Can Eating More Plants Help Us Age Better? What the Science Says About Diet and Biological Aging
I'm 54 years old. That's one age I know with certainty.
But recently, I had a DEXA scan that gave me another number: 40.
The scan looked at things like my lean body mass, visceral and subcutaneous fat, and bone density, and used those measures to estimate a biological age.
Did I smile when I saw that number? Of course I did. 😂
But did I immediately conclude that my body is literally 40 years old—or that I've somehow cracked the code on aging? Definitely not.
In fact, the results gave me a few things to work on. It suggested that I increase my lean body mass, which means being more consistent about strength training twice a week instead of once. And, to support that extra day of strength training, I need to make sure I'm getting enough plant protein throughout the day. And, despite being a plant-based dietitian, working on consistently eating enough fruit is a daily effort. (Knowing something is good for you and actually doing it every day are two very different things!)
Mostly, though, that little number made me curious:
What exactly is biological age?
And perhaps more importantly for those of us moving through midlife: Can the choices we make now influence how our bodies age in the decades ahead?
The emerging science suggests they may.
And food—particularly the quality of the foods we eat—appears to be one piece of that puzzle.
You Know Your Chronological Age—But How Old Is Your Body?
Chronological age is simple. It's the number of years you've been alive.
Biological age is more complex.
It attempts to describe how our cells, tissues, organs, and physiological systems are functioning relative to what's typical for our chronological age.
That's why two people can both be in their 50's and have very different health profiles.
One may have greater muscle mass, stronger cardiovascular fitness, better blood sugar regulation, lower levels of chronic inflammation, and better physical function than the other.
Genetics certainly play a role, but so do decades of exposures and behaviors—from nutrition and movement to sleep, smoking, alcohol, stress, socioeconomic conditions, and our environments.
Researchers are now using various tools to try to quantify aspects of this process.
Some biological-age models use clinical biomarkers found in blood. Others use measures of physical function or body composition. And some of the most fascinating newer tools are epigenetic clocks, which look at patterns of DNA methylation—chemical modifications to DNA that affect how genes are regulated.
None of these gives us one definitive "true age" of the body. They're different windows into a very complicated biological process.
Which brings us to a much bigger question.
What Is Actually Happening When We Age?
For years, aging was often reduced to a simple story about oxidative stress and free radicals damaging our cells.
Oxidative stress is involved in aging—but today's science paints a much more interesting picture.
Researchers have identified multiple interconnected biological processes associated with aging, including changes in how our cells produce and use energy, regulate genes, respond to nutrients, repair damage, and manage inflammation.
In other words, there isn't one "aging switch" we need to turn off.
And there certainly isn't one antioxidant, supplement, superfood, or wellness hack that's going to do it.
Instead, aging appears to be influenced by many systems interacting over a lifetime.
And some of those systems are responsive to the way we live.
Why Midlife May Be an Especially Important Window
For women, this conversation becomes particularly interesting around midlife.
The menopausal transition doesn't simply change our menstrual cycle. Shifting estrogen and other hormone levels are accompanied by changes in bone, muscle, body composition, cholesterol, insulin sensitivity, vascular health, and other physiological systems.
There's even research suggesting that the menopausal transition is associated with changes in measures of biological aging.
That doesn't mean menopause is a disease—or something we need to "fix."
It does mean our 40s, 50s, and beyond may be a particularly valuable time to ask:
What can I do now to support the body I want to live in later?
I'm much more interested in that question than "How do I stay young?"
Because maybe healthy aging isn't about trying to hold onto a younger version of ourselves.
Maybe it's about supporting who we want to become—feeling strong at 60, hiking at 70, exploring at 80, and continuing to be curious, connected, moving, learning, and laughing along the way.
Personally, I hope to still get excited when a butterfly shows up in my garden for years to come. 🦋
That's healthspan—not simply adding years to life, but supporting our health and well-being throughout those years.
And nutrition appears to be one way we can help.
Diet and Biological Aging
This is where the research gets fascinating.
Scientists aren't only studying whether certain diets are associated with heart disease, diabetes, cancer, or mortality anymore. They're also asking whether dietary patterns are associated with how quickly our bodies appear to be aging biologically.
One 2024 study analyzed more than 22,000 U.S. adults and compared their dietary patterns with measures of biological and phenotypic age acceleration.
The researchers found that greater adherence to a healthful plant-based dietary pattern was associated with slower biological aging.
