Looking for a natural source of caffeine? Nutritionists say green tea, a popular beverage consumed worldwide, is the way to go. Green tea is derived from the leaves of the Camellia sinensis plant and comes in several varieties. It can be enjoyed hot, cold or even in powdered form, and it’s recognized for its high antioxidant content and health benefits. But how much green tea should you drink to achieve these benefits? Marie Ann Munezero, a Kigali-based nutrition consultant, says green tea contains less caffeine than coffee. This, she says, means that one can take the beverage without significantly disturbing their sleep pattern. Munezero explains that our cells naturally accumulate oxidative damage during regular cell metabolism. “A class of molecules called antioxidants can prevent or even reverse that damage. One of the most powerful antioxidants is called epigallocatechin gallate,” she says. Munezero says that epigallocatechin gallate has been shown to reduce the growth of breast and prostate tumours. The minimal amount of processing of green tea means that it retains many of the phytonutrients that are available in the actual tea plant. According to Munezero, green tea may also be good for the heart. She says the phytonutrients in green tea may also help one lose weight and maintain it. Studies have shown that the caffeine present in green tea acts as a stimulant that has been shown to aid fat burning and improve exercise performance in various studies. And that the massive range of antioxidants known as catechins helps burn fat and boost the metabolism that is key to lose weight. Besides, studies on black or green tea leaf have demonstrated that they may have positive effects in the areas of cardiovascular health, osteoporosis, obesity, and bowel conditions. Munezero goes on to note that the green tea contains antioxidants, which have been shown to inhibit cardiovascular disease development and inflammation. She says that tea may also have psychological and neurological effects, such as increases in alertness and information processing, that is not due to caffeine but a chemical (theanine) in the tea leaves. Not all cholesterol is bad for you. Low-density lipoprotein (LDL) cholesterol is associated with cardiovascular risk, while high-density lipoprotein (HDL) cholesterol could actually protect one against heart disease. Research also shows that the phytonutrients in green tea appear to be connected to balanced LDL and HDL cholesterol levels, helping to keep them in a healthy range. Erick Musengimana, a nutritionist at Rwanda Diabetes Association, Kigali, says green tea contains the amino acid L-theanine, which is found almost exclusively in tea plants. He says that L-theanine acts as a neurotransmitter in the brain, meaning that it sends signals to neurons. Several studies have shown that L-theanine appears to increase alpha-wave generation in the human brain, signalling a state of relaxation. Alzheimer’s disease is characterised by profound changes in memory and thinking abilities. This neurodegenerative disease currently has no cure. However, Musengimana says the antioxidants in green tea appears to reduce the likelihood that one will develop Alzheimer’s disease. On the other hand, the flavonoids in green tea, including epigallocatechin gallate, have been shown to decrease the liver’s glucose production. Musengimana says that this means that the body regulates blood sugar more effectively, keeping the glucose levels within a healthy range. He points out that type 2 diabetes is becoming a big health condition all over the world, due to the lifestyle people are exposed to. He says that it has been proven that drinking green tea could lower the risk of one developing this condition, therefore, its ideal to take it on a regular basis.
