Healthy Food & Healthy Living by Dr. Ayala

Battle of the diets: Which is best for your heart?

Misinformation is a common problem when it comes to diet advice – it spreads through diet books, blogs and social media outlets such as TikTok, Instagram and Twitter. According to Christopher D. Gardner, the director of nutrition studies at the Stanford Prevention Research Center, misinformation has reached critical levels, leading to widespread confusion about what we should eat to prevent disease and promote health.

To help us make sense of the barrage of diet messages we receive, a team of scientists, cardiologists, health experts and dietitians headed by Gardner evaluated common diet plans to determine how they comply with evidence-based guidelines for promoting heart health. Their findings appear in the journal Circulation.

So let’s start with what we know promotes heart and metabolic health: We should eat plenty of vegetables and fruit, prefer whole to refined grains, choose healthy proteins, mostly from plants, but also from fish and seafood, and if consuming meat and poultry avoid processed and fatty forms, prefer plant oils to animal and tropical oils, limit ultra processed foods, minimize sugary drinks and foods with added sugars, and moderate alcohol intake.

The best and the worst

The panel identified 10 popular diet plans. These include (1)  DASH  (Dietary  Approaches  to  Stop  Hypertension)-style, (2) Mediterranean-style, (3) pescetarian,  (4)  ovo/lacto-vegetarian,  (5)  vegan,  (6)  low-fat,  (7)  very low-fat, (8) low-carbohydrate (including Zone, South Beach, low glycemic), (9) Paleolithic (Paleo), and (10) very low-carbohydrate/ketogenic patterns (which includes Atkins and the ketogenic diet). For the several vegetarian style diets the researchers considered optimal versions of the diets – chips and soda are vegan, yet don’t represent a plant-based diet, as eating more plants is a central tenet of this food philosophy. Same applies to the other diet plans.

They then compared these popular diets to the ideal diet as defined by the American Heart Association’s dietary guidelines. Diets were ranked using a 0-100 point system.

And the results: 

The best diets are Mediterranean, DASH-Style, pescetarian, and ovo/lacto-vegetarian diets. They score high (above 85 points) because they emphasize vegetables, fruit, whole grain, healthy oils and moderate alcohol intake. They are also flexible, providing a wide range of choices. They also score high on sustainability, and have a lower environmental impact.

The lowest scoring diets: Paleo diets and very low carb/ketogenic diets with a score of under 55 points. Following these diets doesn’t align as well with dietary guidelines. These diets are promoted for weight loss and the notion that carbs are bad is widespread, but painting carbs with a broad brush eliminates healthy carbs, such as fruits, vegetables, legumes and whole grains, the cornerstone of a healthy diet. So although the Atkins and keto diet restrict some foods that should be limited, such as added sugar and refined grains, they miss the point on many other healthy, whole, fiber-rich plant based carbs, and introduce lots of animal products and fatty meats.

Taking the long view

Although the ketogenic and low carb diet may curb appetite and lead to short term weight loss, they’re not a good long-term plan. These diets often increase “bad” cholesterol levels, which can elevate the risk of heart disease, they impose a strain on the kidneys, and they’re difficult to maintain long term due to their restrictiveness. “A diet that’s effective at helping an individual maintain weight loss goals, from a practical perspective, needs to be sustainable,” says Gardner.

The Keto and paleo diets not only have a lower dietary quality, they also have a higher carbon footprint according to a recent study in the American Journal of Clinical Nutrition. The keto diet, which is a high-fat low-carb diet, is estimated to produce almost 3 kg of carbon dioxide for every 1,000 calories of food. The paleo diet, which prioritizes meats, nuts and vegetables, emits 2.6 kg of carbon dioxide for every 1,000 calories. A vegan diet, on the other hand, generates 0.7 kg of carbon dioxide per 1,000 calories – less than a fourth of a keto diet.

Common sense would suggest that it’s moderation that’s key to a sustainable, healthy diet. 

The sensible, practical, socially acceptable diet plan you can keep long term is the most promising plan for weight control and for wellness. 

Dr. Ayala

 

Can we really blame diabetes on diet choices?

