The Health Benefits of Eating Seasonally

Eating seasonally refers to eating the fruits and vegetables that are harvested near you at that time of year. When you eat this way, your meals change as the months change.

Two old health traditions build their approach to food around this idea. Ayurveda refers to the traditional system of health care from India. Traditional Chinese medicine refers to a system of health care that developed in China over thousands of years. Both systems view the body and mind as primed to receive nourishment in rhythm with nature’s cycles. Both teach you to eat cooling, water-rich foods like watermelon and cucumbers in hot weather and warming foods like roasted root vegetables and stews in cold weather.

Modern research gives you several practical reasons to eat with the seasons.

Your gut bacteria change with the seasons

Trillions of bacteria live in your gut, and the food you eat has a strong effect on which of them thrive.

A 2014 University of Chicago study found this pattern in 60 Hutterites in South Dakota. The Hutterites are a religious group who live and eat together on shared farms, and most of their fresh produce comes from their own gardens in summer and fall. The researchers tested the same people in winter and in summer and found consistent shifts in their gut bacteria between the two seasons. A group of bacteria known for breaking down plant fiber made up about 30 percent of their gut bacteria in summer and about 11 percent in winter.

The researchers named the extra fruits and vegetables the Hutterites ate in summer as the most likely cause of the shift. More produce brings more plant fiber for those bacteria to break down.

Fresher food

Vitamin C starts to break down as soon as a fruit or vegetable is picked. In a review from the University of California, Davis, green beans stored in the refrigerator for seven days lost 77 percent of their vitamin C, and spinach lost 75 percent. Local produce spends fewer days on trucks and in warehouses, so more of its vitamin C is still there when you eat it.

How shipped fruit is ripened

Fruit that travels a long way is picked green and firm because ripe fruit bruises and spoils on the trip. Before it reaches the store, much of this fruit is ripened in sealed rooms with ethylene gas. Ethylene is a hormone that fruit makes naturally as it ripens. According to the U.S. Department of Agriculture, this method is used on bananas, tomatoes, avocados and pears, along with other fruits. Local farmers can let fruit ripen longer on the plant because it only travels a short distance to market.

Frozen produce

Frozen fruits and vegetables are usually picked ripe and frozen soon after harvest. Frozen produce holds its vitamin C as well as fresh produce from the grocery store, and in several tests it came out ahead.

UC Davis researchers compared eight fruits and vegetables fresh and frozen. Vitamin C in the frozen foods matched the fresh foods in five of the eight and was higher in the frozen foods for the other three. A University of Georgia study found no difference in most of its comparisons. Where it found a difference, frozen produce beat fresh produce stored for five days in a refrigerator in more cases than the reverse.

Most vegetables are blanched before freezing. Blanching is a quick heating in hot water or steam, and it costs some vitamin C. After that, frozen vegetables lose vitamins slowly.

Local produce eaten within a few days of picking is the best choice when you can get it. Frozen is the best backup.

Eating seasonally in Florida

Most seasonal food charts are written for places with cold winters, so they do not match Florida. In Florida, the main growing season runs from fall through spring. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Extension office in Manatee County calls summer, June through August, the off-season because the heat is so intense that most vegetables do not grow well.

Here is what the Florida Department of Agriculture and Consumer Services lists by season:

Fall: Oranges, grapefruit and tangerines start in September and last through spring. Tomatoes, sweet corn and squash start in October.
Winter: Strawberries run from December through April, and broccoli runs from January through March.
Spring: Blueberries and peaches come in during April and May. Watermelon starts in April.
Summer: Mangoes run from May through August. Avocados start in June, and lychees come in during June and July.

If you live outside Florida, ask at your local farmers’ market or call your county extension office to learn what grows near you and when.

Local honey for allergies

Eating a spoonful of raw local honey every day is a traditional way to ease seasonal allergies. Honey from local bees contains small amounts of pollen from local plants. The reasoning is that eating this pollen in small amounts over time trains your body to tolerate it before pollen season arrives.

Two studies found that eating honey every day eased allergy symptoms. In a 2011 study from Finland, people with birch pollen allergy ate honey every day from November through March, before birch pollen season. One group ate honey with birch pollen added, and another group ate regular honey. During the season, the birch pollen honey group reported 60 percent lower symptom scores, twice as many days with no symptoms and 70 percent fewer days with severe symptoms than a third group that took only its usual allergy medicine. The birch pollen honey group also used 50 percent less antihistamine medicine than the medicine-only group and less antihistamine than the regular honey group. On symptoms, the birch pollen honey group and the regular honey group came out about the same.

In a 2013 study from Malaysia, 40 adults with allergic rhinitis, the medical term for hay fever, all took a daily antihistamine for four weeks. Half of them also ate a large daily dose of raw honey for those four weeks. The other half ate honey-flavored corn syrup. At eight weeks, a month after both groups finished treatment, only the honey group was still improving, and only the honey group showed significant improvement in individual symptoms.

The pollen match is closest when the honey is truly local because local bees collect pollen from the plants that grow around you. Buy raw honey from a beekeeper in your area or at a farmers’ market. Start with a spoonful a day a few weeks before your allergy season, keep going through the season and track how you feel. A spoonful is far less than the large dose used in the Malaysian study, and honey is still sugar, so count it in your daily sugar.

How to start

Shop at a farmers’ market and ask the farmers what they picked that week. Your money goes to a farm in your own area, and that helps keep local farms in business.

Keep a few bags of frozen vegetables in your freezer so you can put a vegetable on the plate on any night. This habit fits the idea behind Crowding Out, which is to add good food first so there is less room left for junk.

Change your vegetables as the seasons change. If you eat the same few vegetables all year, trade one of them for something that just came into season.

In cooler months, make soups and stews with in-season vegetables. A stew made with bone broth is an easy way to eat more vegetables when the weather turns cool.

Try these changes for a month and notice how your body responds. Pay attention to your energy and your digestion, and keep the changes that work for your body.