But here's the interesting part:
An unhealthful plant-based dietary pattern was associated with faster biological aging.
That means simply calling something "plant-based" isn't enough.
More on that in a minute.
Research specifically in women is also intriguing.
A 2024 Women's Health Initiative study looked at 4,500 postmenopausal women between the ages of 50 and 79. Researchers compared diet quality with several DNA methylation-based measures of biological aging.
Greater adherence to higher-quality dietary patterns—including the Healthy Eating Index, DASH diet, and Mediterranean-style diet—was associated with slower epigenetic aging on several measures.
What do these eating patterns have in common? They're all plant-centric, emphasizing foods like fruits, vegetables, whole grains, beans, nuts, and seeds.
Then there's a small but fascinating randomized study involving 21 pairs of identical twins. One twin ate a healthy vegan diet while the other ate a healthy omnivorous diet for eight weeks.
Several measures of epigenetic age declined in the vegan group over those eight weeks.
That's interesting!
It's also very preliminary.
The study was small, lasted only eight weeks, and the vegan group consumed fewer calories and lost more weight, which makes it difficult to know how much of the change was attributable specifically to eating vegan.
That's an important distinction because nutrition science rarely gives us a simple "Food X causes Outcome Y" answer.
What we're beginning to see across studies, however, is a larger pattern:
Higher-quality dietary patterns rich in whole and minimally processed plant foods are consistently associated with healthier aging.
We can't yet say that eating more plants will literally turn back your biological clock.
But we have increasingly good reasons to believe that what we eat can influence some of the biological pathways involved in how we age.
Plant-Based Isn't Automatically Healthy
This may be one of the most important takeaways from the research.
A soda and potato chips can technically be plant-based.
So can lentil soup, berries, walnuts, roasted broccoli, oats, tofu, and sweet potatoes.
Our bodies know the difference even if the label doesn't.
When researchers distinguish between healthful plant-based diets and less-healthful ones, the healthful versions emphasize foods like:
vegetables and leafy greens
fruits and berries
beans, lentils, peas, and other legumes
whole grains
nuts and seeds
soy foods such as tofu, tempeh, and edamame
herbs and spices
Less-healthful plant-based patterns tend to include more refined grains, sugary drinks, sweets, and other highly processed foods.
This is why, when we're talking specifically about nutrition and healthy aging, I prefer focusing on plant-powered or plant-forward eating rather than the vegan label alone. Veganism can encompass important ethical considerations around animals and the planet, while from a nutrition standpoint, the quality of the foods on our plates still matters.
You don't have to eat 100 percent plant-based to benefit from eating more plants.
And if you are fully plant-based, as I am, emphasizing whole and minimally processed plant foods—and making sure nutritional needs are met—still matters.
How Might Plants Support Healthy Aging?
There isn't one magical mechanism—and that's exactly what makes plants so fascinating.
Whole plant foods deliver thousands of nutrients and bioactive compounds that interact with multiple systems throughout the body.
They may help calm chronic inflammation
Aging is often accompanied by persistent, low-grade inflammation—sometimes called inflammaging.
Dietary patterns rich in vegetables, fruits, whole grains, legumes, nuts, and seeds tend to provide fiber, unsaturated fats, vitamins, minerals, and phytochemicals associated with healthier inflammatory and metabolic profiles.
That matters because chronic inflammation is intertwined with many of the conditions that become more common with age.
They provide phytochemicals—not just "antioxidants"
Berries contain anthocyanins. Tomatoes provide lycopene. Carrots and leafy greens offer carotenoids. Cruciferous vegetables contain glucosinolates. Cocoa, herbs, spices, tea, beans, nuts, seeds, and countless other plants contain their own families of phytochemicals.
These compounds do much more than simply "neutralize free radicals."
Researchers are investigating their roles in cell signaling, inflammation, gene expression, mitochondrial function, vascular health, and communication with our gut microbes.
That's one reason I'm much more interested in eating a diversity of plants than identifying the latest anti-aging superfood.
They feed the gut microbes that feed us
This piece of the aging conversation deserves far more attention.
Our gut microbiome changes as we age, and alterations in microbial diversity and function have been associated with inflammation, metabolic health, immune function, and age-related disease.
One of the primary ways we influence that microbial ecosystem is through food.