Many chronic diseases are attributable, at least in part, to diet, among them are type 2 diabetes, heart disease and several forms of cancer. 

Type 2 diabetes is an enormous burden on human health and longevity worldwide, It’s has wide consequences for the people suffering from it, and on healthcare systems, as type 2 diabetes affects most organ systems including the heart, kidney, eye, brain, and liver, it increases the chances of cancers, infections, and dementia. 

Type 2 diabetes may run in families, but its rapid rise makes it clear that there’s much more than genetics at play. In the last 40 years type 2 diabetes incidence has risen 5 fold, 1 in 10 adults live with the disease and this is occurring worldwide. It’s clear that diet plays a big role, whether through weight gain and obesity or directly: by affecting sugar metabolism, inflammation, and changes in the gut. 

To what extent does your diet drive the incidence of diabetes, and which foods are most to blame?

To assess that researchers from Tufts University looked at data from 184 countries from 1990-2018. They looked at diet components, as well as age, sex, education, and where people lived. Their model relies on information from the Global Dietary Database, population demographics, global type 2 diabetes incidence estimations, and published research on how food choices impact type 2 diabetes. The findings appeared recently in Nature Medicine.

And the conclusions: about 70 percent of new cases of type 2 diabetes are attributable to a suboptimal diet and could have been avoided with a better diet. Eating too much of the wrong foods – such as refined rice and wheat, sugary drinks, processed and unprocessed meats – can explain 60 percent of the harm. Not eating enough of the protective foods – such as fruits, vegetables, nuts, seeds and whole grains – explains the 40 percent rest of the risk.

Poor diet drives type 2 diabetes in men more than in women, according to the study, in younger people more than in older ones, and in city dwellers more than in rural ones. And although men and city-dwellers with higher education tended to have a greater burden of type 2 diabetes caused by their diet, the opposite was seen in wealthier countries where living in urban areas and a higher education was predictive of a healthier diet. Interestingly, the link between a country's economic development and its diet-attributable type 2 diabetes burden has become weaker over the years – which suggests that as highly processed foods spread worldwide and expand so does type 2 diabetes.

The assessment that 70 percent of type 2 diabetes is diet related is astounding. It’s higher than previously assessed: Another study estimates 40 percent of cases are due to a suboptimal diet. This study, however, looks at 11 dietary factors instead of just six in other studies. Either way, many people could change the trajectory of their health by making healthier food choices and the biggest culprit is refined/highly processed foods – and especially refined carbs.

The diet to prevent diabetes

To lower your risk of type 2 diabetes it's important to control weight gain, which is a major risk factor for the disease. Other important lifestyle risk factors include inactivity and smoking.

Pay special attention to these diet principles to lower your risk:

Skip the sugary drinks: Excess added sugar is an established risk for diabetes, sugary drinks are the leading source of added sugar in our diet, and many studies show a clear link between soda consumption and the development of type 2 diabetes. These include randomized controlled studies that showed that sugary drinks aren’t just associated with diabetes – they cause obesity, insulin resistance and chronic inflammation, which are the harbingers of type 2 diabetes. 

Choose whole, unprocessed foods: Select whole grain over refined grains, eat nuts, beans, legumes, make sure you eat plenty of fruits and veggies (non-starchy vegetables, a potato isn’t in this category).Limit meat, especially processed meat.

Dr. Ayala

Your gut needs some exercise

The closest thing to a silver bullet for wellness is exercise. Want to keep your mind sharp? Exercise. Want to fend away type 2 diabetes and heart disease? Move more. Feeling down? Try working out.

How does physical activity achieve all that? Exercise strengthens the heart and improves blood circulation, it releases endorphins, it reduces inflammation, it increases muscle strength and endurance, builds stronger bones, and can improve sleep – yet another keystone of wellness.

But there’s another mechanism connecting physical activity and our physiology: our gut inhabitants. Each of us is a universe of microorganisms: We host trillions of microbes. Bacterial cells outnumber our cells 9 to 1, their genetic material outweighing ours 150 to 1. 

