To understand why, you first need to understand what you’re buying.
Green vs. red pepper
Botanically a fruit, though considered a vegetable in the culinary sense, these are more similar than you would think.
The difference between a sharp-tasting green bell and a sweet red bell pepper is one small thing; when they are harvested. Both are cultivars of the Capsicum annuum species. The green are picked premature, which is why they taste different; slightly bitter. The red are fully ripe, so they’re sweetest.
Midway between being green and red, a pepper will turn yellow and then orange. Those are more ripe than green, which means less bitterness and a sweeter flavor.
Even though all colors of peppers come from the same plant species, not all cultivars (short for cultivated varieties) produce every shade.
For plants that produce the yellow and orange peppers, they’re at those color phases for a shorter amount of time. That’s why they cost more than red.
Since the green are picked extra early, they are the slowest to spoil. That’s why they are the cheapest bell pepper you can buy. A non-organic of average-size typically runs $0.70 to $1.30, while red will be around $2.00. Yellow and orange are often the most expensive, averaging $2.50 a piece. USDA certified organic push the price even higher.
The least common variety is the purple bell pepper. Nicknamed the Purple Holland and Purple Beauty, they are a totally natural, non-GMO cultivar. Compact in size, their flavor is more comparable to green, yet even crunchier.
Differences in nutritional values
Which bell pepper has the most vitamin C?
A large yellow pepper offers 500% of the daily value for C. Red offers 349% and green is lowest at 219%. When comparing equal weight of each, all colors of peppers have higher vitamin C content than fresh oranges, which are 145% for the same 5.8 oz weight.
Green wins for being the lowest calorie pepper, but every color is guilt-free food.
Here’s how the rest of their values compare…
|Nutrition Facts For 1 Large Fruit (164g/5.8 oz)
percentages are for U.S. daily values
|Green Pepper||Red Pepper||Yellow Pepper|
|Total Fat||0.3g (0%)||0.5g (0%)||0.4g (0%)|
|Sodium||5mg (0%)||7mg (0%)||4mg (0%)|
|Potassium||287mg (8%)||346 (10%)||347 (10%)|
|Total Carbs||8g (2%)||10g (3%)||11g (4%)|
|Fiber||2.8g (11%)||3.4g (13%)||1.5g (6%)|
|Source: USDA National Nutrient Database for Standard Reference, Release 28 (1)|
The USDA database has nearly 225,000 foods listed, including over 2,000 entries for soda alone. Yet they have barely 100 foods containing bell pepper in the title and among those, only 3 entries for the yellow, red, and green. Orange peppers are not even listed, though other research suggests their nutritional values for calories and vitamins falls somewhere between that of red and yellow.
Differences in other phytonutrients
Of course the basic nutrition facts only tell you part of the story. There are many things which are potentially beneficial for your health that won’t be found on a label.
Lutein, zeaxanthin, and lycopene
These are carotenoids which are not classified as essential like vitamin A, yet there is compelling research that they offer health benefits. Particularly for the eyes, as that is where they are found to collect.
Since vitamin A deficiency is virtually unheard of in developed nations and being that so many foods contain it, you should be giving the least amount of weight to this nutrient.
Instead, you should focus on the lutein and zeaxanthin amounts.
Even when eating a healthy and balanced diet, you may be getting a relatively low amount. At least relative to the 10 mg of lutein and 2 mg of zeaxanthin used in the the Age-Related Eye Disease Study 2 (AREDS2).
That was a massive 6-year clinical trial funded by the U.S. government’s NIH. It was dicovered that participants with the lowest dietary intake of these carotenoids could reduce their chance of getting macular degeneration (AMD) by 26% and cataracts by 32% when they supplemented with 10 mg of lutein and 2 mg of zeaxanthin. (2) (3)
Although not reported in mg, the British Journal of Ophthalmology published a study which measured the precise amounts of these and other carotenoids in different colors of peppers. They reported the amounts using mole percent, which is a measurement in chemistry for evaluating the concentration of something. (4)
|Lycopene||Alpha-carotene||Beta-carotene (vitamin A)|
The only noteworthy carotenoid that red bell wins for is lycopene. As discussed in our article on nightshade vegetables, lycopene is a rare carotenoid. Very few foods contain it. The amount it has is 474 mcg per 100g (3.5 oz). That’s about 1/6th the lycopene of tomatoes.
Evidence of lycopene having anti-cancer activity is disappointing when tested on a stand-alone basis (i.e. lycopene supplements). However when it’s combined with other carotenoids naturally found alongside it, the effects appear greater than the sum of the parts.
That chart comes from an in vitro (lab) study using cultured human prostate cells. You can read more about it in our article titled Are canned tomatoes bad for you?
Total antioxidant content
Vitamins A, C, lutein, and zeaxanthin are all antioxidants found in green, yellow, and orange bell peppers. The red has those plus lycopene, which is another antioxidant.
In addition to these, all colors of peppers contain dozens of other molecules which are less potent, yet still contribute to the overall antioxidant activity.
None contain capsicum, which is the compound that gives hot chili peppers their heat.
Which color has the most antioxidant activity?
So far we have compared amounts for individual antioxidants. The best way to compare their combined activity is using ORAC values. That’s a measurement based on weight, which looks at the total antioxidant activity that can be measured in the lab for a 100g sample. Here are the ORAC values for the common colors:
- Raw yellow = 1,043
- Raw orange = 984
- Raw green = 935
- Raw red = 821
Raw yellow bell peppers have the most antioxidants. They have 27% more than the sweet red, which have the lowest activity. Despite being the cheapest, the green have 14% more antioxidants than red.
Many antioxidants – particularly vitamin C – get destroyed by the heat of cooking. Here’s a look at how some of their values measure after being cooked:
- Sauteed red = 847
- Grilled yellow = 694
- Sauteed green = 615
Did the red actually go up? Nope. Remember that ORAC is based on using equal weights of each food, regardless of form (raw or cooked). After cooking any type of veggie, they weigh less since water has evaporated. As a result, the amount used in a 100g sample ends up being more. That’s why the ORAC is higher for the sauteed versus raw red.
What bell pepper is healthiest?
At 30 to 50 per large pepper, the calorie count does vary by color, though all qualify as being low calorie foods that are good for weight loss and dieting. If you want the lowest calorie, it will be the green.
The bell pepper that is the sweetest will be red and yellow, closely followed by orange. Each will have 5-7g of sugar per large fruit, which is made of roughly half fructose and half glucose. Unlike processed sugars, these are bound to fibers in the plant, which means their glycemic impact is negligible. They’re good for you if you’re diabetic.
If you want to get nitpicky and eat the kind with the lowest sugar content, that will be the green pepper. It does not taste sweet like the reds and yellows.
Even though it’s the lowest in antioxidants, the best bell pepper for cooking will be red. The reason is because it’s the only color that contains lycopene, an antioxidant that becomes up to 4x more bioavailable after being cooked. (5)
Since vitamin C is destroyed from the heat of frying, grilling, baking, and boiling, the high amount found in yellow won’t be there after cooking. This is why yellow bell pepper is better raw.
When you take all nutritional values into account, the best bell pepper to eat for health benefits will be the orange color. It has the highest amounts of lutein and zeaxanthin. Their consumption is linked to risk reduction for age-related eye diseases. Since their sweetness and bitterness falls between green and red, the orange peppers are a happy compromise for those with picky palates, too.
When on a budget, there’s nothing wrong with paying half the price for the common and regular green pepper. With more lutein and zeaxanthin than yellow and red, they are quite healthy for you. A strong second place winner.