How does diet affect longevity? Study shows good nutrition is more complex than you think

NEW YORK – How does our diet affect how we age? It’s a relatively simple question, but researchers at Columbia University report that the answer is extremely complex. Eating an apple, for example, is a good idea nutritionally, but that’s just one of countless food choices people make over the course of a single day.

Scientists explain that the vast majority of research on this topic in the past has focused on the effects of a single nutrient on a single outcome. This conventional, one-dimensional approach to studying the effects of diet on health and aging does not allow us to see the bigger picture. In other words, rather than tweaking a set of nutrients individually, scientific research into healthy eating needs to take a more holistic approach based on “balancing nutrient ensembles.”

“Our ability to understand the problem has been complicated by the fact that both the diet and physiology of aging are highly complex, multidimensional and involve a large number of functional interactions,” says Alan Cohen, PhD, associate professor of environmental health sciences at the Columbia Mailman School, in a university edition. “Thus, this study further supports the importance of looking beyond ‘one nutrient at a time,’ as the one answer to the age-old question of how to live long and healthy lives fits all.”

Through a series of multidimensional modeling techniques, the study authors tested the effects of nutrient intake on physiological dysregulation in a group of older adults. This led to the discovery of key patterns among specific nutrients associated with minimal biological aging.

“Our approach provides a roadmap for future studies to explore the full complexity of the nutritional aging landscape,” notes Prof. Cohen, who also works with the Butler Columbia Aging Center.

Scientists found 4 trends linking diet and longevity

The data included 1,560 older men and women between the ages of 67 and 84 years. The researchers randomly selected all of these participants between November 2003 and June 2005 from the Montreal, Laval, or Sherbrooke areas of Quebec, Canada. They examined each person annually for a total of three years and followed them over a four-year period. The goal of this effort was to assess, on a large scale, how nutrient intake is related to the aging process.

The research team quantified both aging and age-related loss of homeostasis (physiological dysregulation) through the integration of blood biomarkers. The team placed nutritional effects within the geometric framework for nutrition and applied them to macronutrients and 19 micronutrients. From there, the study authors created eight models that examined different dietary predictors. They were also sure to consider various additional relevant factors such as income, educational level, age, physical activity, number of comorbidities, gender and current smoking habits.

This process led to the identification of four broad patterns:

• The optimal level of nutrient intake was dependent on the aging metric chosen. Increased protein intake improved or decreased some parameters of aging, but increased carbohydrate levels improved or decreased others.
• In certain cases, medium amounts of nutrients performed well for numerous outcomes.
• There seems to be a wide tolerance for nutrient intake patterns, and it doesn’t deviate too much from the norms (homeostatic plateaus).
• The optimal levels for one nutrient often depend on the levels of another (vitamin E and vitamin C). Simpler analytical approaches are unable to capture and uncover such associations.

There is an app for that

Would you like to find out more? The study authors also developed an interactive tool to explore how different combinations of micronutrients affect different aspects of aging.

Overall, these results are consistent with previous experimental work in mice, which found that a high-protein diet may accelerate the aging process at a young age, but may be more beneficial at older ages.

“These results are not experimental and need to be validated in other contexts. Specific findings, such as the importance of combining vitamin E and vitamin C, may not be replicable in other studies. But the qualitative finding that there are no simple answers to optimal nutrition will likely stand: it was evident in almost all of our analyzes from a variety of approaches, and is consistent with evolutionary principles and much previous work,” Prof. Cohen closes.

The study is published in the journal BMC biology.