Anyone who reads my blogs will be aware of the importance I place on having the support of strong scientific evidence for making lifestyle changes. I have been struck in recent months by the amount of new research that has been published regarding the benefits of eating plant-based. The following is a synopsis of some of the ongoing study focusing on cardiovascular disease, diabetes, cancer and dementia that continues to build on the already impressive quantity of evidence supporting the enormous benefits to be gained from eating whole plant foods.
PREVENTION OF EARLY DEATH FROM ALL CAUSES
From November 2021 (1);
Current food systems are a threat to the health of both human beings and their environment. The Eat-Lancet diet is the first global reference diet aimed at the improvement of these health risks and encouraging more sustainable food systems. The EAT-Lancet diet encourages high intake of fruit, vegetables, legumes and whole grains, and limited intake of animal products and saturated fat.
Researchers looked at 22,421 participants from the Malmö Diet and Cancer cohort in Sweden aged between 45 and 73 years and found that those with the most adherence to the Eat-Lancet diet… …lowered their risk of early death from all causes (including cancer and heart disease) by 25%
…lowered their risk of early death due to cancer by 24%
…lowered their risk of early death due to cardiovascular disease by 32%
when compared to those with the lowest adherence to the diet.
From September 2020 (2);
More than 500,000 participants from the European Prospective Investigation into Cancer and Nutrition cohort (EPIC) were rated for the quality of their nutritional intake. Those eating more red and processed meat were found to be at greater risk of early death from all causes, including cancer, cardiovascular disease, respiratory conditions and diseases of the digestive system than those eating higher amounts of nutritionally valuable food such as fruits, vegetables and legumes. In addition, strong associations of saturated fat from animal products with respiratory conditions were observed. The researchers noted that increasing intake of fiber from plant foods could prevent these problems.
PREVENTION OF CARDIOVASCULAR DISEASE
From April 2021 (3);
Dietary nitrates improve blood flow and play a key role in cardiovascular health. The major dietary sources of nitrates in human beings are vegetables including spinach, lettuce and other green leafy vegetables, and potatoes. In a prospective cohort study of 53,150 Danish participants, those ingesting the most vegetable nitrates had lower systolic and diastolic blood pressure. When compared to participants consuming the lowest amount of dietary nitrate, eating a moderate amount of vegetable nitrate was associated with…
…15% lower risk of cardiovascular disease
…12% lower risk of ischemic heart disease
…15% lower risk of heart failure
…17% lower risk of ischemic stroke
…26% lower risk of peripheral artery disease hospitalization
Researchers concluded that consuming at least 60 mg per day of vegetable nitrate (about 1 cup of green leafy vegetables) can lessen the risk of cardiovascular disease.
From April 2021 (4);
An editorial published in the Journal of the American Heart Association honed in on the reasons that red meat and egg yolk consumption increase risk of cardiovascular disease. It explained common misconceptions that egg and meat intake is harmless stemming from the influences of the food industry and confusion among national dietary guidelines. The authors point out that egg and meat intake is unquestionably linked to diabetes; raised cholesterol levels; increases in inflammation; and raised risk for heart disease including heart attacks, stroke and death.
From April 2021 (5);
A meta-analysis encompassing eight observational studies that had compared the association between vegetarian and non-vegetarian diets and major cardiovascular events found that those eating vegetarian diets were linked to a 30% reduced risk of coronary heart disease compared to those eating non-vegetarian diets.
From March 2021 (6);
The PURE Study, a prospective look at mortality and cardiovascular disease in 21 countries, compared processed meat consumption with heart disease and mortality. Those eating more than 150 gm of processed meat a week increased their risk of heart disease by 46% and of early death by 51% when compared with those who did not eat processed meat. One hot dog weighs about 50 gm.
From March 2021 (7);
The 2021 UK Biobank prospective study compared meat intake with negative health outcomes in almost 474,000 middle-aged adults who were followed for an average of 8 years. The research concluded that those eating meat three times a week or more had worse health consequences when compared to those eating less meat.
