Well, the research is basically split down the middle with coffee. And, honestly there is more research in favor of coffee being healthy for us.
It is classified as a drug and it is a stimulant. So, people who struggle with anxiety, nervousness or ADD might have problems with coffee. One really big disadvantage is that it seems to cause people to sleep less. This is huge since 20% of Americans have occasional sleep problems and 10% struggle with chronic insomnia. But, the issue here is that everyone metabolizes coffee differently. I can drink a cup-o-joe and fall right to sleep. Others cannot. (The gene responsible for detoxifying caffeine or not is CYP1A2.)
Another very big issue is the its effect on the digestive system. 1.) Coffee increases stomach acid secretion. With the whole nation taking antacids like Prilosec or Tums, this is certainly a negative. So, specifically, if someone has acid reflux or an ulcer, coffee will not allow the gut lining to heal and that person will have continued digestive discomfort. 2.) Another digestion issue is that it has a laxative effect. Depending on who you are this may be good or bad. You decide. A word of caution, it is probably not a good idea to depend on coffee for your regularity. There are hydration issues at stake here, both with coffee use and the movements that it causes.
There is good about coffee, though. It is a great anti-oxidant, It helps people focus, It has been linked to a delayed onset of Alzheimers Disease and some researchers claim it can prevent Parkinsons.
I hate to use flippant quips, but it seems appropriate here. Moderation.
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