Individuals who increased their daily consumption of coffee by more than a cup over time had an 11% reduced risk of developing type 2 diabetes compared with people whose consumption stayed the same, according to a study in the journal Diabetologia. Individuals who reduced their coffee intake by more than a cup a day had a 17% higher risk of diabetes.
Need an excuse to drink yet another cup of coffee today? A new study suggests that increasing coffee consumption may decrease the risk for type 2 diabetes.
The apparent relationship between coffee and type 2 diabetes is not new. Previous studies have found that drinking a few cups or more each day may lower your risk – with each subsequent cup nudging up the benefit.
This most recent study, published in the journal Diabetologia, was more concerned with how changing coffee consumption – either increasing it or decreasing it over time – might affect your risk.
The conclusion: People who upped their consumption by more than a cup per day had an 11% lower risk of type 2 diabetes compared with people whose consumption held steady. Decreasing coffee consumption by the same amount – more than a cup a day – was associated with a 17% increased risk of type 2 diabetes.
The data is based on an analysis of more than 120,000 health professionals already being followed observationally long term. Researchers looked at the study participants’ coffee drinking habits across four years to reach their conclusions.
Just how much coffee each day provides a benefit?
“For type 2 diabetes, up to six cups per day is associated with lower risk,” said Shilpa Bhupathiraju, a research fellow at the Harvard School of Public Health and lead study author, citing previous research. “As long as coffee doesn’t give you tremors, doesn’t make you jittery, it is associated with a lot of health benefits.”
In the case of diabetes, the reasons behind the supposed protection conferred by coffee are not clear, but there are theories based on animal research.
One involves chemicals present in coffee – phenolic compounds and lignans – that may improve glucose metabolism, according to Bhupathiraju. She added that coffee is rich in magnesium, which is also associated with a lower risk of type 2 diabetes.
Coffee drinking linked to longer life
Wait, though. Before you scramble out to purchase your fourth latte of the day, it is important to note that the type of coffee matters.
Lattes and other types of specialty drinks – often laden with sugar – were not studied. The type of coffee involved in this study tended to be a simple eight-ounce cup of black coffee containing about 100 milligrams of caffeine.
“People think of (increasing their intake) as going and drinking an extra blended drink,” said Bhupathiraju. “We are not talking about ‘frappuchinos’ or lattes. It’s black coffee with milk and sugar.”
Coffee good for you, but it’s OK to hold back
And while coffee may be associated with a reduction in some chronic diseases (not just diabetes, but cardiovascular disease, certain cancers, and – according to a New England Journal of Medicine study – with a longer life, overall) scientists are still reluctant to call coffee a panacea.
That doesn’t mean you can’t enjoy one more cup in the meantime.
Eminent cardiologist Gordon Tomaselli has warned against applying the results of a small study linking caffeinated coffee with better blood vessel function to other products such as energy drinks.
It often happens that if something is shown to be of benefit, others jump on the band wagon to claim those benefits by association. Remember all the fuss over red wine’s health benefits? Resveratrol, the substance from grape seeds was studied. Pretty soon everyone started believing red wine was a health food. (It can be in moderation). This is the point that is often missed in many cases involving food and nutritional supplements.
In the case of energy drinks, the beverage industry is looking for anything that offers a ray of hope to stave off increased regulation. Consumers require some perspective when the conversation turns to regulation.
Nine out of ten poisoning deaths in the U.S. related to prescription drugs. In 2006, 275 adverse supplement reactions were reported. Of those 275 dietary supplements calls, 41% involved symptomatic exposures; and two-thirds were rated as probably or possibly related to supplement use. Eight adverse events required hospital admission. Sympathomimetic toxicity was most common, with caffeine products accounting for 47%.
So it’s not surprising that a small study showing that coffee may help perk up your blood vessels gets taken out of context and gets applied to an entire beverage category. After all, it’s caffeine and caffeine is good. Must be true that more caffeine is better.
It follows that products with caffeine or caffeine related substances would jump on the band wagon to tout the health benefits even if none exist. Coffee is a natural substance with complex phytonutrients. Those substances work synergistically in our bodies to deliver the benefits to human health. Just because a product formulation includes healthy individual ingredients, it doesn’t necessarily follow that the consumer is getting the same health benefits those substances were proven to have.
Those cups of coffee that you drink every day to keep alert appear to have an extra perk – especially if you’re an older adult. A recent study monitoring the memory and thinking processes of people older than 65 found that all those with higher blood caffeine levels avoided the onset of Alzheimer’s disease in the two-to-four years of study follow-up. Moreover, coffee appeared to be the major or only source of caffeine for these individuals.
Researchers from the University of South Florida (www.usf.edu) and the University of Miami (www.miami.edu) 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 will appear in the online version of an article to be published June 5 in the Journal of Alzheimer’s Disease, published by IOS Press (http://health.usf.edu/nocms/publicaffairs/now/pdfs/JAD111781.pdf). 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.
“Moderate daily consumption of caffeinated coffee appears to be the best dietary option for long-term protection against Alzheimer’s memory loss,”
“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.
“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, readilyavailable, 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.
- Full bibliographic information“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.