Written by Katelyn McIntosh, RD
The weather is warmer, the days are longer, the seasons are changing — summer is here. Along with longer days comes an agricultural abundance. With so much fresh produce available, it's the perfect time to think about eating seasonally.
Eating seasonally and locally means buying and consuming produce — fruits, vegetables, and herbs — that are grown and harvested during their natural growing period in your region. When possible, bonus points for choosing what's grown close to home.
Why eat seasonally?
Nutrition
Produce picked in season is harvested at its peak ripeness, which is when vitamin, mineral, and phytonutrient levels are typically at their highest. This translates to potential benefits like improved immune function and reduced inflammation and oxidative stress. By contrast, out-of-season produce is often picked early and artificially ripened during storage, which can diminish its nutritional value.
Vitamin C is among the most affected nutrients. Green peas, for example, can lose up to half their Vitamin C within just two days of being picked — primarily due to photo-oxidation, a chemical process that breaks down nutrients when produce is exposed to light and air after harvest.
Gut health and fiber diversity
When it comes to fiber, variety matters. Eating seasonally is a natural and effective way to diversify your fiber intake throughout the year, which supports a healthy gut microbiome. Research has found measurable seasonal fluctuations in gut bacteria that correspond with changes in diet; when people eat differently in summer versus winter, their microbial communities shift accordingly.
Two great seasonal examples: asparagus, available in late spring, is exceptionally high in inulin, a soluble fiber that acts as a prebiotic, feeding beneficial probiotic strains in the gut. Brussels sprouts, more abundant in fall, contain sulfur-based compounds called glucosinolates that break down during digestion into antimicrobial agents, helping control the overgrowth of harmful bacteria in the upper digestive tract.
Taste
Perhaps the most immediately noticeable benefit is that seasonal produce simply tastes better. When fruits and vegetables are allowed to ripen fully on the vine or in the ground before harvest, the difference can be remarkable.
How to eat seasonally
One of the easiest ways to eat in season is visiting local farmers’ markets. In-season produce is typically more affordable due to regional abundance, and buying local strengthens your community's economy while reducing the carbon footprint of long-distance food transport. As an added bonus, thousands of farmers' markets across the country accept SNAP benefits. To explore what's in season in your area throughout the year, the USDA offers a free seasonal produce guide, linked here.
The Longevity Diet connection
Prioritizing fresh, plant-based foods is a core principle of the Longevity Diet — the everyday eating pattern based on the habits of the world's longest-living populations, that is the foundation of everything we do at Prolon. Eating seasonally is one of the simplest ways to put that principle into practice. And if you want a plant-based reset this summer, the Prolon 5-Day Fasting Mimicking Diet (FMD) is built for exactly that — five days of plant-based food, formulated to nourish your body while keeping it in a fasting state, so you can head into summer at your best.
Sources:
Bouranis, Jordan A., et al. “Interplay between Cruciferous Vegetables and the Gut Microbiome: A Multi-Omic Approach.” Nutrients, vol. 15, no. 1, 2023, article 42. PubMed Central, https://pmc.ncbi.nlm.nih.gov/articles/PMC9824405/. Accessed 31 May 2026.
Cecere, Giulia, et al. “The Influence of Seasonal Variations in Clinical Trials Based on Gut Microbiota Studies.” Nutrients, vol. 16, no. 20, 2024. PubMed Central, https://pmc.ncbi.nlm.nih.gov/articles/PMC12566549/. Accessed 31 May 2026.
“Farmers Markets Accepting SNAP Benefits.” Food and Nutrition Service, U.S. Department of Agriculture, 28 Aug. 2025, https://www.fns.usda.gov/snap/farmers-markets-accepting-benefits. Accessed 31 May 2026.
García-Alonso, Alejandra, et al. “Nutritional Composition of Green Asparagus (Asparagus officinalis L.), Edible Part and By-Products, and Assessment of Their Effect on the Growth of Human Gut-Associated Bacteria.” Food Research International, vol. 163, Jan. 2023, article 112284. ScienceDirect, https://doi.org/10.1016/j.foodres.2022.112284. Accessed 31 May 2026
Kuhnle, Gunter, and Keshavan Niranjan. “Frozen and Tinned Foods Can Be Just as Nutritious as Fresh Produce – Here’s How.” Connecting Research, University of Reading, 10 Apr. 2023, https://research.reading.ac.uk/research-blog/2023/04/10/frozen-and-tinned-foods-can-be-just-as-nutritious-as-fresh-produce-heres-how/. Accessed 31 May 2026.
“Seasonal Produce Guide.” SNAP-Ed, U.S. Department of Agriculture, https://snaped.fns.usda.gov/resources/nutrition-education-materials/seasonal-produce-guide. Accessed 31 May 2026.
