There Is No Best Diet For Everyone, Study Finds. Here’s What to Eat More Of

People often say: My family is from (fill in the blank) so that's why I love to eat the way I do. Now a new study debunks that and finds that no matter where your ancestors are from or what type of food you grew up on, there are two universal truths: Plant-based food is better for you, and processed food is worse for you. Beyond that, there may not be a single best diet for everyone, the study authors found. But those two truths are confirmed by this research. The authors and supervising doctors include researchers from Kings College, London, to Trento, Italy, Malmo Sweden, Madrid Spain, and Mass General, in Boston.

This large new international study published this month suggests that while individuals may live and eat differently the world over, our gut bacteria is driven by the foods we eat.  And that gut bacteria determines how you respond to food, and how healthy you are overall. To avoid obesity, heart disease, type 2 diabetes, and other diseases, try to eat to cultivate a healthy gut microbiome, which is universally determined by food and diet. The authors did not suggest that there is a single "best" diet for everyone–since our individual genetics create an intricate interplay between our bodies and the foods we eat–there are basic universal reactions to two food groups: Plant-based foods create healthy gut bacteria, and processed foods create unhealthy gut bacteria, which are also linked directly to markers in the blood such as inflammation, blood sugar, and blood lipids that drive up risk for obesity, heart disease, type 2 diabetes, and inflammation.

So no matter if you and your ancestors hail from Italy, England, Asia, Africa, or any other part of the globe, your body runs healthier on whole plant-based foods than potato chips this study found. Studying over 1,000 people's gut microbiome (their intestinal reactions to the foods they eat), the authors, who live and work in several countries and together produced the data) found that the single worst thing anyone can eat is processed food.

The microbiome, or gut bacteria, that our bodies have created to metabolize, absorb and reject certain components in the food we eat changes depending on what we throw into the system. Garbage brings on a vastly different set of bio-organisms than healthy whole foods, leafy greens, and nutrient-dense fruits, vegetables, and whole grains. The chemicals added sugar, salt, and preservatives that are found in bags of chips, bottled dressings, highly-processed meat and crackers, cookies and processed bread all work differently on our gut microbiome systems than the type of foods that our ancestors ate, that could be foraged, harvested from small crops, and caught in the forest. The human body, no matter what part of the world your ancestors lived in, was not meant to be a receptacle for chemicals and processed sugars, carbs, and additives.

In the study, which The New York Times wrote about this week, published in the journal NatureMedicine, over 1,000 people were studied to find out the effects of different diets on their microbiomes, and the effect that had on overall health, including heart disease, diabetes, and obesity. Called "Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals" the author's purpose was to see whether, despite individuality in our genetic code, food can change our body's microbiome, which in turn can change our health outcomes. For years, doctors have believed that the tiny gut bacteria that we harbor in the billions, affects our health even more than our genetics. This study appears to confirm that: "The gut microbiome is shaped by diet and influences [the] host metabolism; however, these links are complex and can be unique to each individual,." the study states.

"We found many significant associations between microbes and specific nutrients, foods, food groups, and general dietary indices, which were driven especially by the presence and diversity of healthy and plant-based foods," the authors wrote. "Microbial biomarkers of obesity were reproducible across external publicly available cohorts and in agreement with circulating blood metabolites that are indicators of cardiovascular disease risk." This essentially means that while we are all different, igenetically, our gut bacteria is driven more by what we eat than any other factor. And those billions of bacteria call the shots when it comes to our future health. Eat more plant-based foods and you lower your risk for obesity and heart disease, no matter what your family history. Eat processed foods and you drive up your risk of disease, even if no one else in your immediate family has ever had heart disease or conditions related to being overweight.

The specific "good bacteria" markers are present in those with the healthiest diets, the study found. These microbes called Prevotella copri and Blastocystis spp., were indicators of healthy metabolism, and are in evidence in those people who have the healthiest blood markers for heart health and lowest inflammation, including the healthiest post-meal ability to metabolize fats and sugars. So if you eat more plant-based food and less junk food, your gut bacteria are ready to go to work keeping your blood sugar low and your blood lipids at a healthy level. The opposite is true of junk food eaters. The bacteria in the gut from a regular diet of processed foods are "bad" or lazy bacteria that allow your glycemic level to rise, your blood lipids to go unchecked, leading to inflammation, higher cholesterol, and ultimately heart disease, obesity, and the potential risk for diabetes.

"The panel of intestinal species associated with healthy dietary habits overlapped with those associated with favorable cardiometabolic and postprandial markers," the study states,  "indicating that our large-scale resource can potentially stratify the gut microbiome into generalizable health levels in individuals without clinically manifest disease."

The study's authors, Francesco Asnicar, Sarah E. Berry, Nicola Segata were supervised by Andrew T. Chan, Curtis Huttenhower, Tim D. Spector, Nicola Segata, working together from researchers and supervisors from across the globe, including: the University of Trento, Trento, Italy (Francesco Asnicar), King’s College London, London, UK (Sarah E. Berry), School of Medicine, University of Nottingham, Nottingham, UK (Ana M. Valdes), and Mass General Hospital, Harvard Medical School, Boston, MA, USA( Long H. Nguyen, David A. Drew & Andrew T. Chan).