Study shows adding salmon to a vegetarian diet significantly lowers risk of colorectal cancer. Follow Foods For Long Life on Facebook and Pinterest. |
Colorectal Cancer Risk and Diet
Last week there was a lot of attention given to a recent study that showed a dramatic decrease in colorectal cancer risk for people following plant-based diets, especially those that included fish. This is significant because colon cancer is the second leading cause of death in men and women combined in the United States (lung and bronchial cancer is the top killer.)
The Study
Researchers at Loma Linda University did an analysis on 77,659 people. After 7 years, 490 of the participants in this study had colorectal cancer. Review of the participants' food frequency questionnaires revealed that those who ate a vegetarian diet had a 22% lower risk of colorectal cancer than those who were non-vegetarians and consumed meat at least once a week.
But the results are far more dramatic when you look at the type of vegetarian diets the participants followed.
* Semi-vegetarians (ate meat less than once a week) were 8% less likely to develop colorectal cancer.
* Vegans (ate no meat, seafood, eggs or dairy) had a 16% reduced risk.
* Lacto-ovo vegetarians (ate eggs and milk products but no meat and seafood) had an 18% reduced risk.
* Pescavegetarians (vegetarians who also ate fish) were 43% less likely to develop the disease!
These are pretty startling numbers. Several things stand out.
* Eating even small amounts of meat (semi-vegetarians) appears to reduce the benefit of a vegetarian diet with respect to lowering the risk of colorectal cancer by 8 to 10 percent.
* Adding fish to a vegetarian diet seams to significantly increase protection against this dreaded disease.
Why is a Vegetarian Diet Protective?
There are countless studies that suggest that eating a diet rich in vegetables, fruits, whole grains, nuts and seeds protects against cancer, heart disease, and other diseases. With these healthful foods comes a natural source of dietary fiber, vitamins, minerals and phytonutrients linked to better health and longevity. I personally think dietary fiber is key. Although some studies have had mixed results trying to link high fiber diets to a lower risk of colon cancer, to me it is common sense that anything that helps potential toxins move through the GI tract more swiftly is going to do this.
The Benefits of Fish
Certain forms of omega-3 fatty acid and vitamin D, that are plentiful in fish, are often linked to the prevention of cancer and a host of other diseases. Unfortunately, except for a small amount of vitamin D contained in some mushrooms, these nutrients are not found in plants.
Omega-3
Vegans and vegetarians get plenty of omega-3 from chia, hemp and flax seeds as well as other plant sources. But these are short-chain alpha-linolenic, ALA, fatty acids. The long-chain omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are found in fish and shellfish. EPA and DHA have more potent benefits than ALA and although the body can derive these beneficial omega-3 fatty acids from ALA, it doesn't do this efficiently or sufficiently.
Why is omega-3 important? Numerous studies have shown that omega-3, especially from fish, reduces the inflammatory process that leads to many chronic diseases such as cancer, heart disease, autoimmune diseases such as rheumatoid arthritis, asthma and more. It has also been shown to protect against depression, cognitive decline, and attention deficit and hyperactivity disorder (ADHD). Adding fish to a vegetarian diet, with its contribution of EPA and DHA omega-3 fatty acid, most certainly contributed to the decreased risk of colorectal cancer in this study.
Vitamin D
Other studies have shown that vitamin D is effective in colorectal cancer prevention so perhaps the contribution of this nutrient from the fish consumed in this study lead to similar prevention.
In one such study, PhD researcher Edward Gorham revealed, after examining the data from five observational studies, that by increasing the serum level of vitamin D to 34 ng/ml, the incidence of colorectal cancer could be reduced by half. He reported, "We project a two-thirds reduction in incidence with serum levels of 46 ng/ml, which corresponds to a daily intake of 2,000 IU of vitamin D. This would be best achieved with a combination of diet, supplements and 10 to 15 minutes per day in the sun."
