If a miracle anti-aging pill does exist, chances are that it comes in a shell.
Nuts – and it doesn't matter if you're munching on almonds, walnuts, Brazil nuts, pistachios or peanuts (which are technically legumes) – are shown time and time again to prevent the development of chronic diseases, promote longevity and, according to a new study published in The American Journal of Clinical Nutrition, take on inflammation, the single greatest marker of aging.
"Nuts are rich in monounsaturated and polyunsaturated fatty acids, fiber, vitamins and minerals that have a synergistic effect to reduce inflammation and its effects on the body," says study co-author Ying Bao, assistant professor of medicine at Harvard Medical School. Her previous research, published in The New England Journal of Medicine, found that people who ate nuts seven or more times per week had 20 percent lower risk of dying on any given day.
Here are six ways nuts can help you age gracefully and live the longest, healthiest life possible:
1. Have a Healthier Heart
"Based on our research, the biggest benefit of nut consumption is in the reduction of heart disease," Bao says. In fact, when she and colleagues tracked data on 119,000 men and women covering 30 years, those who ate a serving of nuts about every day were 29 percent less likely to die from heart disease.
"This is particularly important for older adults, as heart disease kills more people than any other disease and aging is a major risk factor for heart disease," Bao says. According to the World Heart Federation, the likelihood of suffering a stroke doubles every decade after age 55.
Apart from their health-healthy fatty acids, nuts are rich in plant sterols, fiber and copper, all of which have been linked to reduced cholesterol and blood pressure levels, notes Jim White, a registered dietitian and spokesman for the Academy of Nutrition and Dietetics. The American Heart Association recommends eating four servings of unsalted nuts per week for cardiovascular health. One serving is 1.5 ounces, or a handful.
2. Keep Your Mind Sharp
You know the inflammation that nuts are so good at fighting? Well, that's critical to preventing cognitive decline and dementia into old age. For instance, research out of Huntington Medical Research Institutes shows that in patients with Alzheimer's disease, levels of inflammation are higher, partly due to lower levels of omega-3 polyunsaturated fatty acids, explains Alfred Fonteh, neuroscience research scientist at HMRI.
Nuts, however, are rich in omega-3s, and walnuts in particular are ripe with docosahexaenoic acid, or DHA, a type of omega-3 that is a primary structural compound in the human brain. "DHA is the source of molecules that protect neurons, molecules that resolve inflammation and molecules that help repair free radical damage of tissues," Fonteh says. "What's more, monounsaturated fatty acids rich in nuts also control how toxic proteins are removed from the brain."
"Therefore, a dietary source of omega-3 fatty acids and monounsaturated fatty acids from nuts may replenish what is lost in the brain and enhance the ability of the brain to remove toxic peptides that would otherwise kill neurons," he says. Case in point: In a 2015 JAMA Internal Medicine study of older adults, those who followed a Mediterranean dietsupplemented with nuts over the course of six years enjoyed better cognitive function than those who ate a Mediterranean diet sans nuts.
3. Prevent Age-Related Weight Gain
Nuts are rich in both fat and calories. But studies show they still help people lose, not gain, weight through the years. For example, in one Harvard School of Public Health study, middle-aged women who noshed on nuts at least twice a week were 27 percent less likely to become obese over the course of the eight-year study period.
Again, nuts' ability to fight inflammation may play a role in preventing age-related weight gain. And while they are rich in calories, White notes that nuts' combination of fat, fiber and protein aid in satiety to make weight-management easier. Plus, interestingly enough, your body may not truly absorb all of the calories listed on your almonds' nutrition label. That's because nuts have a very large thermic effect – meaning that your body burns many calories chewing and digesting them, he says.
4. Prevent and Manage Type 2 Diabetes
In addition to curbing age-related weight gain, nuts lower levels of blood glucose and insulin, to help both prevent and manage Type 2 diabetes. While research published in Diabetes Care shows that regularly eating pistachios improves metabolic health in people with prediabetes, Bao's research shows that people who consistently eat any type of tree nut may be up to 20 percent less likely to die from diabetes.
To prevent blood sugar and insulin spikes that are associated both with the development of Type 2 diabetes as well as poor diabetes management, nuts are especially helpful when integrated into high-carb meals. Their blend of fiber, fat and protein slows digestion to turn high-GI (glycemic index, a measure of post-meal blood sugar response) meals into low-GI ones.
5. Ease Aching Joints
Nuts are a vital part of a joint-healthy diet, according to the Arthritis Foundation, and are particularly beneficial for people dealing with osteoarthritis or rheumatoid arthritis. Nuts' benefits on your joints may come down to two mechanisms: weight loss and inflammation reduction.
"Musculoskeletal diseases, such as osteoarthritis, are strongly correlated with obesity," says Reema Kanda, a clinical dietitian at Hoag Orthopedic Institute in California. In fact, in people who are overweight, even modest weight loss can ease pressure on joints to help relieve symptoms.
"What's more, preventing excessive in inflammation can prevent degeneration of joints and help repair," Fonteh says. He notes that in people with joint disease and arthritis, levels of inflammatory enzymes are markedly higher. After all, the most obvious sign of inflammation is swelling, and arthritis sufferers are used to seeing – and feeling – joint inflammation.
6. Sidestep Cancer
Age is the main risk factor in the development of cancer, according to research published in Current Biology. And while nuts can't keep the years from passing, they may be able to reduce biological markers of aging and reduce the risk of developing cancer. While little research exists on the topic of nut consumption and cancer prevention, a promising study in Cancer Epidemiology, Biomarkers & Prevention found that women who regularly eat nuts are less likely to develop colorectal cancer.
And, turning to people who already have or do develop cancer, a 2016 study from Hao, published in the British Journal of Cancer, found that prostate cancer patients who consumed nuts five or more times a week were 34 percent less likely to die of the disease compared to those who ate nuts less than once per month. Meanwhile, as many cancer patients actually die of complications of cardiovascular disease, rather than cancer itself, eating nuts may be doubly beneficial among those battling cancer.