BOSTON—According to a Northeastern University study released Monday, eggs—discovered last week by a University of California-Santa Cruz study to be unhealthy, raising serum cholesterol by as much as 20 percent—have beneficial effects on cardiovascular health this week. "Contrary to what was previously thought, consuming an egg a day can lower a person's blood pressure and increase the heart's efficiency for the next week," the Northeastern study stated. The report urged Americans to increase egg consumption immediately, as eggs may be unhealthy again as soon as next Monday.