For every 70 gm of red and/or processed meat consumed daily there was…
…31% increased risk of pneumonia
…30% increased risk of diabetes
…19% increased risk of diverticular disease
…15% increased risk of ischemic heart disease
…10% increased risk of colon polyps
Higher intake of poultry was associated with…
…17% increased risk of gastro-oesophageal reflux disease
…14% increased risk of diabetes
…12% increased risk of gastritis and duodenitis
…11% increased risk of gallbladder disease
…10% increased risk of diverticular disease
Study authors illuminate possible mechanisms for these increased risks such as higher intakes of sodium, iron, nitrates and nitrites, bacteria, and saturated fat from consuming meat; higher LDL cholesterol levels; and changes in gut microbiota associated with meat consumption.
From February 2021 (8);
Using data from the Women’s Health Initiative (WHI), a large prospective cohort study of over 102,000 post-menopausal women who were followed for an average of 18 years, it was determined that those consuming more plant-based protein …
…had a 14% lower risk of all-cause mortality
…had a 22% lower risk of death from cardiovascular causes
…had a 19% reduced risk of death from conditions of dementia.
In addition, substituting plant protein for animal protein was also found to lower mortality risk.
From January 2021 (9);
A meta-analysis published in the International Journal of Epidemiology revealed that substituting plant-based protein for animal-based protein lowered cardiovascular disease risk. Replacing protein from eggs, processed meat, poultry and other animal sources with legumes, nuts and whole grains lowered the risk for cardiovascular disease and death by up to 54%. The more animal protein that was replaced with plant protein, the higher the risk reduction.
From December 2020 (10);
A prospective cohort study looked at the relationship between risk of coronary heart disease and total meat intake, processed meat intake and unprocessed red meat intake as well as the effects of substituting other protein sources for red meat. Here are its findings.
One serving per day of total red meat (red or processed meat) was associated with a 12% increased risk of coronary heart disease.
One serving per day of unprocessed red meat was associated with an 11% increased risk of coronary heart disease.
One serving per day of processed red meat was associated with a 15% increased risk of coronary heart disease.
Authors attribute these higher risks to increased intake of saturated fat, heme iron and proinflammatory compounds found in meat as well as increased cholesterol levels.
On the other hand, one serving per day of plant protein sources (nuts, legumes and soy) was associated with…
…14% LOWER risk of coronary heart disease when compared to total red meat consumption
…13% LOWER risk of coronary heart disease when compared to unprocessed red meat consumption
…17% LOWER risk of coronary heart disease when compared to processed red meat consumption
Authors attribute these lower risks to the replacement of saturated fat with polyunsaturated fat from plant sources.
From November 2020 (11);
A prospective study followed participants of the Nurses’ Health Study (NHS) Health Professionals Follow-up Study. Those consuming diets containing the most pro-inflammatory foods such as red and processed meat showed a 38% increased risk for cardiovascular disease and a 28% increased risk for stroke when compared to those participants eating less inflammatory foods (vegetables and whole grains).
From March 2020 (12);
The results of three prospective cohort studies illustrated the beneficial effects of the isoflavones found in tofu on the risk of coronary heart disease. Higher intakes of tofu were associated with an 18% reduced risk of coronary heart disease compared with lower intakes of tofu. Isoflavones bind to estrogen receptors, blocking them from binding estrogens and inducing a cascade of positive effects including stimulation of nitric oxide synthesis by the endothelial cells in artery walls, reduction of oxidative stress, reduced inflammation and rapid dilation of blood vessels. Isoflavone consumption can also reduce LDL-cholesterol oxidation and may interact with the gut microbiota to produce beneficial bioactive compounds and increase the diversity of the microbiome. Isoflavones are also found in other soy products such as cooked soybeans, tempeh, soy yogurt and cheese, and soy milk.
From March 2020 (13);
Findings presented at the American Heart Association’s EPI Lifestyle Scientific Sessions by the Harvard T.H. Chan School of Public Health saw those eating the most plant protein 27% less likely to die of any cause and 29% less likely to die from heart disease during the study period when compared with those participants eating the least plant-sourced foods.