Fiber and other compounds in plants become fuel for gut microbes, which can produce beneficial metabolites such as short-chain fatty acids. These compounds help support the intestinal barrier, immune regulation, and metabolic health.
So when you eat beans, oats, berries, onions, greens, whole grains, nuts, and seeds, you're not only feeding yourself.
You're feeding an entire ecosystem inside you.
They can support metabolic health
Blood sugar regulation, blood pressure, cholesterol, vascular health, and body composition all become increasingly important as we move through midlife.
Plant-forward dietary patterns have repeatedly been associated with better cardiometabolic health—and several of these metabolic and inflammatory measures are themselves incorporated into some biological-age models.
This is another reason I'd hesitate to give phytochemicals all the credit.
It's the whole package that matters.
Fiber + plant protein + unsaturated fats + vitamins + minerals + phytochemicals + the foods these plants may replace.
That's nutritional wealth.
Food isn't the entire healthy-aging story, either.
Maintaining muscle and bone becomes especially important for women as we move through midlife and beyond—which means adequate nutrition needs to work alongside resistance training and other weight-bearing movement.
My own DEXA results were a good reminder of this. My bone density was encouraging, while my lean body mass showed me an area where I could give my future self a little more support.
For me, that means adding another strength-training session each week and being more intentional about getting enough plant protein throughout the day.
And maybe that's a more useful way to think about healthy aging.
Not perfection. Not trying to achieve the "youngest" biological age possible.
Paying attention, getting curious, and asking: What could I do today to support the body I want to live in tomorrow?
Build an Aging-Supportive Plate
You don't need an "anti-aging diet."
And please don't feel like you need to overhaul everything you're eating tomorrow.
Instead, think about what you can add.
If breakfast is oatmeal, could you add berries, walnuts, chia seeds, or ground flax?
If you're making a salad, could you turn it into a meal with chickpeas, lentils, edamame, tofu, tempeh, quinoa, nuts, or seeds?
Could you add greens to something you already eat?
Could you swap a refined grain for a whole grain?
Could beans take the place of meat in one meal this week?
Could you keep frozen berries or vegetables around so plants are available even when life gets busy?
Could you experiment with a vegetable you've never tried—or revisit one you thought you hated?
You don't need pomegranate powder, an "anti-aging" supplement, or an exotic berry shipped from the other side of the world.
Beans count.
Oats count.
Frozen blueberries count.
Sweet potatoes count.
Cabbage counts.
Peanut butter counts.
And diversity counts.
Instead of asking, "What's the healthiest food I can eat?"
try asking:
"Where can I add another plant?"
Those additions accumulate.
Aging Isn't Something to Fight—It's Something to Support
There's an enormous industry built around convincing women that aging is a problem.
Erase the wrinkles.
Reverse your age.
Fix your metabolism.
Get your old body back.
But what if we stopped trying to make ourselves younger and started asking a different question?
How can I support the body I have today—and the one I hope to live in for decades to come?
Maybe that's a colorful meal.
A handful of berries.
Beans added to dinner.
Lifting something heavy.
Taking a walk.
Getting enough sleep.
Spending five minutes outside.
Or simply nourishing yourself enough.
None of these choices guarantees us a particular outcome, and healthy aging isn't a test we pass or fail.
But they are small ways we can care for ourselves now while supporting the healthspan we hope to have later.
Your future self is someone you're going to spend a lot of time with.
Let's nourish her well.
Research
López-Otín C, et al. Hallmarks of aging: An expanding universe. Cell. 2023.
Wang J, et al. Healthful plant-based diets are negatively associated with the rate of biological aging: A national study based on US adults. Nutrition Research. 2024.
Reynolds LM, et al. Diet Quality and Epigenetic Aging in the Women's Health Initiative. Journal of the Academy of Nutrition and Dietetics. 2024.
Dwaraka VB, et al. Unveiling the epigenetic impact of vegan vs. omnivorous diets on aging: insights from the Twins Nutrition Study (TwiNS). BMC Medicine. 2024.
Levine ME, et al. Menopause accelerates biological aging. Proceedings of the National Academy of Sciences. 2016.
Shen X, et al. Plant-based diets and the gut microbiome: findings from the Baltimore Longitudinal Study of Aging. American Journal of Clinical Nutrition. 2024.
Ogilvie AR, et al. Fracture Risk in Vegetarians and Vegans: the Role of Diet and Metabolic Factors. Current Osteoporosis Reports. 2022.