A healthy microbiome is essential for maintaining overall health and well-being. The gut microbiome plays an essential role in digestion, nutrient absorption, immune system function, and even mental health. Our gut bacteria also produce beneficial metabolites, such as short-chain fatty acids that can improve gut health, reduce inflammation, and even affect brain function. 

Fitness shapes the gut

We already know that athletes have unique microbiomes. But athletes lead unique lifestyles, are often lean and adhere to strict nutrition regimens. Would exercise by itself affect the microbiome in non-athletes?

A new study in the FASEB Journal looked at how duration and intensity of physical activity and muscle strength (as measured by a dynamometer which assesses hand grip) affects the gut microbiome in 350 people aged 40 and 65 years with normal and overweight BMI. 

And the results: Physical activity increases the richness and diversity of those in the study that exercised more. Exercise has more of an effect on the gut microbiome in normal-weight people than overweight people. Also, people with normal weight who had stronger grip strength had more of a certain type of beneficial gut bacteria.

How much exercise does it take? Moderate physical activity for more than 150 minutes a week was enough to positively affect the gut microbiome.

Exercise will likely improve your gut microbiome, and don’t forget the most important behavior linked with a healthy microbiome: eat whole plant foods, lots of fiber, and reduce refined and highly processed foods. Focus on vegetables and fruits, and foods high in fiber. Dietary fiber, including non-digestible carbohydrates “roughage” provide food for intestinal bacteria. In consuming these dietary nutrients, the bacteria produce their own byproducts, which make their way into our bloodstreams and affect our metabolism in a beneficial way.

Dr. Ayala

Why cooking helps with weight loss and wellness

There’s a clear link between eating home cooked meals and diet quality. Eating more home-cooked meals is also associated with lower risk of obesity.

Teaching cooking skills is an important method for improving eating habits, and is more effective than just instructing people about nutrition, but what kind of cooking should be emphasized in these lessons? 

The healthfulness of cooking practices depends on both ingredients and techniques. Health promoting cooking methods include using whole grains, adding herbs and spices, using healthy oils such as olive oil, incorporating fruits and vegetables, using onion and garlic, and using lower amounts of fat. On the other hand are health compromising cooking methods such as deep frying, use of processed foods, animal fat, processed meat, and adding sugar and sweeteners in cooking. A method for quantifying healthy cooking has been established – the Healthy Cooking Index applies a point for each health promoting behavior, and deducts a point for health compromising actions. 

A new study in Appetite looks at about 150 overweight or obese people undergoing a weight loss program. The participants were assessed for cooking practices after the weight loss intervention.

And the results: those who had a higher healthy cooking score achieved more weight loss and ate healthier.

Next, the researchers attempted to identify cooking patterns and came up with three types of cooking: Red Meat Simple, Vegetarian Simple, and Health and Taste Enhancing. 

Red Meat Simple cooks used fewer healthful additions, such as whole grains, fruit, and vegetables, or olive oil while using more red meat and animal fat and cooked meat to high temperatures. 

Vegetarian Simple cooks cooked less meat, were more likely to add fruit and vegetables, to cook with herbs and spices, use healthy cooking techniques (baking, boiling, or steaming), moderate salt and oil use, and to avoid deep frying and cooking meats to high temperatures or charring. 

The Health and Taste Enhancing cooking is characterized by higher use of taste enhancers including herbs,  spices and alliums, as well as healthful use of oils such as olive oil, fruits, vegetables, and whole grains. These kind of cooks were more likely to marinade meat prior to cooking, and to use low-fat cooking methods and moderate the salt and oil when cooking. 

The researchers found that The Red Meat Simple cooking pattern was associated with less weight loss compared to the other patterns.

Why would that be? Healthier cooking habits translate diet advice into everyday life, and make guidelines into meals. Eat-more-veggies is an abstract aspiration, while a tasty salad bowl is an adoptable habit.

Other studies have shown that hands-on cooking lessons resulted in weight loss compared to guidance followed by demonstration only.

