By vegan naturopath Robyn Chuter
One of the presentations I was most looking forward to at the 2014 International Plant-Based Healthcare Nutrition Conference (PBNHC) was the one that Dr William Li, the Medical Director and Co-founder of the Angiogenesis Foundation, was slated to give. Having watched Dr Li’s TED talk, Can we eat to starve cancer?, I was keen to learn more about the effect of angiogenesis. (If you’re thinking right now, ‘What the heck is angiogenesis and why should I even care about it?’, don’t worry, I’ll get to that in a minute.)
Unfortunately, due to a family emergency Dr Li was unable to attend the 2014 conference. So I was excited to see he was back on the conference agenda for this year’s PBNHC, and I’m happy to say that his presentation was every bit as good as I’d hoped for!
First, a brief explanation of angiogenesis: ‘angio’ means blood vessel, and ‘genesis’ means the beginning of something. So angiogenesis is the formation of new blood vessels from existing ones.
You’ve actually experienced angiogenesis multiple times throughout your life, although you probably didn’t realise it. For starters, you wouldn’t exist without the angiogenesis that allowed your mother’s body to develop the placenta which nourished you until you were born. Then, every time you ever grazed your knee or cut yourself, angiogenesis kicked in, allowing granulation tissue to form and wounds to heal. If you’re a woman, you’ve been experiencing angiogenesis once a month since your menstrual periods began.
Those are all normal forms of angiogenesis, necessary for life, health and reproduction. But when angiogenesis goes bad, it can go very, very bad. As Dr Li explained, many common disease processes involve abnormal angiogenesis, including:
- Cancer – tumours cannot grow to a clinically significant size until they have become angiogenic; but once they do, they can grow 16 000 times their pre-angiogenic size in a matter of just a few weeks.
- Atherosclerosis – angiogenesis occurs within the cholesterol-laden plaques that grow inside blood vessels, making the plaque more unstable and prone to rupturing and forming a clot that can lead to a heart attack.
- Obesity – in order for fat deposits to grow, they must develop a network of blood vessels to nourish them. Fat cells send angiogenic signals to neighbouring blood vessels when they become overstuffed with fat, and the new blood vessels secrete growth factors that stimulate immature fat cells to develop and multiply. This creates a vicious circle of fat mass expansion.
- Psoriasis – uncontrolled angiogenesis contrubites to the formation of psoriatic plaques.
- Arthritis – the formation of a pannus (an abnormal layer of fibrovascular tissue or granulation tissue) over joint surfaces, causing loss of bone and cartilage, is driven by angiogenesis.
- Endometriosis – the abnormal growth of uterine lining tissue on other pelvic structures is an expression of aberrant angiogenesis.
- Kaposi’s sarcoma – this hallmark symptom of AIDS is associated with a herpesvirus that triggers angiogenesis.
- Alzheimer’s disease – abnormal blood vessels that grow in the brain due to inappropriate angiogenesis release a neurotoxin that kills neurons (brain cells).
- Macular degeneration – angiogenesis is the driving force in this age-related cause of blindness.
- Multiple sclerosis – angiogenesis is found in the demyelinating lesions characteristic of MS.
- Rosacea – both the initial development of this distressing skin condition and its persistent presence involve angiogenesis.
So that’s the bad news about angiogenesis.
The good news is that a host of compounds found in whole plant foods inhibit abnormal angiogenesis (without blocking the normal angiogenesis that we need for wound healing and pregnancy).
Some of the all-star angiogenesis inhibitors that Dr Li highlighted are:
- Resveratrol, a pigment found in red grapes, peanut skins, pistachios, blueberries, cranberries, cacao and cocoa. In laboratory experiments, resveratrol inhibited angiogenesis in tumours by up to 75%
- Ellagic acid, found in blackberries, cranberries, pecans, pomegranates, raspberries, strawberries, walnuts, goji berries and grapes.
- Genistein, found primarily in soy beans and products made from them such as tofu and tempeh.
- EGCG, found in green tea, which not only inhibits pathological angiogenesis but also mobilises the endothelial progenitor stem cells needed for tissue repair.
Many food compounds and foods inhibit angiogenesis more strongly than anti-angiogenic drugs, according to Dr Li, but without the nasty side effects which include black, tarry stools; bleeding gums; body aches and pains; burning, tingling, numbness, or pain in the hands, arms, feet, or legs; chest pain or discomfort; chills; cloudy urine; and convulsions.
Our food selection and preparation practices can profoundly affect the amount of anti-angiogenic activity that we reap from what we eat and drink.
- Broccoli stems, which most people discard, have 2.5 times the anti-angiogenic power of broccoli florets. You can put them in soup, or take my client Dennis’ tip and use them, thinly sliced, as ‘dippers’ for hommous!
- ‘Dunking’ your teabag instead of letting it just sit in your cup, increases the amount of antiangiogenic compounds in your tea.
- Simmering tomatoes increases their trans-lycopene (a powerful angiogenesis inhibitor) activity by 50% after 2 minutes, and by 250% after 30 minutes.
- The Rubygem strawberry cultivated in Queensland has the highest anti-angiogenic activity of all strawberries.
- Whole wheat has almost double the anti-angiogenic activity of white.
- Carrot greens have 2.5 times the anti-angiogenesis power of the actual carrot, so buy Dutch carrots and eat them greens and all!
Now can you see why I was so excited about Dr Li’s presentation? Understanding the effects of abnormal angiogenesis, and how to control it through simple dietary choices, gives us enormous power to take charge of our health destiny rather than buy into the popular notion that we are doomed to succumb to ‘age-related’ diseases such as cancer, heart disease, arthritis, dementia and macular degeneration.