NutritionFacts.org

Large cohort studies do indeed show that the greatest health gains in terms of step count occur roughly between 3,500 and 8,000 to 10,000 steps per day, and that more steps are associated with a lower risk of death. However, a halving of the risk at 8,000 compared to 4,000 steps is a far more precise claim than the research supports: the available studies show consistent associations, not exact risk ratios at those specific numbers. Moreover, this is observational research, so it has not been proven that the difference is actually caused by those extra steps.

That regular exercise reduces the risk of premature death is well established: going from no activity to 150 minutes of moderate exercise per week is associated with a 31% lower risk of dying early. But that finding is a long way from the claim that jogging extends life expectancy by five to six years. That specific figure cannot be supported by the available research, and reducing the risk of death is not the same as a concrete measure of life expectancy in years. So the claim asks more of the evidence than it can deliver.

Getting more exercise reduces your risk of dying early, and the biggest gains come from even modest amounts of physical activity. Research shows that 150 minutes of moderate exercise per week reduces the risk of premature death by 31% compared to being inactive. The claim that walking 15 minutes a day extends life expectancy by an average of three years goes beyond what this research actually establishes: that precise figure cannot be supported by the available evidence. So the direction is correct, but the specific numbers do not hold up.

Walking does indeed reduce the risk of premature death, but the direction and the figure in the claim are not quite right. Research shows that the step from no activity to 150 minutes of moderate exercise per week reduces the risk of death by around 31%, with the benefit levelling off beyond that point. Fifteen minutes a day amounts to just under 105 minutes per week, which falls below the 150-minute threshold and therefore yields a smaller benefit than 31%, though it still represents a meaningful gain. The claim that the reduction is specifically 15% for exactly 15 minutes a day cannot be substantiated on the basis of the available research.

Exercise demonstrably reduces the risk of premature death, and the direction of the claim is correct. The figure of 31% found in the research applies specifically to the step from no activity at all to 150 minutes of moderate exercise per week. The claim uses 'approximately 30%' as a single fixed value for all active people, but the actual benefit varies: more exercise provides some additional gain, though this levels off thereafter. 'Physically active adults' is therefore too broad a category to attach to a single figure.

Research shows that GrimAge, a specific epigenetic clock, predicts mortality better than chronological age alone. The claim therefore points in the right direction, but is formulated too broadly: not all epigenetic clocks perform equally well, and they do not work equally well in every cell type. Moreover, the evidence is associative, meaning that a lower epigenetic age does not automatically mean that you will also live longer.

Research shows that newer epigenetic clocks such as PhenoAge and GrimAge are more strongly associated with health and life expectancy than calendar age, and that they are currently the best-supported method for measuring biological ageing. As for telomere length, a commercial blood test is difficult to translate into concrete health advice, which makes it relatively less useful. However, the two methods are not directly compared in terms of accuracy in predicting chronological age, so that specific point of comparison cannot be firmly established based on the available evidence.

Research shows that epigenetic clocks can predict biological aging and are linked to a greater risk of serious diseases, including conditions that arise later in life. However, the claim is more specific: it names cognitive decline, physical frailty, and the progression of Alzheimer's and Parkinson's disease explicitly, whereas the available literature does not specifically mention these conditions. Moreover, studies emphasize that the associations are correlational and that the clocks are not yet a clinical decision-making tool, which tempers the certainty implied by the claim.

Research shows that higher epigenetic age scores are linked to a greater risk of serious illness and death, but the specific figures of 8 to 15 percent per 5 years of aging acceleration have not been demonstrated in the available literature. The direction of the claim is therefore correct, but the precise percentages cannot be confirmed or refuted on the basis of the available research. In addition, the associations are correlational and large long-term studies are still lacking, which means that such specific estimates should be interpreted with caution.

Research provides solid support for the claim that eliminating industrial trans fats prevents heart attacks and deaths: trans fats worsen the cholesterol profile, raise inflammatory markers and substantially increase the risk of a heart attack, even at low intake levels. The policy of removing them from the food supply is therefore considered well-founded. However, the specific figures of more than 10,000 heart attacks and thousands of deaths per year cannot be firmly established on the basis of available research, and will depend heavily on the country and population being discussed.

Eating fibre has demonstrable benefits for blood sugar regulation, blood pressure and gut health, and the link with cardiovascular disease and diabetes is biologically well supported. However, whether a high fibre intake significantly reduces all of these conditions goes beyond what the available evidence firmly establishes for each outcome: the effects vary by fibre type, by individual and by condition. Combining all these outcomes into one confident statement implies a degree of certainty that the research does not yet fully provide.

There are preliminary indications that ground flaxseed benefits bowel function, but human studies with constipation as a direct outcome are scarce. The effects on blood pressure and blood lipids in people with diabetes are the best supported by the available research. However, the claim adds weight loss, fasting blood sugar and HbA1c as established benefits, while the evidence for these outcomes in this population is not yet strong enough to be so categorical. The direction of the claims sounds plausible, but presenting all these outcomes together as proven goes beyond what current research allows.

