in savings each year in addition to improved quality of life,” Dr. Cao said.

The USF-UM study was funded by the NIH-designated Florida Alzheimer’s Disease Research Center and the State of Florida.

Article citation:
“High Blood Caffeine Levels in MCI Linked to Lack of Progression to Dementia;”  Chuanhai Cao, David A. Lowenstein, Xiaoyang Lin, Chi Zang, Li Wang, Ranjan Duara, Yougui Wu, Alessandra Giannini, Ge Bai, Jianfeng Cai, Maria Greig, Elizabeth Schofield, Raj Ashok, Brent Small, Huntington Potter and Gary W. Arendash;  Journal of Alzheimer’s Disease, 29 (2012) 1-14,  DOI 10.3233/JAD-2012-111781.

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USF Health’s mission is to envision and implement the future of health. It is the partnership of the USF Health Morsani College of Medicine, the College of Nursing, the College of Public Health, the College of Pharmacy, the School of Biomedical Sciences and the School of Physical Therapy and Rehabilitation Sciences; and the USF Physician’s Group. The University of South Florida is a global research university ranked 50^th in the nation by the National Science Foundation for both federal and total research expenditures among all U.S. universities.

Media contacts:
Shani Jefferson, USF Health Byrd Alzheimer’s Institute, 813-396-0675 or  sjeffer1@health.usf.edu
Anne DeLotto Baier, USF Health Communications, (813) 974-3303 or abaier@health.usf.edu

For reasons not yet understood, African Americans have the highest incidence of colorectal cancer of all ethnic groups in the U.S.

Kent Robinson prefers to remember his father as the robust, active man who would be the first to scramble to the top of a roof to make a needed repair.

“He went from construction and fixing roofs to bedridden not too long after his diagnosis,” said Robinson, whose 86-year-old father was diagnosed with metastatic colon cancer late last year after exploratory surgery.

Robinson, 42, flew home to Freeport, Bahamas, in December to help his family move his father from the hospital into a nursing home. “Before that he had never been to the doctor. When I saw him, he was skin and bones and had a colostomy bag,” he said.  “The change hit me like a ton of bricks.”

A nurse at the nursing home suggested that Robinson and his six older siblings – five brothers and one sister — get screened for colorectal cancer.  “She said all you guys should really get checked out. This cancer can be very hereditary.”

Robinson pushed the recommendation aside for several months after returning home to Tampa.  His younger sister had died of breast cancer at age 35, and two cousins on his father’s side had also died of cancer.    But, Robinson figured he was healthy, didn’t smoke or drink and exercised routinely.

Then, while visiting his primary care physician at USF Health for a routine physical, the doctor emphasized the need for early screening because Robinson’s family history heightened his risk.  “I decided I needed to just do it,” Robinson said.

* * *

During Robinson’s screening colonoscopy in early March, USF Health gastroenterologist Dr. Arthi Sanjeevi removed two precancerous growths, or polyps, from the inner wall of  his colon.  One, the size of a dime, could have turned into cancer “if he had not sought timely screening,” said Dr. Sanjeevi, an assistant professor of gastroenterology in the USF Health Division of Digestive Disorders and Nutrition.

Dr. Sanjeevi told Robinson she was glad he came in when he did.

USF Health gastroenterologist Dr. Arthi Sanjeevi speaks with patient Kent Robinson on a follow-up visit.

Dr. Sanjeevi points to a long-term study, published earlier this year in the New England Journal of Medicine, which found that colonoscopies not only prevent colorectal cancers, but dramatically cut deaths from the disease.

Dr.  Sanjeevi has heard all the reasons why people do not get colonoscopies, a somewhat involved and invasive test that uses a lighted instrument to examine the rectum and complete colon.  They’re embarrassed; they don’t want to go through the prescribed bowel cleanse with laxatives the day before the screening; they’re afraid of a bowel perforation (an extremely rare complication when the procedure is performed by an experienced colonoscopist).  She says she even had to persuade her parents to get screened after her aunt was diagnosed with colon cancer in her 70s.“One misconception is the idea that you’re protected if you have no family history of colorectal cancer,” she said. “But, if you take all comers with colon cancer, only 5 percent actually had a family history.”

