Oftentimes, the simplest foods are best for your health, and this is
certainly the case for nuts, in which Mother Nature has crafted a nearly
perfect package of protein, healthy fats, fiber, plant sterols,
antioxidants, and many vitamins and minerals.
Among nuts, the case may be made that walnuts are king, as research
shows they may boost your health in a number of ways at very
easy-to-achieve "doses."
Eating just one ounce of walnuts a day (that's about seven shelled
walnuts) may be all it takes to take advantage of their beneficial
properties.
Walnuts belong to the tree nut family, along with Brazil nuts,
cashews, hazelnuts, macadamia nuts, pecans, pine nuts, and pistachios.
Each has its own unique nutritional profile.
One-quarter cup of walnuts, for instance, provides more than 100
percent of the daily recommended value of plant-based omega-3 fats,
along with high amounts of copper, manganese, molybdenum, and biotin.
Some of the most exciting research about walnuts includes:
Cancer-Fighting Properties
Walnuts may help reduce not only the risk of prostate cancer, but breast
cancer as well. In one study, mice that ate the human equivalent of 2.4
ounces of whole walnuts for 18 weeks had significantly smaller and
slower-growing prostate tumors compared to the control group that
consumed the same amount of fat but from other sources.
Overall the whole walnut
diet reduced prostate cancer growth by 30 to 40 percent. According to
another study on mice, the human equivalent of just two handfuls of
walnuts a day cut breast cancer risk in half, and slowed tumor growth by
50 percent as well.1
Heart Health
Walnuts contain the amino acid l-arginine,
which offers multiple vascular benefits to people with heart disease,
or those who have increased risk for heart disease due to multiple
cardiac risk factors.
If you struggle with herpes, you may want to avoid or limit walnuts, as
high levels of arginine can deplete the amino acid lysine, which can
trigger herpes recurrences.
Walnuts also contain the plant-based omega-3 fat alpha-linolenic acid
(ALA), which is anti-inflammatory and may prevent the formation of
pathological blood clots. Research shows that people who eat a diet high
in ALA are less likely to have a fatal heart attack and have a nearly
50 percent lower risk of sudden cardiac death.
Eating just four walnuts a day has been shown to significantly raise blood levels of heart-healthy ALA, and walnut consumption supports healthful cholesterol levels.
Separate research showed that eating just one ounce of walnuts a day may decrease cardiovascular risk, and among those at high cardiovascular risk, increased frequency of nut consumption significantly lowers the risk of death.
Rare and Powerful Antioxidants
Antioxidants are crucial to your health, as they are believed to help
control how fast you age by combating free radicals, which are at the
heart of age-related deterioration.
Walnuts contain several unique and powerful antioxidants that are
available in only a few commonly eaten foods. This includes the quinone
juglone, the tannin tellimagrandin, and the flavonol morin.6
Walnuts contain antioxidants that are so powerful at free-radical scavenging that researchers called them "remarkable,"7 and research has shown that walnut polyphenols may help prevent chemically-induced liver damage.8
In another study, researchers found that nuts, especially walnuts,
have potent antioxidant powers. Walnut polyphenols had the best efficacy
among the nuts tested and also the highest lipoprotein-bound
antioxidant activity. The researchers concluded:9
"Nuts are high in polyphenol antioxidants which by binding to
lipoproteins would inhibit oxidative processes that lead to
atherosclerosis in vivo. In human supplementation studies nuts have been
shown to improve the lipid profile, increase endothelial function and
reduce inflammation, all without causing weight gain."
Weight Control
Adding healthful amounts of nuts such as walnuts to your diet can
help you to maintain your ideal weight over time. In one review of 31
trials, those whose diets included extra nuts or nuts substituted for
other foods lost about 1.4 extra pounds and half an inch from their
waists.10 Eating walnuts is also associated with increased satiety after just three days.11
Improved Reproductive Health in Men
One of the lesser-known benefits of walnuts is their impact on male
fertility. Among men who consume a Western-style diet, adding 75 grams
(a bit over one-half cup) of walnuts daily significantly improved sperm
quality, including vitality, motility, and morphology.12
Brain Health
Walnuts contain a number of neuroprotective compounds, including vitamin E, folate, melatonin, omega-3
fats, and antioxidants. Research shows walnut consumption may support
brain health, including increasing inferential reasoning in young
adults.
One study also found that consuming high-antioxidant foods like
walnuts "can decrease the enhanced vulnerability to oxidative stress
that occurs in aging," "increase health span," and also "enhance
cognitive and motor function in aging."14
Diabetes
The beneficial dietary fat in walnuts has been shown to improve
metabolic parameters in people with type 2 diabetes. Overweight adults
with type 2 diabetes who ate one-quarter cup of walnuts daily had
significant reductions in fasting insulin levels compared to those who
did not, and the benefit was achieved in the first three months.
The outermost layer of a shelled walnut – the whitish, flaky (or
sometimes waxy) part – has a bitter flavor, but resist the urge to
remove it. It's thought that up to 90 percent of the antioxidants in
walnuts are found in the skin, making it one of the healthiest parts to
consume.16 To increase the positive impacts on your health, look for nuts that are organic and raw, not irradiated or pasteurized.
Furthermore, be aware that walnuts are highly perishable and their
healthful fats easily damaged. If you're purchasing shelled walnuts in
bulk, avoid those that appear shriveled or smell rancid, or that you
cannot verify are fresh. Walnuts should be stored in an airtight
container in your refrigerator or freezer, whether they are shelled or
unshelled. Walnuts are great as a quick snack, but if you're not a fan
of their flavor, you can still get their therapeutic benefits by
blending them into smoothies. Or you can try one of the other healthful
nuts available.
You can further improve the quality of walnuts by soaking them in
water overnight, which will tend to lower some of the enzyme inhibitors
and phytic acid. After soaking, you can dehydrate them at low
temperature of around 105 to 110 degrees Fahrenheit until they are
crispy again, as they are far more palatable when they are crunchy.