The cooking patterns analysis hints at what's most important to impart in cooking classes: “complexity is not a necessary aspect of healthy cooking,” the authors write. “Having more advanced technical cooking skills and, in turn, making more complex dishes does not necessarily yield healthier food consumption. Promoting cooking practices that are likely to positively impact the nutritional content of the foods prepared and deterring the use of practices that are likely to negatively impact the nutritional content of foods we prepare may be more important than trying to achieve advanced levels of culinary expertise.”

Cooking plants 

Since what’s missing most from the American diet is plant based foods and whole foods, practicing kitchen skills on these ingredients is the most valuable.

A study looking at the veggie consumption and cooking skills of university students in Brazil found that less than half the students ate vegetables regularly, but knowing how to cook was significantly associated with eating veggies daily. These results are in agreement with another study of more than 1000 freshmen in the US that found that confidence in the ability to cook from basic ingredients and to follow a recipe was associated with eating more fruits and vegetables and better weight status. 

The basic skills we all need as cooks should include salads knowhow, what to make with whole grains, and a few basic cooking techniques that incorporate vegetables with grains and with protein sources, such as making a stir fry, cooking a soup, and oven roasting.

Knowing how to make healthy, tasty, simple and affordable meals is key to health and weight control, it’s a practice that’s central to wellbeing.

Dr. Ayala

How sustainable are the keto and paleo diets?

Food is one of the most direct ways in which we connect to nature. Even the most urban dwelling person eating a processed diet eats what comes from nature. 

Food choices also affect nature. Food production is intimately intertwined with the environment and with our climate, especially with the exponential growth of the human population and our expanding consumption patterns.

And food choices matter: Our diet affects our own health, and also the health of our planet, as the carbon footprint of different food choices carries different environmental costs. 

The American diet changes over time, and as people aspire to improve their health and weight status they’re open to hearing about new eating patterns – and their environmental impact. On the rise are the Mediterranean style diet and several plant forward ones, and the paleo and keto diet are also gaining a following – it’s estimated that ~10 percent of Americans are giving them a try. A new study in the American Journal of Clinical Nutrition looks at the carbon footprint of these and other popular diets.

The study includes more than 16,000 people whose diet was categorized into vegan, vegetarian, pescatarian, paleo, keto, or omnivore – which includes all other diets. The carbon footprint of each dietary pattern was calculated using a previously developed database of food impacts on the environment called dataFIELD. The diet quality of each diet was assessed by comparing it to the Healthy Eating Index (HEI) and the Alternate Healthy Eating Index (AHEI). 

And the results: Keto and paleo diets have a higher carbon footprint and a lower mean diet quality than vegetarian, vegan, and pescatarian diets. The keto diet, which is a high-fat low-carb diet, is estimated to produce almost 3 kg of carbon dioxide for every 1,000 calories of food. The paleo diet, which prioritizes meats, nuts and vegetables, emits 2.6 kg of carbon dioxide for every 1,000 calories. A vegan diet, on the other hand,  generates 0.7 kg of carbon dioxide per 1,000 calories – less than a fourth of a keto diet.

How much difference could changing your diet make? “For any given day, if a third of the omnivores consumed a 2000 kcal vegetarian diet, and assuming accompanying shifts in domestic production, the savings would be equivalent to eliminating 340 million passenger vehicle miles,” the authors write. Over a year this would amount to about 5 percent of what we needed to do to meet the US targets of the Paris accords, and improve our diet quality, reducing risk of chronic disease.

An omnivore’s compromise

The single most environmentally-impactful food choice regards animal products. Animal food production emits much more greenhouse gasses than plant foods. Beef production emits 10 times more than chicken, and 20 times as much as growing legumes, nuts and seeds. 

Studies show that vegan and vegetarian diets emit less greenhouse gasses. Several other diets that are usually adopted for health benefits – such as the Mediterranean-style diet and the DASH diet also carry a smaller carbon footprint than the typical American diet.

We can all take steps towards greater sustainability by eating more plants and less meat, eating less processed foods, choosing organic when possible, preferring produce that's locally grown and in season, and avoiding waste.

Even the smallest steps count in a world with more eight billion people making food choices.

Dr. Ayala