Spend a little time each day enjoying the sunshine but diet sources and supplements are also suggested. |
Vitamin D Supplements
The vitamin D council recommends supplementing with vitamin D3 since that is the form produced by the skin in response to sunlight and certain studies claim higher efficacy than other forms. However, D3 is derived from lanolin and is not vegan. Vitamin D2 is the vegan form.
Some Fish Provide Both Omega-3 and Vitamin D
Salmon, trout, herring, anchovies and sardines are good low-mercury sources of EPA and DHA omega-3 fatty acids as well as vitamin D.
What To Do?
To minimize your risk of colorectal cancer, consider the following:
* Avoid eating meat, especially red or processed meat.
* Eat a plant-centric diet packed with vegetables, fruit, whole grains, nuts, and seeds. It's always best to eat organic and non-GMO when possible.
* Eat low-mercury, high omega-3 fish, such as wild salmon, to get beneficial EPA and DHA omega-3 fatty acids into your diet. Bake or broil but NEVER deep-fry fish.
If you are a vegan or vegetarian for ethical reasons and will not consider eating fish, then you can get what you need from vegan micro-algae oil. Deva makes a 300mg DHA and EPA supplement. These tend to be pricey and don't contain nearly as much as a piece of fish. It takes 5 of these capsules to get as much omega-3 fatty acid as one 3 ounce piece of salmon. But it's a good and necessary solution if you are opposed to eating fish.
Since omega-3 reduces inflammatory responses that lead to disease, you can take a simple C-Reactive Protein (CRP) test to evaluate the level of inflammation in your body. It's a great indicator for heart disease (much better, in my opinion, than cholesterol), cancer, and many other degenerative disorders. You can also test your level of DHA and EPA by taking a blood test to see if your body is adequately converting ALA to these more potent forms of omega-3.
* Besides eating fish, get vitamin D from sunlight and supplements. I personally take 2,000 IU per day. When I spend more time indoors in the winter, I increase it to 4,000 IU. Vegans can easily get what they need from the sun and supplements as well as fortified foods. Most non-dairy milks are fortified with vitamin D.
But don't always count on the sun to give you what you need. People with darker skin, or those who wear sun block, who are older, and who live further from the equator are more likely to be deficient. In fact, MOST people are deficient in this critical nutrient! To understand if you are, take a 25-hydroxy vitamin D test. According to the vitamin D council, a sufficient result is between 40 to 80 ng/ml. According to the National Institutes of Health, the normal range is 30 to 74 ng/ml.
Summary
I write this blog because I believe that diet has a powerful effect on our health. This gives us a lot of control over the quality of our life, even if we have less than stellar family genes. Studies such as this should encourage us to refine our diets even further to optimize our health.
Many of my readers are vegans for reasons of compassion and can take this information and adjust their diets with supplements and sunshine to optimize their health.
For those of you not opposed to eating fish and who are trying to develop the healthiest diet possible, you may want to consider a well-designed pescavegan or pescavegetarian diet that can provide the fish, fiber and critical nutrients needed for excellent health.
Salmon Recipes
Salmon, one of my Top 20 Foods for Health and Longevity, is very low in mercury and packed with EPA and DHA omega-3 fatty acids. Here are three easy and delicious salmon recipes you might enjoy:
Baked Atlantic Salmon with Roasted Onions and Cherry Tomatoes on Wilted Spinach, or Mango and Black Bean Salsa with Honey Lime Baked Salmon, and Baked Honey Mustard Coho Salmon.
Baked Honey Mustard Coho |
Thank you Joey! This is a great followup to what I just read in a Harvard Health blog my cousin had forwarded. More wild salmon, please. -- Liz
ReplyDeleteVegan D3 is now available, I get it at my local Whole Foods but it can be ordered online as well.
ReplyDeleteI might also add that the environmental impact of fish production is very high. A pound of farmed salmon, as I understand it, requires many pounds of wild caught fish for feed. We are truly killing our oceans by over-fishing them. Thus I hope your readers will continue to consider the vegan option, with supplementation as needed, for the sake of the planet as well as for the lives of the individual sentient fish beings.