Yes, we know that colored fruits and vegetables are healthier. A bunch of studies have illustrated the effects of the different pigments that make up our food colors: Pigments such as carotenoids and anthocyanins produce different colors in our foods.
But you probably figured that losing weight or our cholesterol levels had little to do with the colors of the foods we eat.
Think again.
A new study published in the European Journal of Clinical Nutrition has found that the colors of the fruits and vegetables we eat will affect our attempts at weight loss and our cardiovascular health differently.
Three-year diet and nutrition study
The researchers followed 1,272 people over two three-year periods: From 2006 to 2009 and from 2008 to 2011. They examined each of the subjects before and after the three years. They also analyzed their respective diets at the beginning and end of the three year period.
Their examinations included cholesterol measures, weight and waist circumference. As you could guess, waist circumference measures ones level of abdominal fat – think the pouch.
The subjects’ ages averaged 40 years old for the men and 37 years old for the women.
The researchers grouped fruits and vegetables into red/purple, yellow, green, orange or white. Remember these were both fruits and vegetables combined. So a red berry is in the same group as a purple vegetable.
The diet questionnaires taken at the beginning of the three-year period and again at the end allowed the researchers to group the men and women into groups: Each consuming greater amounts of a particular color.
On average the men and women ate 706 grams per day of red/purple fruits and vegetables, 185 grams per day of yellow foods, 141 grams per day of green foods, 152 grams per day of orange foods and 141 grams per day of white fruits and vegetables.
The results were slightly different between men and women, with some consistencies.
Red and purple foods kept the pounds off
Among the men, the researchers also found those who ate more red/purple fruits and vegetables saw reduced weight by 13 percent compared to the other groups. They had 14 percent lower abdominal fat compared to those eating other colored foods over the three-year period.
Those men who ate more yellow fruits and vegetables had 9 percent lower total cholesterol. They also had 11 percent lower LDL-cholesterol (the “bad” cholesterol lipid).
Furthermore, those men who ate more green and white fruits and vegetables were also associated with reduced abdominal fat gain over the three-year period.
Some different effects among women
The women who consumed more red and purple fruits and vegetables over the three-year period also had lower body weight and less abdominal fat compared to those who ate more of fruits and vegetables of different colors.
Those women who ate more red and purple foods also had lower blood sugar and reduced total cholesterol compared to the other groups.
But those women who consumed more yellow fruits and vegetables had greater weight gain over the three-year period compared to other groups.
The cardiometabolic effect of food color
The researchers utilized the term “cardiometabolic risk factors” as they described the results. Both men and women who ate more red and purple fruits and vegetables had lower weight and abdominal fat at the end of the three years. Eating more yellow fruits and vegetables resulted in more weight gain among women. And eating more green and white fruits and vegetables among men reduced their bad cholesterol.
No villains, only victors
No one can argue that all fruits and vegetables are healthy. But those foods that are colored red, purple and green colors tend to be healthier because they contain color pigments that translate to differing qualities.
For example, the color red and purple from fruits and vegetables – such as cherries or blueberries or eggplant – comes from pigments called anthocyanins. These are polyphenols with a significant ability to neutralize oxidation.
In other words, they are potent antioxidants. Antioxidants reduce heart disease and inflammation because they reduce oxidation. It is oxidation that damages our blood vessels and causes arteriosclerosis and artery stiffness from the plaque produced as a result of the damage.
But how do red and purple food colors affect our weight?
This is a bit more complicated. Much of weight gain is the result of inflammation as well. The pathways are complex, but they have to do with lipid oxidation. And again, the antioxidants in red and purple foods help neutralize this type of oxidation.
Starchier foods
Certainly, green foods also contain antioxidants, as do other fruits and vegetables. But it is the levels of these that is taking place in this study. Green foods and white foods also helped with weight loss – over the yellow and orange groups.
But the yellow foods also produced greater weight gain in the women but improved cholesterol factors among the men. This illustrates a varying degree of how men and women process starches – because yellow foods tend to be starchier.
For men, the starch normalized lipids likely because starchy fruits and vegetables also tend to contain significant fiber, and this is good for cholesterol.
But women – who genetically tend to process and convert starches differently – had more weight gain as a result of more yellow foods.
Yellow food color and breast cancer
Let’s not get hasty about the starchier yellow foods. At the same time, it should be noted that the central factor in yellow – and orange – foods is their carotenoid levels. As we illustrated in this research, women who consume greater amounts of carotenoids – yellow and orange fruits and vegetables – have a reduced risk of breast cancer.
The rainbow diet
The bottom line of this point is not that we should neglect any part of the rainbow. Eating a good mix of food colors – a rainbow diet in other words – will provide a good mix of nutrients and phytochemicals.
But this study does provide some guidance: If one is looking to reduce weight, an emphasis on the red and purple foods is warranted. But if a man is seeking to reduce bad cholesterol lipid types, then an increase in starchier yellow fruits and vegetables is warranted.
The other guidance of this study is not eat a wide variety of food colors. Some families can focus on only a few types of fruits and vegetables – thinking that any fruit and any vegetable have about the same result.
Well, now we know that is just not true.
REFERENCES:
Mirmiran P, Bahadoran Z, Moslehi N, Bastan S, Azizi F. Colors of fruits and vegetables and 3-year changes of cardiometabolic risk factors in adults: Tehran lipid and glucose study. Eur J Clin Nutr. 2015 Apr 8. doi: 10.1038/ejcn.2015.49.
Adams C. The Ancestor’s Diet: Living and Cultured Foods to Extend Life, Prevent Disease and Lose Weight. Logical Books, 2021.