Coffee may not be as bad as previously thought

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Drinking coffee might keep us up at night, but new research has given us a reason to sleep easy knowing that the popular drink isn’t as bad for our arteries as some previous studies would suggest.

The research from Queen Mary University of London has shown that drinking coffee, including in people who drink up to 25 cups a day, is not associated with having stiffer arteries. The research, led by Professor Steffen Petersen, was presented recently at the British Cardiovascular Society (BCS) Conference in Manchester and part-funded by the British Heart Foundation (BHF).

Arteries carry blood containing oxygen and nutrients from your heart to the rest of your body. If they become stiff, it can increase the workload on the heart and increase a person’s chance of having a heart attack or stroke.

Study debunks earlier claims

The study of over 8,000 people in the UK debunks previous studies that claimed drinking coffee increases arterial stiffness. Previous suggestions that drinking coffee leads to stiffer arteries are inconsistent and could be limited by lower participant numbers, according to the team behind this new research.

Coffee consumption was categorized into three groups for the study. Those who drink less than one cup a day, those who drink between one and three cups a day and those who drink more than three. People who consumed more than 25 cups of coffee a day were excluded, but no increased stiffening of arteries was associated with those who drank up to this high limit when compared with those who drank less than one cup a day.

The associations between drinking coffee and artery stiffness measures were corrected for contributing factors like age, gender, ethnicity, smoking status, height, weight, how much alcohol someone drank, what they ate and high blood pressure.

Of the 8,412 participants who underwent MRI heart scans and infrared pulse wave tests, the research showed that moderate and heavy coffee drinkers were most likely to be male, smoke, and consume alcohol regularly.

“Despite the huge popularity of coffee worldwide, different reports could put people off from enjoying it. Whilst we can’t prove a causal link in this study, our research indicates coffee isn’t as bad for the arteries as previous studies would suggest,” said Dr Kenneth Fung, who led the data analysis for the research at Queen Mary University of London.

“Although our study included individuals who drink up to 25 cups a day, the average intake amongt the highest coffee consumption group was 5 cups a day. We would like to study these people more closely in our future work so that we can help to advise safe limits,” said Professor Metin Avkiran, Associate Medical Director at the British Heart Foundation. “”There are several conflicting studies saying different things about coffee, and it can be difficult to filter what we should believe and what we shouldn’t. This research will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.”

Coffee may help prevent prostate cancer

For the first time, scientists have identified compounds found in coffee which may inhibit the growth of prostate cancer. This is a pilot study, carried out on drug-resistant cancer cells in cell culture and in a mouse model; it has not yet been tested in humans. This work is presented at the European Association of Urology congress in Barcelona, after publication in the peer-reviewed journal The Prostate*.

Coffee is a complex mixture of compounds which has been shown to influence human health in both positive and negative ways. There is increasing evidence that drinking certain types of coffee is associated with a reduction in incidence of some cancers, including prostate cancers. Now Japanese scientists have studied the effects of two compounds found in coffee, kahweol acetate and cafestol, on prostate cancer cells and in animals, where they were able to inhibit growth in cells which are resistant to common anti-cancer drugs such as Cabazitaxel.

The researchers initially tested six compounds, naturally found in coffee, on the proliferation of human prostate cancers cells in vitro (i.e. in a petri-dish). They found that cells treated with kahweol acetate and cafestol grew more slowly than controls. They then tested these compounds on prostate cancer cells which had been transplanted to mice (16 mice). 4 mice were controls, 4 were treated with kahweol acetate, 4 with cafestol, with the remaining mice being treated with a combination of kahweol acetate and cafestol.

A pilot study, more research needed

Study leader, Dr Hiroaki Iwamoto (Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Japan, first author of the study) said:

“We found that kahweol acetate and cafestol inhibited the growth of the cancer cells in mice, but the combination seemed to work synergistically, leading to a significantly slower tumour growth than in untreated mice. After 11 days, the untreated tumours had grown by around 3 and a half times the original volume (342%), whereas the tumors in the mice treated with both compounds had grown by around just over one and a half (167%) times the original size.

“It is important to keep these findings in perspective. This is a pilot study, so this work shows that the use of these compounds is scientifically feasible, but needs further investigation; it does not mean that the findings can yet be applied to humans. We also found the growth reduction in transplanted tumour cells, rather than in native tumour cells. What it does show is that these compounds appear to have an effect on drug resistant cells prostate cancer cells in the right circumstances, and that they too need further investigation. We are currently considering how we might test these findings in a larger sample, and then in humans.”

