Coffee, tea, and red wine all have notable health benefits, lowering risk of diabetes, heart disease, and cancer in epidemiological and lab animal studies. There’s been a lot of debate as to how it all works, and multiple mechanisms may be involved. For instance, all three of these can evoke hormesis, the compensatory rise in cellular defense that occurs upon exposure to small doses of toxins.
A theory that they are all antioxidants via scavenging of free radicals was formerly popular, but in my opinion that mechanism is negligible, because levels of the constituents of coffee, tea, and red wine in the blood stream remain low after ingestion and are quickly cleared from the body.
However, it just so happens that these beverages all chelate (pronounced “key-late”) iron, and prevent it from being absorbed into the body from food. Hindrance of iron absorption is, in my opinion, the major way that coffee, tea, and red wine improve health.
Red wine with meals reduces the susceptibility of blood plasma to be oxidized.(1) White wine had the opposite effect. Alcohol-free red wine enhances plasma antioxidant capacity, alcohol-free white wine has little effect.(2)
Tea, both green and black, can inhibit cancer cells and lowers risk of heart disease.(3) Most studies have focused on green rather than black tea, but the theaflavins in black tea may be more effective than the catechins in green tea in preventing oxidation.(4)
Coffee has lots of health benefits that I’ve written about previously, so I’ll just refer you to my article.
Coffee, tea, and red wine all chelate iron.(5)
Assuming that iron chelation is the major mechanism of their health benefits, which one of these should we prefer if we’re looking after our health? Obviously drinking one doesn’t exclude the others, but which one is the healthiest, most beneficial drink?
I have your answer: it’s tea.(6)
Drinking tea with a simple meal of bread and butter lowered iron absorption, compared to no tea, by as much as 95%.
The order in which the various drinks tested inhibited iron absorption was:
black tea > cocoa > coffee > herb teas. (Red wine was not directly compared, but we’ll look at that below.)
All of these strongly inhibited iron absorption, which was dependent on the amount of polyphenols in each beverage. More polyphenols means less iron absorption.
The following graph is taken from the paper and shows polyphenol content vs iron absorption.
Black tea had the highest polyphenol content and was the most potent iron chelator, followed by cocoa, red wine, and herb teas. (One herb tea was fairly potent, but most of them were much less effective.)
We know from other data that coffee is about 2/3 as potent as tea in terms of iron chelation.
My sense of all this is that in terms of coffee, tea, and red wine, unless you’re totally gung-ho about getting your iron down, all of these work quite well. (If your iron level is very high, you should be borderline fanatical about lowering it.)
Coffee with breakfast, tea with lunch, red wine with dinner: works for me. Have some chocolate for dessert.
It should be noted that to get these effects and most of the health benefits, you should drink them with or shortly after a meal. Drinking them before a meal has no effect on iron, though it may have other health benefits.
As mentioned, most of the work on health benefits of tea has been done on green tea, although in the West, we drink black tea much more. (Judging by the researchers, I’d say ethnic and patriotic considerations motivate most green tea research.)
Since only green tea contains catechins, and only black tea contains theaflavins, and both compounds affect health beneficially, it’s difficult to decide whether green or black is more effective.
Some epidemiological studies on cancer incidence have found lower cancer rates in heavy green tea drinkers, but not black. This might not be due to any ineffectiveness of black tea, but is due perhaps to green tea drinkers having lower iron stores overall, since most of them come from cultures with lower iron consumption than in the West. It’s possible that heavy iron intake in the West overwhelms the iron-lowering effect of black tea.
But in green tea itself, a huge difference in catechin content exists, and it’s very likely that the higher the catechin content, the healthier.
Matcha is a type of green tea that’s made from top leaves of the tea plant, is finely ground, and has a high catechin content. Japanese matcha was found to have 137 times the amount of the catechin EGCG as China green tea, which is the highest known and more than 3 times the amount seen in any other tea.(7)
I haven’t tried matcha myself, but by all accounts it’s the best green tea, though a tad on the expensive side. I need to stop with my ordinary Chinese green tea bags and get some.
Prostate cancer seems like one of those mysterious things that men get but can’t do much about, or at least that’s what the mainstream would have you believe. It’s not.
In a study of men who had a prostate condition that leaves them at high risk of prostate cancer, 30 men took a green tea capsule three times a day. The capsules contained 200 mg catechins, half of which was EGCG, for a total of 600 mg daily of catechins.
Another 30 men took a placebo.
Of the men who took the placebo, 30% developed prostate cancer after one year.
Of the men who took green tea capsules, only 3% developed cancer, for a 90% reduction in risk.(8)
Naturally, the mainstream medical establishment avidly promotes the use of green tea in prostate cancer prevention. Oh, wait, they don’t. There’s no money to be made doing that, besides the fact that it would be giving credence to “natural” therapies.
The following is a brief excerpt from my forthcoming book on iron and health, and deals with food and drink that increase iron absorption.
Some dietary components increase the absorption of iron. Alcohol can increase iron absorption of a meal by 25% compared to no alcohol with the meal. Many alcoholics eventually develop iron overload because of this. Red wine doesn’t have this effect, as the polyphenols in it bind to iron. But beer, white wine, and liquor will all increase iron absorption if drunk with a meal.
Vitamin C strongly increases iron absorption. It should not be taken with meals if you want to decrease iron. Likewise, drinks containing it, such as orange juice, do the same. Any acidic drink will also, such as cranberry juice or tomato juice.
Sugar and high-fructose corn syrup strongly increase hormones that in turn increase iron absorption. Soda and other sweet drinks appear to be a good way to get to iron overload.
Breakfast cereals are often iron-fortified, so avoid these for iron lowering.
Many foods are high in iron but low in absorption. For instance, people deficient in iron are often advised to eat spinach, but other components in spinach hinder iron absorption, so if you’re trying to lower iron, I wouldn’t worry too much about spinach.