A cup of joe keeps the doctor away — or rather, two or three or even up to four cups may keep them even further away. 

That's according to a number of new studies, says Sharon Basaraba, a medical journalist and North by Northwest's longevity consultant.

"For decades doctors were telling patients to stay away from coffee for their hearts' sake,"  Basaraba told host Sheryl MacKay.

However, she said there is plenty of research to show that moderate coffee consumption can help reduce diabetes and cardiovascular disease, improve long-term cognition, and she added that recently, the news for coffee drinkers has gotten even better.

Doesn't matter if caffeinated or not

Basaraba said a study published this month examined over 5,100 men and women who had been diagnosed with colorectal cancer, and about 4,000 who had no history of the disease.

The researchers found that adults who drank between one and two cups of coffee a day had about a 26 per cent lower risk of developing colon cancer, and those who drank more than two and a half cups a day lowered their risk even more — by 50 per cent.

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It can be very difficult to do nutrition science well and come up with robust studies about the health effects of coffee. (Getty Images/Hero Images)

"The lower risk interestingly didn't even seem to depend on what kind of coffee the people drank" Basaraba said, as the study's participants had consumed all kinds of different coffee, including espresso, instant coffee and even decaffeinated coffee.

Then there is a Harvard study from 2015 that looked at more than 200,000 men and women in the health profession, and had 30 years of follow-up, something that Basaraba said is "very significant in the research world."

"The study found that people who drank between three and five cups of coffee a day were about 15 per cent less likely to die of any cause compared to people who didn't drink any coffee at all, and there were also lower rates of death from specifically stroke, heart disease and neurological conditions like Parkinson's," Basaraba said.

Two to four cups is the 'sweet spot'

"Even heavy coffee drinkers in that study — say more than five cups a day — had a 12 per cent lower risk of death during the study period."

Basaraba said that result was similar to other research that reviewed 21 different studies published in 2014, which she said found that "the benefit seems to peak at three or four cups a day, and dropped off for people who drank more."

"So if we're looking at what the dose might be for this drug of choice, under four cups seems to be that sweet spot."

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Most recent studies have shown that coffee drinking is likely beneficial, say researchers. (Getty Images)

She said that result was also similar to a 2013 study out of Japan that compared the benefits of green tea and coffee, which she said are actually very similar in that they both contain healthy antioxidants and polyphenols.

The study, which examined 82,000 people over a 13-year-period, "concluded that both green tea and coffee consumption were associated with a lower risk of cardiovascular disease and strokes — [drinking] two to four cups a day of either."

Rich in antioxidants

Basaraba said that researchers don't exactly know why coffee is showing all these benefits, but said the leading theory is that coffee is rich in antioxidants, which repairs cellular damage that happens everyday.

Basaraba said that, of course if one loads their coffee with cream or sugar or high fructose corn syrup-rich flavourings, then one's cup of joe won't be very healthy.

"And I will offer this caveat: if it's cancer and heart disease that you're trying to avoid, pursuing simple lifestyle habits — the boring ones: regular exercise, eating a varied diet — are going to do more for you than ramping up your coffee habit," she said.

"The good news is you just don't have to give up your coffee."

With files from CBC's North by Northwest


To hear the full story listen to the audio labelled: Drinking up to four cups of coffee a day may actually be good for you, studies suggest