Dangers And Benefits Of Coffee: A Never-Ending Debate | Nutrition & Dieting articles | Well Being center

Arguably one of the most popular beverages in the world, perhaps second only to water, coffee is extensively consumed around the globe. The relevance of its potential impact on health derives precisely from its worldwide consumption, which can reach an astonishing 7 million tons per year.

For years, coffee has had a poor reputation, but as more information on its phytochemical properties emerges, it appears that, in fact, this natural compound isn’t as negative as people had originally thought it was. This is strengthened by the knowledge of the substances that make up coffee – a long list indeed, that includes not only caffeine (the most widely known), but also phenols, lactones, niacin, vitamin B3, magnesium and potassium.

The diversity of coffee constituents leads to a high number of biological targets where this beverage can exert potentially serious effects. Naturally, this has raised great interest among the medical community.

Coffee and diabetes

One of the most significant potential health benefits of coffee is related to the decreased risk of type 2 diabetes mellitus.

For instances, a prospective study of more than 17,000 people found that the risk of developing type 2 diabetes mellitus was 50% lower in those who consumed at least 7 cups of coffee daily compared to those who drank 2 cups or less.

In a smaller cohort of Swedish women who were investigated during a period of 18 years, those who drank at least 3 cups of coffee daily had a risk of type 2 diabetes mellitus that was 50% lower than the risk for those who consumed less than 2 cups daily.

Robust, randomized clinical trials have also been conducted to look into this potential effect. However, since most of them take place during a relatively short period of time, no improvements in glucose tolerance or insulin sensitivity were observed. Seeing that the opposite was found in much longer epidemiological studies (such as the ones described above), it is thought that it is long-term, routine coffee consumption that may contribute to the normalization of glucose tolerance.

Coffee and Parkinson’s disease

Parkinson’s Disease is neurological disorder that develops, essentially, subsequently to motor neuron degeneration. Epidemiological studies have consistently demonstrated an inverse association between coffee consumption and Parkinson’s disease. Studies in animal models suggest that caffeine consumption decreases the risk of Parkinson’s disease by protecting against dopaminergic neurotoxicity. More specifically, caffeine appears to stimulate the antioxidant defense mechanism of the immune system by inducing the expression of mRNA and enzymes mitigating the negative effects of free radical on neurodegeneration.

Coffee and cancer

Evidence also exists supporting a chemopreventing role of coffee consumption.

There are many studies in the scientific literature highlighting the beneﬁts of coffee consumption on cancer risk, being the potential effects on decreasing the risk of colorectal cancers one of the most studied.

Researchers observed the declines in colorectal cancer among individuals consuming two or more cups of decaffeinated coffee daily. Later, other studies further suggested that such a risk reduction was due to the diterpene content of coffee.

See Also: The Good And Bad Of Coffee

Other type of cancer – hepatocellular carcinoma – has gotten plenty of attention as well, due to its risk being potentially influenced by coffee consumption. Several case-control studies in Europe and at least two prospective cohort studies in Japan have observed signiﬁcant inverse associations between coffee consumption and the risk of hepatocellular carcinoma. Nevertheless, the mechanism behind this risk decline is not yet clear. Although caffeine and chlorogenic acid have been found to inhibit chemically induced hepatic carcinogenesis in animal models, more research is needed to determine the nature of the relationship between coffee and caffeine intake and hepatocellular carcinoma in humans.

Potential Positive Effects Of Coffee Might Be Offset By Its Negative Influence On Heart

Despite these potentially positive effects of coffee intake, the fact is that less encouraging data on this natural product also exists. The potential negative effects on the cardiovascular system, for instances, are some of the most extensively researched.

In general, case-control studies have found high coffee intakes to be associated with signiﬁcantly increased risk of coronary heart disease or myocardial infarction.

Two separate meta-analyses that combined the results of eight case-control studies found that coronary heart disease risk was 40–60% higher in those who consumed 5 or more cups of coffee daily compared to those who did not drink coffee. However, prospective cohort studies have not generally found any relevant associations between coffee consumption and the risk of coronary heart disease. As for the effects on people with established coronary heart disease, no robust studies have yet been conducted and, consequently, no inferences can be made.

Coffee and high blood pressure

It has been well-established that acute consumption of caffeine at dietary levels raises blood pressure in normotensive and hypertensive individuals. However, chronic consumption seems to be associated with a tolerance to the pressor effects of caffeine. Still, additional prospective cohort studies are needed to clarify the relationships between long-term coffee and caffeine consumption and the risk of hypertension.

Coffee and osteoporosis

The results of controlled calcium balance studies in humans indicate that caffeine consumption leads to a small negative calcium balance in individuals with inadequate calcium intakes. The negative shift in calcium balance has been estimated to be about 4–6 mg of calcium per cup of coffee, and is caused by a minor reduction in the efﬁciency of calcium absorption. Although this does not sound much overall, three prospective cohort studies in the US found that coffee or caffeine consumption was associated with the risk of hip fracture in women.

Since the remaining evidence is mixed and given the multifactorial etiology of osteoporosis, the relationship between coffee or caffeine consumption and the risk of osteoporosis is still very unclear.

However, the best evidence currently available suggests that ensuring adequate calcium and vitamin D intake and limiting coffee consumption to 3 cups/day to limit the risk of osteoporosis and bone fractures, particularly in the elderly.

To drink or not to drink??

Debate still persists as to whether coffee is beneﬁcial or somewhat troublesome for human health. Naturally, further research is warranted for any conclusions to be effectively drawn. In the absence of full and conclusive data it would reasonable to use a common sense approach. If, for whatever reason, you are in danger of cardiovascular diseases or have any other serious health conditions, you should probably limit your consumption of coffee. If, on the other hand, your general health is good, drinking coffee might help in keeping it this way for years ahead.