Researchers estimated that replacing 5% of calories from animal protein with an equal number of calories from plant protein was associated with a 50% decreased risk of death from any cause including heart disease. Additionally, replacing 2% of processed meat protein with plant protein was associated with a 32% decreased risk of death from any cause.
In practical terms, substituting one serving per day of red or processed meat with plant foods such as legumes, nuts and whole grains could reduce the risk of heart disease by up to 47%.
From February 2020 (14);
An analysis of six prospective cohort studies published in JAMA Internal Medicine found that two or more servings per week of processed meat, red meat or poultry were significantly associated with increased cardiovascular disease risk and higher risk of death from cardiovascular disease when compared to no meat consumption.
PREVENTION OF DIABETES
From January 2021 (15);
A study of participants from the Health Professionals Follow-up Study tracked the healthfulness of a diet and diabetes rates. Compared to those eating a consistently plant-based diet (including whole grains, legumes, fruits and vegetables), participants not eating plant-based had a 12% to 23% increased risk of developing type-2 diabetes. Increasing plant-based foods in a diet also lowered diabetes risk. Researchers pointed to increased fiber and polyphenol antioxidant intake from plants as well as reduced animal fat consumption as the drivers of these results.
From July 2020 (16);
Another study of participants from the Nurses’ Health Study found that those eating the most whole grains (including dark bread, brown rice and whole-grain breakfast cereal) had a 29% reduced risk for type-2 diabetes compared to those eating the lowest amount of whole grains.
From April 2020 (17);
The 2020 EPIC-InterAct case-cohort study that took place in eight European countries illustrated that increasing fruit and vegetable intake by 66 gm per day was associated with reducing the risk for type-2 diabetes by 25%.
PREVENTION OF CANCER
From September 2021 (18);
As part of the Health Professionals Follow-up Study, researchers compared plant-sourced food intake with the incidence and mortality of prostate cancer in over 47,000 men and found that those eating the most plant-based foods decreased their risk of dying from prostate cancer by 19% as well as lowered the risk of developing advanced prostate cancer in younger men.
From June 2020 (19);
The American Cancer Society published new guidelines for reducing the risk of cancer, especially colon and breast cancer, based on the latest evidence. They called for increasing intakes of plant-based foods in their whole form, especially nutrient-dense fruits, vegetables, legumes and whole grains, and excluding or limiting red and processed meat, sugar-sweetened beverages and highly processed foods and refined grain products. These guidelines are consistent with the ones from the American Heart Association and the American Diabetes Association for the prevention of coronary heart disease and diabetes as well as for health promotion in general.
From April 2020 (20);
A systematic review of 19 prospective studies looking at the relationship of fiber intake and breast cancer incidence discovered that those consuming the highest amount of fiber had an 8% lower risk for both premenopausal and postmenopausal breast cancer when compared to those consuming the least amounts of fiber. Soluble fiber was associated with a 10% decrease in risk while insoluble fiber was associated with a 7% decrease in risk.
PREVENTION OF COGNITIVE DECLINE
From June 2020 (21);
The dietary intake of participants in the Canadian Longitudinal Study on Aging (CLSA) was followed and their test scores for verbal fluency, a measure of cognitive decline, was tracked. Those who consumed more than ½ a serving of legumes/pulses/nuts per day and more than 3 servings of fruits/vegetables daily scored higher on their cognitive tests than those who ate less of these foods.
From April 2020 (22);
Flavonoids are phytonutrients present in foods such as berries, apples and other plant-based foods that can protect against Alzheimer’s disease. Researchers compared flavonoid intake with incidence of dementia for 2,801 participants of the Framingham Heart Study Offspring Cohort. Those with the highest total flavonoid intake from oranges, pears, strawberries and other plant-based foods were found to be 40% less likely to develop Alzheimer’s disease and related dementias when compared to those with the lowest flavonoid intake.
IMPROVEMENT OF OVERALL HEALTH
From July 2021 (23);
An article was published in the Journal of the American College of Nutrition that summarized the known effects of eating plant-based.
