Harvard scientists recently found that 60-year-olds who ate five weekly servings of walnuts had a 1.3-year increase in lifespan. Walnuts may protect against diabetes, cancer, and Alzheimer’s.
New evidence suggests that regular walnut consumption may contribute to a longer life.1
In a landmark study using data collected over 20 years, scientists with Harvard University discovered a link between eating more walnuts and a lower overall risk of death among older adults.
This observational study found that 60-year-old Americans who ate five or more servings of walnuts per week lived roughly 1.3 years longer than those who never ate walnuts.1 They also had a 14% lower risk of death from any cause and a whopping approximate 25% lower risk of dying from cardiovascular disease.
Walnuts contain healthy fats, fiber, vitamins, minerals, and many different compounds with proven health benefits.
Harvard research published in the journal Nutrients in 2021 now links walnuts to greater life expectancy.1
Compared to people who never ate walnuts, consuming five servings of walnuts per week (with one serving being one ounce) resulted in:1
The study authors noted that even if your diet needs improvement, eating just half an ounce (a half-serving) of walnuts daily could lower the risk of death from any cause by 12%.
The team from the Harvard T.H. Chan School of Public Health analyzed data from 67,014 women enrolled in the Nurses’ Health Study and 26,326 men in the Health Professionals Follow-up Study. Participants had an average age of just over 63 years.1
All subjects had completed a survey on walnut consumption and were relatively healthy at the start of the average 20-year follow-up period. Their diets were checked every four years. This allowed scientists to identify associations between varying levels of walnut intake and life expectancy.
It’s important to note that the researchers found an approximate 1.3-year increase in life expectancy associated with higher walnut consumption—among subjects who had already reached the age of 60.1
“Even a few handfuls of walnuts per week may help promote longevity,” noted lead investigator Yanping Li, PhD, “especially among those whose diet quality isn’t great to begin with.”2
Walnuts contain nutrients that play an important role in a healthy diet. One ounce contains 4 grams of protein, 2 grams of fiber, and 45 mg of the mineral magnesium.3
They also contain ALA (alpha-linolenic acid), an omega-3 fatty acid found in plants.3
ALA may improve blood lipids (fats)4-6 as well as the function of endothelial cells that line the arteries.7-9
Walnut consumption has also been associated with reduced oxidative stress.10,11
These nutritional contents may help explain walnuts’ contribution to healthy aging and longevity.
Walnuts’ powerful effects on lifespan and risk of death may result from their ability to help inhibit many conditions that can shorten lifespan. These conditions range from high blood pressure and obesity to diabetes and cancer.
Walnuts are believed to reduce the risk of cardiovascular disease.12
One possible reason is that walnut consumption is linked to a reduction in blood pressure, even among those with existing hypertension.13
High blood pressure is a key risk factor for heart disease and stroke.
High cholesterol levels can also result in the development of vascular disease.
Preclinical data suggest that walnuts may reduce the production of lipids and improve blood lipid levels.14
In a randomized controlled trial, a diet enhanced with 1.5 ounces of walnuts daily significantly reduced fasting levels of multiple atherogenic lipids and lipoproteins, including total cholesterol, non-HDL cholesterol, LDL-cholesterol, triglycerides, and apoB (apolipoprotein B).15
Another clinical trial of healthy adults between 63 and 79 years old showed that eating about two ounces of walnuts daily for two years:16
Type II diabetes is dangerous for its potential long-term complications, including cardiovascular disease, chronic kidney disease, nerve damage, vision problems, and cognitive impairment.17,18
Accumulating evidence suggests that walnuts and their components may help lower blood sugar and reduce the long-term health ris associated with diabetes.19
A human trial found that consumption of walnut oil daily for three months lowered blood sugar levels in diabetes patients by about 8%. This held true for both the fasting glucose level and the three-month (HbA1c) blood glucose level.20
A flavonoid in walnuts called myricetin has been linked to antidiabetic effects due to its ability to enhance the activity of an insulin receptor.21
Limited evidence suggests that walnut consumption may lower the risk of certain cancers.
In one lab study, walnuts’ peptide fractions inhibited the growth of breast cancer cells by about 63% and colon cancer cells by about 51%.22
Animal studies have found that feeding walnuts to mice inhibits the development of tumors and decreases tumor growth rate and size.23
One analysis compared the estimated lifelong consumption of walnuts, peanuts, and almonds of breast cancer patients with people free from breast cancer. Compared to those with no consumption, those with high consumption had a two to three times lower risk of breast cancer.24
Lab and animal studies show that compounds present in walnuts reduce oxidative damage and inflammation in brain cells.25 In a mouse model of Alzheimer’s disease, walnuts reduced oxidative damage to lipids and proteins.26
In an animal model of Alzheimer’s disease, mice were fed walnuts for about 10 months, a significant portion of their lifetimes. Compared to mice given no walnuts, they showed improvements in memory, learning ability, and more.27
Additional research suggests that walnuts may also lower the risk or progression of other brain disorders, including Parkinson’s disease, stroke, and depression.28
Adding a handful of walnuts to your daily diet appears to be a simple way to improve overall health and possibly even extend your lifespan.
A recent, large study by Harvard University scientists found that 60-year-olds, eating five weekly servings of walnuts, had an approximate 1.3-year increase in lifespan.