Budget Coffee Chains' Large Servings Pose Hidden Caffeine Risks

Column by Moon Ja-young, Director of Cheonan Jaseng Hospital of Korean Medicine

Korean budget coffee brands dominating the domestic market are now gaining popularity overseas. One Korean brand recently opened its first store in a prime Tokyo commercial district and has captured local office workers' hearts by selling up to 1,400 cups daily. Social media posts show long queues forming outside the brand's Japanese locations. The brand's large (L) size iced Americano offers 940ml for 400 yen (approximately 3,600 won). Compared to premium brands' venti size (580ml) priced at 565 yen (approximately 5,085 won), the volume is 1.6 times larger while the price is about 30% cheaper. The "large-volume, low-price" strategy proven in Korea has hit the mark in Japan as well.

A similar trend is emerging in the United States. A U.S. coffee and donut chain's 48-ounce (approximately 1.4 liters) "bucket coffee" being test-marketed is gaining buzz through social media. The bucket coffee is 1.5 times larger than the existing large size (32 ounces) and priced at around $8 (11,460 won). Even without dedicated online promotion, some customers are planning long-distance drives just to find stores carrying the product.

The "large-volume, low-price" strategy appears to be a universal formula that transcends race and borders. However, hidden behind this trend are easily overlooked health concerns. Korea's Ministry of Food and Drug Safety recommends a daily caffeine intake limit of 400mg for healthy adults. A typical cup of coffee contains an average of 100mg of caffeine. Yet according to information disclosed on major Korean budget coffee brands' websites, the average caffeine content per serving exceeds 400mg. A single cup fills or exceeds the daily recommended amount. Drinking two or more cups may cause symptoms such as insomnia and nervousness.

The greater concern is that maintaining such consumption habits over the long term can accelerate the onset of osteoporosis. Osteoporosis is a condition where bone density decreases and strength weakens significantly, increasing the likelihood of fractures. Caffeine, coffee's main component, can inhibit bone formation and interfere with calcium and iron absorption, raising the risk of developing osteoporosis.

Osteoporosis is easy to miss because it shows no clear symptoms even as it progresses. As osteoporosis worsens, dull pain and fatigue may appear in the back or lower back, and fractures can occur from minor impacts. The weakened bone support also increases the risk of developing various musculoskeletal conditions such as herniated discs.

Those who frequently consume coffee or feel dullness in their musculoskeletal system, including the lower back, should consider getting precise examinations such as bone density tests. Osteoporosis is primarily treated with bone resorption inhibitors that prevent bone loss or bone formation promoters that stimulate bone generation. In Korean medicine, individualized herbal prescriptions help suppress bone density decline.

According to a study published in the international journal BMC Complementary and Alternative Medicine by a joint research team from Jaseng Hospital of Korean Medicine and Seoul National University's College of Pharmacy Natural Products Research Institute, the herbal compound "Yeonkolbogangwhan (JSOG-6)" was found effective in suppressing osteoporosis and protecting bones. The research team increased osteoporosis-inducing factors in experimental mice's serum by 18.8% to 117.6%, then administered Yeonkolbogangwhan. The results showed that osteoblasts (MC3T3-E1), which are involved in bone formation and regeneration, tended to improve as the concentration of Yeonkolbogangwhan increased.

I don't want to take away the pleasure of a "value" cup of coffee. But we must not forget that large-volume coffee consumed habitually every day can gradually harm bone health. If you want to enjoy delicious coffee for years to come, start by maintaining appropriate intake levels. Walking for about 30 minutes while getting moderate sunlight is also a good approach. Only with strong bones can you continue to savor the leisure of a cup of coffee for a long time.