Trends can be helpful – sometimes. But they can also be wrong. That’s why it’s always smart to try to understand the science behind any trend or to see if there even is science to understand.
One of the hottest nutritional trends today is the role of fermented foods in human health. Fermented foods are thought to have originated in China 2,000 or more years ago.1 Back then, ancient people relied on fermentation to preserve foods and keep them from rotting.
Today, fermented foods are being consumed for their health-benefits and, some say, for their ability to prevent cancer. Let’s take a closer look.
What is fermentation exactly? Fermentation involves a slow and controlled decomposition of foods by microbes, generally via bacteria and yeast. These microbes convert sugars into acids, alcohols, and carbon dioxide. Besides their use for culinary purposes, these microbes also enhance nutrient potency, remove toxins, deliver probiotic bacteria, and inhibit foodborne pathogens.
These additional benefits are believed to help the body fight illnesses such as cancer.
The lowdown on fermented foods and cancer
A growing body of studies shows that certain strains of bacteria in fermented foods promote health and help prevent cancer. It’s beyond the scope of this article to explore every type of food, however, the research is solid. Numerous cellular studies, animal studies and human studies show that, in general, fermented foods can stop cancer from growing. The research suggests that fermented foods work against cancer in four ways:2
- Initiating apoptosis
- Suppressing cell proliferation
- Arresting the cell cycle
- Inhibiting inflammation
Even more benefits will probably be confirmed in the future. Research suggests that fermented foods also influence intestinal microbes, inactivate carcinogens, boost antioxidant intake, and control your immune response. Together, the benefits of eating fermented foods can greatly reduce your cancer risk.
The mechanism behind the cancer-fighting activity of fermented foods depends largely on the type of food, type of fermentation, phytochemical makeup, and microbial composition of the food.
A meta-analysis of 61 studies found that intake of fermented dairy decreased cancer risk significantly.3 This study included 1.9 million participants, a very large cohort. Fermented foods’ cancer-fighting ability was especially strong against colon, bladder and esophageal cancer.
Another way fermented foods help fight cancer is with their high probiotic levels.
The probiotic benefit of fermented foods
Over 100 trillion bacteria live in your intestines – more than ten times the number of cells in your entire body.
Many of them are “good guys” that help keep you healthy by counteracting harmful bacteria that could otherwise overrun you. These are probiotics (meaning literally “for life”) – as opposed to antibiotics (“against life”).
These tiny life-giving probiotic bacteria are common in certain foods – particularly traditional fermented foods such as sauerkraut, kimchi, some pickles, kombucha, yogurt, and kefir.
It’s a well-established fact that probiotics found in fermented foods benefit humans.4 Here’s what we now know about them from numerous scientific studies. They:
- Help guard you against harmful microorganisms5
- Strengthen your immune system6
- Reduce metabolic disorders
- May help you lose weight7
- Provide enzymes to improve your digestion8
- Neutralize dietary carcinogens
- Boost your immune system
- Help reduce cancer risk
Studies show probiotics in fermented foods are especially powerful against cancer
A modern Western diet heavy with processed foods does your health no favors. For one thing it upsets the critical balance between good and bad bacteria in your gut, leading to whole-body issues.
Fermented foods that are rich in probiotics can help fight cancer. In fact, a PubMed search using the words “probiotic and cancer” serves up a whopping 2,168 results. Here are a few examples:
- Fermented foods are rich in probiotics, and the probiotics Lactobacillus (L.), acidophilus, and Bifiobacterium bifidum – alone or in combination – showed antitumor and anti-proliferative effects in animal models of colon cancer.
- Fermented milk with probiotic bacteria L. rhamnosus GG and L. casei reduced precancerous lesions in rats prone to liver cancer.9
- Milks fermented with various LAB and bifidobacterial strains of probiotics seem to inhibit breast cancer growth in animals. And in humans, studies show a negative correlation between yogurt consumption and breast cancer development. In other words, the women who ate more yogurt experienced fewer incidences of breast cancer.10
- A pilot study suggests that probiotics help clear HPV-related abnormalities.11 HPV is linked to numerous types of cancer.12
- The probiotic LAB proved beneficial in animals against oral cancer and skin cancer.13
- The probiotic L. casei CRL431 was studied against fibrosarcoma—a cancer that starts in the tissues that wrap around tendons— and inhibited tumor growth in a dose-dependent manner.14
Don’t fermented foods cause cancer?
Some studies do suggest an increase in gastric cancer from fermented foods. Sounds scary, but here’s what the science says…
The studies on high-salt fermented foods were all done in Asia, except for one European study. The results revealed a significant increase – nine percent– in stomach cancer risk (but not in deaths), for every 20 grams (less than one ounce) of fermented high-salt veggies.
