July 21, 2021 10 min read

I’m sure we were all told to eat our vegetables as we were growing up. Although some of us didn’t exactly run to the fridge for broccoli or cabbage as our first selection; we intuitively knew that vegetables were healthy for us!

Some people learn to love vegetables and others never really acquire a taste for them, but the idea that vegetables are good for you is a deeply ingrained dietary philosophy.

But are vegetables really necessary to be healthy or can we get by without eating them? 

And if they are necessary, what exactly are the benefits of eating them? 

Do they help with fat loss, do they help build muscle, and what other benefits can you expect from eating more vegetables?

Let’s jump in and answer these questions below!

Here are some claims you may have heard about vegetables: 

  • You need to eat a lot of vegetables to be healthy!
  • You can be healthy without vegetables if you get your micronutrients from other sources.
  • Vegetables are harmful to some people.
  • Excessive intake of plant foods is unhealthy!

Supporting the argument that vegetables are good for you, two large reviews that included hundreds of thousands of participants recently found eating more fruits and vegetables reduces all-cause mortality along with deaths by heart disease and cancer (1,2). 

In support of the argument that vegetables are harmful to some people; people can develop food sensitivities to veggies and many plant foods contain anti-nutrients like phytins and lectins that can cause inflammation in your body and interfere with nutrient absorption (3,4).

As you can see there is some controversy and debate surrounding vegetables. But keep in mind, that there are always extremes or outliers on either end of the spectrum. 

Evolutionary biology tells us that with some exceptions like the Inuit and other peoples like the Maasai and Sami, most ancient and modern hunter-gatherers derive between 20 and 55 percent of their calories from plants (5).

Overall, humans evolved to eat vegetables as part of their diet most of the time. 

So, how do vegetables benefit your health?

Plants make chemicals like sulforaphane, capsaicin, and resveratrol to protect themselves from insects and other predators, including humans (6).

These types of compounds can have harmful effects in high doses, but in the proper amount, many of them can benefit your health.

Hormesis is a process that occurs when your body experiences a stressor and becomes stronger as a result, e.g: the process of building lean muscle. 

Scientists think that some of the health benefits of vegetables occur due to hormesis (7).

Essentially, low or moderate intake of polyphenols and other plant compounds activates a specific controlled stress response in your body that leads to better function and protects your cells in the long run (7).

Brain Health

While it may seem intuitively obvious that vegetables are good for your brain, most people don’t stop to think about why. In the case of brain health, and cognition, vegetables exhibit medicinal properties beyond most other foods.

One study found that for every 100 gram increase in daily plant food intake, senior citizens’ risk of dementia and cognitive decline decreased by 13% (8).

Polyphenols found in vegetables are most likely the reason for enhanced cognitive performance in these studies (9). Polyphenols are compounds that we get through certain plant-based foods. They’re packed with antioxidants and potential health benefits.

The bottom line: eating more vegetables increases your antioxidant capacity, decreases your risk of cognitive decline, and reduces your risk of neurodegenerative diseases (10).

Scientists accredit these benefits to flavonoids, carotenoids, and other bioactive substances found in plants (11).

Prevention of Cancer

There are numerous large studies showing that consuming more vegetables than the average person helps prevent cancer, and reduces your overall risk of dying of cancer (2,12,13). 

One study even went on to conclude that if everyone ate 800 grams of vegetables per day, it might prevent up to 8 million premature deaths per year (1). The benefits for cancer prevention are partly due to phytonutrients in vegetables, and partly due to their fiber. 

Broccoli and other cruciferous veggies appear to be the most valuable players in regards to preventing cancer. They can protect your gastrointestinal tract, lungs, prostate, or breasts against cancer thanks to chemicals called glucosinolates (14).

Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants such as kale, cauliflower, broccoli, arugula, bok choy, brussels sprouts, cabbage, and much more.

Improved Heart Health

Cardiovascular disease and other heart related issues have been the leading killer of people across the world for more than 50 years in a row. But according to several large reviews of published scientific papers, eating more vegetables reduces your risk of heart disease and death by cardiovascular issues (1,2,15).

Plant foods contribute to your heart health because they contain fiber, vitamins, minerals, and phytonutrients (16).

The protective mechanisms of vegetables may not only include some of the known bioactive nutrient influences dependent on their antioxidant, anti-inflammatory, and electrolyte properties, but also include their functional properties, such as low glycemic load and energy density. 

Taken together, the totality of the evidence accumulated so far does appear to support the notion that increased intake of vegetables may reduce cardiovascular risk.

It's clear that vegetables should be eaten as part of a balanced diet, as a source of vitamins, fiber, minerals, and phytochemical, and the evidence now suggests that a complicated set of several nutrients may interact with genetic factors to influence cardiovascular disease risk. Therefore, it may be more important to focus on whole foods and dietary patterns rather than individual nutrients to successfully impact on cardiovascular disease risk reduction (16).

Improved Colon Health

Vegetables can enhance the health of your colon and gut through their fiber content, as well as the phytonutrients they offer.