Water-soluble fibres, of which psyllium is one, lower post-meal blood sugar and improve long-term blood sugar regulation in people with diabetes. This effect has been demonstrated in humans on multiple occasions. However, fibre supplements specifically are less well studied and the trials are too small in scale to draw firm conclusions at this point. The step from 'dietary fibre helps' to 'psyllium as a supplement improves both fasting blood sugar and HbA1c' is therefore larger than the available evidence supports.

Research shows that fresh broccoli sprouts are a rich source of sulforaphane and that many commercial supplements contain considerably less bioavailable sulforaphane, but the precise ratio of 'many times higher' cannot be substantiated on the basis of the available evidence. Moreover, it has not yet been established whether higher blood levels of sulforaphane in humans also lead to measurable health benefits. The direction of the claim is plausible, but the strong wording goes further than what current research demonstrates.

The evidence that a high salt intake raises blood pressure and increases the risk of cardiovascular disease is solid and consistent. Nevertheless, the statement goes slightly further than the research justifies: restricting salt is most beneficial for people who already have elevated blood pressure or a genetic predisposition to it, and they are the ones who benefit most. Whether reducing salt can fully prevent high blood pressure in everyone is a stronger claim than what the evidence supports.

Research shows that fine particulate matter is consistently associated with poorer cognitive performance and possibly faster memory decline, but whether this represents a truly causal effect has not yet been proven. The MIND diet is associated with less cognitive decline, but the only large controlled trial does not confirm this benefit. A specific protective effect of the MIND diet against the structural brain damage caused by fine particulate matter, such as brain shrinkage and white matter loss, has not been demonstrated in the research; the claim therefore goes beyond what the evidence supports.

Research consistently shows that air pollution, and fine particulate matter in particular, is associated with an increased risk of heart and lung disease, and that cleaner air demonstrably saves lives. The evidence for this is robust. The link with cancer is somewhat more nuanced: chronic inflammation, a mechanism that fine particulate matter can trigger, is a recognised risk factor for certain types of cancer, but the evidence largely comes from observational studies. The claim that fine particulate matter is causally linked to cancer therefore goes a step further than what current research conclusively demonstrates.

Research clearly confirms that air pollution costs millions of people their lives every year and that the damage to health is serious and robustly demonstrated. However, the specific claims that it is the second leading cause of death in the world and that it accounts for more than 8 million deaths per year are not supported by those exact figures in the available research. The direction is correct: air pollution is one of the largest preventable causes of death worldwide, but that precise ranking and that specific number cannot be firmly established on the basis of the current evidence.

In cohort studies, dietary patterns rich in flavonoids are associated with lower rates of cardiovascular disease, and there are indications pointing in the same direction for dementia. However, it is nearly impossible to rule out that the overall lifestyle, rather than the flavonoids themselves, is responsible. Moreover, trials using isolated flavonoids as supplements deliver far more modest results than the cohort research suggests.

Population studies suggest that people who eat a lot of garlic and onions develop certain cancers and cardiovascular diseases less often. However, this is observational research, and people who eat a lot of garlic often have different dietary habits in general. Trials in which garlic was given as an intervention show, at best, modest effects on blood pressure and cholesterol.

This is an estimate by the World Health Organization, produced using a mathematical model, not an actual count. Such models rely on assumptions about intake per country and on the relationship between trans fats and heart disease. That industrial trans fats are harmful and that eliminating them saves lives is not in dispute; the precise number is.

It is plausible that refined sugar has a stronger effect on the reward system than sugar in whole fruit, and this is consistent with what we know about absorption rates. However, the idea of 'bypassing natural self-control mechanisms' assumes a system that has not been demonstrated in this way, and food addiction is not recognised as a diagnosis.

The first part is correct: processing makes food absorb more quickly, causing sugar and fat to enter the bloodstream sooner and at higher levels. The leap to addiction potential is an interpretation. The speed of absorption may explain why you feel hungry again sooner, but that is not the same as addiction.

This finding comes from a single study in which the brain responded more strongly to the combination of sugar and fat than to either one alone, which is a striking result. It is a small brain-imaging study that has never been replicated on a larger scale. Plausible, but not yet an established mechanism.

The association has been found using questionnaires that measure addictive eating behaviour, and these consistently point to ultra-processed food. Whether this can actually be called an addiction is disputed among researchers, however: there is no recognised diagnosis, and the questionnaire is derived from one designed for drug use.

Essentially correct, and by now broadly supported. Review studies link ultra-processed food to higher rates of cardiovascular disease, type 2 diabetes and premature death. The research remains observational, but the pattern is consistent, and one randomised trial shows that people spontaneously eat more of it.