New study investigates ‘optimal’ diets for healthy aging

A fascinating new study, published in Nature Medicine, asks an important but difficult-to-answer question: What’s the best dietary pattern to support healthy aging?

Below, we’ll unpack how the scientists explored this question and, importantly, what they discovered about diet and long-term health. 

A history of confusion

More than 2,000 years ago, Hippocrates advised people to eat sour foods to lose weight, and in the late 1800s, Horace Fletcher was famous for encouraging people to chew each mouthful 100 times for good health.

It’s no surprise that unusual diets were widespread when scientific knowledge was either nonexistent or basic.

Shedding evidence-based light on an old problem

Understanding what we should eat to support our health is vital. As the authors of the new study write: 

“Diet is the first leading behavioral risk factor for noncommunicable diseases and mortality burden globally.” In other words, a poor diet is the leading cause of death and disease in the world.

In particular, the authors focus on the global disease burden for older adults. As the average lifespan has increased, many people now experience years of poor health toward the end of their life. 

To investigate which eating pattern best supports healthy aging, the researchers compared adherence to eight healthy dietary patterns and followed participants for 30 years. They selected these patterns:

• Alternative Healthy Eating Index (AHEI)

• Alternative Mediterranean Index (aMED)

• The Dietary Approaches to Stop Hypertension (DASH)

• The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND)

• The Healthful Plant-Based Diet (hPDI)

• The Planetary Health Diet Index (PHDI)

• The reversed Empirically Inflammatory Dietary Pattern (rEDIP)

• The reversed Empirical Dietary Index for Hyperinsulinemia (rEDIH) 

Although each of these patterns is designed in different ways, they all involve higher intakes of plants and whole foods, and reduced intakes of less healthy foods, like red and processed meats and soda.

Healthy diet, healthy life

In total, the researchers had access to data from 105,015 participants, including 70,091 women and 34,924 men.

According to the paper, after 30 years of follow-up, around 1 in 10 participants “achieved healthy aging.” The researchers also calculated five specific aspects of healthy aging: 

• 37.9% reached the age of 70

• 22.8% remained free of 11 common chronic diseases

• 33.9% maintained cognitive health

• 28.1% maintained physical function

• 26.5% maintained mental health

The scientists found that following any of the eight dietary patterns closely was associated with greater odds of healthy aging. 

Those who followed the dietary patterns most closely had between 8.4% and 12.4% increased chances of achieving healthy aging compared with those who followed the patterns least closely.

Their analysis also showed that sticking closely to any of the eight dietary patterns was associated with all five aspects of healthy aging. 

The strongest associations were:

• Surviving to 70 and cognitive health were most closely linked to PHDI.

• Physical function and mental health were most closely linked to AHEI.

• Being free from chronic diseases was most closely linked to rEDIH.

What should you do?

The dietary acronyms above are a little confusing, so the authors break down what the results mean in plain, acronym-free language:

Higher intakes of the following foods were associated with greater odds of healthy aging: 

• fruits

• whole grains

• vegetables

• added unsaturated fats (yes, that includes seed oils)

• nuts

• legumes

• low-fat dairy 

Higher intakes of the foods and nutrients below were associated with lower odds of health aging:

• trans fats

• salt

• overall meat consumption

• red and processed meats 

These foods and nutrients were also consistently associated with each of the five aspects of healthy aging — reaching 70, remaining disease-free, maintaining cognitive health, and so on. 

The scientists also found that consuming more unsaturated fats, like polyunsaturated fatty acids, was strongly linked with surviving to 70 and maintaining physical and cognitive functions.

In short, this study aligns well with ZOE’s philosophy: Focus on a varied, plant-based, whole-food diet that includes nuts and seeds, and limit your intake of high-risk processed foods and red and processed meats.