These results showed that eating more plants…
…reduces the risk of noncommunicable chronic diseases including type-2 diabetes, cancer, and heart disease by almost 50%.
…reduces the risk of cognitive diseases including Alzheimer’s disease by almost 50%
In addition, plant-based diets, with their richness of nutrients such as phytochemicals and antioxidants, are linked to increased longevity.
From June 2020 (24);
An editorial was published that was part of a research project of Frontiers of Nutrition on the prevention and treatment of chronic diseases through diet. It demonstrated that investigations on the health benefits of dietary patterns is extensive and vibrant and that the prevention, treatment and reversal of chronic diseases are “achievable, economical, powerful, and possible”. The authors review several papers published on the benefits of diets based on food rich in antioxidants and fiber (vegetables, legumes, fruits and whole grains) and limited in fat, sugar, animal products and processed foods. They attest that eating plant-based lowers the risk for chronic diseases such as type-2 diabetes, heart disease and rheumatoid arthritis on a level comparable with medications and without the adverse effects that accompany drugs. Moreover, side effects of plant-based eating include improvements in body weight and gut microbiota populations as well as benefits to the environment.
1 Stubbendorff, A., Sonestedt, E., Ramne, S., Drake, I., Hallström, E., Ericson, U. Development of an EAT-Lancet index and its relation to mortality in a Swedish population. Am J Clin Nutr. November 13, 2021. Doi: 10.1093/ajcn/nqab369.
2 Deschasaux, M., Huybrechts, I., Julia, C., et al. Association between nutritional profiles of foods underlying Nutri-Score front-of-pack labels and mortality: EPIC cohort study in 10 European countries. BMJ. 2020 Sep 16; 370:m3173-m3186. Doi: 10.1136/bmj.m3173.
3 Bondonno, C.P., Dalgaard, F., Blekkenhorst, L.C., et al. Vegetable nitrate intake, blood pressure and incident cardiovascular disease: Danish Diet, Cancer, and Health Study. Eur J Epidemiol. Published online April 21, 2021. Doi: 10.1007/s10654-021-00747-3.
4 Spence, J.D., Srichaikul, K.K., Jenkins, D.J.A. Cardiovascular harm from egg yolk and meat: more than just cholesterol and saturated fat. J Am Heart Assoc. 2021: e017066. Doi: 10.1161/JAHA.120.017066.
5 Jabri, A., Kumar, A., Verghese, E., et al. Meta-analysis of Effect of Vegetarian Diet on Ischemic Heart Disease and All-cause Mortality. Am J Prev Cardiol. Published online April 9, 2021. Doi:10.1016/j.ajpc.2021.100182.
6 Iqbal, R., Dehghan, M., Mente, A., et al. Associations of unprocessed and processed meat intake with mortality and cardiovascular disease in 21 countries [Prospective Urban Rural Epidemiology (PURE) Study]: a prospective cohort study. Am J Clin Nutr. Published online March 31, 2021. Doi:10.1093/ajcn/nqaa448.
7 Papier, K., Fensom, G.K., Knuppel, A., et al. Meat consumption and risk of 25 common conditions: Outcome-wide analyses in 475,000 men and women in the UK Biobank study. BMC Med. 2021; 19(1): 53-67. Doi: 10.1186/s12916-021-01922-9.
8 Sun, Y., Liu, B., Snetselaar, L.G., et al. Association of major dietary protein sources with all-cause and cause-specific mortality: Prospective cohort study. J Am Heart Assoc. 2021 Feb 24;e015553. Doi: 10.1161/JAHA.119.015553.
9 Zhong, V.W., Allen, N.B., Greenland, P., et al. Protein foods from animal sources, incident cardiovascular disease and all-cause mortality: a substitution analysis. Int J Epidemiol. 2021;50(1):223-233. Doi: 10.1093/ije/dyaa205.
10 Al-Shaar, L., Satija, A., Wang, D.D., et al. Red meat intake and risk of coronary heart disease among US men: Prospective cohort study. BMJ. 2020; 371: m4141-m4150. Doi: 10.1136/bmj.m4141.