Kahweol acetate and cafestol are hydrocarbons, naturally found in Arabica coffee. The coffee-making process has been found to affect whether these compounds remain in coffee after brewing (as with espresso), or whether they are stripped out (as when filtered).

Professor Atsushi Mizokami (Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Japan) added:

“These are promising findings, but they should not make people change their coffee consumption. Coffee can have both positive and negative effects (for example it can increase hypertension), so we need to find out more about the mechanisms behind these findings before we can think about clinical applications. However, if we can confirm these results, we may have candidates to treat drug-resistant prostate cancer.”

May reduce risk of Alzheimer’s, Parkinson’s

Coffee has been shown to have numerous health benefits and researchers in Toronto may have found two more. They say that drinking coffee may protect you against both Alzheimer’s and Parkinson’s disease. And they’re not just talking about the full-strength caffeinated variety.

“Coffee consumption does seem to have some correlation to a decreased risk of developing Alzheimer’s disease and Parkinson’s disease,” says Dr. Donald Weaver, co-director of the Krembil Brain Institute at Toronto Western Hospital. “But we wanted to investigate why that is — which compounds are involved and how they may impact age-related cognitive decline.”

Dr. Weaver enlisted Dr. Ross Mancini, a research fellow in medicinal chemistry and Yanfei Wang, a biologist, to help. The team chose to investigate three different types of coffee — light roast, dark roast, and decaffeinated dark roast.

“The caffeinated and de-caffeinated dark roast both had identical potencies in our initial experimental tests,” said Dr. Mancini in a news release. “So we observed early on that its protective effect could not be due to caffeine.”

Mancini says this is due to a group of compounds known as phenylindanes, which are created as a result of the roasting process for coffee beans. Phenylindanes are the only compound investigated in the study that inhibit both beta amyloid and tau, two protein fragments common in Alzheimer’s and Parkinson’s, from clumping.

“So phenylindanes are a dual-inhibitor. Very interesting, we were not expecting that.” said Dr. Weaver.

Dark roast is best

As roasting leads to higher quantities of phenylindanes, dark roasted coffee appears to be more protective than light roasted coffee.

“It’s the first time anybody’s investigated how phenylindanes interact with the proteins that are responsible for Alzheimer’s and Parkinson’s,” said Dr. Mancini. “The next step would be to investigate how beneficial these compounds are, and whether they have the ability to enter the bloodstream, or cross the blood-brain barrier.”

The fact that it’s a natural compound vs. synthetic is also a major advantage, says Dr. Weaver. Last year, a study found that Italian-style coffee can lower the risk of prostate cancer.

“Mother Nature is a much better chemist than we are and Mother Nature is able to make these compounds. If you have a complicated compound, it’s nicer to grow it in a crop, harvest the crop, grind the crop out and extract it than try to make it.”

But, he admits, there is much more research needed before it can translate into potential therapeutic options.

“What this study does is take the epidemiological evidence and try to refine it and to demonstrate that there are indeed components within coffee that are beneficial to warding off cognitive decline. It’s interesting but are we suggesting that coffee is a cure? Absolutely not.”

The findings were published in Frontiers in Neuroscience.

Wake up and smell the coffee

Regular coffee drinkers can sniff out even tiny amounts of coffee and are faster at recognizing the aroma, compared to non-coffee drinkers, new research has found.

Habitual coffee drinkers are not just more sensitive to the odor of coffee and faster to identify it, but the more they craved coffee, the better their ability to smell it became. It is the first time evidence has been found to prove coffee addicts are more sensitive to the smell of coffee.

The results could open the door to potential new ways of using aversion therapy to treat people addicted to substances with a distinct smell, such as tobacco and cannabis.

The research was led by Dr Lorenzo Stafford, an olfactory expert in the Department of Psychology at the University of Portsmouth.

He said: “We found the higher the caffeine use, the quicker a person recognized the odor of coffee.

Higher caffeine users have better sense of smell

“We also found that those higher caffeine users were able to detect the odour of a heavily diluted coffee chemical at much lower concentrations, and this ability increased with their level of craving. So, the more they desired caffeine, the better their sense of smell for coffee.

“We have known for sometime that drug cues (for example, the smell of alcohol) can trigger craving in users, but here we show with a mildly addictive drug, that craving might be linked to an increased ability to detect that substance.

“Caffeine is the most widely consumed psychoactive drug and these findings suggest that changes in the ability to detect smells could be a useful index of drug dependency.”

The team wanted to examine if there were any differences in the ability of people to smell and respond to the odour of coffee, depending on whether or not they were big coffee drinkers. The results point firmly to a link, with heavy coffee drinkers being more sensitive to the smell of coffee, and the smell being linked to their cravings.

