Last month “Nutrition 2018” was held in Boston. It was the inaugural flagship meeting of the American Society for Nutrition. Evidence from several studies was presented showing that a primarily plant-based diet is linked to numerous health benefits. Obviously, the quality of the food was important as well. Here is a summary of 5 papers that were presented:
- A 13 year study of 6000 people in the Netherlands found that a higher proportion of dietary plant protein to animal protein was linked to lower risks of developing heart disease.
- A study of 4500 Brazilians showed that those eating more plant-based protein were 60% less likely to have coronary artery plaque than those consuming more animal-based protein.
- South Asians living in the US that followed a vegetarian diet had a lower number of risk factors for heart disease and diabetes (lower body mass index, smaller waist circumference, less abdominal fat, lower cholesterol levels, lower blood sugar levels) than those that ate meat.
- A 4-year American study of over 125,000 adults showed that a whole food plant-based diet (whole grains, fruits, vegetables, nuts, etc.) led to less weight gain than a processed plant-based diet (sweets, refined grains, fries, etc.).
- A study on 30,000 American adults demonstrated that improving the quality of the plant-based component of diet decreased mortality by 30% whereas improving the quality of the animal-based components had little effect. Among people with chronic health problems these beneficial effects were even more pronounced.
These recent research findings add to the mounting body of evidence supporting the health benefits of a whole food plant-based diet.
Zhangling Chen et al., from Erasmus Medical Centre in the Netherlands, presented new research on diet at this year’s European Congress on Obesity. Their findings were based on a long-term study observing around 10,000 middle-aged and elderly adults from the Rotterdam Study. The results showed that people eating a higher proportion of plant-based foods have lower waist circumferences and BMIs, mainly due to lower body fat mass.
As we already know, obesity is associated with elevated levels of inflammation and greater risks of getting “diseases of affluence” such as diabetes, heart disease, stroke, cancer and osteoarthritis.
According to the authors: “a more plant-based and less animal-based diet beyond strict adherence to vegan or vegetarian diets may be beneficial for preventing overweight/obesity in middle-aged and elderly populations. In other words, eating to protect against obesity does not require a radical change in diet or a total elimination of meat or animal products. Instead, it can be achieved in various ways, such as moderate reduction of red meat consumption or eating a few more vegetables. This supports current recommendations to shift to diets rich in plant foods, with low consumption of animal foods.” This conclusion is reassuring and encouraging for all those that would like to make some dietary changes but are intimidated by the effort and motivation required to completely overhaul their diets. We have to start our journey somewhere…and just a few steps in the right direction can start to make a difference!
It’s well-known that obesity can cause or exacerbate osteoarthritis (OA) through excessive mechanical loading. But another mechanism through which obesity can affect joint health is via inflammation and we now know that our gut microbes play a crucial role.
Recent research by Schott et al. has looked into the link between obesity, gut microbes and OA. They found a difference between the types of gut bacteria in obese mice compared to lean mice. The obese mice had more pro-inflammatory and fewer anti-inflammatory species than lean mice. The imbalance led to accelerated knee OA due to systemic inflammation and macrophage migration to the synovium. Interestingly, they found that oligofructose, a non-digestible prebiotic fibre, can help restore a normal lean gut microbiota in obese mice. The restoration of lean gut microbes was “associated with reduced inflammation in the colon, circulation and knee and protection from OA”.
Obviously one could wonder whether these findings apply to humans. About a year ago Dai et al. published the results of long-term studies on around 6000 people. Their findings consistently showed that higher total fibre intake was related to a lower risk of getting symptoms of knee OA!
Intermittent fasting (IF) is proven to have beneficial effects on aging, cancer, cardiovascular diseases and neurodegenerative diseases. However, it isn’t known whether the benefits of IF are due to caloric restriction (CR), as with fasting, or whether they’re due to changes in eating pattern. Recent studies have discovered that the browning of white fat can improve insulin sensitivity and energy expenditure by producing heat. Both exercise and cold exposure have been shown to transform white fat into brown fat.
