Studies and research

Introduction

A host of studies and research around the world demonstrate the benefits of fruits and vegetables, and of course apples!

Regular consumption of fruit and vegetables has long been recognized as having a protective effect against many cancers. What's more, studies have also shown that eating fruit and vegetables increases life expectancy.

Visit Canada's Food Guide recommends filling half your plate with vegetables and fruit. A large part of their protective effect is attributed to phytonutrients, powerful antioxidants such as carotenoids, flavonoids, isoflavonoids and phenolic acids. A diet rich in fruit and vegetables helps to prevent oxidative stress, thereby preventing chronic disease and reducing the effects of aging. Most of the phytonutrients found are flavonoids. Apples are an important source of flavonoids. The antioxidant activity of 100 g of apples is equivalent to 1500 mg of vitamin C.

Several scientific studies have demonstrated the link between eating apples and reducing the risks associated with certain cancers, cardiovascular disease, asthma, diabetes and Alzheimer's disease.

Cancers

A research team from Cornell University in New York has identified a group of photochemical compounds that are more abundant in apple peel and appear to suppress or inhibit the growth of at least three types of human cancer cells: colon, breast and liver.
Agric. Food Chem.200755114366-4370

A 15-year study examining the association of apple consumption with all-cause and disease-specific mortality found that higher apple consumption was associated with lower cancer mortality in women aged 70 and over.
Hodgson, J., Prince, R., Woodman, R., Bondonno, C., Ivey, K., Bondonno, N., ... . Lewis, J. (2016). Apple intake is inversely associated with all-cause and disease-specific mortality in elderly women. British Journal of Nutrition, 115(5), 860-867

Pancreas

American researchers conducted a study of the dietary habits of 183,518 residents of California and Hawaii. They found that a high dietary intake of flavonoids could help reduce the risk of developing pancreatic cancer, particularly in smokers. Fruits and vegetables especially rich in flavonoids include onions, apples, berries, kale and broccoli.
Biomedecine & Pharmacotherapy, Vol. 52 no.6 pp. 296-301, 2002
American Journal of Epidemiology, Volume 166, Issue 8Pages 924-931, 2007

Lungs and asthma

An epidemiological study conducted by the Finnish National Institute of Public Health on 9,959 men and women over a 24-year period concluded that consumption of flavonoids, mainly from apples, reduced the risk of developing lung cancer. The risk reduction was particularly significant in younger people and non-smokers.
American Journal of Epidemiology, 1997, 146 : 223-230

Researchers at the University of Hawaii have demonstrated in an epidemiological study that increased consumption of quercetin, a flavonoid found in abundance mainly in apples, was associated with a reduced risk of developing lung cancer.
Journal of National Cancer Institute, Vol 92, No. 2, January 19, 2000

Eating apples and pears may protect against asthma. According to an Australian study published in 2003 on food and nutrients, it was possible to conclude that there was a negative correlation between apple and pear consumption and asthma.
American Journal of Clinical Nutrition 2003; 78:414-421

European researchers have studied the consumption of specific foods during pregnancy and their impact on children born to these women. They found that eating apples during pregnancy had a protective effect in children against the development of asthma.
Thorax Online, March 2007

A study by British researchers has shown that people who eat at least two apples a week have a 22% to 32% lower risk of asthma than those who eat fewer apples.
Am. J. Respir. Crit. Care Med, Issue 64, Pages 1823-1828, 2001

Prostate

An in vitro study has demonstrated that quercetin may prevent the growth and development of prostate cancer by blocking the activity of androgen hormones.
Carcinogenesis, Vol. 22 no.3 pp. 409-414, 2001

The University of Texas at Austin has conducted research showing that ursolic acid found in apple peel would slow the progression of prostate cancer.
npj Precision Onc 1, 18 (2017)

Breast

A study carried out by researchers at Cornell University has demonstrated that the phytonutrients contained in apples can reduce the risk of breast cancer. The study showed that the incidence of tumors was reduced by 17, 39 and 44% in rats fed the equivalent of one, three and six apples a day.
Journal of Agricultural and Food Chemistry, Volume 53 Issue 6, 2341-2343, 2005

Researchers at the University of Teheran have discovered that the pectic acid contained in apples may cause the destruction of specific breast cancer cells. Thus, pectic acid may have the potential to improve cancer treatment as a natural product.
Delphi L, Sepehri H, Khorramizadeh MR, Mansoori F. Pectic-Oligoshaccharides from Apples Induce Apoptosis and Cell Cycle Arrest in MDA-MB-231 Cells, a Model of Human Breast Cancer. Asian Pac J Cancer Prev. 2015;16(13):5265-71