* * *

The U.S. Preventive Services Task Force recommends screening for colorectal cancer beginning at age 50, although screening should begin at an earlier age for those with risk factors such as a family history of polyps or colorectal cancer. Screening tests include colonoscopy, sigmoidoscopy, stool blood tests, stool DNA, CT colonography (virtual colonoscopy) and barium enema. However, Dr. Sanjeevi said, colonoscopy is still considered the preferred method because it is the only test that both detects and removes precancerous polyps during the same exam.

While there has been an unprecedented decline in the overall incidence and death rates from colorectal cancer in the last several years, several studies have shown an increase for patients younger than 50, most significantly among those ages 40 to 44. An epidemiological study published last year by Dr. Jorge Marcet and colleagues at the USF Health Department of Surgery (Journal of the American College of Surgeons) suggests lowering the recommended age for beginning colorectal cancer screening to 40, “an age at which the incidence mirrors other accepted screened cancers.”

Dr. Sanjeevi stands beside a monitor displaying a precancerous colon polyp, which was removed during a screening colonoscopy.

In addition, for reasons not yet understood, African Americans have the highest colorectal cancer incidence and death rates of all ethnic groups in the United States. Both the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy recommend that African Americans begin screening at age 45.

“More recently, data has indicated that colorectal cancer may start at an earlier age and progress more aggressively in African Americans than in the general population,” Dr. Sanjeevi said. “There’s increasing evidence that that certain ethnic subsets, including African Americans may have a higher prevalence of genetic mutations resulting from microsatellite instability in their tumors.”

Microsatellite instability — a key factor in colorectal, endometrial, gastric and other cancers — arises when damaged DNA is replicated due to defects in the normal DNA repair process.  This leads to inactivation of major tumor suppressor genes that regulate cell growth and prevent cancer.

* * *

Robinson will continue to monitor his health for any signs of colon cancer (change in bowel habits, constipation, diarrhea, blood in the stool, etc.) and return for a follow-up colonoscopy in five years. In the meantime, he’s working on convincing his older siblings to get screened for colorectal cancer.

He cherishes more than ever the time spent with his 7-year-old daughter Aladrienne. “I wouldn’t want my life cut short when I could be spending it with her,” Robinson said. “I want to see her graduate high school, go to college and walk her down the aisle.”

The message he wants others to hear is one he’s taken to heart: Do everything you can to avoid the risk of being diagnosed with colorectal cancer in the advanced stages when the disease is more difficult to treat, he said. “Don’t be embarrassed to get a colonoscopy. It’s a medical procedure, and it’s better to know than not know.”

Photos by Eric Younghans, USF Health Communications

Thorough bowel prep needed for optimal colonoscopy results

If you don’t have an effective preparation of the bowel, the results of your screening colonoscopy won’t be optimal, says USF Health gastroenterologist Dr. Arthi Sanjeevi. “The prep needs to be high quality so that any polyps, big or small, can be detected.”

Bowel preparation for colonoscopy refers to laxatives taken before the procedure to cleanse the colon of all fecal debris.  If you’re insides aren’t as clean as possible, it’s harder to for the camera at the tip of the colonoscope to “see” polyps, especially the harder-to-detect flat kind, or even a small cancer.

How can you maximize your chances of an effective bowel preparation?  Dr.Sanjeevi suggests the following:

• Ask if the doctor might recommend split dosing. Split dosing refers to taking half the prescribed laxative the night before the colonoscopy and the other half on the day of the procedure (6 to 8 hours before the colonoscopy).  Several studies have shown that split dosing significantly improves the quality of preparation for colonoscopy. Taking the entire laxative the night before a colonoscopy is good for flushing out fecal debris, but the large lag time leaves the potential for intestinal secretions from the small intestine to enter the right side of the large intestine between the end of the bowel prep and the start of the colonoscopy. This right side is critical to view because cancers commonly develop here.

• Start eating a low-fiber diet three to four days before your colonoscopy. Avoiding high-fiber foods, like whole grain cereals, nuts, raw or leafy vegetables and fruits, will help clean out the large intestine.

• Take a daily stool softener, such as Colace or ducolax, beginning the week before your procedure.

• Stay away from all solid foods after breakfast the day before your colonoscopy and adhere to the recommended clear liquid diet. That includes no dark or colorful liquids such as red or purple fluids, or heavier beverages such a milk or smoothies that may stick to the walls of the digestive tract and impair visibility.