11 Li, J., Lee, D.H., Hu, J., Tabung, F.K., et al. Dietary inflammatory potential and risk of cardiovascular disease among men and women in the U.S. J Am Coll Cardiol. 2020 Nov 10; 76(19): 2181-2193. Doi:10.1016/j.jacc.2020.09.535.
12 Ma, Le; Liu, Gang; Liu, Ding, Ming; Zong, Geng; Hu, Frank B.; Willett, Walter, C.; Rimm, Eric B.; Manson, JoAnn E.; Sun, Qi. Isoflavone Intake and the Risk of Coronary Heart Disease in US Men and Women: Results From 3 Prospective Cohort Studies. Circulation. March 2020; 141: 1127-1137. Doi.org/10.1161/CIRCULATIONAHA.119.041306.
13 Haslam, D.E., Rehm, C.D., Song, M., Hu, F.B., Zhang, F.F., Bhupathiraju, S.N. American Heart Association EPI | LIFESTYLE 2020 Scientific Sessions – Abstracts P510 and P512. March 5, 2020: Phoenix, AZ.
14 Zhong, V.W., Van Horn, L., Greenlandy, P., et al. Associations of processed meat, unprocessed red meat, poultry, or fish intake with incident cardiovascular disease and all-cause mortality. JAMA Intern Med. 2020; 180(4): 503-512. Doi:10.1001/jamainternmed.2019.6969. Published online February 3, 2020.
15 Chen, Z., Drouin-Chartier, J.P., Li, Y., Baden, M.Y., Manson, J.E., et al. Changes in plant-based diet indices and subsequent risk of type 2 diabetes in women and men: Three U.S. prospective cohorts. Diabetes Care. Published January 13, 2021. https://doi.org/10.2337/dc20-1636.
16 Hu, Y., Ding, M., Sampson, L., et al. Intake of whole grain foods and risk of type 2 diabetes: results from three prospective cohort studies. BMJ. 2020; 370: m2206-m2218.
17 Zheng, J.S., Sharp, S.J., Imamura, F., et al. Association of plasma biomarkers of fruit and vegetable intake with incident type 2 diabetes: EPIC-InterAct case-cohort study in eight European countries. BMJ. 2020; 370: m2194-m2208.
18 Loeb, S., Fu, B.C., Bauer, S.R., et al. MP32-06 Association of plant-based dietary patterns with prostate cancer risk. J Urol. Published online September 1, 2021. Doi: 10.1097/JU.0000000000002036.06.
19 Rock, C.L., Thomson, C., Gansler, T., Gapstur, S.M., McCullough, M.L. et al. American Cancer Society guideline for diet and physical activity for cancer prevention. CA Cancer J Clin. 2020 Jul; 70(4): 245-271. Doi: 10.3322/caac.21591.
20 Farvid, M.S., Spence, N.D., Holmes, M.D., Barnett, J.B. Fiber consumption and breast cancer incidence: A systematic review and meta-analysis of prospective studies. Cancer. 2020; 126: 3061-3075. Doi.org/10.1002/cncr.32816.
21 Fuller-Thomson, E., Saab, Z., Davison, K.M., et al. Nutrition, immigration and health determinants are linked to verbal fluency among anglophone adults in the Canadian Longitudinal Study on Aging (CLSA). J Nutr Health Aging. 2020; 24: 672-680.
22 Shishtar, E., Rogers, G.T., Blumberg, J.B., Au, R., Jacques, P.F. Long-term dietary flavonoid intake and risk of Alzheimer disease and related dementias in the Framingham Offspring Cohort. Am J Clin Nutr. 2020; 112(2): 343-353. Doi:10.1093/ajcn/nqaa079.
23 Kahleova, H., Levin, S., Barnard, N. Plant-based diets for healthy aging. J Am Coll Nutr. 2021 Jul; 40(5):478-479. Doi: 10.1080/07315724.2020.1790442
24 Kahleova, K., Katz, D.L. Vegetarian dietary patterns in the prevention and treatment of disease. Front Nutr. 2020; 7: 92. Doi: 10.3389/fnut.2020.00092.