It’s important to note that stomach cancer rates are consistently higher in Asia and Eastern Europe. The world’s highest rates are in Korea, Mongolia, and Japan. China is #6. Notably, North America and Africa have the lowest rates of stomach cancer.
Researchers also failed to consider confounding factors, which can skew results.
For one thing, H. pylori infection is a leading cause of stomach cancer. In the U.S., H. pylori is treated with antibiotics. Unfortunately, these studies did not factor H. pylori infection into their investigation.
It’s possible they ignored other confounding factors too. Such as exposure to occupational toxins and genetic mutations (especially in Asia).
Fermented foods also produce N-nitroso compounds. These compounds may interact with H. pylori so as to cause cancer in sensitive people.
A separate meta-analysis, this one with 700,000 participants, found no link between yogurt or cheese consumption and dying from cancer.15 In other words, these foods certainly aren’t causing cancer.
Make friends with your digestion today
There are other compelling reasons to introduce more fermented foods into your daily diet:
1. Support a healthy gut that properly breaks down complex carbohydrates. The probiotic LAB helps digestion.
2. Keep you from getting sick from pathogens you consume every day because your microscopic LAB battle them for you. They secrete antimicrobial proteins that kill off bad bacteria, and more.
3. Help your body produce vitamins – especially many B vitamins (B1, B2, B3, B5, B6, B12), and vitamin K.
4. Restore gut equilibrium after a round of antibiotics. Antibiotics are brutal. They wipe out everything, good and bad. Fermented foods can help reseed the good guys. Even without antibiotics, your body needs probiotics. Research shows that the lower your gut microbe diversity, the more predisposed you are toward chronic disease – obesity, asthma, inflammatory bowel disease, and more.
5. Restores gut wall integrity to prevent leaky gut – a condition in which your intestinal walls leak contents into your bloodstream. That leads to asthma, eczema, schizophrenia, Alzheimer’s, and other conditions.
Not all fermented foods are created equal
It’s important to note that pickled foods and fermented foods are not one and the same.
Pickled foods are made quickly using heat and vinegar, and therefore lack many of the benefits of fermented foods.
For maximum benefit, buy refrigerated pickles and sauerkraut made without vinegar.
Truly fermented foods are never heated high enough to kill the probiotics. Avoid pasteurized varieties. Also avoid preservatives and added sugars. If the food manufacturer lists the number of probiotics, so much the better.
The more variety, the more benefit
Add several varieties of fermented foods to your diet. All of these can also be made at home:
- Sauerkraut – an Eastern European staple that literally means “sour cabbage.” Buy from the refrigerated case.
- Kimchi – a traditional Korean side dish with hundreds of varieties. Made from a base of cabbage, radish, scallions, and spices. Easily available at Asian markets or specialty grocery stores.
- Fermented pickles – from your grocer’s refrigerated section.
- Kombucha – fizzy fermented tea, a good soda alternative. In your grocer’s refrigerated section.
- Yogurt – milk plus a starter cultures of bacteria. Choose unsweetened ones with live cultures.
- Kefir – thinner-than-yogurt dairy drink made of kefir grains (bacteria + yeast). In the dairy case. In most states, you’ll be hard-pressed to find yogurt and kefir that have not been pasteurized.
You can also make your own fermented food. Cabbage is one of the cheapest vegetables you can buy. A few minutes of chopping and a few days of fermenting, and you’re good to go with your own sauerkraut.
If you’ve not eaten fermented vegetables before, start slow – about one tablespoon a day – and build from there.
Best regards,
Lee Euler,
Publisher
References:
- https://pubmed.ncbi.nlm.nih.gov/25568828/ Accessed on April 10, 2021
- https://www.scielo.br/scielo.php?pid=S0101-20612020005027203&script=sci_arttext Accessed on April 10, 2021
- https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.31959 Accessed on April 10, 2021
- https://pubmed.ncbi.nlm.nih.gov/30402482/ Accessed on April 10, 2021
- https://pubmed.ncbi.nlm.nih.gov/12801956/ Accessed on April 10, 2021
- https://pubmed.ncbi.nlm.nih.gov/19584499/ Accessed on April 10, 2021
- https://pubmed.ncbi.nlm.nih.gov/25884980/ Accessed on April 10, 2021
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4058509/ Accessed on April 10, 2021
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4127615/ Accessed on April 10, 2021
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4127615/ Accessed on April 10, 2021
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4127615/ Accessed on April 10, 2021
- https://www.cdc.gov/cancer/hpv/index.htm Accessed on April 10, 2021
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4127615/ Accessed on April 10, 2021
- Perdign G, de Jorrat M, Valdez J, de Budeguer M, Oliver G. Cytolytic effect of the serum of mice fed with Lactobacillus casei on tumor cell. Microbiol-Aliments-Nutr. 1995;13:15–24.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5073921/ Accessed on April 10, 2021
