Avoiding nutritional causes of disease

Graduate Division

Nipping Peanut Allergies in the Bud:

Rates of childhood peanut allergies in the Western world have doubled in the last decade: the current rate is estimated at 1.4-3 percent. Many public schools now forbid peanut butter, fearing that one child could trigger another’s severe allergy.

Peanut allergies are also emerging in Africa and Asia. However, Israeli children, who lead a Western lifestyle, have startlingly low rates of peanut allergies—ten times lower than that of Jewish children with similar ancestry living in the United Kingdom. While prevailing philosophies in the US and UK have been to avoid peanut products in early life, Israeli children commonly consume a peanut puff snack called Bamba beginning as early as six months of age. Could exposure, rather than avoidance, be the correct route toward reducing peanut allergy?

These discrepancies led Gideon Lack at King’s College in London to put together a clinical trial that began in 2006 called the Learning Early About Peanut Allergy (LEAP) Trial. They enrolled a cohort of about 600 four- to eleven month-old infants at high risk for developing peanut allergy: those who had an egg allergy, severe eczema, or both. In a skin allergy test for peanut sensitivity, about 500 tested negative and 100 tested as mildly positive. Within these two groups, the infants were randomized between diets including and avoiding peanut products until age 5 (infants who exhibited an allergic reaction to both skin and dietary peanut protein also avoided consuming it).

The children on the peanut-containing diet were given at least six grams of peanut protein per week spread among at least three meals, via the Israeli snack Bamba (with smooth peanut butter instead for picky eaters who disliked it). Enrollment took place between 2006 and 2009 in the US and UK, with additional allergy tests performed at 12, 30, and 60 months  of age.

The trial’s results were published this February in the New England Journal of Medicine and presented at the American Academy of Allergy, Asthma and Immunology Annual Meeting in Houston, Texas.

The verdict: consuming peanut protein from infancy reduced peanut allergy rates by 86 percent! Only 1.9 percent of peanut-consuming five-year olds developed allergy, compared to 13.7 percent in the peanut-avoiding group. There was also a significant reduction in peanut allergy in the children who had a positive skin test at the beginning of the study: 10.6 percent at 60 months compared to 35.3 percent. The study is continuing to monitor the children to assess long-term allergy.

Sources: NEJM, NIH

New FDA Nutrition Guidelines:

The 2015 Dietary Guidelines Advisory Committee announced new guidelines on nutrition this week that put a spotlight on the health concerns associated with added sugar, while loosening restrictions on dietary cholesterol. These new guidelines are a response to several decades of research on the rising rates of metabolic syndrome, a metabolic misbalance that often leads to heart disease and diabetes and is diagnosed by high blood pressure, a large waist line and high blood levels of triglycerides, cholesterol and sugar.

A large number of health studies that identified added sugar as a causal factor for metabolic disease were recently curated and compiled by the UCSF-led “Sugar Science” organization that aims to make this information available to the public. While the recommended amounts of added sugar are six teaspoons per day for women and nine for men, the average American adult consumes 19.5 teaspoons per day. A major source of this added sugar (47%) is sugar-sweetened beverages. The report states that: “To decrease dietary intake from added sugars, the U.S. population should reduce consumption of sugar-sweetened beverages and of desserts and sweet snacks.”

Other studies have found that dietary cholesterol intake does not correlate strongly with blood cholesterol levels, leading to the reversal of fifty years of warnings about avoiding high-cholesterol foods. Those warning originated in 1961 guidelines from the American Heart Association. The report’s new stance is: “Cholesterol is not a nutrient of concern for overconsumption.”

The full report can be found at: www.health.gov/dietaryguidelines/2015-scientific-report

Sources: Health.gov, SugarScience.org, Boston Globe