Colorectal cancer is considered a major public health issue, a leading cause of cancer mortality and morbidity worldwide. Epidemiological, pre-clinical and clinical investigations have consistently highlighted important relationships between large bowel inflammation, gut microbiota, and colon carcinogenesis. 

Many experimental studies and clinical evidence suggest that polyphenols like resveratrol, curcumin, chlorogenic acid, quercetin, and piperine reduce your risk of colon cancer and can increase the effectiveness of cancer therapies in people who already have colon cancer.

These effects are most likely related to the immunomodulatory properties of polyphenols able to modulate cytokine and chemokine production and activation of immune cells (17).

In addition, a recent scientific review concluded eating more vegetables may also prevent dysbiosis and improve or reverse irritable bowel syndrome (18).

Vegetables are loaded with micronutrients 

While it’s possible to get many essential micronutrients from animal products, vegetables are an easier way to get magnesium, betaine, and potassium.

According to the evidence; increasing your veggie intake is also an excellent way to get more vitamin C and carotene and improve your overall micronutrient profile (19,20).

Data indicates that increased vegetable consumption increases micronutrient, carbohydrate and fiber intakes and possibly reduces fat intake, with no overall effect on energy intake.

Therefore, health benefits may act through an improvement in overall diet profile alongside increased micronutrient intakes.

They are also abundant in fermentable fiber

As opposed to the insoluble fiber found in grains, vegetables are high in soluble or 'fermentable fiber'. This form of fiber acts as a prebiotic, nourishing your gut microbiome.

Your gut bacteria (and other microorganisms like fungi and archaea) play many essential roles in your body such as: 

  • Digestion
  • Metabolism
  • Production of neurotransmitters
  • Gut-brain signaling
  • Immune function
  • Control of inflammation
  • Gene expression

Thanks to fermentable fiber, a diverse diet rich in vegetables results in a high-quality, diverse microbiome that supports your health (21-23).

As you know, fiber can aid in feelings of fullness as well as assist in digestion, but aside from the numerous vitamins, minerals, and fiber that vegetables provide, they are also chock-full of antioxidants and other amazing phytochemicals that help to protect our cells from free-radical damage. 

In addition to aiding in disease prevention, phytochemicals are essential to general health and wellbeing. 

What exactly are phytochemicals? 

Phytochemicals are defined as bioactive nutrient plant chemicals in fruits, vegetables, grains, and other plant foods that may provide desirable health benefits beyond basic nutrition to reduce the risk of major chronic diseases such as cancers, heart disease, and type-2 diabetes (24).  

If those aren't god enough reasons to eat more veggies; are you aware that vegetables can also help you shed fat?

Vegetables & fat loss – increased veggie intake is key for sustained fat loss

Increasing your vegetable intake will help build more muscle and aid in fat loss. A high intake of vegetables every day is the secret to dramatic changes in body composition as they can help you to shed fat without the tiresome chore of counting calories.

Firstly, they provide “bulk” to the diet but contribute very few calories. Due to their high-bulk yet low-energy content, vegetables force the body to burn more energy during processing of meals and “tricks” the metabolism into staying elevated during times of calorie restriction.

Secondly, a high intake of vegetables will enable your supplements to work more effectively. They keep blood sugar concentrations steady so your protein supplements are channeled towards building muscle and not energy production. These factors are essential to building lean muscle mass

Thirdly, a high intake of vegetables promotes fat loss by increasing satiety which is the feeling of fullness from eating less food. It’s a strategy that makes sticking to a calorie-controlled diet much easier. Not many people actually realize that a large plate piled high with a variety of colorful veggies contains less than 300 calories, and most people would have a hard time eating all of them!

Practical application

It’s quite clear from the evidence that a higher consumption of vegetables would provide active people with a greater array of nutrients and more health benefits. People often stick to consuming the same one to two types of vegetables and miss out on the nutritional benefits that a variety of veggies can provide.

Different vegetables provide different essential nutrients.

When in doubt about selection, go for color. The brighter and richer the color, the more nutritious the vegetable is. Veggies with the highest nutritional value are dark green, bright yellow, red and orange (such as squash, sweet potato, carrots, and pumpkin).

 Also, the cruciferous veggies (such as broccoli and cauliflower) contain a multitude of nutrients that protect our DNA against oxidative damage that cause disease. The truth is that science is only just starting to uncover an array of powerful, yet little known compounds that occur naturally in vegetables.

So when in doubt, eat more veggies!