A recent study by Kim et al. from the University of Toronto looked into the mechanisms underlying intermittent fasting’s effects on health. They separated mice into 2 groups: an IF group and a control group. The IF group was not fed for 1 day and then fed for 2 days in a row whereas the control group was fed daily. This went on for 4 months. By the end of the study, both groups had been fed the same amount of calories. After 4 months, the IF mice weighed significantly less and had increased insulin sensitivity and a more stable glucose metabolism. Additionally, they had a lower proportion of white fat because it had been converted into brown fat. The IF mice had higher levels of adipose vascular endothelial growth factor (VEGF). VEGF helps form new blood vessels and activates adipose macrophages (white blood cells) which are critical for the browning of white fat and heat production. Interestingly, IF led to the browning of visceral white fat while cold exposure leads to the browning of subcutaneous white fat.
The authors note that health is not solely about “what and how much” we eat but also “when and how often”.
This month a fascinating report was published in Annals of the Rheumatic Diseases. It was a collaborative study between Tufts University (Boston) and the University of Manchester. Dai et al looked into the link between dietary fibre and knee osteoarthritis (OA). They used data from the Osteoarthritis Initiative (4796 participants) and the Framingham Offspring Osteoarthritis Study (1268 participants). The first group was followed for 4 years and the second group was reassessed after 9 years. The findings consistently showed that higher total fibre intake was related to a lower risk of symptoms of knee osteoarthritis (pain, stiffness, and swelling). It was unclear whether fibre had an effect on the result of knee x-rays.
The authors note that “there is increasing evidence suggesting that OA shares similar metabolic characteristics including obesity, dyslipidaemia and inflammation with cardiovascular diseases and diabetes”. Clinical trials have already shown the beneficial effect of dietary fibre on reducing body weight, blood pressure, blood sugar and in reducing circulating C reactive protein (a marker of inflammation). Increasing our intake of fibre can help improve musculoskeletal problems in addition to bettering our overall health. Fibre can be found in cereal grains, fruits, vegetables, nuts and legumes.
Apparently tomatoes are the 4th most mentioned trigger for gout flare-ups after seafood, alcohol and red meat. This is according to a group of researchers from the University of Otago in New Zealand. They have published a new paper in BMC Musculoskeletal Disorders that may have found a biological basis to substantiate the claim. The study revealed a positive association between the consumption of tomatoes and blood urate levels.
For some time, I’ve been puzzled about what constitutes a healthy diet. Surely I can’t be the only one? We’re fed so much conflicting and fluctuating advice that it’s difficult to know what to believe…and that’s without even delving into the plethora of commercial weight-losing fad diets out there! I think we can all appreciate that we are what we eat…but what should we eat?
I decided to do a little research, just because I thought someone out there must have the answer! After ploughing through a few books most of which were okayish to good I came across a book that was life changing! Incidentally, it had been on my reading list for a few years but after reading the summary, I decided I wasn’t ready to apply the changes it recommended…
The book is “The China Study” by T. Colin Campbell. Campbell is professor emeritus of nutritional biochemistry at Cornell University. He has been at the forefront of nutrition research for over 40 years and has authored over 300 research papers. He was program director of the China Study which was the culmination of a 20 year partnership between Cornell University, Oxford University and the Chinese Academy of Preventative Medicine. The China Study is considered the most comprehensive study of nutrition ever conducted! In addition, he has served on numerous panels and boards tasked with allocating research grants and providing government with nutritional guidelines.
Although medicine has progressed over the last century, we’re still woefully inadequate at dealing with diseases of affluence such as cancer, diabetes and coronary heart disease. The main reason we’re struggling is that the answer lies not in medical breakthroughs but in our diet. It is possible to free ourselves from these diseases but the system has done a great job of burying the evidence. By the ‘system’ I mean: the pharmaceutical industry, food industry, medical industry, academia and government. These industries are profoundly connected and intertwined but unfortunately they prioritise their own financial profit rather than our health. The players with the most money wield the greatest influence. Sadly, for us, the truth doesn’t financially benefit the ‘system’! Campbell writes about this in depth in both “The China Study” and “Whole”.
