Category Archives: Diets and Lifestyles

DNA – Supporting Healthy Cells

DNA, ONE OF THE BODY’S 5 DEFENSE MECHANISMS

This column is about the 5th of Dr. William Li’s 5 body defense mechanisms, from his book “Eat to Beat Disease, The New Science of How Your Body Can Heal Itself.” The human body contains some 37 trillion cells. Each cell contains 46 chromosomes, made up of 2 strands of bunched-up DNA, in the form of a double helix. Three percent of DNA makes up our genes, and the other 97 percent serves as a template to make the 10,000 proteins that are necessary for life.
Your DNA gets more than ten thousand DNA-damaging hits every day, some of which are spontaneous due to chance “when trillions of cells are working and replicating nonstop…” Others are causes by factors noted in the paragraph below. If these genetic hits occur to a man’s sperm or a woman’s ovum (“egg”), abnormalities in progeny can occur. DNA damage to non-reproductive cells is linked to several diseases, including Alzheimer’s, atherosclerosis, autism, all types of cancer, depression, diabetes, inflammatory bowel disease, obesity, Parkinson’s, PTSD, rheumatoid arthritis, schizophrenia, and lupus.
The following are some of the factors that can damage DNA: age, inflammation, free radicals (oxidation), infection (e.g. liver and cervical cancer result from viral infections), ultraviolet radiation from the sun, radiation from medical imaging, radon from the ground, tobacco smoke, air pollution, toxic chemicals in our environment, and emotional stress. Dr. Li notes that “our cells have evolved with powerful repair processes…This prevents the vast majority of abnormalities that might develop in our DNA from being passed on when DNA replicates itself…”
Anti-oxidants in food (but not in supplement form) destroy free radicals, which helps prevent DNA damage, but doesn’t repair it once it occurs. One way damaged DNA gets repaired is through enzymes that recognize abnormalities and replaces them with normal parts. Due to DNA repair enzymes, “fewer than one of every one thousand errors introduced to our DNA are estimated to become permanent mutations…” If there is too much damage to fix, cell self-destruction occurs, called apoptosis.
Telomeres are another form of DNA defense and repair. These are caps on the end of DNA strands, that keep the DNA from shortening and unraveling. Telomerase is an enzyme that continually repairs telomeres. Smoking, stress, poor sleep, unhealthy diet, and lack of exercise damage telomeres.
One way DNA protects us is through epigenetics—turning genes on and off through our environment such as what we eat and physical activity. There is a saying in medicine that speaks to this: “Genetics loads the gun but environment pulls the trigger.” A healthy lifestyle with proper diet and regular exercise turns on many health-promoting genes, whereas an unhealthy lifestyle turns off these genes and turns on disease-promoting genes.
Foods that positively influence DNA repair include spinach, carrots, red peppers, lentils, beans, and mushrooms, kiwifruit, berries, broccoli, tomatoes, watermelon, guava, pink grapefruit. Foods that promote telomerase include soy, turmeric, and coffee beans, tea, nuts, and seeds. Foods with positive epigenetic effects include cruciferous vegetables, coffee, tea, turmeric. Exercise promotes DNA health as well. Dr. Li recommends avoiding the following foods for optimal DNA health: fatty foods, processed meat, and sugar-sweetened beverages.
Dr. Li notes lab studies suggest that a few non-plant foods can promote DNA health as well: clams, oyster sauce, pacific oysters, tuna, and yellowtail fish. However, positive lab studies don’t always translate into positive results in humans and you can’t go wrong with just sticking to plants.
Next week’s column will be the last in this series about Dr. Li’s book and will be about protecting yourself from the top killers.

Protect Your Brain From ALZHEIMER’S with Plants, Not Pills

This is the last article in a series about preventing Alzheimer’s, based on Dr. Neal Barnard’s evidence-based book “Power Foods for the Brain.” Other physicians have websites and have written books on this subject, but many of these books are not based on good science, and many of the authors are biased because they sell supplements. The last article discussed how metals such as copper, zinc, iron and possibly aluminum can adversely affect the brain, especially in combination with animal products.