 

References: 

1.Aune, D., Giovannucci, E., Boffetta, P., Fadnes, L. T., Keum, N., Norat, T., Greenwood, D. C., Riboli, E., Vatten, L. J., and Tonstad, S. (2017) Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol 46, 1029-1056

2.Wang, X., Ouyang, Y., Liu, J., Zhu, M., Zhao, G., Bao, W., and Hu, F. B. (2014) Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ 349, g4490

3.Cheryan, M. (1980) Phytic acid interactions in food systems. Crit Rev Food Sci Nutr 13, 297-335

4.Dolan, L. C., Matulka, R. A., and Burdock, G. A. (2010) Naturally occurring food toxins. Toxins (Basel) 2, 2289-2332

5.Cordain, L., Miller, J. B., Eaton, S. B., Mann, N., Holt, S. H., and Speth, J. D. (2000) Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr 71, 682-692

6.Mattson, M. P. (2008) Dietary factors, hormesis and health. Ageing Res Rev 7, 43-48

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8.Jiang, X., Huang, J., Song, D., Deng, R., Wei, J., and Zhang, Z. (2017) Increased Consumption of Fruit and Vegetables Is Related to a Reduced Risk of Cognitive Impairment and Dementia: Meta-Analysis. Front Aging Neurosci 9, 18

9.Lamport, D. J., Saunders, C., Butler, L. T., and Spencer, J. P. (2014) Fruits, vegetables, 100% juices, and cognitive function. Nutr Rev 72, 774-789

10.Zielinska, M. A., Bialecka, A., Pietruszka, B., and Hamulka, J. (2017) Vegetables and fruit, as a source of bioactive substances, and impact on memory and cognitive function of elderly. Postepy Hig Med Dosw (Online) 71, 267-280

11.Rendeiro, C., Rhodes, J. S., and Spencer, J. P. (2015) The mechanisms of action of flavonoids in the brain: Direct versus indirect effects. Neurochem Int 89, 126-139

12.Peleteiro, B., Padrao, P., Castro, C., Ferro, A., Morais, S., and Lunet, N. (2016) Worldwide burden of gastric cancer in 2012 that could have been prevented by increasing fruit and vegetable intake and predictions for 2025. Br J Nutr 115, 851-859

13.Bradbury, K. E., Appleby, P. N., and Key, T. J. (2014) Fruit, vegetable, and fiber intake in relation to cancer risk: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC). Am J Clin Nutr 100 Suppl 1, 394S-398S

14.Abdull Razis, A. F., and Noor, N. M. (2013) Cruciferous vegetables: dietary phytochemicals for cancer prevention. Asian Pac J Cancer Prev 14, 1565-1570

15.Zhan, J., Liu, Y. J., Cai, L. B., Xu, F. R., Xie, T., and He, Q. Q. (2017) Fruit and vegetable consumption and risk of cardiovascular disease: A meta-analysis of prospective cohort studies. Crit Rev Food Sci Nutr 57, 1650-1663

16.Alissa, E. M., and Ferns, G. A. (2017) Dietary fruits and vegetables and cardiovascular diseases risk. Crit Rev Food Sci Nutr 57, 1950-1962

17.Mileo, A. M., Nistico, P., and Miccadei, S. (2019) Polyphenols: Immunomodulatory and Therapeutic Implication in Colorectal Cancer. Front Immunol 10, 729

18.Tomasello, G., Mazzola, M., Leone, A., Sinagra, E., Zummo, G., Farina, F., Damiani, P., Cappello, F., Gerges Geagea, A., Jurjus, A., Bou Assi, T., Messina, M., and Carini, F. (2016) Nutrition, oxidative stress and intestinal dysbiosis: Influence of diet on gut microbiota in inflammatory bowel diseases. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 160, 461-466

19.Appleton, K. M., Hemingway, A., Saulais, L., Dinnella, C., Monteleone, E., Depezay, L., Morizet, D., Armando Perez-Cueto, F. J., Bevan, A., and Hartwell, H. (2016) Increasing vegetable intakes: rationale and systematic review of published interventions. Eur J Nutr 55, 869-896

20.Fulton, S. L., McKinley, M. C., Young, I. S., Cardwell, C. R., and Woodside, J. V. (2016) The Effect of Increasing Fruit and Vegetable Consumption on Overall Diet: A Systematic Review and Meta-analysis. Crit Rev Food Sci Nutr 56, 802-816

21.Klimenko, N. S., Tyakht, A. V., Popenko, A. S., Vasiliev, A. S., Altukhov, I. A., Ischenko, D. S., Shashkova, T. I., Efimova, D. A., Nikogosov, D. A., Osipenko, D. A., Musienko, S. V., Selezneva, K. S., Baranova, A., Kurilshikov, A. M., Toshchakov, S. M., Korzhenkov, A. A., Samarov, N. I., Shevchenko, M. A., Tepliuk, A. V., and Alexeev, D. G. (2018) Microbiome Responses to an Uncontrolled Short-Term Diet Intervention in the Frame of the Citizen Science Project. Nutrients 10

22.Lawrence, K., and Hyde, J. (2017) Microbiome restoration diet improves digestion, cognition and physical and emotional wellbeing. PLoS One 12, e0179017

23.Ercolini, D., and Fogliano, V. (2018) Food Design To Feed the Human Gut Microbiota. J Agric Food Chem 66, 3754-3758

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Dr. Paul Henning

About Dr. Paul

I'm currently an Army officer on active duty with over 15 years of experience and also run my own health and wellness business. The majority of my career in the military has focused on enhancing Warfighter health and performance. I am passionate about helping people enhance all aspects of their lives through health and wellness. Learn more about me

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