Digestive system

A literature review of research carried out on various digestive system cancers has shown that a better diet, especially one rich in micronutrients, fiber and phytonutrients from plants, including flavonoids, can play a significant role in protecting against cancers of the digestive system (pharynx, esophagus, stomach, colon and rectum).
Nutrition and Carcinogenesis, Volume 551, Issues 1-2, Pages 9-28, 2004

Researchers at the Institut de recherche contre les cancers de l'appareil digestif in France have studied the anti-carcinogenic effects of polyphenols contained in apples. They observed that the use of these polyphenols on colon cancer cells in rats inhibited growth and led to destruction (apoptosis) of the cancer cells. The protective effect was obtained with the human equivalent of two apples a day.
Carcinogenesis advance access published online on March 24, 2005

To validate studies already carried out on animals, a team of European researchers carried out a case-control study involving 592 people with colorectal cancer and 765 without. By studying their diets, it was found that people without colorectal cancer generally ate more apples than those with the disease. Furthermore, the results of the study showed that the more apples a person ate per day, the lower the risk of developing colorectal cancer. It was also found that eating at least one apple a day significantly reduced the risk of colorectal cancer. Researchers attribute the protective effect of apples to their content of flavonoids and other polyphenols, which can inhibit cancer and cell proliferation.
European Journal of Cancer Prevention: Volume 19, Issue 1, Page 42-47, 2010

Cardiovascular diseases

For every 10 grams of fiber consumed per day, the risk of developing heart disease could be reduced by 14%, and the risk of dying from cardiovascular disease could be reduced by 27%. Fiber in fruit appears to provide better protection than fiber in cereals.
Archives of Internal Medicine : Volume 164, no 4, Feb 23, Pages 370-376

In a study of 34,000 post-menopausal women, apples were found (along with pears and red wine) to reduce the risk of mortality from coronary heart disease and cardiovascular disease. According to the researchers, it is their rich flavonoid content that enables them to reduce the risk of heart disease.
The American Journal of Clinical Nutrition, March 2007
The American Journal of Clinical Nutrition : Volume 79, Issue 3, Pages 522-523, 2017

According to the results of a study of adults over the age of 50, eating an apple or taking statin drugs every day would have the same effect - preventing or delaying cardiovascular disease. Statins are widely prescribed around the world for people with high cholesterol. However, choosing to eat an apple rather than take statins would have fewer side effects.
British Medical Journal 2013; 347

A twelve-month study of 160 post-menopausal women aged between 45 and 65 demonstrated that eating apples reduces the risk of cardiovascular disease. In fact, six months after the start of the study, the group of women who ate dried apples every day saw their total cholesterol levels drop by 13% and LDL lipoproteins fall by 24%.
Journal of the Academy of Nutrition and Dietectics : V. 112, Issue 8, Pages 1115-1168, 2012

A study by UK researchers has shown that the flavonoids in apples help reduce the risk of cardiovascular disease by lowering blood pressure. What's more, apples contain soluble fiber, which is thought to lower cholesterol levels.
Bondonno CP, Yang X, Croft KD, Considine MJ, Ward NC, Rich L, Puddey IB, Swinny E, Mubarak A, Hodgson JM. Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial. Free Radic Biol Med. 2012 Jan 1;52(1):95-102
Brouns, F., Theuwissen, E., Adam, A. et al. Cholesterol-lowering properties of different pectin types in mildly hyper-cholesterolemic men and women. Eur J Clin Nutr 66, 591-599 (2012)

In a study conducted for the University of Western States, a researcher found that for every 25g of apples consumed per day, the risk of stroke was reduced by 9%.
American Heart Association. Volume 42, Issue 11, November 2011 ; Pages 3190-3195

According to a study published by a professor at the University of Leeds, the high quantity of polyphenols contained in apples protects against the development of cardiovascular disease and type 2 diabetes.
Williamson G. The role of polyphenols in modern nutrition. Nutr Bull. 2017 Sep;42(3):226-235.

