A nutritionist explains when it's worth buying organic - and how much more it will cost you

Regular milk: $4.39 per gallon

Organic milk: $6.99 per gallon

Worth it? Yes.

"When cows are treated with hormones to increase their growth, those hormones also pass into their milk supply and end up in your cereal bowl," says Batayneh. "One hormone used in cows, rBST, stimulates the production of insulin-like growth factor (IGF-1), which, when elevated in humans, may be linked to an increased risk of cancer."

Another option may be almond milk, which I found was priced the same for both organic and nonorganic: $3.49 per carton.

Regular strawberries: $3.99 per pound

Organic strawberries: $4.49 per pound

Worth it? Yes.

"Strawberries are a highly contaminated fruit found on the Environmental Working Group's (EWC) Dirty Dozen, a list of twelve produce products that carry the most pesticides," says Batayneh. "Their soft skin makes them more permeable to pesticides and chemicals than other fruits, which means they'll absorb and carry more pesticide residues."

Regular cantaloupe: $3.49 each

Organic cantaloupe: $3.99 each

Worth it? Yes.

"Despite their thick, tough skin, organic cantaloupes are worth the splurge: Studies have found that they often contain the most persistent chemicals, which can be absorbed into their edible portions," explains Batayneh.

Regular peaches: $3.49 per pound

Organic peaches: $3.99 per pound

Worth it? Yes.

"In the EWG's most recent test for pesticide residues, 98% of peach samples showed a positive test for at least one pesticide residue," explains Batayneh. "Like strawberries, their thin skin makes them more vulnerable to pesticide exposure."

Regular avocados: $2.50 each

Organic avocados: $2.79 each

Worth it? No.

"Avocados have a place on the EWG’s 'Clean 15' due to their thick, scaly skin, which blocks the entry of pesticides into their meat and makes conventionally grown avocados just as healthy and safe as the organic ones," explains Batayneh.

Regular tomatoes: $1.99 per pound

Organic tomatoes: $2.99 per pound

Worth it? Yes.

"Tomatoes have thin, delicate skins, leaving their insides vulnerable to harsh chemicals," says Batayneh. "In addition, organic tomatoes may actually contain more nutrients than their conventional counterparts."

Regular pork bacon: $5.99 per 10-ounce package

Organic pork bacon: $6.49 per 8-ounce package

Worth it? Yes.

When it comes to meat, stay on the safe side and opt for organic, recommends Batayneh — in order for pork bacon to be labeled organic, pigs must be fed certified organic feed, and no antibiotics or growth hormones are allowed.

Regular chicken: $10.16 for a 4.08-pound chicken ($2.49 per pound)

Organic chicken: $9.54 for a 3.19-pound chicken ($2.99 per pound)

Worth it? Yes.

Spend the extra money on organic chicken, Batayneh advises. Buying organic ensures your chicken won't contain any antibiotics or growth hormones that regular chicken may have. This holds true for beef also. However, when it comes to seafood, go regular: "The USDA doesn't even provide guidelines or a definition for organic seafood, so you'll only be paying for a few extra letters on your food," she tells us.

Regular apples: $1.99 per pound

Organic apples: $2.99 per pound

Worth it? Yes.

"Apples are the first item listed on the EWG's Dirty Dozen," says Batayneh. "In fact, the FDA has detected 36 different pesticides on the skin (a nutrient-rich part of the fruit!) of apples that may be dangerous to your health."

It turns out that buying organic kiwis isn't worth it, but they were my only option in this particular store:

Organic kiwis: $0.59 each

Worth it? No.

"Because most people eat kiwis without the peel — where most of the pesticide residues are found — kiwis are safe to eat whether they're conventionally grown or not," explains Batayneh. "Plus, their fuzzy, tough exterior helps keep pesticides from getting inside the edible portion."

Regular onions: $1.49 per pound

Organic onions: $1.99 per pound

Worth it? No.

"Onions are generally more resistant to pests, bugs, and diseases due to their high sulfur content, which means they're usually not treated with the high levels of pesticides and chemicals that other fruits and vegetables are," says Batayneh.

Garlic was one of the only products I could not find in organic form at Whole Foods, which ended up being fine, as it's not worth it, Batayneh tells us: "Like onions, garlic is a member of the Alliaceae family. They're known for being incredibly resistant to damage from insects and other destructive organisms."