Dr. Barnard is founding president of the respected PCRM (Physician Committee for Responsible Medicine). His book has a chapter about “foods that build your vitamin shield.” Vitamin E and three B vitamins—B6, B12 and folic acid– protect against cognitive impairment when ingested in a plant-based diet. However, studies using these vitamins in supplement form indicate they are not beneficial, and can even cause harm:

  • Vitamin E pills in doses over 400 units a day increase the risk of heart disease.
  • Vitamin A pills in smokers increase the risk of lung cancer.
  • Folate is found in many vegetables. Folic acid, present in many vitamin pills and in fortified food is made artificially and is not exactly the same as natural folate. There is evidence that folic acid increases cancer risk.

We evolved to get vitamins, minerals and other micronutrients through the food we eat. Sudden, huge doses of vitamins in pill or liquid form are not natural, and can cause harm such as oxidation and inflammation, that contribute to several maladies including heart disease, cancer and dementia.

According to Dr. Barnard, here’s how you can get brain-healthy vitamins through what you eat:

  • Traces of vitamin E are present in broccoli, spinach, sweet potatoes, mangoes and avocados. Larger amounts are found in nuts and seeds– particularly almonds, walnuts, hazelnuts, pine nuts, pecans, pistachios, sunflower seeds, sesame seeds and flaxseed. Dr. Barnard mentions a study that showed that “every 5 mg. of vitamin E in a person’s diet reduced the risk of developing Alzheimer’s disease by 26 percent.”
  • Best sources of B6 are whole grains, green vegetables, beans, sweet potatoes, bananas and nuts.
  • Sources of folate are broccoli, green leafy vegetables, beans, peas, citrus fruits, and cantaloupe.
  • The caveat is that there is one supplement we should take, particularly if we are vegan– vitamin B12, which is made by bacteria in dirt. B12 is found in meat, fortified cereals, fortified soy milk and nutritional yeast. With treated water and pre-washed produce, most of us don’t eat much dirt these days. Vegans should take a 1000 mg. B12 supplement daily, and Dr. Barnard argues that even meat-eaters should take a daily 2.5 mg. supplement, particularly if over age 50 (older people don’t absorb B12 from their diet as well).

Previous articles have discussed how Alzheimer’s may prove to be a vascular disease. While that hasn’t been proven yet, we do know that Alzheimer’s patients have clogged arteries in their brains, and that the risk factors for heart disease (such as hypertension, high cholesterol, smoking, diabetes) are also risk factors for Alzheimer’s. Therefore, what’s good for the heart is good for the brain. Avoid or at least cut back on meat; dairy; eggs; processed food; added oil, salt and sugar. Eat mostly, or ideally exclusively,  vegetables, fruit, whole grains, nuts and seeds.

In a recent video on his website nutritionfacts.org, Dr. Michael Greger talked about the marked increase in Alzheimer’s in Japan over the past few decades, as meat, dairy and egg consumption increased by 500 percent. We know what we need to do to ensure healthy brains as we age. Why is it so difficult, then, for so many Americans to modify their lifestyle? Next week’s column will be about food cravings.

Paleo Diet Overcooked

The Paleo lifestyle is hardly trending anymore. Between January and March of 2012, two medical panels and a number of articles have  pointed out shortcomings  in Paleo’s nutritional values and cast doubt on a society’s ability to replicate primitive diets in a contemporary world.

The U.S. News & World Report publishes annual rankings of various diets based on evaluations by a panel of doctors and health experts who assess a range of factors including weight loss, ease of adherence, and health risks. This year, Paleo ranked 34 out of 35, far behind the vegan diet at 19 and even various classics like Atkins, South Beach and the Zone.

At the same time, the federal committee advising the 2015 Dietary Guidelines panel is recommending that Americans take most red meat off the table. Some of their reasons are echoed in a review of pertinent research published in late April by a dietician in the Huffington Post. The author notes that even the best Paleo studies to date consider only short-term risk factors, leaving disease and death rates in question while ignoring some of the best data on the long term hazards of consuming red meat.