Lactose intolerance, also called lactase deficiency and hypolactasia, is the inability to digest lactose, a sugar found in milk and to a lesser extent milk-derived dairy products.

Lactose intolerant individuals have insufficient levels of lactase, the enzyme that metabolizes lactose into glucose and galactose, in their digestive system. In most cases this causes symptoms such as abdominal bloating and cramps, flatulence, diarrhea, nausea, borborygmi (rumbling stomach) and/or vomiting after consuming significant amounts of lactose. Some studies in the U.S. and elsewhere suggest that milk consumption by lactose intolerant individuals may be a significant cause of irritable bowel syndrome.

Most mammals normally become lactose intolerant after weaning, but some human populations have developed lactase persistence, in which lactase production continues into adulthood. It is estimated that 75% of adults worldwide show some decrease in lactase activity during adulthood. The frequency of decreased lactase activity ranges from 5% in northern Europe through 71% for Sicily to more than 90% in some African and Asian countries. This distribution is now thought to have been caused by recent natural selection favoring lactase persistant individuals in cultures that rely on dairy products. While it was first thought that this would mean that populations in Europe, India and Africa that had high frequencies of lactase persistence shared a single mutation, it has now been shown that lactase persistence is caused by several independently occurring mutations.

Bernard Jeffrey McCullough (October 5, 1957 – August 9, 2008), better known by his stage name, Bernie Mac, was an American actor and comedian. Born and raised on the South Side of Chicago, Mac gained popularity as a stand-up comedian. He joined comedians Steve Harvey, Cedric the Entertainer, and D. L. Hughley as The Original Kings of Comedy.

After briefly hosting the HBO show Midnight Mac, Mac appeared in several films in smaller roles. His most noted film role was as Frank Catton in the remake Ocean's Eleven and the titular character of Mr. 3000. He was the star of The Bernie Mac Show, which ran from 2001 through 2006, earning him two Emmy Award nominations for Outstanding Lead Actor in a Comedy Series. His other films included starring roles in Booty Call, Friday, The Players Club, Head of State, Charlie's Angels: Full Throttle, Bad Santa, Guess Who, Pride, Soul Men, Transformers and Madagascar: Escape 2 Africa.

Mac suffered from sarcoidosis, a disease in which abnormal collections of chronic inflammatory cells (granulomas) form as nodules in multiple organs, particularly the lungs and lymph nodes. Lung scarring or infection may lead to respiratory failure and death. Mac had said the condition was in remission in 2005. His death on August 9, 2008 was caused by complications from pneumonia.