What You Eat in Midlife Could Define Your Health at 70, New Study Finds

How likely are you to reach age 70 without chronic diseases like diabetes, heart problems, or cognitive decline? A major new study suggests that your midlife diet could be a huge factor.

Researchers from the Harvard T.H. Chan School of Public Health tracked more than 100,000 Americans in their 40s to 60s for up to 30 years, examining their eating habits and long-term health outcomes. Their findings, published in Nature Medicine on March 24, are eye-opening: those who followed healthy diets in midlife were far more likely to age disease-free—regardless of their other lifestyle habits.

Dr. Leana Wen, a wellness expert and emergency physician, weighed in on the significance of the findings during a CNN interview. According to Wen, participants who ate more whole foods—such as fruits, vegetables, whole grains, nuts, legumes, and lean proteins—had a significantly better chance of living to 70 without major health problems.

In contrast, those who consumed more ultraprocessed foods, sugary drinks, and red or processed meats were much less likely to enjoy a healthy old age.

Out of the 105,015 participants, only about 9.3% (9,771 people) reached 70 without chronic illness or cognitive or physical decline. But their diets stood out.

“This study confirms what many other studies have hinted at: healthy eating in your 40s and 50s is a powerful predictor of healthy aging,” said Dr. Wen.

While participants didn’t follow any specific diet plans, researchers categorized their eating habits into eight recognized dietary patterns known for promoting health:

1. Alternative Healthy Eating Index (AHEI)
2. Alternative Mediterranean Diet (aMED)
3. DASH (Dietary Approaches to Stop Hypertension)
4. MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay)
5. Healthful Plant-Based Diet Index (hPDI)
6. Planetary Health Diet Index (PHDI)
7. Empirically Inflammatory Dietary Pattern (EDIP)
8. Empirical Dietary Index for Hyperinsulinemia (EDIH)

Despite their differences, these diets shared common features: an emphasis on plant-based foods, healthy fats, and minimally processed meals. Some focused on reducing sodium (like DASH), while others looked at inflammatory response or insulin levels.

Dr. Wen emphasized that midlife—our 40s, 50s, and 60s—is a crucial window for shaping long-term health.

“Everyone should view nutrition as part of their future health planning. It’s never too late to start making better choices.”

She also noted that even though the study didn’t track younger individuals, plenty of research suggests that the earlier healthy habits begin, the better the outcomes.

The study also made clear what not to eat. Foods that negatively affected healthy aging included:

• Sugary beverages (like sodas and sweetened fruit drinks)
• Ultraprocessed foods
• Foods high in sodium and trans fats
• Processed meats

Wen recommends checking nutrition labels. If a product has a long list of ingredients, preservatives, and additives—it’s probably ultraprocessed. Choose simpler, whole-food alternatives when possible.

Beyond personal choices, the study also sheds light on food accessibility.

“We need policies that make healthy food more affordable and accessible,” Dr. Wen said. “Right now, ultraprocessed options are often cheaper and easier to find than fresh produce.”

She urged policymakers to recognize the long-term value of nutrition in preventing disease, lowering healthcare costs, and maintaining a productive, healthy population.

If you’re in your 40s, 50s, or 60s, now is the time to rethink your diet. Prioritizing whole, minimally processed foods today could be your best shot at a healthier, more vibrant tomorrow.