Longevity Diet

The truth behind whether there is one “best” diet

More and more studies are being done to answer the age-old question: “What is the best diet?” The answer often depends on your personal goals. But, if your goal is to live a longer and healthier life with less risk of chronic disease, keep reading.

When it comes to reducing your risks of heart disease, obesity, diabetes, and several cancers, as well as supporting bone and brain health, there seems to be a dietary pattern that gets recommended over and over again. And for good reason. Yet another big review study was recently published that looked at data from a whopping 153 studies (involving 6,550,664 participants!) to answer this seemingly simple question.

Researchers from several universities across the United States reviewed existing studies to see if there was an association between dietary patterns and “all-cause mortality”

They looked for studies that compared what adults ate and for how long they lived. Studies were included as long as they met minimum criteria, regardless of the findings. Interestingly, even though dozens of studies met these inclusion criteria, a clear pattern emerged.

Here’s what they found. Adults who ate more vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included) were associated with a decreased risk of death from all causes. These dietary patterns were also low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. In other words, a long life is linked to eating an abundance of plants, along with some fish, and optionally lean meat or poultry. 

Is there a name for this type of healthy diet? A number of different “diets” recommend this eating style. They include the Mediterranean, prudent, Healthy Eating Index, DASH (Dietary Approaches to Stop Hypertension), or plant-based diets. These are all considered to be high-quality diets with nutrient-dense foods and are associated with better health, regardless of diet type or dietary pattern name.

You’ll notice that this study isn’t recommending one specific diet or foods, but rather it takes a more holistic view of the overall eating style or pattern and looks at broad categories of foods in several different named diets. 

Pro Tip: “Dietary patterns are the quantities, proportions, variety, or combination of different foods, beverages, and nutrients in diets as well as the frequency with which they are habitually consumed.”

You may be asking yourself when should someone start adopting an eating pattern like this? 

How does now sound? Regardless of which life stage you’re in, having a higher-quality, more nutrient-dense diet will help support your health and longevity. These nutrition recommendations can apply to any age and stage to help reduce your risk of chronic diseases and mortality.

Overall, “nutrient-dense dietary patterns, regardless of pattern label or name, were associated with significantly lower all-cause mortality risk.”

Let’s sum up. Enjoy more:

  • vegetables
  • fruits
  • legumes
  • nuts
  • whole grains
  • unsaturated vegetable oils 
  • fish
  • lean meat or poultry (if you want to eat meat)

Enjoy less:

  • red and processed meat
  • high-fat dairy
  • refined carbohydrates or sweets

Backgrounder articles:

About the study:

  • “In this systematic review of 1 randomized clinical trial and 152 observational studies (!) on dietary patterns and all-cause mortality [death from any/all causes], evidence showed that dietary patterns characterized by increased consumption of vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included) among adults and older adults were associated with decreased risk of all-cause mortality. These healthy patterns consisted of relatively low intake of red and processed meat, high-fat dairy, and refined carbohydrates or sweets.”
  • How did they choose which 153 studies to include? Before they did any searching for studies, they pre-defined their “inclusion criteria.” Some of their requirements were that the studies were published between January 1, 2000 and October 4, 2019, participants in those studies had to include adults from age 17-84. Then they searched for all of the studies they could find and included all of those that met the inclusion criteria. Each of the 153 studies were then scrutinized for bias and were graded on the strength of their evidence. The total number of participants in these 153 studies was 6,550,664 (that’s a lot of participants!).
  • The researchers stated that, “results across studies were highly consistent.” This means that most of the studies showed similar results, even though none of the studies were included or chosen based on their results.
  • What makes this study even stronger is that “most studies were conducted with rigorous methods and at low or moderate risks of bias across domains.”
  • “Labels that were assigned to the dietary patterns varied widely (e.g., Mediterranean, prudent, Healthy Eating Index, DASH, and plant-based), highlighting that high-quality diets with nutrient-dense foods are associated with better health, regardless of diet type or dietary pattern name.”
  • Conclusion: “This review found that a dietary pattern with nutrient-dense foods was associated with reduced risk of death from all causes.”
  • Note that all studies have limitations. That’s why systematic reviews of multiple high-quality studies are so strong. They look at multiple studies in a systematic way to reduce bias. For this one, all but one study was observational (as is typical in nutrition research). Because they were based on participant-reported consumption and didn’t have to change what they ate, we can’t claim cause and effect. Also, the researchers did not quantify amounts of recommended food categories, so we can’t use this study to provide numbers of servings.
  • We can’t say that this dietary pattern “prevents” death, just that it appears to reduce risk of many chronic diseases or it’s associated with a longer life (correlation does not equal causation).
  • This is a systematic review of 153 studies of adults, 1 of which was a randomized control trial and the other 152 were observational studies. This means it’s quite a strong study with a lot of data that were reviewed to create this overall review. 
  • Study strength is rated a 7/7 according to this chart: https://www.compoundchem.com/2015/04/09/scientific-evidence/