A study by UK researchers has shown that apple polyphenols and fiber can beneficially modulate the composition and activity of the gut microbiota. The intestinal microbiota may serve as a potential new target for the prevention of cardiovascular disease. In addition, pectin is a gelling agent and has an impact on transit time, gastric emptying and nutrient absorption by the gut.
Nutrients 2015, 7(6), 3959-3998;

Chronic illness

An epidemiological study of 10,045 men and women showed that high consumption of quercetin, mainly from apples, reduced the risk of heart disease, cancer, type 2 diabetes and asthma.
The American Journal of Clinical Nutrition 2002;76:560-8

The anti-inflammatory action of quercetin in apples is caused by inhibition of enzymes such as lipoxygenase and inhibition of inflammatory mediators. For this reason, quercetin is suitable for the treatment of mast cell-derived allergic inflammatory diseases such as asthma, sinusitis and rheumatoid arthritis.
Mlcek J, Jurikova T, Skrovankova S, Sochor J. Quercetin and Its Anti-Allergic Immune Response. Molecules. 2016 May 12;21(5):623

Weight loss

A study carried out in Brazil showed that eating 3 apples or pears a day in overweight women was associated with weight loss. The study involved non-smoking women aged between 30 and 50.
Nutrition, Volume 19, Issue 3, Pages 253-256, 2003

American researchers conducted a weight maintenance study involving over 124,000 adults over a 24-year period. They were able to demonstrate that people who consumed flavonoid-rich foods were able to maintain a healthy weight. They may also help prevent obesity, diabetes and several cancers. Apples are an important source of flavonoids.
BMJ 2016; 352: i17

Eating a whole apple would reduce the speed at which the stomach empties, compared to a pureed or juiced apple (processed apple). This satiety effect would have a major positive effect on weight loss, causing a greater sense of fullness and satiety in healthy adults.
The Journal of Nutrition, Volume 150, Issue 11, November 2020, Pages 2890-2899

Cellular health

Researchers at the University of California have discovered that the flavonoids contained in apples and apple products can help improve health. The study found that flavonoids, components of apples and apple products, help protect cells from destruction through their ability to promote cell communication and interfere with invading organisms that would otherwise cause damage that can increase the risk of heart disease and certain cancers.
Experimental Biology and Medicine : Volume 231, Issue 5, Pages 594-598, 2006

A study conducted by Cornell University has found that apple peel, which contains a significant amount of phytonutrients and flavonoids in particular, has significant antioxidant activity and prevents the proliferation of cells linked to liver and breast cancer in humans.
J. Agric. Food Chem, 2008, 56, 21, pp 9905-9910

Brain health

A study conducted on mice has confirmed that consumption of antioxidant-rich fruit and vegetables could prevent the free radical damage associated with age-related cognitive decline such as Alzheimer's disease. Research has shown that an intake of apple juice can compensate for oxidative stress combined with poor diet and genetic make-up.
The Journal of Nutrition, Health and Aging, Volume 8, Number 6, Pages 492-496, 2004

Another study also found that antioxidants in apples protect brain cells against oxidative stress, which causes neurodegenerative diseases such as Alzheimer's. The study, conducted on rat brain cells, reinforced the theory that the risk of developing Alzheimer's and similar diseases could be reduced by diet, particularly foods rich in antioxidants. Environment and genetics also play an important role in the development of this disease.
Journal of Food Science, Volume 69, No 9, 2004

A new study conducted at the University of Massachusetts on mice suggests that drinking apple juice may protect against the oxidative damage to cells that contributes to age-related memory loss. The results of this study demonstrated that an additional intake of apple juice can protect aged mice against oxidative stress caused by a deficient diet. Furthermore, high mental acuity was achieved when aged mice consumed the human equivalent of 2-3 cups of apple juice, or approximately 2-4 apples per day.
Journal of Alzheimer's Disease, Volume 8, No 3, December 2005, p. 283-287

A clinical study of institutionalized individuals found that apple juice consumption may be a useful supplement to alleviate symptoms associated with the progression of Alzheimer's disease.
Am J Alzheimers Dis Other Demen. 2010 Jun;25(4):367-71

A growing number of studies indicate that consumption of apples and apple juice may be beneficial in improving brain health and reducing symptoms of Alzheimer's disease. In combination with diet, apples and apple juice may protect against oxidative damage to the central nervous system that can lead to memory loss.
Journal of Alzheimer's Disease, 2009, 16:1

Muscular system

An apple a day can help prevent muscle wasting and atrophy, according to a new study. The study revealed that apple peel, which contains ursolic acid, can combat the effects of aging on muscles.
Cell Press, Volume 13, ISSUE 6, P627-638, June 08, 2011

Intestinal health

Researchers at the University of Denmark have discovered that eating apples increases the number of good intestinal bacteria.
BMC Microbiology 2010 10:13