Our favourite beverages- coffee and tea, we love to start our day in the morning with our steaming hot cuppa and unwind in the evening again with another hot cup of these beverages. While coffee and tea do have a host of nutritional benefits, many people are unaware of the presence of tannins and caffeine in these. Why do they pose a problem?

Drinking tea or coffee with your meals can limit how much iron and zinc you absorb from the food you're eating and from the supplements you take with your meals. Iron is needed for the production of red blood cells and zinc helps boost immunity.

Tannins:

It is quite common to drink either tea or coffee after meals or with snacks. But this may not necessarily be the best thing. Tannins in tea are polyphenols (antioxidants derived from plants). They inhibit absorption of iron, calcium and zinc. Tannins bind with proteins decreasing the ability to digest and assimilate protein. A diet that contains iron (heme) from meat is not affected by tannins. Vegetarian diets that contain non-heme or plant derived iron are affected by tannins. Vitamin C helps in iron absorption and this helps combat the negative effects of tannins. Adding a dash of lime juice to tea (green or black tea) or taking a glass of freshly squeezed unsweetened musambi (sweet lime) or orange juice is a way to boost iron absorption in a vegetarian diet. While green tea naturally contains a negligible amount of tannins, brewing methods of preparing tea can play a role in boosting the caffeine intake.

Note: Though called teas, herbal teas are different. These are infusions made by steeping flowers, spices, roots, leaves or bark from any plant other than the tea bush in hot water and it does not contain caffeine. These are better called infusions or tisane to prevent confusion with tea made from leaves of the tea plant.

Caffeine:

Caffeine may reduce the absorption of manganese, zinc, copper, iron, magnesium, vitamin A and many of the B vitamins. A study done by Tufts University in 2002 found that coffee can inhibit iron absorption by as much as 87% if consumed with or up to an hour after a meal.

Vitamin D and Calcium

Vitamin D aids in the absorption of calcium in the body while caffeine inhibits vitamin D receptors within your body, especially when you take supplemental forms. Caffeine is a diuretic which causes frequent urination, these results in loss of water soluble vitamins (B-complex and Vitamin C)

Calcium is also affected by caffeine the same way as it affects Vitamin D. Coffee reduces calcium absorption in the body along with loss in urine which results in bone loss. A low bone mineral density is especially seen in people who regularly drink large amounts of caffeine (in coffee or colas) as compared to those who have these beverages less than once in a month.

Bottom line- This does not mean that we need to forgo these beverages which are so much a part of our daily lives. Instead, avoid drinking anything with caffeine or tannins for at least 30 minutes after eating or taking mineral supplements. After eating wait for 1 hour to make sure you get the most nutrition from your meal. Also, limit tea and coffee to just 2 small cups in a day, as due to their diuretic effects, these can make you dehydrated quickly.