The study is published in Experimental and Clinical Psychopharmacology.

Caffeine on the mind

Just looking at something that reminds us of coffee can cause our minds to become more alert and attentive, according to a new U of T study.

“Coffee is one of the most popular beverages and a lot is known about its physical effects,” says Sam Maglio, an associate professor in the Departments of Management at U of T Scarborough and the Rotman School of Management. “Much less is known about its psychological meaning — in other words, how even seeing reminders of it can influence how we think.”

The study, co-authored by Maglio and published in the journal Consciousness and Cognition, looks at an effect called priming, through which exposure to even subtle cues can influence our thoughts and behaviour.

“People often encounter coffee-related cues, or think about coffee, without actually ingesting it,” says Maglio, an expert on consumer behavior. “We wanted to see if there was an association between coffee and arousal such that if we simply exposed people to coffee-related cues, their physiological arousal would increase, as it would if they had actually drank coffee.”

Arousal in psychology refers to how specific areas of the brain get activated into a state of being alert, awake and attentive. It can be triggered by a number of things, including our emotions, neurotransmitters in the brain, or the caffeinated beverages we consume.

Four separate studies

In this case the researchers, including Maglio and Eugene Chan, a former PhD student at Rotman, wanted to explore how simply being exposed to things that remind us of coffee may have an effect on arousal.

Across four separate studies and using a mix of participants from Western and Eastern cultures, they compared coffee- and tea-related cues. They found that participants exposed to coffee-related cues perceived time as shorter and thought in more concrete, precise terms.

“People who experience physiological arousal – again, in this case as the result of priming and not drinking coffee itself – see the world in more specific, detailed terms,” says Maglio, whose past research has looked at how uncertainty can affect our perception of time.

“This has a number of implications for how people process information and make judgments and decisions.”

However, the effect was not as strong among participants who grew up in Eastern cultures. Maglio speculates that the association between coffee and arousal is not as strong in less coffee-dominated cultures.

“In North America we have this image of a prototypical executive rushing off to an important meeting with a triple espresso in their hand. There’s this connection between drinking caffeine and arousal that may not exist in other cultures.”

Maglio says next steps for the research will look at associations people have for different foods and beverages. Just thinking about energy drinks or red wine for instance could have very different effects on arousal.

Impact on bowels

Coffee drinkers know that coffee helps keep the bowels moving, but researchers in Texas are trying to find out exactly why this is true, and it doesn’t seem to be about the caffeine, according to a study presented at Digestive Disease Week (DDW) 2019. Researchers, feeding rats coffee and also mixing it with gut bacteria in petri dishes, found that coffee suppressed bacteria and increased muscle motility, regardless of caffeine content.

“When rats were treated with coffee for three days, the ability of the muscles in the small intestine to contract appeared to increase,” said Xuan-Zheng Shi, PhD, lead author of the study and associate professor in internal medicine at the University of Texas Medical Branch, Galveston. “Interestingly, these effects are caffeine-independent, because caffeine-free coffee had similar effects as regular coffee.”

Coffee has long been known to increase bowel movement, but researchers have not pinpointed the specific reason or mechanism. Researchers examined changes to bacteria when fecal matter was exposed to coffee in a petri dish, and by studying the composition of feces after rats ingested differing concentrations of coffee over three days. The study also documented changes to smooth muscles in the intestine and colon, and the response of those muscles when exposed directly to coffee.

Effect on rats

The study found that growth of bacteria and other microbes in fecal matter in a petri dish was suppressed with a solution of 1.5 percent coffee, and growth of microbes was even lower with a 3 percent solution of coffee. Decaffeinated coffee had a similar effect on the microbiome.

After the rats were fed coffee for three days, the overall bacteria counts in their feces were decreased, but researchers said more research is needed to determine whether these changes favor firmicutes, considered “good” bacteria, or enterobacteria, which are regarded as negative.

Muscles in the lower intestines and colons of the rats showed increased ability to contract after a period of coffee ingestion, and coffee stimulated contractions of the small intestine and colon when muscle tissues were exposed to coffee directly in the lab.

The results support the need for additional clinical research to determine whether coffee drinking might be an effective treatment for post-operative constipation, or ileus, in which the intestines quit working after abdominal surgery, the authors said.

 

 

About the Author

Truman Lewis
Truman has been a bureau chief and correspondent in D.C., Los Angeles, Phoenix and elsewhere, reporting for radio, television, print and news services, for more than 30 years. Most recently, he has reported extensively on health and consumer issues for ConsumerAffairs.com and FairfaxNews.com.