The Truths about Coffee:

1. Coffee and the Heart: Drinking coffee may cause an increased heart rate, but it is usually due to caffeine. Some individuals may experience symptoms such as dizziness and a rapid heartbeat, known as "caffeine intolerance." Adjusting coffee consumption based on individual sensitivity can help alleviate these symptoms.

 2. Instant Coffee and Health: Instant coffee is believed to be harmful due to the chemical processes involved. Some products may contain harmful ingredients like creamer and sugar if consumed excessively. 

Regular consumption of instant coffee has been linked to a higher risk of breast cancer. 

3. Moderation is Key: Despite the benefits, it is essential to consume coffee in moderation.

The New England Journal of Medicine suggests limiting daily consumption to 3-5 cups (235ml per cup). Excessive caffeine intake can have adverse effects on the body. 

Daily caffeine intake for regular adults should not exceed 400mg, and for pregnant or lactating women, it should not exceed 200mg.