Research shows that as many as 40 percent of cancers can be avoided by factors that are under your control – one of which is the food you choose to eat.
But today we’re not going to talk about overhauling your diet. This news is much simpler than that. Research shows that consumption of one healthy snack can lower your risk of cancer, especially if you make eating it a daily habit.
And if you’ve already had cancer, researchers say you’re nuts if you don’t try it…
How many nuts do you eat a day? You might want to consider increasing the amount. Here’s why…
The U.S. “Dietary Guidelines for Americans 2020 to 2025” recommends 20 grams a day of nuts five days a week. That translates into about ¾ of an ounce a day. What’s more, their definition of “nuts” may be broader than yours and includes seeds and soy products.
Even so, only four in ten U.S. adults eat these snacks on any given day and many folks choose to avoid nuts, seeds, and soy products all together.
One reason could be the belief that their high fat and calorie content will lead to obesity. A one ounce serving of almonds, for example, contains 200 calories and that’s certainly quite a lot.
But according to a top scientist, nut and seed consumption doesn’t necessarily lead to obesity. In fact, the research suggests the opposite is true.
Nut eaters are slimmer
Charles Fuchs, director of the Yale Cancer Center said, “…what’s really interesting is that in our studies and across the scientific literature in general, regular consumers of nuts tend to be leaner.”
This isn’t because nut eaters have healthier lifestyles; this is accounted for by scientists. The reasons aren’t clear but possible explanations are that not all the fat in nuts is absorbed into the body, or that nuts increase the number of calories we burn, or perhaps nuts help us feel fuller for longer.
Weight concerns, therefore, should not be an issue so long as portion sizes are kept reasonable, especially as nuts have so many beneficial properties, including protection against cancer.
Tree nuts lower cancer risk
In 2020, scientists in China carried out a review of nut consumption and the risk of cancer.
They only included studies that were well designed, relatively high quality, with a large number of participants, and long-term follow up. They analyzed 33 studies.
In addition, all the studies were prospective, meaning participants were free of cancer at the beginning and then followed over time.
Results showed the more nuts people ate, the lower the risk of cancer. A minimum intake of nine grams a day was required to have a positive effect, with the risk of cancer decreasing by ten percent for every 20 grams a day increment in consumption. The effect was strongest for colorectal, pancreatic, and gastric cancer.
Bad news for peanut lovers, however. Only tree nuts reduced the risk of cancer, not peanuts, which are classed as legumes. Tree nuts are almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios, and walnuts.
The Chinese researchers concluded by writing that “this study provides compelling evidence about the association between nut intake and decreased risk of cancer, especially cancers of the digestive system.”
The mechanisms for this protection are not known for sure but the researchers put forward various suggestions.
Packed with cancer protection
Nuts contain a wide variety of factors with recognized health benefits. These include monounsaturated and polyunsaturated fats, fiber, protein, vitamin E, folic acid, niacin, calcium, magnesium, potassium, selenium, and natural plant chemicals – phytosterols and polyphenols.
There’s “extensive evidence,” they write, that nuts can benefit long-term health through better blood sugar control, lower inflammation and reduced oxidative stress.
Numerous nut components give broad spectrum protection against the development of cancer.
Cellular and rodent studies demonstrate resveratrol, ellagic acid, anacardic acid and omega 3 and 9 fatty acids can obstruct critical signaling pathways that allow cancer cells to survive, grow and spread.
These pathways include NF-kB – a protein complex that’s involved extensively in cancer development and progression; matrix metalloproteinases – enzymes that dissolve surrounding collagen and connective tissue so tumor cells can spread; and VEGF – a growth factor that helps supply new blood vessels for cancers to grow.
Cancer protection also comes from some of the above-mentioned nut components as well as others such as quercetin and vitamin E (tocopherols and tocotrienols) that have antioxidant and anti-inflammatory properties.
In addition to the prevention of cancer, scientists are also interested in whether nuts can help to prevent recurrence of cancer in those who have already been treated for the condition. This has been researched in three forms of cancer.
Firstly, colon cancer.
Increases overall survival by 57 percent
A major study conducted by scientists from Yale, Harvard, and other American universities followed 826 participants for 6.5 years following surgery and chemotherapy for stage III colon cancer.
Compared to those who didn’t consume nuts, participants who regularly consumed at least two, one-ounce servings of a variety of nuts – including peanuts – each week demonstrated a 42 percent improvement in disease-free survival and a 57 percent improvement in overall survival.
In participants who only ate tree nuts, disease-free survival increased to 46 percent.
In further analysis the scientists observed a significant improvement in both disease-free survival and overall survival with increasing tree nut consumption, whereas the associations with peanuts or peanut butter did not reach statistical significance.
They wrote, “Our data are consistent with a wealth of existing observational and clinical trial data reporting health benefits of nut consumption on many chronic diseases, including reductions in the risk of type 2 diabetes, insulin resistance, metabolic syndrome, cardiovascular disease, and all-cause mortality.”
They added that “preclinical studies suggest that the contents of nuts may inhibit the growth of a colon cancer cell line and may decrease the rate of colorectal cancer growth and angiogenesis [formation of new blood vessels that allows cancer to spread] in mice.”
Medical researchers also tested benefits of nuts in prostate cancer patients.
Death reduced by 34 percent
In another major study that was led by researchers at Harvard, a team analyzed data on 47,299 men over a period of 26 years during which researchers asked participants about dietary and non-dietary factors every four years.
This entailed filling out a food frequency questionnaire covering everything eaten including nuts. Non-dietary factors included smoking status, physical activity, body mass index and medical records.
After taking all these factors into account, the researchers found nuts provided no protection against a diagnosis of prostate cancer.
However, they found patients who consumed nuts five or more times a week, after diagnosis of cancer confined to the prostate, had a significant 34 percent lower rate of overall mortality than those who consumed nuts less than once per month.
Lead researcher Ying Bao said, “This is important, since more men live with prostate cancer than die from it.”
The most recent research was published last year, this time looking at nuts in relation to long-term breast cancer survivors.
Breast cancer recurrence and mortality slashed
Researchers from Vanderbilt University, Nashville, Tennessee, examined overall and disease-free survival in 3,449 breast cancer patients living in China.
Participants filled out a food survey five years after diagnosis and were tracked for another five years. Many demographic and lifestyle factors were also taken into account in the analysis.
The authors summed up their findings by writing, “This large cohort study found that nut consumption among long-term breast cancer survivors was associated with a 52 percent reduced risk of recurrence or breast cancer mortality following a dose-response pattern.
“The association was stronger for survivors with stage I-II breast cancer than those with stage III-IV breast cancer. This study provides evidence for promoting nut consumption as a modifiable lifestyle factor among breast cancer survivors.”
Senior author Xiao-Ou Shu described the association as “quite strong and robust” and the study does back up the above colon and prostate findings.
However, participants’ nut intake was extremely low at just over half an ounce a week. It would be surprising if eating the equivalent of 13 almonds a week could bring about such a large risk reduction. Another large study is needed to confirm these findings.
Nevertheless, the overall analysis demonstrates that eating a handful of tree nuts every day can help you fight cancer and other diseases. So, if you aren’t snacking on nuts already, I’d recommend it.