At work I usually drink instant coffee, but I found out that one can buy French press mugs. I did some research about which of these methods of preparing coffee is healthier, it seems that there's no consensus. Assuming that the taste doesn't matter, which method would you recommend? We're talking about one, maximum two cups a day, so no extreme amounts.
As far as I know there are no health concerns about coffee aside from caffeine consumption. Unless there are additives in instant coffee that I'm unaware of then there ought to be no substantive difference between the two (French Press and instant). Instant coffee is simply coffee which was freeze dried either by spraying droplets in the air or crushed after freezing.
Therefore the health concerns, if any, would be relative to the amount of caffeine you consume. You mention that you drink two cups a day. That is below every recommended max consumption I've ever seen (4 cups).
When I read this question I recalled reading somewhere that a french press was supposed to have health benefits compared to filter coffee since there is no filter to remove the coffee oils from the cup. In looking for an article to confirm however, I found this article from Harvard health blog that said it may increase cholesterol if you drink too much (>4 cups a day).
If you search enough you can also find articles that claim the oils are good for you.
Overall, I do not think this choice will significantly affect your health unless you drink many cups of coffee a day, in which case the caffeine is probably of greater concern.
Based on @MT San's comment, I did some additional research and came up with this article. It appears the antioxidant contents of instant coffee are in general not affected, or possibly even concentrated, but the amount of acrylamide in instant coffee can be as much as twice the levels in freshly brewed coffee. Overexposure to acrylamide can cause nervous system damage and increases the risk of cancer.
As MT says, it is very difficult to say. What amount results in overexposure to acrylamide, and do the antioxidant concentrations negate the negative? Here's the source article.
- the difference is that when making instant coffee you add the coffee in the cup and make it resulting in drinking the coffee together with the "coffee beans". this is difficult for your body to digest. With the french press the raw coffee is not drank but filtered and you drink the coffee juice.
- the instant coffee goes through a process and then is sold to you whereas the french press coffee is grinded coffee beans.
So basically the french press coffee is better for you.
Recently, it came out that California is requiring some coffee shops to post that coffee may cause cancer because of the Acrylamide as Nate M and MT San pointed out.
However, many more articles and studies have come out recently to counteract this as more experts are weighing in and saying that if anything at the very least the benefits of coffee is neutral. There is some bad but its not that bad, and the good isn't that great. I linked to a few articles talking about that below.
Regarding the debate for french press vs. instant coffee, this could come down to a personal preference. Some things to think about regarding French Press are how is the coffee grounds stored, how are the coffee ground, is there availability to fresh and clean and hot water, how hot is the water, how much patience do you have, and how do you like it.
I love my french press and would do that over instant any day. However, I get whole beans, store them in an air-tight jar ( coffee vault ), and then hand grind them daily when I brew it in my french press. All of this many people do not have the patience for the coffee, especially since after that, you have to let the coffee steep for a few minutes (similar to Tea).
In the past I had bad coffee (which could affect the health benefits) when the grounds weren't stored properly, or the grinder wasn't cleaned/sanitized properly.
Also, I make sure to measure the temp of the hot water I put in. Currently we have a water purifier that has a "hot water" setting, and I use that. The water is about 170, which is important not to be above 190. Many coffee houses, home brewers and even Keurigs will brew at 200+, but can be adjusted to as low as 180. Coffee shops will do this so it stays hotter longer. The proof is inconclusive, but I think there is some studies suggesting that the temperature has something to do with the production of the Acrylamide. This does greatly affect the taste of the coffee. You can find something here at the Physics Fact Book, and something here at the five senses.
One of my best friends will only drink instant coffee, and loves it, and has been for about 30 years. He likes how quick it is, and likes the taste, but he also adds cream.
Overall health benefits / disadvantage are leaning towards positive results, assuming its in moderation and everything is clean and clear, regardless of the method.
Something new to possibly check things out that might be good for you that is a blend of both world....the MiniPresso. It can make regular coffee, not just espresso, but it has a concept design similar to a french press.
Recent articles on health benefits and such....