Harvard
Nutritional Epidemiologist Gives Ancel Keys Memorial Lecture On
Personalized Versus Public Health Nutrition
Over One Million
Deaths Averted Since 2000 Because Of Improved Diets
Harvard University’s
Frank Hu, Chair of the Department of Nutrition at the Chan
School of Public Health, delivered the Ancel Keys Memorial
Lecture at the annual meeting of the American Heart Association in
Chicago late last year. In his talk, entitled “Personalized versus
Public Health Nutrition in Prevention of Cardiometabolic Diseases”, Hu
described an improved understanding of the role of fats and
carbohydrates in cardiovascular disease risk and the changes which
reflect this new understanding in the most recent dietary guidelines.
Shift to Systems
Epi
Also, there has been a
growing recognition of the importance of overall dietary patterns and
diet quality scores in assessing mortality risk even though the role
of specific dietary constituents may be unknown. According to Hu, the
shift in thinking in nutritional epidemiology has given the field a
bigger picture view of diet and
health which now emphasizes there is more than one way to eat a
healthy diet and that it is never too late to improve diet. Hu
described this new thinking as a paradigm shift from a “black box epi”
to a “systems epi” approach defined as “the integration of population,
laboratory, analytical, and translational approaches.”
Alexa, What Should I
Eat?
Speaking of laboratory
advances, Hu noted the opportunities afforded by the omics
technologies which have led to the idea of “precision nutrition”. He
described its goals as more precise measurements of dietary intakes
and diagnostics of nutritional status as well as more accurate
prediction of disease risk. The idea is to identify better nutritional
intervention targets and to personalize nutritional therapy or optimal
diets for each individual based on their genetics and other factors.
Many questions remain
as to whether or not this approach will provide any generalizable
information and be feasible in clinical practice. Hu illustrated this
uncertainty by raising the question of whether or not someday people
would be asking---“Alexa, what should I eat?” Today, posing that
question elicits only a suggested recipe and not personalized dietary
advice .
Population Approach
In contrasting
approaches to nutrition, Hu emphasized the health impacts that can be
had by taking a more population-based approach to improving the
quality of the US national diet. He reminded the audience of the
obesogenic environment in much of the US. Diets of Americans score
only about 50 out of 110 on a scale of diet quality, Hu reported in a
recent JAMA piece cited below. However, modest but positive changes
in national diet quality since the beginning of this century have
cumulatively resulted in an estimated 1.1 million fewer deaths and
chronic disease cases. He cited the example of regulations that have
nearly eliminated trans fats from the food supply in the US and other
countries to demonstrate the crucial role nutrition policies play in
creating a healthier food environment. Hu emphasized how public health
approaches such as education, policy, and regulation should remain the
key interventions.
Diet Histories of the
Future
In light of recent
criticisms targeted at the difficulties of achieving accurate diet
exposure histories, Hu noted that repeated measures of food
frequency questionnaires or 24-hour recalls improve accuracy. Going
forward, future methods will likely require a combination of
self-reported measures, biomarkers, smart phones, and sensors to
achieve reliable diet exposures.
More Information
Readers interested in
learning more about these trends and findings in nutritional
epidemiology may read a viewpoint article on these topics by Hu and
colleague Walter Willett in a recent JAMA article (Nov 27,
2018) and read a very informative interview Hu gave to Medscape after
his Ancel Keys Lecture entitled “Nutrition Research: Restoring Respect
to a Field Under Siege.”
https://wb.md/2Tca6RU
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