By Jeffrey Kopman
As more studies on birth order emerge, being the oldest sibling is turning out to be less a source of trivial pride and more of a reason to make a doctor's appointment. The latest finding: First-borns face an increased risk for diabetes and hypertension.
Researchers at the University of Auckland in New Zealand evaluated 85 healthy children, including 32 first-borns, between the ages of 4 and 11. They found that the first-born children had trouble absorbing sugars, which puts them at higher diabetes risk, and had higher daytime blood pressure.
The first-borns' diabetes risk was further magnified by insulin sensitivity that was 21 percent lower, on average, than their younger sibilings', according to the study, which was published in the Journal of Clinical Endocrinology & Metabolism,
"Although birth order alone is not a predictor of metabolic or cardiovascular disease, being the first-born child in a family can contribute to a person's overall risk," said Wayne Cutfield, one of the study’s researchers in a press release.
Scientists attributed the increased risk to the effects that a mother’s first pregnancy has on her uterus. These physical changes better prepare the uterus for future pregnancies. Later fetuses benefit from an increased flow of nutrients that help produce healthier children.
However, the news is not all bad for first-borns. Researchers also found that the 32 first-borns were taller and slimmer than the 53 other children.
“Although first-borns were taller and slimmer, these children had reduced insulin sensitivity and increased daytime blood pressure compared to later-borns,” the study concludes. “This finding may have important public health implications, in light of a worldwide trend toward smaller families.”
Previous birth order studies have revealed some predictors for a child’s future health and personality. The results are a mixed bag of good and bad for first and later-born babies:
Asthma and Allergy Rates. In 2008, research from the Isle of Wight in the United Kingdom revealed higher asthma and allergy rates in first-born babies. A sample of 1,200 newborns showed that first-borns were at a higher risk of having increased cord-blood IgE levels, a strong indicator of allergic development. Similar to the heightened diabetes risk of first-borns, these elevated rates were linked to the condition of the uterus before pregnancy.
Heart Disease. A study conducted by Dr. Maurizio Ferratini of the Fondazione Don Carlo Gnocchi in Milan found that first-borns could face up to a 60 percent increased risk of developing heart disease compared to their siblings. The Italian study of 348 coronary heart disease patients reported that nearly half were first-borns, compared to only 30 percent of the national population.
Intelligence. First-borns might be at an increased risk for specific health conditions, but being the oldest sibling isn’t all bad. In addition to developing taller and thinner physically, first-borns are have several desirable personality traits. The oldest child is typically smarter than their younger siblings. Researchers at Adelphi University cited a first-born's tendency to be more of a "perfectionist" as a possible explanation.
Leadership. According to Dr. Kevin Leman, author of The Birth Order Connection, “first-borns are natural leaders.” The majority of U.S. politicians have been first-borns, and even America’s first president was a first-born. George Washington is just one of many notable first-borns in the Oval Office. Abraham Lincoln, Thomas Jefferson, and Franklin D. Roosevelt are some of the many first-born presidents.
"First Is Worst: First Born Kids Have Higher Diabetes Risk" originally appeared on Everyday Health.