Are vegetarian diets always healthy? My answer from personal experience is “no.”
Before I became a Certified Nutritionist and Weight Loss Coach, I was a vegetarian for 14 years. But, I did not eat a high-quality healthy diet. My diet focused on carbs and desserts and did not feature plant-based foods much at all. So now that I am a Nutritionist and Dietician and a vegetarian client comes to me, I ask a lot of questions about what they eat.
A major study finds that vegetarian diets could reduce the chances of aging healthily—unless older adults eat high-quality plant-based foods rich in nutrients.
In a recent study published in the journal npj Aging, researchers investigated the impact of vegetarian diets on healthy aging in older adults in China. Their findings indicate that vegetarians may be less likely to achieve healthy aging than omnivores. However, this difference may be driven by diet quality, as vegetarians with higher-quality diets showed no significant difference from omnivores in healthy aging.
Background
Vegetarian diets, which emphasize plant-based foods while restricting or eliminating animal products, are becoming more common. Research has linked these diets to reduced risks of cancer, diabetes, obesity, and cardiovascular diseases, particularly in middle-aged and younger populations.
They are also associated with benefits such as improved metabolic health. However, little is known about their effects on older adults, who may face nutritional deficiencies from vegetarian diets due to reduced intake of essential nutrients such as calcium, iron, vitamin B12, omega-3 fatty acids, and protein.
These deficiencies could contribute to muscle loss, bone fractures, and disability. Additionally, the influence of vegetarian diets on health outcomes, including cognitive function, mental health, and chronic diseases in older adults, remains unclear.
About the Study
In this study, intended to determine are vegetarian diets always healthy, researchers utilized data collected from the Chinese Longitudinal Healthy Longevity Survey to investigate the impact of vegetarian diets on healthy aging, taking into account diet quality.
• This ongoing cohort study included individuals aged 60 and older across 22 provinces in China.
• Multiple survey waves were conducted between 1998 and 2018 to assess health status, diet, and lifestyle.
• The study included 2,888 participants who were initially healthy and had dietary data available for analysis.
• Researchers defined healthy aging as the ability to survive until 80 without experiencing serious chronic diseases, cognitive decline, physical impairments, or poor mental health.
• Dietary intake was assessed using a simplified food frequency questionnaire.
• Participants were categorized as vegan, ovo-vegetarian, pesco-vegetarian, or omnivorous, and diet stability from age 60 was examined.
• The healthy plant-based diet index (hPDI) — which prioritizes whole grains, fruits, and vegetables — and unhealthy plant-based diet index (uPDI) — which includes refined grains and sugary beverages — were also calculated.
Findings of Study on Vegetarian Diets
• The participants were, on average, 72.1 years old, and 45% were female. Those following vegetarian diets were less likely to be male and more likely to belong to the Han ethnic group.
• On average, they had lower income and education levels—factors that may partially explain observed health disparities.
• Only 13% of participants followed a vegetarian diet, and fewer than 3% were vegan.
• Over the six years of follow-up, 572 participants met the criteria for healthy aging.
Vegetarians were 35% less likely to attain healthy aging than omnivores.
• Among vegetarians, vegans had the lowest odds, being 57% less likely to achieve healthy aging than omnivores (OR = 0.43; 95% CI: 0.21–0.89).
• Long-term adherence to vegetarian diets was linked to a higher risk of chronic diseases, physical disability, and cognitive impairment.
• Vegetarians had nearly double the odds of experiencing physical function impairment compared to omnivores.
• Those who remained omnivorous from 60 onward were 78% more likely to achieve healthy aging than consistent vegetarians.
• Similarly, individuals who were initially vegetarian but adopted omnivore diets had improved health outcomes
• Further analysis showed a dose-response association between stricter vegetarian diets and poorer health outcomes (p-trend < 0.05).
• Diet quality played a role, as vegetarians with poor plant-based diets displayed a significantly higher risk of chronic diseases, physical limitations and cognitive decline.
Are Vegetarian Diets Always Healthy? Conclusions
This study examined the impact of vegetarian diets on healthy aging in older adults. Findings indicate that maintaining an omnivorous diet from age 60 was linked to higher odds of attaining healthy aging than consistent vegetarianism, particularly for vegans.
While diet quality influenced outcomes, vegetarians following high-quality diets (hPDI, emphasizing whole foods) showed no significant disadvantage relative to omnivores.
These results suggest that vegetarianism may not universally promote healthy aging and highlight the need for a balanced diet incorporating animal-based nutrients.
Prior research on vegetarian diets and health outcomes has been inconsistent, largely focusing on middle-aged adults. This study adds to the literature by considering overall health in older adults.
Potential drawbacks of vegetarian diets include deficiencies in protein, vitamin B12, and vitamin D, which may contribute to impaired physical and cognitive function. No clear association was found between vegetarian diets and mental health outcomes.
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Also, if you need help from a former vegetarian in managing your diet, please contact this Irvine Nutritionist through my website,