In “Whole”, Campbell briefly explains how a whole food, plant-based diet could help decrease global warming, preserve fresh water supplies, decrease human poverty and of course, stop the animal cruelty in modern livestock farms. It turns out that a lot of our problems are linked but our reductionist view has prevented us from seeing the whole picture.
In “The China Study”, Campbell amasses and impressive, both in depth and breadth, amount of evidence in favour of the health benefits of a whole food, plant-based diet. There is now overwhelming scientific evidence that this diet can help us:
- Live longer
- Look and feel younger
- Have more energy
- Lose weight
- Lower our blood cholesterol
- Prevent and even reverse heart disease
- Lower our risk of prostate, breast and other cancers
- Preserve our eyesight in our later years
- Prevent and treat diabetes
- Avoid surgery in many instances
- Vastly decrease the need for pharmaceutical drugs
- Keep our bones strong
- Avoid impotence
- Avoid stroke
- Prevent kidney stones
- Keep our baby from getting Type 1 diabetes
- Alleviate constipation
- Lower our blood pressure
- Avoid Alzheimer’s
- Beat arthritis
- And more…
Campbell’s 8 principles of food and health are:
- Nutrition represents the combined activities of countless food substances. The whole is greater than the sum of the parts.
- Vitamin supplements are not a panacea for good health.
- There are virtually no nutrients in animal-based foods that are not better provided by plants.
- Genes do not determine disease on their own. Genes function only by being activated, or expressed, and nutrition plays a critical role in determining which genes, good and bad, are expressed.
- Nutrition can substantially control the adverse effects of noxious chemicals.
- The same nutrition that prevents disease in its early stages (before diagnosis) can also halt or reverse disease in its later stages (after diagnosis).
- Nutrition that is truly beneficial for one chronic disease will support health across the board.
- Good nutrition creates health in all areas of existence. All parts are connected.
His advice is to “consume plant-based foods in forms as close to their natural state as possible (whole foods). Eat a variety of vegetables, fruits, raw nuts and seeds, beans and legumes, and whole grains. Avoid heavily processed foods and animal products. Stay away from added salt, oil and sugar. Aim to get 80 percent of your calories from carbohydrates, 10 percent from fat, and 10 percent from protein.”
I know this advice may contradict certain beliefs that we hold but the evidence against animal protein and dairy is pretty damning. I can only suggest that you read “The China Study” to familiarise yourself with the mountain of evidence. Whether we act on it or not is another question but at least it will be an informed decision! Exactly how we act on it is something I hope to tackle in another post.
Last month a group of researchers from Tufts University published a fascinating article in The American Journal of Clinical Nutrition. Their objective was to determine how changes in intake of protein foods, glycemic load (GL) of carbohydrates, and the interrelationship between the two influence long-term weight gains. The GL of food is a number that estimates how much the food will raise a person’s blood glucose level after eating it. Glycemic load accounts for how much carbohydrate is in the food and how much each gram of carbohydrate in the food raises blood glucose levels.
They followed a group of over 120,000 men and women for 16 to 24 years whilst adjusting for body mass index and lifestyle changes such as smoking, physical activity, television watching and sleep duration.
- Meat, chicken (with skin) and regular cheese were positively associated with long-term weight gain
- No association for milk, legumes, peanuts, eggs
- Yogurt, peanut butter, nuts, chicken (without skin), low-fat cheese and seafood were associated with weight loss
- Increases in GL were associated with weight gain
Protein & Glycemic Load Synergy
- Changes in GL of carbohydrates affect the usual weight changing effects of protein foods; for example, increased cheese intake was associated with weight gain when GL increased, with weight stability when GL did not change, and with weight loss when GL decreased.
“Our study adds to growing new research that counting calories is not the most effective strategy for long-term weight management and prevention,” said senior author Dariush Mozaffarian. “Some foods help prevent weight gain, others make it worse. Most interestingly, the combination of foods seems to make a big difference. Our findings suggest we should not only emphasize specific protein-rich foods like fish, nuts, and yogurt to prevent weight gain, but also focus on avoiding refined grains, starches, and sugars in order to maximize the benefits of these healthful protein-rich foods, create new benefits for other foods like eggs and cheese, and reduce the weight gain associated with meats.”