What you eat over a lifetime quietly shapes how long – and how well – you live. Longevity researchers have spent decades trying to untangle exactly which foods accelerate aging and which ones protect against it. As Dr. Pooja Gidwani, an internal medicine doctor and longevity expert, put it, “diet is one of the biggest contributors to your longevity.” The evidence keeps pointing in the same direction: a handful of food categories show up again and again in the data as genuine threats to a long, healthy life. Here are the five that experts warn against eating too often.
1. Processed Meats
Of all the foods studied in the growing field of longevity nutrition, processed meat consistently earns the worst reputation. Processed meat was the type of food most strongly associated with increased risk of all-cause mortality in a major 2024 Harvard study published in The BMJ. That finding wasn’t isolated – it came from a large research effort tracking tens of thousands of participants over decades. The research drew data from more than 540,000 people who provided information about their eating habits and health in the mid-1990s, when they were between 50 and 71 years of age.
The connection between processed meat and early death runs through several biological pathways. A large body of evidence has shown that higher consumption of red meat, especially processed red meat, is associated with higher risk of type 2 diabetes, cardiovascular disease, certain types of cancers including those of the colon and rectum, and premature death. Research from Harvard’s T.H. Chan School of Public Health found that increasing total processed meat intake by half a daily serving or more was associated with a 13% higher risk of mortality from all causes. A separate Lancet Planetary Health study published in 2024 modeled what reducing processed meat consumption could do for public health, concluding that reductions in processed meat consumption could result in substantial health co-benefits in the USA by reducing the incidence of type 2 diabetes, cardiovascular disease, colorectal cancer, and death.
2. Sugar-Sweetened Beverages
Soda, sweetened teas, energy drinks, fruit punches – they’re all part of a category that longevity researchers treat with serious concern. “We observed that highly processed meat and soft drinks were a couple of the subgroups of ultra-processed food most strongly associated with mortality risk and eating a diet low in these foods is already recommended for disease prevention and health promotion,” said researcher Erikka Loftfield, presenting findings at NUTRITION 2024. The data on these drinks is extensive and consistent across multiple research groups. A robust body of evidence has linked habitual intake of sugar-sweetened beverages with weight gain and a higher risk of type 2 diabetes mellitus, cardiovascular diseases, and some cancers.
The global scale of the damage done by these beverages is striking. A 2024 study published in Nature Medicine estimated that 2.2 million new type 2 diabetes and 1.2 million new cardiovascular disease cases were attributable to sugar-sweetened beverages worldwide in 2020. Beyond cardiovascular risk, evidence from experimental studies has demonstrated that high intake of sugar-sweetened beverages has detrimental effects on health benefits, including accelerating chronic inflammation, disordering lipid metabolism, and promoting oxidative stress. The U.S. Dietary Guidelines, updated for 2020–2025, recommend that people age 2 years or older limit added sugars intake to less than 10% of their total daily calories.
3. Ultra-Processed Breakfast Foods and Packaged Snacks
The morning cereal aisle and the snack food section of any grocery store are packed with products that longevity researchers now view with real skepticism. High intake of ultra-processed foods – particularly processed meats, sugary breakfast foods, and sugar- or artificially sweetened beverages – may increase risk of early death, according to a landmark 2024 Harvard study published in The BMJ. These items tend to be engineered for flavor and shelf life rather than nutritional value, and their impact on the body accumulates over time. Eating too much ultra-processed food could speed up the biological ageing process, Monash University-led research has found, with the study published in the journal Age and Ageing showing an association between increased consumption of ultra-processed foods and biological ageing.
The numbers behind this research are hard to dismiss. A 2025 meta-analysis published on PubMed, pooling data from 18 studies involving more than 1.1 million participants, found that participants with the highest ultra-processed food consumption had a 15% increased risk of all-cause mortality compared to those with the lowest. The Monash University study went further, calculating that for every 10% increase in ultra-processed food consumption, the gap between biological and chronological age rose by 2.4 months. Packaged savory snacks and ultra-processed breakfast foods are among the most frequently consumed items in this category, and ultra-processed foods now account for more than 60% of daily calories in Americans.
4. Refined Grains in Ultra-Processed Form
The picture on refined grains is nuanced but important. When refined grains appear in heavily processed products – think commercially made white bread, pastries, crackers, and fast-food buns – they become part of a dietary pattern consistently tied to worse health outcomes. The PURE study, rolled out in 21 countries, found that the intake of refined grains including bread, pasta, and desserts but not whole grains was positively correlated with the risk of mortality, including CVD mortality, and the authors report that adding 200 kcal to the diet daily as white bread increased the risk of mortality. The contrast with whole grain alternatives is stark. In an analysis of 19 cohort studies encompassing more than one million participants, each one-ounce daily serving of whole grains was associated with a 14% lower risk of death from heart disease, a 3% lower risk of death from cancer, and a 9% lower risk of total mortality.
The biological mechanism isn’t complicated. Refined carbohydrates in white bread cause rapid spikes and crashes in blood glucose levels, and these fluctuations in blood sugar can lead to insulin resistance, impairing muscle protein synthesis and increasing the risk of muscle loss. Over years and decades, that cycle of blood sugar disruption contributes to metabolic disease. A 2025 umbrella review published in the journal Advances in Nutrition, which examined 41 systematic reviews and meta-analyses involving over one million participants, found that higher consumption of nuts, whole grains, fruits, vegetables, and fish was associated with lower mortality rates – reinforcing that swapping refined grain products for whole grain alternatives is one of the clearest dietary upgrades available.
5. Highly Processed Meats and Soft Drinks Combined – The Dietary Pattern That Ages You Fastest
Longevity researchers increasingly agree that it’s not just individual foods but recurring dietary patterns that determine how quickly or slowly you age. Diets higher in ultra-processed foods – particularly processed meats and sugary or artificially sweetened beverages – were linked to poorer aging outcomes, and these individuals were less likely to maintain physical and cognitive function or reach older age without chronic disease. This finding came from a landmark study published in Nature Medicine by researchers at Harvard, which analyzed data from more than 105,000 adults over a 30-year span. The United States emerged with the greatest opportunity to increase longevity, due to Americans’ widespread consumption of foods like processed meat and added sugars, combined with low intake of longevity-promoting foods like whole grains, nuts, legumes, and fish.
A large multicentre study covering nine European countries and published in The Lancet in January 2025, including nearly 430,000 participants, reinforced this message. Ultra-processed foods were positively associated with all-cause mortality, as well as mortality from circulatory diseases, cerebrovascular disease, ischemic heart disease, digestive diseases, and Parkinson’s disease. The dose-response relationship makes the case even more directly: a 10% higher risk of all-cause mortality was detected with each 10% increment in ultra-processed food consumption. As Blue Zones researcher Dan Buettner summarizes, “people who live the longest eat whole foods, lots of fruits and vegetables, and occasional lean meats, and they avoid processed food.” The pattern of what the longest-lived populations consistently skip is every bit as instructive as what they eat.
